U.S. patent application number 12/331454 was filed with the patent office on 2009-06-11 for system for producing a flight plan.
Invention is credited to David Agam, Leedor AGAM.
Application Number | 20090150012 12/331454 |
Document ID | / |
Family ID | 40722457 |
Filed Date | 2009-06-11 |
United States Patent
Application |
20090150012 |
Kind Code |
A1 |
AGAM; Leedor ; et
al. |
June 11, 2009 |
SYSTEM FOR PRODUCING A FLIGHT PLAN
Abstract
A flight planning system includes one or more flight management
system and a flight plan manager that constructs a flight plan
according to static information from the flight management system.
A flight management system that also constructs flight plans
includes a flight plan manager that constructs a flight plan
according to information stored in the flight management system. In
constructing the flight plan, either flight management system may
compute values of flight plan parameters, such as PNR, PET, ETOPS
and LROPS, based on dynamic information related to the flight. On
the ground, one of either type of flight management system is
selected from a plurality thereof for producing a flight plan for a
respective aircraft or aircraft model.
Inventors: |
AGAM; Leedor; (Savyon,
IL) ; Agam; David; (Savyon, IL) |
Correspondence
Address: |
DR. MARK M. FRIEDMAN;C/O BILL POLKINGHORN - DISCOVERY DISPATCH
9003 FLORIN WAY
UPPER MARLBORO
MD
20772
US
|
Family ID: |
40722457 |
Appl. No.: |
12/331454 |
Filed: |
December 10, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61012469 |
Dec 10, 2007 |
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Current U.S.
Class: |
701/3 |
Current CPC
Class: |
G01C 23/005 20130101;
G08G 5/0034 20130101 |
Class at
Publication: |
701/3 |
International
Class: |
G05D 1/00 20060101
G05D001/00 |
Claims
1. A flight planning system for producing a flight plan for an
aircraft, comprising: (a) a flight management system; and (b) a
flight plan manager for constructing the flight plan in accordance
with static information obtained by said flight plan manager from
said flight management system.
2. The flight planning system of claim 1, further comprising: (c)
an output interface for outputting the flight plan.
3. The flight planning system of claim 2, wherein said output
interface includes a printer.
4. The flight planning system of claim 2, wherein said output
interface includes a transmitter for transmitting system output to
a recipient.
5. The flight planning of claim 1, comprising a plurality of said
flight management systems, each said flight management system being
for a respective aircraft set
6. The flight planning system of claim 1, wherein said constructing
of said flight plan includes computing a respective value of at
least one parameter selected from the group consisting of a point
of no return, a point of equal time, an extended twin-engine
operations requirement and a long range operations requirement.
7. The flight planning system of claim 1, further comprising: (c)
an input interface for providing said flight plan manager with
dynamic information.
8. The flight planning system of claim 7, wherein said input
interface includes a manual user interface.
9. The flight planning system of claim 7, wherein said input
interface includes a receiver for wireless reception of at least a
portion of said dynamic information.
10. An aircraft comprising the flight planning system of claim
1.
11. A flight management system comprising: (a) a flight plan
manager for constructing a flight plan in accordance with
information stored within the flight management system.
12. The flight management system of claim 11, further comprising:
(b) an output interface for outputting the flight plan.
13. The flight management system of claim 12, wherein said output
interface includes a printer.
14. The flight management system of claim 12, wherein said output
interface includes a transmitter for transmitting system output to
a recipient.
15. A method of producing a flight plan for a flight, comprising
the steps of: (a) providing, to a flight management system, dynamic
information related to the flight; and (b) computing a respective
value of at least one parameter of the flight plan, by said flight
management system, based at least in part on said dynamic
information.
16. The method of claim 15, wherein said at least one parameter is
selected from the group consisting of a point of no return, a point
of equal time, an extended twin-engine operations requirement and a
long range operations requirement.
17. The method of claim 15, further comprising the step of: (c)
outputting the flight plan, by said flight management system.
18. The method of claim 17, wherein said outputting includes
printing the flight plan.
19. The method of claim 17, wherein said outputting includes
transmitting system output to a recipient.
20. A method of producing a flight plan for an aircraft, comprising
the steps of: (a) operationally coupling a flight plan manager to a
plurality of flight management systems, each said flight management
system being for a different respective aircraft set; (b)
selecting, by said flight plan manager, from among said flight
management systems, one said flight management system whose
respective aircraft set includes the aircraft; and (c) producing
the flight plan, by said flight plan manager, in accordance with
information obtained by said flight plan manager from said one
flight management system.
21. The method of claim 20, further comprising the step of: (d)
providing an identifier of the aircraft to said flight plan
manager, said flight plan manager then selecting said one flight
management system in accordance with said identifier.
22. The method of claim 21, wherein said identifier includes an
aircraft registration of the aircraft.
23. A method of producing a flight plan for an aircraft, comprising
the steps of: (a) operationally coupling a shared front end to a
plurality of flight planning systems, each said flight planning
system being for a different respective aircraft set; (b)
selecting, by said shared front end, from among said flight
planning systems, one said flight planning system whose respective
aircraft set includes the aircraft; and (c) producing the flight
plan, by a flight plan manager of said one flight planning
system.
24. The method of claim 23, further comprising the step of: (d)
providing an identifier of the aircraft to said shared front end,
said shared front end then selecting said one flight planning
system in accordance with said identifier.
25. The method of claim 24, wherein said identifier includes an
aircraft registration of the aircraft.
Description
[0001] This is a continuation-in-part of U.S. Provisional Patent
Application No. 61/012,469, filed Dec. 10, 2007
FIELD AND BACKGROUND OF THE INVENTION
[0002] The present invention relates to the field of aviation, and
more particularly, to a system for producing a flight plan.
[0003] The definition of "flight plan" used herein is taken from
the FAA Airman's Information Manual (2008), Volume 3 General
Technical Administration, Chapter 25 Operational Control for Air
Carriers, Section 3-1925. The term "flight plan" means a paper
document or a file of electronic data prepared for purposes of
flight planning, flight control and navigation. Flight planning
consists of selecting an appropriate aircraft cruise schedule and
applying forecast wind, temperature and aircraft performance data
to a planned route to predict estimated time en route (ETE) and
estimated fuel consumption.
[0004] The term "ATC flight plan" refers herein to a plan filed by
a pilot or a flight dispatcher with the aviation authorities (e.g.
FAA in the USA) prior to takeoff in order to obtain an ATC
clearance. Absent an ATC clearance, the flight is not authorized to
depart.
[0005] An ATC flight plan is the subset of information extracted
from the flight plan, and includes additional information such as
departure and arrival points, aircraft registration, estimated
times, alternate airports, type of flight, e.g. IFR (instrument
flight rules) or VFR (visual flight rules), name of pilot in
command (PIC), number of persons on board, and so forth as per an
official ATC flight plan form (e.g. FAA form 7233-4).
[0006] In most countries, ATC light plans are required for flights
under instrument flight rules. Under visual flight rules, ATC
flight plans are optional unless the flight crosses national
borders, however they are highly recommended, especially when
flying over inhospitable areas, such as over water, as they provide
a way of alerting rescuers if the flight is overdue.
[0007] The term "flight planning" refers in the art to the process
of producing a detailed flight plan, and is referred in the prior
art as to "flight plan" ("FP"). Flight planning involves two
safety-critical aspects: fuel calculation, to ensure that the
aircraft can safely reach its destination, and compliance with air
traffic control requirements, to minimize the risk of mid-air
collision. In addition, planners normally wish to minimize flight
cost by appropriate choice of route, height, and speed, and by
loading the minimum necessary fuel on board.
[0008] Flight planning requires accurate weather forecasts at
various flight levels, so that time and fuel consumption
calculations can account for the effects of head/tail winds and
outside air temperature (OAT). Safety regulations require aircraft
to carry fuel beyond the minimum required to fly from departure
airport to destination airport, allowing for unforeseen
circumstances or for diversion to an alternate airport if the
planned destination airport becomes unavailable for landing.
[0009] Under the supervision of air traffic control, aircraft
flying in controlled airspace must follow predetermined routes
(e.g. airways), even if such routes are not as economical as a more
direct flight. Within these airways, aircraft must maintain flight
altitudes (ALT) or flight levels (FL) as appropriate, depending on
the route being flown and the direction of travel. Flying off
airways is permitted after attaining approval from the appropriate
authorities.
[0010] Producing an accurate optimized flight plan requires
numerous calculations, so commercial FP systems make extensive use
of computers. An approximate un-optimized flight plan can be
produced by manual calculations in an hour or so, Some aircraft
operators have their own internal system for producing flight
plans, while others employ the services of external planners such
as Jeppessen of Englewood Colo. USA amd Compuflight, Inc. of Port
Washington N.Y. USA. In both cases, nowadays producing a flight
plan is generally dependent on using computer programs, and as such
the pilot has a limited control on the produced flight plan. For
example, if the fuel consumption of a Boeing 737 is used for
preparing the flight plan instead of the fuel consumption of a
Boeing 747, an air disaster may occur.
Acronyms
[0011] The following acronyms are used herein:
[0012] AFDS autopilot & flight director system
[0013] AFS auto flight system
[0014] AHRS attitude heading and reference system
[0015] A.I.P. aeronautical information publication
[0016] ALT flight altitude
[0017] A/P autopilot
[0018] AFM aircraft flight manual
[0019] ALT/FL altitude/flight level
[0020] A/T autothrottle
[0021] ATC air traffic control
[0022] ATIS automatic terminal information service
[0023] BR brake release
[0024] CAS calibrated airspeed
[0025] CPT critical point
[0026] DCT direct
[0027] DOW dry operating weight
[0028] EADI electronic attitude display indicator
[0029] EFIS electronic flight instrument system
[0030] EHSI electronic horizontal status indicator
[0031] ETOPS extended twin-engine operations
[0032] ETP equal time point
[0033] F/D flight director
[0034] F/F fuel flow
[0035] FIR flight information region
[0036] FL flight level
[0037] FMC flight management computer
[0038] FMGS flight management and guidance system
[0039] FMS flight management system
[0040] FOB fuel on board
[0041] FP flight plan
[0042] FPL flight plan (generally used when referring to an ATC
flight plan)
[0043] GPS global positioning system
[0044] G/S ground speed
[0045] IAS indicated airspeed
[0046] IFR instrument flight rules
[0047] IRS inertial reference system
[0048] LMC last minute change
[0049] LNAV lateral navigation
[0050] LROPS long range operations
[0051] MOD moderate turbulence or icing
[0052] MPTOW maximum permissible takeoff weight
[0053] MR must ride items
[0054] MSA minimum safe altitude
[0055] MSL mean sea level
[0056] MTOW maximum design takeoff weight
[0057] MZFW maximum zero fuel weight
[0058] NAM accumulated air distance
[0059] NAT north atlantic ocean
[0060] ND navigation display
[0061] NM nautical mile
[0062] OAT outside air temperature
[0063] OCC operations control center
[0064] OM operations manual
[0065] OTS organized track system
[0066] PET point of equal time
[0067] PFD primary flight display
[0068] PIC pilot in command
[0069] PNR point of no return
[0070] QNE 1013.25 Mb altimeter subscale setting (International
Standard Atmosphere)
[0071] QNH altimeter setting to obtain the field elevation when on
the ground
[0072] RSVM reduced vertical separation minimum
[0073] RWY runway
[0074] SELCAL selective call
[0075] SEV severe turbulence or icing
[0076] SID standard instrument departure
[0077] STAR standard terminal arrival route
[0078] TAS true airspeed
[0079] T/O takeoff
[0080] TOW takeoff weight
[0081] VFR visual flight rules
[0082] VNAV vertical navigation
[0083] VOR-DME vhf omni range-distance measuring equipment
[0084] W/V wind direction and speed
[0085] WX weather
[0086] ZFW zero fuel weight
SUMMARY OF THE INVENTION
[0087] According to the present invention there is provided a
flight planning system for producing a flight plan for an aircraft,
including: (a) a flight management system; and (b) a flight plan
manager for constructing the flight plan in accordance with static
information obtained by the flight plan manager from the flight
management system.
[0088] According to the present invention there is provided a
flight management system including: (a) a flight plan manager for
constructing a flight plan in accordance with information stored
within the flight management system.
[0089] According to the present invention there is provided a
method of producing a flight plan for a flight, including the steps
of: (a) providing, to a flight management system, dynamic
information related to the flight; and (b) computing a respective
value of at least one parameter of the flight plan, by the flight
management system, based at least in part on the dynamic
information.
[0090] According to the present invention there is provided a
method of producing a flight plan for an aircraft, including the
steps of: (a) operationally coupling a flight plan manager to a
plurality of flight management systems, each flight management
system being for a different respective aircraft set; (b)
selecting, by the flight plan manager, from among the flight
management systems, one the flight management system whose
respective aircraft set includes the aircraft; and (c) producing
the flight plan, by the flight plan manager, in accordance with to
information obtained by the flight plan manager from the one flight
management system.
[0091] According to the present invention there is provided a
method of producing a flight plan for an aircraft, including the
steps of: (a) operationally coupling a common front end to a
plurality of flight planning systems, each flight planning system
being for a different respective aircraft set; (b) selecting, by
the common front end, from among the flight planning systems, one
the flight planning system whose respective aircraft set includes
the aircraft; and (c) producing the flight plan, by a flight plan
manager of the one flight management system.
[0092] A basic flight planning system of the present invention
includes a flight management system, e.g. for a specific aircraft
or for a specific aircraft model, and a flight plan manager for
constructing the flight plan in accordance with static information
obtained by the flight plan manager from the flight management
system. "Static" information is defined herein as information that
does not change from flight to flight, for example, performance
characteristics of the specific aircraft or of aircraft of the
specific model.
[0093] Preferably, the flight planning system includes an output
interface for outputting the flight plan, the ATC flight plan and
the dispatch release. In various embodiments, the output interface
includes a printer for printing the flight plan, the ATC flight
plan and the dispatch release and/or a transmitter for transmitting
the flight plan, the ATC flight plan and the dispatch release to
the relevant OCC or dispatch office. The ATC flight plan may also
be transmitted directly to the relevant aviation authority for
obtaining a flight clearance
[0094] In some embodiments, the flight planning system includes a
plurality of the flight management systems, with each flight
management system being for a respective aircraft set. An "aircraft
set" could have a single member (a specific aircraft) or several
members (e.g. all aircraft of a specific model).
[0095] Preferably, constructing the flight plan includes computing
a value of a point of no return (PNR), if applicable, and/or a
value of a point of equal time (PET) and/or a value of an extended
twin-engine operations requirement (ETOPS), if applicable, and/or a
value of a long range operations requirement (LROPS), if
applicable.
[0096] Preferably, the flight planning system also includes an
input interface for providing the flight plan manager with dynamic
information. "Dynamic" information is defined herein as information
that changes from flight to flight, for example, the identities of
departure and destination airports, but the flight plan itself is
excluded from this definition of "dynamic information". In various
embodiments, the input interface includes a manual user interface
and/or a receiver for wireless reception of at least a portion of
the dynamic information. Examples of dynamic information that could
be received by the receiver include weather reports at the
departure and destination airports.
[0097] The scope of the present invention also includes an aircraft
that includes a flight planning system of the present
invention.
[0098] A basic flight management system of the present invention
includes a flight plan manager for constructing a flight plan in
accordance with information stored within the flight management
system. The "constructing" of the flight plan is as opposed to
merely presenting or displaying a flight plan that has been stored
previously in the flight management system.
[0099] Preferably, the flight management system includes an output
interface for outputting the flight plan. In various embodiments,
the output interface includes a printer for printing the flight
plan, the ATC flight plan and the dispatch release and/or a
transmitter for transmitting the flight plan, the ATC flight plan
and the dispatch release to the relevant OCC or dispatch office.
The ATC flight plan may also be transmitted directly to the
relevant aviation authority for obtaining a flight clearance.
[0100] A first basic method of producing a flight plan, for a
flight, includes two steps. In the first step, dynamic information
(other than a flight plan) related to the flight is provided to a
flight management system. In the second step, the flight management
system computes respective values of one or more parameters of the
flight plan, based at least in part on the dynamic information.
Exemplary parameters include a point of no return, a point of equal
time, an extended twin-engine operations requirement and a long
range operations requirement.
[0101] Preferably, the flight management system outputs the flight
plan, e.g. by printing the flight plan or by transmitting the
flight plan to an aviation authority.
[0102] A second basic method of producing a flight plan, for an
aircraft, includes three steps. In the first step, a flight plan
manager is operationally coupled to a plurality of flight
management system, with each flight management system being for a
different respective aircraft set. An "aircraft set" could have a
single member (a specific aircraft) or several members (e.g. all
aircraft of a specific model). In the second step, the flight plan
manager selects the flight manager system whose respective aircraft
set includes the aircraft for which the flight plan is to be
produced. In the third step, the flight plan manager produces the
flight plan in accordance with information obtained by the flight
plan manager from the selected flight management system.
[0103] Preferably, the second method also includes the step of
providing an identifier, such as an aircraft registration, of the
aircraft for which the flight plan is to be produced. The flight
plan manager then selects the appropriate flight management system
in accordance with the identifier. An "aircraft registration" is a
unique alphanumeric string that identifies the aircraft.
[0104] A third basic method of producing a flight plan, for an
aircraft, includes three steps. In the first step, a shared front
end is operationally coupled to a plurality of flight planning
system, with each flight planning system being for a different
respective aircraft set. An "aircraft set" could have a single
member (a specific aircraft) or several members (e.g. all aircraft
of a specific model). In the second step, the shared front end
selects the flight planing system whose respective aircraft set
includes the aircraft for which the flight plan is to be produced.
In the third step, a flight plan manager of the selected flight
planning system produces the flight plan.
[0105] Preferably, the third method also includes the step of
providing an identifier, such as an aircraft registration, of the
aircraft for which the flight plan is to be produced. The shared
front end then selects the appropriate flight management system in
accordance with the identifier.
BRIEF DESCRIPTION OF THE DRAWINGS
[0106] Various embodiments are herein described, by way of example
only, with reference to the accompanying drawings, wherein:
[0107] FIG. 1 is a schematic functional illustration of a FMS-FP
system for use on board an aircraft;
[0108] FIG. 2 is a schematic functional illustration of a FMS-FP
system for use in a ground station;
[0109] FIGS. 3 and 4 show a portions of printouts of an exemplary
flight plans;
[0110] FIG. 5 shows, schematically, an aircraft that has the FMS-FP
system of FIG. 1 on board;
[0111] FIG. 6 is a partial schematic block diagram of a FMS-FP
system for use on board an aircraft;
[0112] FIGS. 7 and 8 are partial schematic block diagrams of FMS-FP
systems for use in ground stations.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0113] The principles and operation of flight plan generation
according to the present invention may be better understood with
reference to the drawings and the accompanying description.
[0114] In the following detailed description, numerous specific
details are set forth in order to provide a thorough understanding
of the disclosure. However, it will be understood by those skilled
in the art that the present invention may be practiced without
these specific details. In other instances, well-known methods,
procedures, components and circuits have not been described in
detail, so as not to obscure the present disclosure.
[0115] In order to facilitate the description herein, the following
terms are defined:
[0116] As mentioned above, the term "flight plan" (FP) refers
herein as the detailed flight plan resulting from a "flight
planning process".
[0117] The term "flight management system" (FMS) refers in the art
to a computerized avionics component for assisting a pilot in
performing activities, decisions and so on, with regard to a
flight.
[0118] The term "FMS based facility" or "FMS/FMC" refers herein to
a system that makes use of an FMS or components of an FMS, such as
an FMC, or any other device performing similar functions (e.g.,
FMGS).
[0119] The term "FMS-FP" refers herein to an FMS/FMC based facility
adapted for producing flight plans.
[0120] As mentioned above, producing a flight plan involves two
safety-critical aspects: (a) fuel calculation; and (b) compliance
with air traffic control requirements. A typical flight management
system of the prior art provides both fuel calculations and
compliance with air traffic requirements.
[0121] The basic purpose of a flight planning system is to
calculate the quantity of the "trip fuel" required by an aircraft
when flying from the departure airport to the destination airport.
Furthermore, in order to indicate that an aircraft is performing as
expected by the manufacturer, a pilot may compare the actual
remaining fuel with the planned remaining fuel at any point of the
flight plan. An aircraft must also carry reserve fuel (as dictated
by air traffic regulations and aviation authorities), to allow for
unforeseen eventualities, such as adverse weather conditions, an
inaccurate weather forecast, instructions from air traffic control
to fly at other than planned altitudes/flight levels due to air
traffic congestions, or an aircraft weight different from that upon
which the flight plan was calculated (e.g. some last-minute change
in aircraft weight due to changes in the load carried). In the case
of last minute change, if required, a new flight plan may be issued
in a very short time period using the aircraft based or ground
based `FMS-FP` system of the present invention.
[0122] A flight plan, in most cases, specifies an "alternate
airport" in addition to a destination airport. The alternate
airport is for use in case the destination airport becomes unusable
while the flight is in progress (due to weather conditions, a
strike, a crash, etc.). In some cases the destination airport may
be so remote that there is no feasible alternate airport; in such a
situation the regulations stipulate additional fuel quantity uplift
enough to circle in the vicinity of the destination airport for a
predetermined time (e.g. 2 hours, expecting the airport to become
available within that time). In this case weather conditions at the
destination airport, in accordance with the regulations, should be
better than under normal situations where an alternate airport does
exist.
[0123] There is often more than one possible route between two
airports. Subject to safety requirements, aircraft operators
generally wish to minimize costs by selecting the best route,
speed, and Altitude/Flight Level.
[0124] A conventional FMS usually includes four major components:
[0125] FMC (flight management computer); [0126] AFS (auto flight
system); [0127] a navigation system including IRS (Inertial
Reference System) and GPS; and [0128] EFIS (electronic flight
instrument system).
[0129] The primary functions of the flight management computer,
FMC, include:
[0130] Giving out real-time lateral navigation information by
showing the route programmed by the pilots, as well as other
pertinent information from the FMS database, such as standard
departure and arrival procedures. This information combined with
the location of the aircraft is used to create a moving map
display.
[0131] Calculating performance data and predicted vertical profile.
Based on the weight of the aircraft, cost index and cruise
altitude, preferably with predicted winds, the FMC calculates a
most fuel efficient vertical path that AFS would follow if AFS is
engaged and both of VNAV and LNAV are engaged.
[0132] Auto flight system: If FMC is taken as the "head" of the
system which does the calculation and gives out command, AFS is the
system who accomplishes it. AFS includes AFDS
(A/P-autopilot-F/D-(flight director) and A/T (autothrottle) if the
aircraft is equipped with A/T. AFDS flies the aircraft with one
"hand" on the control wheel (when A/P is engaged), and the other
"hand" on the throttle (when A/T is engaged). Only when the mode
"LNAV and VNAV", or LNAV, or VNAV is engaged, AFS totally or
partially follows the flight path FMC commands.
[0133] Navigation system. It includes mainly IRS (Inertial
Reference System) or AHRS (Attitude Heading and Reference System)
and GPS (Global Positioning System), as well as existing physical
Navaids such as VOR-DME. OPS is so far the most precise system for
locating the aircraft's position. What IRS and AHRS can do and UPS
cannot do is that IRS gives out raw information that are crucial to
flight such as attitude and heading of the aircraft. The navigation
system sends navigation information to the FMC to calculate, and to
AFS to control the aircraft, and to EFIS system to display. Little
action is needed from the pilots during most phases of flight
(other than monitoring the information displayed, maintaining
continuous radio contact, and, when required, feeding new
information into the FMS).
[0134] EFIS as a display system displays flight information
including commands from FMC and real-time information such as
attitude/flight level, heading, position, planned route and flight
track, etc. EFIS includes EADI (Electronic Attitude Display
Indicator) and EHSI (Electronic Horizontal Status Indicator), or on
some aircraft PFD (Primary Flight Display) and ND (Navigation
Display). Either of these displays lateral or vertical flight
information.
[0135] One example of a conventional FMS/FMC is the Rockwell
Collins FMS-6000, produced by Rockwell Collins, Cedar Rapids Iowa
USA. Such conventional FMS/FMCs are capable of receiving, storing
and using flight plans prepared elsewhere but not of preparing
their own flight plans to be used by the pilots during the
flight.
[0136] The core of producing a flight plan is calculating the
"times" (leg & accumulated times) and the corresponding fuel
consumption (leg & accumulated fuel used and required fuel
reserve) along a certain route and cruise altitude/FL. These
calculations are made in accordance with the aircraft
characteristics, aircraft weight and cost index under predicted
weather conditions, such as W/V and OAT. The Appendix details some
calculations involved in producing a flight plan.
[0137] Presently, flight plans are produced by ground stations that
employ computers that have been designed especially for producing
flight plans.
[0138] According to the present invention, the aviation-related
calculations ability of an FMS/FMC is employed for producing a
Flight Plan. Information related to the aircraft characteristics,
such as fuel consumption, speed and other performance capabilities,
and so forth, is actually stored within data storage of FMS/FMC
systems of an aircraft. Additional information, such as Routes,
SIDs, STARs etc., is available within the FMS/FMC of an aircraft
and supplied by authorized publishers (e.g. governments or
privately owned suppliers), and so forth.
[0139] Authorized (by aviation authorities) weather data suppliers,
regularly supply the required weather data required to produce a
flight plan. These data are fed into the FMS-FP system. Thus, the
ability to perform the major calculations involved in producing a
flight plan is already embedded in an FMS/FMC. As such, as
discovered by the inventors of the present invention, many
conventional flight management systems include both most of the
required information and the computational capability to produce a
flight plan.
[0140] Because the ability to perform the calculations required to
produce a flight plan are already embedded in most FMS/FMCs, in
order to produce a flight plan, according to the present invention
an FMS/FMC is adapted for the additional object of producing a
flight plan. For example, the needed modifications may include
adding an FP-manager for managing and manipulating the process of
producing the flight plan. Such an FP-manager may be, for example,
a software module, embedded in or interacting with an FMS/FMC, that
retrieves the required data from an FMS/FMC, invokes the required
functions of the FMS/FMC, and instructs the FMS/FMC to display and
print out the produced flight plan.
[0141] One class of embodiments of an FP-manager is an application
program and its API (Application Program Interface) as an add-on to
a FMS/FMC based facility. The manufacturer of an FMS/FMC based
facility provides software/hardware facilities through which such
an application program may interact with the functions of the
FMS/FMC based facility. A designer of an FMS-FP may instruct the
FMS/FMC based facility to carry out the required calculations
through the API.
[0142] According to one embodiment of the present invention, an
FMS-FP is installed on an aircraft in order to be used while the
aircraft is on the ground, to produce a Flight Plan.
[0143] According to another embodiment of the present invention, an
FMS-FP is installed in a ground station to produce a Flight
Plan.
[0144] In addition to being used on the ground before takeoff, an
FMS-FP on board an aircraft may be adapted to be used during
flight, e.g. when a new flight plan is to be filed before the next
flight sector, after landing.
[0145] The components of an FMS-FP may be entirely embedded in an
FMS/FMC based facility, or may include components external to the
FMS/FMC based facility.
[0146] An FMS-FP of the present invention has several advantages,
as follows.
[0147] Reliability: As an FMS/FMC has been well-tested before
release and verified during flight, it is a very reliable facility.
As such, employing an FMS/FMC in an FMS-FP results in a very high
reliability product.
[0148] Higher security level: An FMS-FP installed on a specific
aircraft embeds in its database information unique to the aircraft
the FMS-FP is installed in. Because a user does not have to provide
to an FMS-FP installed in an aircraft the specific parameters of
this aircraft, an FMS-FP installed in an aircraft is less
vulnerable to human errors.
[0149] In a ground installation, reducing the vulnerability to
human errors is achieved by linking the input of the aircraft
registration (or tail number) with the associated FMS/FMC.
[0150] Minimizing fuel consumption: Carrying extra fuel results in
increased cost. Because an aircraft operator regularly updates the
parameters of a specific aircraft (such as the fuel consumption of
the specific aircraft due e.g. to deterioration in aircraft
performance), the calculated fuel consumption thereof is quite
accurate, and therefore the aircraft does not have to be fueled
with extra fuel that is not required for the specific Flight Plan.
Furthermore, in the case that the extra fuel consumption is not
taken into account while planning the flight, an additional
regulatory fuel quantity (e.g. 5%) should be added to the estimated
fuel consumption.
[0151] Thus, using an FMS-FP results in reducing aircraft weight by
carrying less fuel and thus reducing the cost of the flights by
consuming less fuel without jeopardizing the safety of the
flight.
[0152] Independence of the FMS-FP: Having the ability to produce a
Flight Plan without being dependent on external suppliers, when
communication facilities are restricted or not available, such as
in disaster or in time of war.
[0153] Simplicity: Although the input information for producing a
Flight Plan is complicated even for a skilled person, the input the
user has to provide to an FMS-FP is quite simple, and as such it is
less vulnerable to human error.
[0154] Minimum human involvement: As mentioned above, if the ground
station Flight Plan supplier mistakenly calculates a Flight Plan
for a Boeing 737 instead of a Boeing 767, it may end in an air
disaster. However, according to the present invention FMS-FP
installed on an aircraft or on the ground already uses the correct
parameters with regard to the aircraft and route, and therefore the
likelihood of such errors occurring becomes insignificant.
[0155] Flexibility: An operator may define the output according to
his preferences, and as such he gets used to a certain format,
thereby noticing exceptions more easily.
[0156] Adapting an FMS/FMC to produce a Flight Plan requires some
changes, notably for inputting information, outputting the Flight
Plan, the ATC flight plan and Dispatch release, coordinating
between the modules of the system such as the input, output,
storage, and computational modules. The module that manipulates the
production of an FMS-FP is referred herein as "FP-manager". The
module may be based on computer components, such as software,
firmware and/or hardware.
[0157] An FMS-FP also may be adapted to perform calculations which
may be required for producing a Flight Plan, but that are not
required for the conventional functionality of an FMS/FMC. For
example, calculations of the PNR, PET or ETOPS/LROPS are not
required in the conventional functionality of an FMS/FMC, but are
required for producing a Flight Plan.
[0158] According to the preferred embodiments of the present
invention, the following data entities may be used for producing a
Flight Plan: [0159] Departure airport: May be provided by menu
selection or manual insertion. [0160] Take-Off [T/O] Runway [RWY]:
May be provided by automatic insertion using the communication
system (e.g. insertion from ATIS), menu selection or manual
insertion. [0161] Weather reports for the departure airport: May be
provided by ATIS, transmission from a data supplier or manual
insertion. This information is required for determining whether a
T/O alternate airport is required. The FMS-FP may also maintain a
list of T/O alternate airports. [0162] MPTOW [Maximum Permissible
Take Off Weight] May be derived from a computerized T/O performance
system and may be automatically inserted into the FMS-FP for the
Flight Plan calculation. The MPTOW may be manually extracted from
pre-computed tables which are supplied usually by the aircraft
manufacturer. In very rare occasions, the MPTOW is calculated using
graphs of the aircraft Operations Manual [OM] or the Aircraft
Flight Manual [AFM]. In case automatic insertion of the MPTOW into
an FMS-FP is not possible, this information must be inserted
manually. [0163] ZFW [Zero Fuel Weight]: May be inserted
automatically through the operations control center [OCC] of an
operator or inserted manually. [0164] Must ride items [MR]: Items
that are part of the load on the aircraft that must be carried and
will not be off-loaded in case the carriage of load is limited
(e.g. long flights that require a large amount of fuel and carrying
all the load will result in exceeding the MPTOW or insufficient
fuel to perform the flight legally). [0165] Last Minute Change
[LMC] of load (e.g. flight cancellation by some passengers or extra
load to be carried). [0166] Destination airport: May be provided by
automatic insertion using the flight schedule, menu selection or
manual insertion. The destination airport data base should include
a list of approved alternate airports in accordance with the
preference of the operator or any other information regarded by the
operator as essential. In case, for any reason, the selection of
the alternate airport cannot be done automatically, a manual
insertion capability is provided.
[0167] The weather reports for destination airport is automatically
received and analyzed to determine which landing category is in
effect. [0168] Applicable routes of the Organized Track System
[OTS] over the North Atlantic Ocean [NAT] (if applicable).
Automatic insertion (via the communication system through the OCC)
or manual insertion. [0169] En-route diversion alternate airports:
May be provided by automatic insertion from the data base and
related to the specific route, by menu selection or by manual
insertion.
[0170] The weather reports for these airports are automatically
received and analyzed to determine whether these airports are
suitable as diversion alternates. [0171] Weather [WX] input: [0172]
At the departure airport: A detailed WX report is used to determine
whether a T/O alternate airport is required. [0173] Along the route
at the appropriate levels:--W/V and OAT and hazardous WX phenomena
(e.g. moderate [MOD] to severe [SEV] turbulence, MOD to SEV icing).
[0174] En-route alternate airports: WX reports must be fed for
these airports to automatically determine the suitability of these
airports as diversion alternate airports and thus enable the
automatic calculation of PET, ETOPS/LROPS and PNR (if
applicable).
[0175] The assessment of whether these airports are suitable may be
done manually and afterwards inserted as `suitable airports` for
the applicable calculation (e.g. calculation of PET, ETOPS/LROPS
and PNR (if applicable)).
[0176] The selection of the suitable PET and ETOPS/LROPS airports
is made in accordance with regulatory requirements and operator's
policy. A computer program may be added to calculate the above and
inserted in the Flight Plan including times and fuel used to the
selected PET airports. The required fuel to the PET airport as
calculated above may sometimes dictate an extra fuel upload to
abide by the regulations. The PNR, if required, is calculated in a
similar manner. Other relevant parameters are listed in FIGS. 1 and
2 as described below. [0177] At the destination airport: A detailed
report used for determining whether the airport is `open` or
`closed` for landing at the estimated time of arrival in accordance
with the regulations. [0178] At the destination alternate airport:
To determine the most suitable alternate airport.
[0179] Although the entire input information to an FMS-FP is fairly
complicated even to a skilled person, normally an operator has to
provide only the following information: [0180] Departure airport,
and optionally the take-off runway; [0181] destination airport; and
[0182] selection of a route from a list of routes.
[0183] When using an FMS-FP in a ground station, the user has also
to input the aircraft registration and so the appropriate specific
aircraft required details are selected. This may also be carried
out by menu selection or by manual insertion.
[0184] Operators usually use the same routes for their flights. For
example, for a JFK-TLV flight there may be a few routes, such as
JFK-TLV-1, JFK-TLV-2, JFK-TLV-3, and JFK-TLV-4, etc. from which a
user may select one of the routes. Each route may be planned in
advance according to the preferences of the operator. The most
suitable of these routes may be selected in accordance with the
operator's policy.
[0185] The following are examples of information that can be
outputted from an FMS-FP, according to preferred embodiments of the
present invention. A user (pilot, aircrew, dispatcher, etc.) may
adapt the output to comply with regulations thereof. [0186] Summary
of the printed flight plan (e.g. ZFW, econ. index, flight time,
accumulated ground distance, accumulated air distance [NAM], FOB,
trip fuel, total fuel reserve etc.). Part of this information is
not a mandatory part of a flight plan, but is requested by most
operators. It varies from operator to operator. [0187] Basis and
validity of flight plan (e.g. time of issue, estimated time of
departure [ETD], validity time of the flight plan in accordance
with the regulations, aircraft F/F deviation in % from the `book`
due to performance deterioration, etc.). Part of this information
is not a mandatory part of a flight plan but is requested by most
operators and varies from operator to operator. [0188] Detailed
flight plan. The format of the printed flight plan differs from
operator to operator but includes similar details. Generally a
detailed flight plan includes the detailed SID, the detailed route,
the detailed STAR, the detailed flight plan to the alternate
airport, PET calculations between the selected diversion airports,
PNR calculations if applicable, the detailed break-down of the
total fuel reserves, and aircraft weight limits compared to the
actual aircraft weights. [0189] Secondary routes analysis. Most
operators require such information in case that the originally
requested route is for some unforeseen reason not available. A
secondary route analysis should include the route description and a
summary of the total time, fuel burn-off at the optimum altitudes
and the total distance (ground and air distances). [0190] ATC
flight plan
[0191] It is required by the regulations to file a request for the
flight through the ATC. Some of the information required to fill in
such a request is extracted from the Flight Plan itself (e.g.
detailed route information, times calculated for pre-determined
points along the route such as FIR crossing etc.). Other
information is related to the aircraft and is available and
extracted from a data base (e.g. aircraft registration, SELCAL
(selective call), description of the emergency equipment, the radio
and navigation equipment etc.). [0192] Dispatch release form is to
be filled before each flight and must include all the relevant
information as required by the regulations However, the layout of
this form may differ from operator to operator and indicates that
all the calculations for dispatching the flight were made and are
satisfactory and do not deviate from the requirements as dictated
by the regulations. It must be signed by the dispatcher and
counter-signed by the pilot in command [PIC]
[0193] As mentioned above, the format of the printed Flight Plan
differs from operator to operator and may include additional output
information, i.e., information that is not required to be filled in
a basic flight plan (that must have all calculations concerning
`time` and `fuel` at the planned ALT/FL.
[0194] The contents of such additional output information is
usually dictated by the chief pilot. This information is usually
inserted in the proper location on the flight plan form so that it
is most useful.
[0195] The additional information may include the following: [0196]
Minimum safe altitude [MSA] for each leg (a section of the flight
between two waypoints). [0197] W/V. [0198] OAT. [0199] W/V and the
wind component during climb and descent at pre-selected ALT/FL's.
[0200] W/V and OAT en-route above and below the cruising ALT/FL to
aid the pilot in deciding whether to climb or descend. [0201]
Distance traveled over each control (used for calculation of the
fees for over-flying rights). [0202] any other relevant
information.
[0203] Referring now to the drawings, FIG. 1 schematically
illustrates an FMS-FP system 10 intended to be installed in an
aircraft, according to a preferred embodiment of the present
invention. FMS-FP system 10 is for use on an aircraft by a pilot of
the aircraft or by a dispatcher as a part of flight preparations,
issuing the flight plan, the ATC Flight Plan and the Dispatch
release (if required).
[0204] As described above, FMS-FP system 10 includes (a) a
computational ability to produce a flight plan, and (b) the
majority of the information required for producing a flight plan
(such as routes, aircraft characteristics and performance) is
already available to FMS/FMC. Thus, in order to employ an FMS/FMC
for producing a flight plan, missing information (such as departure
and destination airports, predicted W/V and OAT) should be provided
to the FMS/FMC. As a result, a conventional FMS/FMC system requires
modifications in order to operate as an FMS-FP system.
[0205] In FIG. 1 the functional blocks relating to the components
that have to be added to an FMS/FMC in order to operate as FMS-FP
system 10 are marked in dashed lines.
[0206] Because the information regarding the departure airport,
destination airport and routes may be stored in the FMS/FMC, a user
may only need to select the required parameters and calculate some
flight plans along the available practical routes between the
airport of departure and airport of destination and select the most
favorable flight plan through an interface and an adapted program.
The required information that is not stored in the FMS/FMC (e.g.
W/V and OAT) may be inputted to FMS-FP system 10 "automatically" or
"manually".
[0207] In addition to the modifications for inputting information,
the FMS/FMC is adapted to render the calculations required for
producing a flight plan. However, because the core of an FMS/FMC
already includes the computational ability to produce a flight
plan, the required modifications are in the level of activating
existing software components supplemented by additional software
programs (e.g. for calculating the PET, ETOPS/LROPS and PNR (if
applicable) and passing the parameter values thereof among the
software modules).
[0208] The user interface of FMS-FP system 10 may also be
implemented on a laptop computer which may be connected to an
FMS/FMC system by wired or wireless communication means.
Furthermore, instructions and/or input data for producing a flight
plan may be provided to FMS-FP system 10 by removable data storage
means, such as a USB drive (a portable storage device connects to a
system by USB interface), CD-ROM, and so on.
[0209] A flight plan is constructed before the departure of a
flight. Weather information and other information required for the
calculation of a Flight Plan is available to FMS-FP system 10 using
communication facilities, and may be provided or available to
FMS-FP system 10 "automatically" or inserted "manually".
[0210] FIG. 2 schematically illustrates an FMS-FP system 20
intended to be installed in a ground station, according to one
embodiment of the present invention.
[0211] As in FIG. 1, in FIG. 2 the functional blocks indicating the
components that have to be added to an FMS/FMC system in order to
operate as FMS-FP system 20 axe marked in dashed lines.
[0212] The major difference between FMS-FP system 10 that is
intended to be installed in an aircraft and FMS-FP system 20 that
is intended to be installed in a ground station is that FMS-FP
system 20 is to be provided with the FMC of all relevant aircraft
operated through that specific ground installation. The appropriate
FMC is selected automatically by inserting the aircraft
registration. The aircraft registration is inserted automatically,
by menu selection or manually.
[0213] The data required to construct a flight plan may be fed into
FMS-FP system 20, for example, via the Internet. Thus, a simple
configuration of the communication may be via a laptop that gets
the information e.g. from a weather forecasting web site, and
provides the information to FMS-FP system 20 by a wired connection,
such as USB (Universal Serial Bus) or by wireless connection.
[0214] FMS-FP system 10 or 20 may obtain weather-related
information from meteorological institutes. Such information may be
provided, for example, in the GRIB format, which is used by
meteorological institutes over the world to transport and
manipulate weather data.
[0215] FMS-FP system 20 operated in a ground station may be
designed to use a plurality of FMS-FP modules, each one associated
with a different aircraft or aircraft model. Such a design may
include a plurality of FMS-FP cards (e.g., integrated circuits),
each card for a different aircraft or for a different aircraft
model, a separate user interface facility for each FMS-FP card, a
combined user interface facility for all the FMS-FP cards, and so
on. Each FMS-FP card (module and so forth) may use its own
FMS/FMC.
[0216] FIG. 3 illustrates a portion of a printout of an exemplary
flight plan sample produced by an FMS-FP installed in an aircraft
or ground station, according to embodiments of the present
invention. Different operators might prefer other layouts for their
flight plans.
[0217] FIG. 4 illustrates a portion of an additional exemplary
printout format of a flight plan produced by an FMS-FP installed in
an aircraft or ground station, according to embodiments of the
present invention. Again, different operators might prefer other
layouts for their flight plans.
[0218] To minimize human error it is most preferable that, on a
flight plan produced by a ground based FMS-FP system, the aircraft
type and aircraft registration are marked prominently at the top of
the page (both on the FMS-FP display screen and on the printed
page).
[0219] FIG. 5 shows, schematically, an aircraft 30 having FMS-FP
system 10 on board.
[0220] FIGS. 1 and 2 above are functional illustrations of
exemplary embodiments of FMS-FP systems according to the present
invention. FIGS. 6-8 are schematic block diagrams that illustrate
the physical components of such systems.
[0221] FIG. 6 is a partial schematic block diagram of a
conventional FMS/FMC based facility as modified in accordance with
the present invention to be a FMS-FP system 100 of the present
invention for use on board an aircraft. FMS-FP system 100 includes
a processor 102, a read-only memory 104, a random access memory
106, a non-volatile memory 108 such as a hard disk or a flash disk,
a user input block 110, a user output block 112 and a transceiver
114, all communicating with each other via a bus 116. User input
block 110 includes conventional input mechanisms such as a
keyboard, a touch screen, a mouse and/or a CD reader. User output
block 112 includes conventional output mechanisms such as a display
screen 118 and a printer 120. Transceiver block 114 includes a
transmitter 122 and a receiver 124 for wireless communication.
[0222] In non-volatile memory 108 are stored an operating system
126, conventional FMS/FMC software 128 and FP-manager software 130.
When FMS-FP system 100 is powered up, processor 102 executes boot
code stored in read-only memory 104 to load operating system 126
into random access memory 106. Subsequent operation of FMS-FP
system 100 is by execution of operating system 126 in random access
memory 106 by processor 102. Operating system 126 loads, as needed,
modules of FMS/FMC software 128 into random access memory 106 for
execution by processor 102. In executing FMS/FMC software 128,
FMS-FP system 100 operates as a conventional FMS/FMC based
facility. In addition, under user control, operating system 126
loads, as needed, modules of FP-manager software 130 into random
access memory 106 for execution by processor 102 to produce a
flight plan as described above. The flight plan, atc FLIGHT PLAN
AND Dispatch release so produced are printed on printer 120 and/or
transmitted to the relevant OCC or Dispatch office by transmitter
122. The ATC flight plan may also be transmitted to the relevant
aviation authority for obtaining a flight clearance.
[0223] FIG. 7 is a schematic block diagram of a FMS-FP system 200
for use in a ground station. FMS-FP system 200 includes several
FMS-FP units 202 that are identical to FMS-FP system 100 as
illustrated in FIG. 6 from bus 116 upwards. In other words, FMS-FP
units 202 lack their own user input blocks, their own user output
blocks and their own transceivers. Each FMS-FP unit 202 is for a
respective aircraft or for a respective aircraft model. Three
FMS-FP units 202 are shown in FIG. 7, but FMS-FP system 200 could
include any desired number of FMS-FP units 202. The missing input
and output facilities of FMS-FP units 202 are provided by a shared
front end 204 to which FMS-FP units 202 are operationally coupled
by data links 206. For example, FMS-FP units 202 could be blades
coupled to shared front end 204 via a network bus. Alternatively,
data links 206 could be wired connections such as USB connections.
Alternatively, FMS-FP units 202 could communicate with shared front
end 204 according to a short-range wireless protocol such as
Bluetooth.TM.. Shared front end 204 includes a user input block 210
that is similar to user input block 110, a user output block 212
that is similar to output user block 112, and a transceiver 214
that is similar to transceiver 114. A user of FMS-FP system 200
uses user input block 210 to provide an identifier, such as a
registration number, of the aircraft for which a flight plan is to
be prepared. Shared front end 204 selects the appropriate FMS-FP
unit 202 to produce the flight plan for that aircraft. The flight
plan, ATC flight plan and Dispatch release so produced are printed
by the printer of user output block 214 and/or are transmitted to
the appropriate recipients by transceiver 216.
[0224] FIG. 8 is a schematic block diagram of another FMS-FP system
300 for use in a ground station. FMS-FP system 300 includes several
FMS/FMC units 302 that are identical to FMS-FP units 202 except for
lacking EP-manager software 130. In other words, FMS/FMC units 302
are conventional FMS/FMC units. The flight planning functionality
of FMS-FP system 300 is provided by FP-manager software 330 in a
shared front end 304 that otherwise is identical to shared front
end 204 and that has its own user input block 310, user output
block 312 and transceiver 314. FMS/FMC units 302 are operationally
coupled to shared front end 304 by data links 306 that are similar
to data links 206. A user of FMS-FP system 300 uses user input
block 310 to provide an identifier of the aircraft for which a
flight plan is to be prepared. Shared front end 304 selects the
appropriate FMS/FMC unit 302 to use for producing the flight plan
for that aircraft and then produces that flight plan by using the
appropriate facilities of the selected FMS/FMC unit 302 while
executing FP-manager software 330 to provide the missing
functionality of the selected FMS/FMC unit 302 as described
above.
[0225] While the invention has been described with respect to a
limited number of embodiments, it will be appreciated that many
variations, modifications and other applications of the invention
may be made. Therefore, the claimed invention as recited in the
claims that follow is not limited to the embodiments described
herein.
APPENDIX
Producing a Flight Plan
[0226] Aircraft Weights Associated with a Flight:
[0227] Payload is the total weight of the passengers, luggage,
cargo and mail in a flight.
[0228] Dry Operating Weight (DOW) is the operational empty weight
of an aircraft and includes all fixed equipment, all system fluids,
unusable fuel, seats and fixtures, galley structure, emergency
equipment, blankets and pillows the weight of the crew members with
their luggage, galley equipment & stores and passenger service
items.
[0229] Zero Fuel Weight [ZFW] is the total of the DOW+Payload.
[0230] Maximum Zero Fuel Weight [MZFW]--is a design limiting
weight. The actual ZFW should never exceed this weight.
[0231] The fuel quantities are expressed in weight units.
[0232] Fuel On Board [FOB] is the total amount of fuel in the fuel
tanks before starting the engines.
[0233] Taxi fuel is the quantity of fuel required to start the
aircraft engines and taxi to the takeoff position. The takeoff
position is also referred to as the Brake Release [BR] point.
[0234] Takeoff fuel equals to FOB less the taxi fuel and is the
amount of fuel available at the BR point.
[0235] Trip fuel is the amount of fuel required to fly the aircraft
from the start of the take off run at the BR point of the departure
airport till the touch down at the destination airport.
[0236] Reserve fuel is the amount of fuel required by the
regulations of the civil aviation authorities, to have remaining in
the fuel tanks upon touch down at the destination airport plus any
extra quantity of fuel that is in the interest of the operator to
carry (e.g. carrying fuel for the following flight sector where
fuel price is higher).
[0237] Aircraft gross weight (also known as Ramp weight or Taxi
weight) is the total aircraft weight at the ramp before engine
start-up.
[0238] Maximum design Taxi weight--is a design limiting weight. The
actual Taxi weight of the aircraft should never exceed this
weight.
[0239] Aircraft takeoff weight [TOW] is the weight of an aircraft
at the BR point and equals to the aircraft gross weight less the
Taxi fuel.
[0240] Maximum design Take Off Weight [MTOW] is a design limiting
weight. The actual TOW should never exceed this weight.
[0241] Maximum Permissible Take Off Weight [MPTOW] is the maximum
permissible aircraft weight at the BR point as resulted due to the
following variable factors: airport elevation, runway length and
slope, outside air temperature, barometric pressure, prevailing
wind, noise restrictions, obstacles in the takeoff flight path,
runway surface conditions and the serviceability of aircraft
components that affect the takeoff performance. MPTOW should never
exceed the MTOW.
[0242] Landing weight is the weight of an aircraft as it lands at
the destination airport and equals to the aircraft weight at the BR
point minus the trip fuel. It comprises of the zero fuel weight
plus the Reserve fuel.
[0243] When twin-engine aircraft are flying across remote areas
(e.g. oceans, deserts, etc.) the route must be carefully planned so
that the aircraft can always reach an airport in case of an
emergency (e.g. an engine failure). The rules applicable are named
ETOPS--Extended-range Twin-engine Operational Performance Standards
and LROPS--Long Range Operations.
Most Common Units of Measurement
[0244] Flight Plans incorporate a mixture of metric and non-metric
units of measurement. The particular units used may vary by
aircraft, by operator, and by location thus for example, different
height units may be used at different points along a route during a
single flight.
[0245] Distance units: Nautical Mile (NM)--Properly defined, one
Nautical Mile is the length of 1 minute of arc of a Quadrant. It is
variable in length. The average length of the NM is 6080 ft and is
named the Standard NM. In practice however the Nautical Mile [NM]
is referred to as such without mentioning the fact that it is a
variable length.
[0246] Distances shown on Aviation charts are rounded to the
nearest nautical mile, and these are the distances which are shown
on a Flight Plan.
[0247] Systems for producing a Flight Plan need to use the actual
values (un-rounded) in their internal calculations for improved
accuracy.
Height Units--Feet or Meters.
[0248] The indicated height of an aircraft is based on the use of a
pressure altimeter. The heights quoted here are thus the heights
under standard conditions of temperature and pressure rather than
the true heights. All aircraft using flight levels [FL] or
Altitudes [ALT], calibrate their altimeters to the same setting
(QNH or QNE) so reducing the risk of midair collision.
[0249] QNH is the altimeter setting to obtain the field elevation
when on the ground.
[0250] In the air, when set to local/regional QNH, the altimeter
will indicate the ALT in relation to MSL
[0251] QNE--When altimeter is set to 1013.2 hPa or 29.92 inches it
will indicate the Pressure Altitude.
[0252] For RVSM [Reduced Vertical Separation Minimum] approved
operators/pilots, the vertical separation of aircraft is 1000 feet
or 300 meters depending on the area flown.
[0253] For non-approved RVSM operators/pilots, the vertical
separation of aircraft is 2000 feet or 600 meters depending on the
area flown.
Speed Units
[0254] The most common speed unit used in producing a Flight Plan
is the Knots i.e. the number of NMs in one hour.
[0255] Indicated Airspeed [IAS]--Airspeed indicator reading, as
installed on the air craft, uncorrected for static source position
error.
[0256] Calibrated Airspeed [CAS]--Airspeed indicator reading, as
installed on the air craft, corrected for static source position
error.
[0257] In most modern air crafts the differences between the IAS
and CAS are negligible.
[0258] True airspeed [TAS] is the actual speed of the aircraft in
relation to the air-mass through which the air craft is
traveling.
[0259] Ground speed [G/S] is the actual speed of the aircraft in
relation to the ground over which the air craft is traveling.
[0260] Mach number [Mach] is the ratio between the TAS and the
Local speed of sound expressed as a percentage of the local speed
of sound. (e.g. Mach 0.84 means that the TAS of the aircraft is 84%
of the speed of sound that exists at the aircraft's
environment.
Routes
[0261] A route is the path along the surface of the earth followed
by an aircraft when flying between airports.
[0262] A route is divided into three main parts, Departure routes,
Airways (or other predetermined route) and Arrival routes
[0263] Departure routes usually referred to as Standard Instrument
Departure [SID].
[0264] The departure routes define the flight path from a specific
runway of the departure airport to a pre-selected waypoint on an
airway, so that the aircraft can join the airway system in a
controlled manner. Some of the climb portion of a flight will take
place along the Departure route.
Airways
[0265] There is a worldwide coverage of airways. Each airway starts
and finishes at a waypoint, and may include some intermediate
waypoints. Airways may cross or join at a waypoint, so an aircraft
can leave one airway and join another at such points. A complete
route between airports often uses several airways. Where there is
no suitable airway between two waypoints, and using airways would
result in a somewhat roundabout lengthy route, air traffic control
may allow a direct [DCT] waypoint to waypoint routing off
airways.
[0266] Most waypoints are classified as compulsory reporting
points, i.e. the pilot (or the automatic transmission of the
onboard Flight Management System [FMS] reports the position of the
aircraft to air traffic control as the aircraft passes over a
waypoint.
[0267] There are two main types of waypoints. Named waypoints are
shown on aviation charts with associated geographical co-ordinates
(latitude and longitude). Such waypoints over land often have an
associated radio beacon so that pilots can easily check the
accuracy of the navigation. Useful named waypoints are always on
one or more airways.
[0268] The Geographic waypoint is a temporary position used in a
Flight Plan, usually in an area where there are no named waypoints,
(e.g. most oceans) Air traffic control require that most geographic
waypoints are expressed in whole degrees of latitudes and
longitudes.
[0269] Arrival routes usually referred to as Standard Terminal
Arrival Routes [STAR].
[0270] On approaching the airport of intended landing and prior the
landing, the aircraft follows the Arrival route which defines a
flight-path from a pre-selected waypoint along an airway to the
landing runway, so that aircraft can leave the airway system in a
controlled manner. Some of the descent portion of a flight will
take place along the Arrival route.
[0271] In locations where an airway structure cannot be setup (e.g.
The North Atlantic area), special procedures are set by the
appropriate authorities so that the safety of the flights will not
be jeopardized and that operators do not suffer an un-acceptable
financial loss.
Computing a Flight Plan
[0272] The result of the calculations while preparing a Flight Plan
entails two main aspects: Time and Fuel.
[0273] Time--To be able to calculate the time required for an
aircraft to travel between any two points along a route, the
distance between these two points and the speed of the aircraft at
this location must be known. Further more, to compensate for the
effect of the wind on the G/S, the direction between the two
points, and the wind direction & speed must also be known.
[0274] The OAT has an effect on the TAS and therefore must be
known.
[0275] Summation of time: the following information must be fed
into the computer to calculate the time between any two points:
[0276] Distance--calculated within the FMS/FMC.
[0277] Aircraft speed (Mach, TAS, CAS as applicable)--inherent in
the FMS/FMC.
[0278] Wind direction & speed--must be inserted before the
calculation.
[0279] OAT--must be inserted before the calculation.
[0280] Fuel--to be able to calculate the fuel burn-off between any
two points it is required to know the Fuel Flow [FF] (the fuel
burn-off per one hour) and the time during which this FF is
applicable.
[0281] The F/F is embedded in the FMS/FMC once the aircraft weight
is determined and a ALT/FL selected (It is sufficient to establish
the ZFW of the aircraft to compute the Flight Plan.
[0282] Summation of fuel:--following information must be fed into
the computer to calculate the fuel burn-off between any two points:
[0283] FF--inherent in the FMS/FMC. [0284] Time--calculated within
the FMS/FMC.
Weather Information
[0285] There are a few national weather centers which provide
worldwide coverage weather forecasts for civil aviation in a
pre-set format. These forecasts are generally issued every 6 hours,
and cover the following next 36 hours at intervals of 6 hours. Each
6-hour forecast covers the whole world using grid-points located at
pre-determined intervals (e.g. 75 NM). At each grid-point the
weather (wind speed, wind direction, air temperature and barometric
pressure) is supplied at different ALT/FL (e.g. 9 ALT/FL) including
the practical range of ALT/FL (e.g. from about 4,500 feet up to
about 55,000 feet.
[0286] Aircraft seldom fly exactly through weather grid-points or
at the exact ALT/FL at which weather predictions are available, so
some form of horizontal and vertical interpolation is generally
required. For 75-NM intervals, linear interpolation is
satisfactory.
Selection of Routes and ALT/FL
[0287] The route selected between any two points determines the
ground distance to be flown while the winds prevailing along the
route at a given TAS determine the G/S and the air distance
(multiplying the time by the G/S will result in the ground distance
while multiplying the time by the TAS will result in the air
distance).
[0288] The regulation for determining the available ALT/FL's to fly
vary from location to location over the globe and therefore will
not always coincide with the optimum ALT/FL suitable for a specific
aircraft at a given weight and the associated OAT prevailing.
[0289] The aircraft weight at any point determines the highest
flight level which can be used. Cruising at a higher ALT/FL (but
not above the `optimum`) generally requires less fuel than at a
lower ALT/FL
Fuel Flow
[0290] The factors varying the FF are: [0291] Aircraft weight;
[0292] ALT/FL; [0293] Aircraft speed; [0294] OAT; [0295] Usage of
different number of air-conditioning and pressurization units; and
[0296] Bleeding air from the engines for the Anti-ice system when
flying in icing conditions. Factors to Consider when Selecting an
Altitude (FL) to Fly [0297] Operational ceiling. (Altitude
capability) [0298] Regulations [0299] Meteorological
conditions--Consider Meteorological Hazards (Icing, Turbulence,
Etc.), Winds Aloft, (Clouds & Visibility--for VFR flights),
[0300] Safety Height [0301] VHF range--for short flights. [0302]
Crew and passenger comfort.--Air density & Turbulence Factors
to Consider when Selecting the Route to Fly [0303] Minimum time
En-route [0304] Regulations [0305] Meteorological
conditions--Consider Meteorological Hazards (Icing, Turbulence,
Etc.), Winds Aloft, (Clouds & Visibility--for VFR flights).
[0306] Safety Height (Consider A/C performance) [0307] Suitable
en-route alternative airports. [0308] Radio & Navigation
facilities along the route. [0309] Type of terrain [0310] Crew and
passenger comfort. [0311] Availability of Air sea rescue
facilities. Factors to Consider when Selecting Alternate Airports
[0312] Weather at Alternate and en-route to alternate. [0313]
Political consideration. [0314] Hours of operation--(Noise
restrictions etc.) [0315] Flight time to Alternate and its location
relative to the elected route. [0316] A/C handling facilities.
(Fuel, Servicing, Loading & Offloading) [0317] Passenger
handling. (Customs & immigration, Restaurant facilities) [0318]
Radio & Navigation facilities at Alternate and en-route. [0319]
Air traffic density. [0320] Regulations. (A.I.P.) [0321] Type of
terrain en-route to and in the vicinity of the Alternate A/P.
[0322] Crew's experience at the Alternate Airport. Factors to
Consider when Selecting the Route to Fly [0323] Minimum time
En-route [0324] Regulations [0325] Meteorological
conditions--Consider Meteorological Hazards (Icing, Turbulence,
Etc.), Winds Aloft, (Clouds & Visibility--for VFR flights).
[0326] Safety Height (Consider A/C performance) [0327] Suitable
en-route alternative airports. [0328] ETOPS/LROPS [0329] Radio
& Navigation facilities along the route. [0330] Type of terrain
[0331] Crew and passenger comfort. [0332] Availability of Air sea
rescue facilities.
Point of No Return--PNR
[0333] Definition: A point along an aircraft's track beyond which a
safe return cannot be made to a selected base within a stipulated
time.
[0334] When required: The PNR is calculated for flights or sections
of flights along which there are no suitable diversion airports so
that in the event of the weather conditions at destination and
destination alternate airports deteriorating below landing minima,
it can easily be seen whether or not a return to a selected base
can be made. In practice, a careful check of latest weather reports
and forecasts for destinations will be made sometime before the PNR
is reached.
Basic Formula:
[0335] t=P*H/(H+O)
or the ratio:
t/P=H/(H+O)
Where:
[0336] P=Endurance available for PNR calculation H=G/S Home (Back)
i.e. PNR to a point A O=G/S Out i.e. a point A to PNR t=time to
reach PNR Note: P is also referred to as "T" Note: P=FOB less the
(Taxi Fuel+Planned Landing Fuel) Note: Other formulae may be used
whereby the P equals to the quantity of fuel available for the PNR
calculations. Note 1: Computer iterations may be required to
accurately position the PNR. Note 2: when calculating the PNR,
computer iterations may be used without the aid of the formula
however, much iteration may be required
Factors Affecting PNR:
[0337] Fuel available: Distance to PNR will vary directly with
endurance available. [0338] Wind: Maximum distance to PNR is
attained when zero wind conditions prevail. Any wind prevailing
(other than zero) will reduce the distance for two reasons: (a) A
head wind on a track will (except when flying up and downwind)
always exceed the tailwind on the reciprocal track and so, the
average of G/S O and H will be less than the TAS i.e. the range of
the aircraft will be less than in still air. (b) The aircraft will
be flying longer on the Leg into wind than on the equal distance
Leg in the reverse direction, and so the overall head wind effect
will exceed the overall tailwind effect and so reducing the
range.
PET--Point of Equal Time:
[0339] The point of equal time is known also as ETP (Equal Time
Point) or CPt--Critical Point)
[0340] Definition: A Point of Equal Time (PET) is a point along an
aircraft's track from which the flying time to two selected bases
is the same. The two bases are often the Departure and Destination
airports.
[0341] Importance of PET: On flights or sections of flights along
which no suitable alternate airports are available, a knowledge of
the PET will enable a rapid decision to be made as to whether, in
the event of an emergency situation developing (e.g. Fire,
sickness, Engine failure etc.), it is quicker to return to a
previous alternate or carry on to the next one.
[0342] It should be noted that in the event that the aircraft
performance varies at the PET with a subsequent reduction in TAS,
e.g. due to an engine failure, the reduced TAS must be used for the
calculations from the PET to both bases. The ETA to the PET will
still be calculated using the C/S Out based on the full TAS.
Formula:
[0343] x=D*H/(H+O)
or the ratio
x/D=H/(H+O)
Where:
[0344] D=The distance between point A and B x=The distance from
point A to PET H=G/S PET back to A
O=G/S PET on to B
[0345] (G/S=ground speed)
Note 1: Computer Iterations May be Required to Accurately Position
the Pet.
[0346] Note 2: when calculating the PET, computer iterations may be
used without the aid of the formula however, much iteration may be
required
Factors Affecting the Position of the PET:
[0347] Wind: In still air the PET will be at the mid point between
the two selected bases, i.e. the air distance to either base is the
same.
[0348] The PET will always move along track from the mid point into
the wind.
[0349] TAS: In still air, a change of TAS has no effect on the
position of the PET, however, with a wind existing, a reduction of
TAS will have a similar effect to that caused by an increase in
wind, i.e. the PET moves along track into the wind.
* * * * *