U.S. patent application number 13/700317 was filed with the patent office on 2013-03-28 for fuelling arrangement and method.
This patent application is currently assigned to FUEL MATRIX LTD. The applicant listed for this patent is Roy Fuscone, Timothy John Waite. Invention is credited to Roy Fuscone, Timothy John Waite.
Application Number | 20130075532 13/700317 |
Document ID | / |
Family ID | 42228484 |
Filed Date | 2013-03-28 |
United States Patent
Application |
20130075532 |
Kind Code |
A1 |
Fuscone; Roy ; et
al. |
March 28, 2013 |
FUELLING ARRANGEMENT AND METHOD
Abstract
A method of fuelling an aircraft for a flight to a predetermined
destination in which the aircraft is loaded, the actual zero fuel
weight of the loaded aircraft is determined, the fuel requirement
of the loaded aircraft for that destination is calculated by fuel
calculation software on the basis of operational flight plan data,
said actual zero fuel weight, and further data relevant to fuel
consumption for that instance of the flight to the predetermined
destination, said further data being processed interactively by the
user by means of a user interface to said fuel calculation
software, and subsequently fuel to meet said fuel requirement is
uplifted to the aircraft under the control of said user.
Inventors: |
Fuscone; Roy; (Maidenhead,
GB) ; Waite; Timothy John; (Queensland, AU) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Fuscone; Roy
Waite; Timothy John |
Maidenhead
Queensland |
|
GB
AU |
|
|
Assignee: |
FUEL MATRIX LTD
Maidenhead
GB
|
Family ID: |
42228484 |
Appl. No.: |
13/700317 |
Filed: |
March 28, 2011 |
PCT Filed: |
March 28, 2011 |
PCT NO: |
PCT/EP2011/054762 |
371 Date: |
November 27, 2012 |
Current U.S.
Class: |
244/135A |
Current CPC
Class: |
B64F 1/28 20130101; B64D
37/00 20130101; Y02T 50/40 20130101; Y02T 50/80 20130101 |
Class at
Publication: |
244/135.A |
International
Class: |
B64F 1/28 20060101
B64F001/28; B64D 37/00 20060101 B64D037/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 29, 2010 |
GB |
1005202.5 |
Claims
1. A method of fuelling an aircraft for a flight to a predetermined
destination wherein the aircraft is loaded, the actual zero fuel
weight of the loaded aircraft is determined, the fuel requirement
of the loaded aircraft for that destination is calculated by fuel
calculation software on the basis of operational flight plan data,
said actual zero fuel weight, and further data relevant to fuel
consumption for that instance of the flight to the predetermined
destination, said further data being processed interactively by the
user by means of a user interface to said fuel calculation
software, and subsequently fuel to meet said fuel requirement is
uplifted to the aircraft under the control of said user.
2. A method according to claim 1 wherein the user interface is on
the aircraft.
3. A method according to claim 1 wherein said further data is
entered at said user interface by the user.
4. A method according to claim 1 wherein the operational flight
plan data includes statistical data based on previous instances of
flights to said destination and the method includes means for
reporting actual fuel consumption data after said flight.
5. A method according to claim 4 wherein actual fuel consumption
data is processed by a user during said reporting.
6. A method according to claim 1 wherein said further data takes
into account one or more of the following: i) taxiing to a runway
different from that in the operational flight plan; ii) operating
at a flight level different from that in the operational flight
plan iii) holding at the destination; iv) weather avoidance, and v)
low visibility procedures.
7. A method according to claim 1 wherein the quantity of fuel
remaining on arrival at the destination is calculated in dependence
upon said further data.
8. A method according to claim 1 wherein contingency fuel
calculated in accordance with the operational flight plan is
re-calculated in dependence upon said further data.
9. A computer program product comprising a computer-readable medium
incorporating program code executable by a processor to implement a
method as claimed in claim 1.
10. An arrangement for calculating the fuel requirement of an
aircraft flight to a predetermined destination, the arrangement
comprising means for determining the actual zero fuel weight of the
aircraft after it has been loaded, a programmed computer arranged
to determine a fuel requirement for said flight on the basis of
operational flight plan data, said actual zero fuel weight, and
further data relevant to fuel consumption for that instance of the
flight to the predetermined destination, said computer being
programmed to process said further data interactively with a user
at a user interface thereof.
11. An arrangement according to claim 10 wherein said computer is
arranged to receive said further data as an input at said user
interface from the user.
12. An arrangement according to claim 10 wherein the user interface
is on the aircraft.
13. An arrangement according to claim 10 which comprises a computer
network including a first terminal which in use prompts the user to
enter said information, said terminal being located on the
aircraft, and a second terminal which in use transmits said
operational flight plan data to said first terminal over said
network.
14. An arrangement according to claim 13 wherein said first
terminal is arranged to transmit actual fuel consumption data for
the completed aircraft flight to the network.
15. An arrangement according to claim 13 wherein the network is
arranged to run a plurality of software modules which exchange
information, the modules including an interactive fuel calculation
module which calculates said fuel requirement and at least an
operational flight plan module which generates said operational
flight plan data.
16. An arrangement according to claim 10 which in use acquires
actual fuel consumption data at the end of the flight and stores
the actual fuel consumption data for use in a future operational
flight plan.
17. An arrangement according to claim 10 wherein said further data
takes into account one or more of the following: i) taxiing to a
runway different from that in the operational flight plan; ii)
operating at a flight level different from that in the operational
flight plan iii) holding at the destination; iv) weather avoidance,
and v) low visibility procedures.
18. (canceled)
19. (canceled)
20. (canceled)
Description
[0001] The present invention relates to a fuelling arrangement and
method, particularly but not exclusively for fuelling an aircraft,
such as a passenger or cargo-carrying commercial airliner or a
military aircraft for example.
[0002] Airline operators face severe challenges in operating
profitably. Airlines also face increasing pressure to reduce carbon
emissions and the associated footprint. A key factor in this is
reducing fuel consumption to the lowest level possible, consistent
with safety.
[0003] Preparations are in place for emissions trading in Europe
(and in other parts of the world). Virtually all airlines with
operations to, from and within the European Union (EU) will come
under the scope of the EU's Emissions Trading Scheme (ETS) from
2012. Airlines were required to submit a monitoring plan by August
2009 and to monitor data from 2010. On 2 February 2009, EU
legislation (Directive EC/2008/101) came into force incorporating
aviation into the EU ETS as from 2012. It is understood that civil
aviation is one of the fastest growing sources of greenhouse gas
emissions, showing long term compound annual growth rates of
emissions of 3 to 4%. A key policy objective of the EU ETS will be
to reduce airline emissions to the level at 2005 by 2050.
[0004] Many efforts are being made by the industry to achieve fuel
savings through a variety of factors from aircraft design to
operating procedures.
[0005] Currently, a passenger-carrying and/or cargo-carrying
commercial aircraft is re-fuelled to a standby figure before and
during loading and then topped up before push-back (tow vehicle
manoeuvres the aircraft for engine start) prior to take-off with a
total quantity of fuel set by an Operational Flight Plan (OFP)
which is prepared by specialist ground staff typically two or three
hours before take-off and takes into account the following: [0006]
i) the aircraft type (eg Boeing B777 (RTM)) and the manufacturer's
fuel consumption data for that type; [0007] ii) a degradation
factor determined empirically for that particular aircraft, which
modifies the fuel consumption data of i) above by a percentage
which is dependent on the age and condition of the airframe (for
example dents will raise the fuel consumption); [0008] iii) the
anticipated aircraft weight(s); [0009] iv) the anticipated route,
speeds and flight levels; [0010] v) expected taxiing time from the
ramp (embarkation/loading point) to the runway, to allow for taxi
fuel; [0011] vi) anticipated meteorological conditions; and [0012]
vii) ATS (Air Transport Safety) procedures and restrictions (for
example Final Reserve Fuel is carried to enable 30 minutes' flying
at holding speed above the destination airport and Contingency Fuel
is carried to allow for deviations from the expected route and
weather conditions and to allow for a margin of error).
[0013] Typically, the OFP is passed to the captain in the form of a
printed sheet shortly before boarding, or, as in some systems (e.g.
the Cirrus.TM. system), the OFP is transmitted electronically to
the cockpit. It typically includes some guidance on modifying the
fairly sophisticated fuel calculation used to generate the minimum
fuel requirement listed in the OFP. For example, it will include an
Estimated Zero Fuel Weight (EZFW) value for the aircraft which is
the estimated total weight (including passengers, cargo and crew)
but excluding the weight of the fuel. The Actual Zero Fuel Weight
(AZFW) is determined after the aircraft has been loaded and is
typically less than the EZFW because some passengers fail to embark
or some cargo is not loaded. Whilst AZFW is more accurate that EZFW
because it is based on accurate information (e.g. actual number of
passengers boarding aircraft and weight of cargo), it should be
noted that the values for AZFW are not accurately determined since
they are typically based on estimates of passenger weights and hand
luggage allowances. Accordingly the OFP gives the captain estimated
values (typically based on accurate information) as an AZFW with
which to adjust (typically, to reduce) the minimum fuel requirement
in order to take this change in circumstances into account.
[0014] However this is a matter of discretion and, typically, not
every change in circumstances which would lead to a change in
minimum fuel requirement is flagged up by the OFP. For example, a
change in runway will affect the taxiing time and hence the minimum
fuel requirement.
[0015] The aircraft captain also has discretion to add extra fuel
("Extra Fuel") to that mandated by the OFP and often does so on the
basis of e.g. changes in the weather or other factors of a more
subjective nature, including lack of confidence in or ignorance of
the safeguards built in to the fuel calculation. There is currently
no consistency between the behaviour of captains in taking this
action and there are currently no consistent guidelines provided to
them.
[0016] In many cases the Extra Fuel is unnecessary. Since the fuel
payload of an airliner is typically a significant proportion of the
total weight of the aircraft, carrying this fuel involves
significant extra fuel consumption of the order of 3-4%/hr of
flight. So, for example, if one tonne of Extra Fuel were carried
unnecessarily on a 12 hour flight, 12.times.4%=48% of the Extra
Fuel would be burnt carrying its own weight, leaving only 520 kg of
the Extra Fuel in the tank for future use on arrival at the
destination. In other words, 480 kg of fuel would be completely
wasted. This calculation disregards the additional fuel demands on
take-off and landing imposed by the Extra Fuel. It also does not
allow for the fact that this waste also leads to the production of
additional carbon dioxide that could be avoided.
[0017] On the other hand, until and unless it may become the case
that all fuel calculations are the sole responsibility of ground
operations, it would not be prudent or acceptable to a captain to
prevent him from uploading Extra Fuel; an element of discretion
must be left in order to take into account discrepancies between
the actual conditions and those on which the operational flight
plan was predicated.
[0018] An object of the present invention is to overcome or at
least alleviate some or all of the above problems.
[0019] Accordingly the invention provides a method of fuelling an
aircraft for a flight to a predetermined destination wherein the
aircraft is loaded, the actual zero fuel weight of the loaded
aircraft is determined, the fuel requirement of the loaded aircraft
for that destination is calculated by fuel calculation software on
the basis of operational flight plan data, said actual zero fuel
weight, and further data relevant to fuel consumption for that
instance of the flight to the predetermined destination, said
further data being processed interactively by the user by means of
a user interface to said fuel calculation software, and
subsequently fuel to meet said fuel requirement is uplifted to the
aircraft under the control of said user. [0020] Preferably said
further data is entered at said user interface by the user. This
enhances the involvement of the user in the fuel calculation and
reduces the temptation to carry unnecessary extra fuel.
[0021] It is highly preferred that the user interface is on the
aircraft, preferably on the flight deck, e.g. in the form of a
screen and keyboard of the captain's laptop computer.
[0022] Typically the operational flight plan (OFP) data will
include parameters dependent upon some or all of items i) to iv)
and vii) noted above and the user (normally, the captain of the
aircraft or perhaps the co-pilot or another responsible member of
the flight crew) will be prompted to enter further data such as one
or more of: the time expected to be spent taxiing to the runway
(and expected taxiing time at destination airport), the holding
time at the destination airport, the amount of contingency fuel
carried and weather information (e.g. at departure, en-route and at
destination), for example. Such data, even if included in the OFP,
is liable to change between the time the OFP is generated and the
time of final fuelling.
[0023] Optionally, the user will still be given the opportunity to
add extra fuel but the interaction between the user and the further
data using the user interface is expected to inspire further
confidence in the fuel calculation and in practice to reduce the
incentive for extra fuel which in nearly all cases should be
unnecessary. Optionally, the user may override the fuel calculation
software and enter its own figures, but should these figures be
less than the calculated fuel requirement produced by the software,
it is preferable that a warning system alerts the user (by visual
or oral means--e.g. a warning notice or an alarm signal) and
optionally other users or a third party, especially if the figures
entered may result in a material breach of internal (airline
specific policy) or industry safety rules.
[0024] A fuel calculation software used in accordance with the
present invention is preferably configured to provide fuel
requirement values for the loaded aircraft for the flight to the
predetermined destination, which values include a safe contingency
fuel amount. The safe contingency fuel amount is preferably
programmed into the software and is typically selected to be at
least the amount of contingency fuel required by industry
regulations and optionally an amount determined by airline policy,
the method of calculating contingency fuel being variable to
account for adjustments in regulations and policies.
[0025] Even disregarding the above confidence factor, the improved
accuracy obtainable by basing the calculation on current (dynamic)
conditions is expected to result in fuel savings of up to 5%, e.g.
from 0.5% to 4% and generally at least within the range 1% to 2.5%.
Typically a printed OFP will give a fuel requirement to a precision
of three significant figures so a saving of 1% is certainly
significant. This also represents a large improvement in profit in
a low-margin and highly competitive industry, as well as a
significant reduction in carbon dioxide emissions which will have
positive environmental and financial implications.
[0026] The user, as used herein in connection with fuel calculation
software of the invention, an interface therefor, an aircraft (to
which the fuel calculation software is applied), a computer
programme according to the invention and computer so programmed,
may be any user for whom the fuel calculation software could be
effective (e.g. a person or group of people charged with
responsibility for fuelling an aircraft with the appropriate amount
of fuel for a flight, or a person or other entity responsible for
an automated system for the same, or in the event that the control
of fuelling is by an automated or computer system such as a third
party planning solution, the user may be a third party flight
planning solution configured to communicate via an application
programming interface or API). The user may be, for example, any
one or more of the captain, first officer, second officer, flight
crew, technical crew, cockpit crew, pilot, co-pilot, flight
dispatcher, flight operations staff, navigation services staff,
company administrator, IT department staff, any management position
holder or any other personnel of an organization responsible for
aircraft fuelling and related efficiency activities (or an
electronic user such as a suitably programmed flight planning
solution system). As used herein, the user or any user type
specified above may be substituted by generic user or other
specific user where the context allows.
[0027] Preferably the data used includes statistical data based on
previous instances of flights to said destination and selectably
the statistical records of the operations of the individual
aircraft or the type of aircraft and/or the individual pilot and
the method includes means for reporting actual fuel consumption
data after said flight. This is preferably performed by the user at
the user interface and has the following advantages: [0028] i) it
enables the user to check actual fuel consumption against
calculated fuel consumption and gives further confidence in the
method; and [0029] ii) it enables the accuracy of the method to be
improved by fine-tuning the operational flight plan data and/or the
processing of the information entered by the user.
[0030] The invention also includes a computer program product
comprising a computer-readable medium incorporating program code
executable by a processor to implement the above processes and
methods.
[0031] A typical process for calculating the fuel requirement for a
flight by an aircraft to a pre-determined destination in accordance
with the invention may include provision of a fuel calculation
software or arrangement or such programmed computer and the
provision of Operational Flight Plan (OFP) data. The Operational
Flight Plan (OFP) is generally used herein in a generic sense and
may include (the context assisting) an initial OFP, a revised OFP
or a final/Master OFP (the latter being the Operational Flight Plan
that the flight actually follows). As far as the method,
arrangement/system and software according to the invention are
concerned, OFP data (typically initial OFP data generated by ground
staff or an OFP generating system in use by the airline) is an
input to the method, arrangement/system and software of the
invention and its source is not critical to the present invention,
but the source should preferably address necessary regulatory
compliance matters. OFP data may be communicated electronically to
a system or arrangement comprising a computer programmed to produce
fuelling information according to the invention, or may be manually
entered (e.g. by the user via a physical interface) or may be
transferred by way of an Application Programming Interface (API)
between an application producing fuelling information according to
the invention and a system for producing or generating Operational
Flight Plans and associated data. Optionally, the arrangement for
calculating the fueling requirement for an aircraft (and/or
software or programmed computer therefore) according to the present
invention may be adapted to form a part of or to seamlessly
integrate or communicate with an operational flight planning system
of which several exist.
[0032] In another aspect the invention provides an arrangement for
calculating the fuel requirement of an aircraft flight to a
predetermined destination, the arrangement comprising means for
determining the actual zero fuel weight of the aircraft after it
has been loaded, a programmed computer arranged to determine a fuel
requirement for said flight on the basis of operational flight plan
data, said actual zero fuel weight, and further data relevant to
fuel consumption for that instance of the flight to the
predetermined destination, said computer being programmed to
process said further data interactively with a user at a user
interface thereof.
[0033] Preferably said computer is arranged to receive said further
data as an input at said user interface from the user. This
enhances the involvement of the user in the fuel calculation and
reduces the temptation to carry unnecessary extra fuel.
[0034] It is highly preferred that the user interface is on the
aircraft, preferably on the flight deck, e.g. in the form of a
screen and keyboard of the captain's laptop computer.
[0035] Preferably said arrangement comprises a computer network
including a first terminal which in use prompts the user to enter
said information, said terminal being located on the aircraft, and
a second terminal which in use transmits said operational flight
plan data to said first terminal over said network.
[0036] Preferably said first terminal is arranged to transmit
actual fuel consumption data for the completed aircraft flight to
the network. This enables the interactive fuel calculation software
to learn from the actual fuel consumption data and improve its
accuracy on subsequent flights.
[0037] The network is preferably arranged to connect a plurality of
software modules which exchange information, the modules including
an interactive fuel calculation module (referred to below as the
DYNAMIC module) which calculates said fuel requirement and
optionally a MANAGEMENT module which typically comprises the
algorithms upon which the calculations are based and which may be
accessed by technical staff and/or a COMPLETE module which is used
to record completed flight data and fuel consumption for comparison
with predicted information. The MANAGEMENT module, if the system is
so configured may communicate with an external operational flight
plan module or system which generates operational flight plan data
(or may be integrated with or form a part of an OFP system). The
naming of modules herein is for convenience and should be
considered in no way limiting.
[0038] Preferably the modules further include a module (referred to
below as the COMPLETE module) which in use acquires actual fuel
consumption data at the end of the flight (e.g. by prompting the
user to enter such data, or by receiving fuel consumption data from
the aircraft instrumentation) and transmits the actual fuel
consumption data to the system management ("MANAGEMENT") module or
to an operational flight plan module or system.
[0039] Another module, HISTORICAL, may be used to maintain a
database of information concerning all aspects of external factors
and their impact on the operational flight plans produced (e.g. by
or in association with the MANAGEMENT module) and the calculations
(e.g. of the DYNAMIC module). Preferably, the data is continually
updated. Optionally, the data provided to the COMPLETE module (i.e.
post-flight data) may also be submitted to the HISTORICAL database,
in an anonymous fashion. The data in HISTORICAL may optionally be
subject to a pattern recognition algorithm to identify inaccuracies
in the HISTORICAL data used. For example, using such bulk data, it
may be possible to determine that an efficiency deterioration
factor needs to be increased for aircraft of a particular type as
it ages, etc.
[0040] Such modular software has the advantage that different
modules may be updated or modified independently.
[0041] The modules may be run on the same or different computers of
the network but a thin client architecture is preferred in which
the modules are all run on a server (typically on the ground) and
the user's computer (typically on the aircraft) acts essentially as
a terminal. This has an advantage that all users can benefit from
upgrades (and the latest information) simultaneously.
[0042] A preferred embodiment of the invention is described below
by way of example only with reference to FIGS. 1 to 7 of the
accompanying drawings, wherein:
[0043] FIG. 1 is a diagrammatic illustration of an aircraft flight
including a refuelling operation calculated by a method and
arrangement in accordance with the invention;
[0044] FIG. 2 is a diagram of the software modules utilised in the
arrangement of FIG. 1;
[0045] FIG. 3 is a diagrammatic initial screenshot generated by the
software modules when run on the network of FIG. 1;
[0046] FIG. 4 is a diagrammatic screenshot for an algorithm which
generates generic OFP fuel consumption data;
[0047] FIG. 5 is a diagrammatic screenshot generated, e.g. by the
MANAGEMENT module, for an alternative algorithm which generates
route-specific OFP fuel consumption data;
[0048] FIG. 6 is a diagrammatic screenshot generated by the DYNAMIC
module on the aircraft at the data entry stage, and
[0049] FIG. 7 is a diagrammatic screenshot generated by the
COMPLETE module on the aircraft at the data entry stage (at the end
of the flight).
[0050] Referring to FIG. 1, which gives an overview of the
arrangement and method, an airliner A (in this case a Boeing
B777(RTM)) is shown at the ramp of terminal T1 about to taxi to a
runway R1 prior to take-off. The captain has the required software
installed onto his on-board tough-notebook (class 1 & 2 device)
or electronic flight bag (EFBs) class 3 device and runs a DYNAMIC
software module after the aircraft has been loaded and the actual
zero fuel weight (AZFW) of the aircraft has been determined. AZFW
is determined by summing the known pre-loaded aircraft weight with
typically an actual determined weight of baggage and an actual
determined weight of passengers and crew (and their carry-on
baggage) or an estimated weight of passengers and crew (and their
carry-on baggage) according to a specific standard (which may be an
internal, national or international authority standard). For
example, a standard that may be used for calculating passenger
weight is: i) 15 kg for a child under 2 years; ii) 40 kg for a
child aged 2-13 years; and iii) 86 kg for an adult aged over 13
years (additional 3-5 kg may be added in winter months to account
for average increase in weight of winter clothing). Alternatively,
actual carriage weight could, in principle, be determined by
utilizing strain gauges or the like fitted to the undercarriage or
suspension system of the aircraft. A weight determining means or
strain-gauge means or the like adapted to fit or releasably attach
to an aircraft, e.g. undercarriage or suspension system, to enable
aircraft carriage load weight to be determined prior to takeoff is
a further aspect. Optionally, said means is configured with a
communication means for communicating the carriage load weight to a
microprocessor and/or for use of the carriage load weight as input
data into the method of fuelling and arrangement for calculating
inventions herein defined.
[0051] As an option, in order to facilitate an actual determined
weight of passengers and crew (and their carry-on baggage), which
may be utilized as input data (or further data) in the method of
fuelling and arrangement for calculating inventions herein defined,
e.g. as input data for the DYNAMIC or LIVE modules described, there
is provided, for generally applicability, as a further aspect of
the invention a method of determining the actual individual and/or
combined weight of passengers (typically boarding pass-carrying
passengers) and/or crew intending to board an aircraft, the method
comprising providing a weighing device for weighing individual or
groups of passengers and/or crew who engage said weighing device
(e.g. by standing on it for a minimum set time) and requiring all
passengers and/or crew intending to board or boarding the aircraft
to engage said weighing device, recording the data for individual
and/or groups of passengers and/or crew and, preferably,
calculating therefrom a total passenger and/or crew weight for the
flight. Preferably, the weight data stored is stored electronically
and communicated by electronic means as input data to a
flight-specific calculation in a microprocessor loaded with a fuel
calculation software. Preferably, individual passenger and/or crew
weight data may be attributed to the individual passenger and/or
crew member by further requiring that the passenger and/or crew
provides identification (e.g. by way of a boarding pass or id card)
to enable weight data to be attributed to the individual (e.g. by a
boarding pass reader or identification pass reader configured to be
in electronic communication with a microprocessor receiving
individual weight data). Preferably, the passengers and/or crew are
required to be weighed with the hand luggage they intend to carry
on board. [Optionally, in a further aspect, a passenger may be
required to provide identification associated with payment details,
e.g. a credit card or loyalty cart, whereby charges may be applied
or rebate issued according to a pre-determined scale according to
whether the passenger is above or below pre-determined maxima and
minima boarding weights included in the purchase price. Such
additional charge and/or rebate system may act as an incentive to
reduce weight in carriage].
[0052] In a further, associated, aspect, there is provide a system
for determining the weight of passengers and/or crew boarding an
aircraft, the system comprising a weighing station comprising a
weighing device for measuring the weight of a passenger or crew
member engaging the weight device and generating individual weight
data and an identification means for identifying the passenger or
crew member being weighed, said weighing device and identification
means preferably being configured such that individual weight data
is attributed to specific passenger or crew member. The system
further comprises a microprocessor or communication means for
storing and/or communicating the individual or cumulative weight
data and identification information, optionally co-attributed. The
weight and identification data generated may then be used as input
data or further data (e.g. to the DYNAMIC or LIVE modules
described) for the calculation of flight fuel requirement for a
specified aircraft flight. In one embodiment, the system is
configured to weigh the passengers and/or crew without their
carry-aboard hand-luggage by, for example, conducting the weighing
step during the scanning of hand-luggage routinely carried out at
airports as a security measure, the hand-luggage being weight
cumulatively on a separate weighing device configured to fit
in-line with a scanning system. Preferably, however, in order to
provide the most accurate data, the system is configured to enable
weighing of passengers and/or crew with their hand luggage and
preferably as close as possible to the boarding of the aircraft,
e.g. at the departure gate or at (e.g. just before or just after)
the door to the aircraft. [Optionally, the system is further
provided with a payment card reader, such as a credit card reader,
or is configured to associate the boarding pass or id card to a
payment method, and which system is programmed to draw a further
charge or issue a rebate from the payment means according to
whether the weight attributed to that passenger and its hand
luggage is greater than or less than pre-determined limits included
in a ticket price].
[0053] The AZFW as discussed above is typically an estimated value
based upon accurate information (e.g. actual number of passengers
with estimated weight, estimated weight of hand luggage and actual
weight of cargo), which we may term standard-AZFW. Preferably, the
AZFW is an accurately determined value, which herein means that
actual passenger weight and actual cargo weight is utilized in the
AZFW value calculation, which may be referred to as accurately
determined-AZFW. Where the AZFW is an accurately determined value
(e.g. as discussed above), the term AZFW used herein may optionally
be substituted with accurately determined-AZFW (or AD-AZFW) as a
preferred feature.
[0054] As explained in more detail below, the Captain enters the
AZFW value and other last-minute information such as the actual
runway (R1) which affects the taxiing time and hence taxiing fuel
consumption, the expected weather and the expected holding time at
the destination terminal (T2). The DYNAMIC software module
calculates the parameters ADJ RAMP FUEL (total fuel, which
illustrates the weight of fuel required to be uploaded (at the
ramp) to the aircraft for the flight), TRIP & TAXI (the
expected fuel consumption during flying and during taxiing
respectively) and displays HISTORICAL FACTS for EXPECTED HOLDING
(information on the expected fuel consumption during holding before
landing at the destination runway R2, explained in detail below)
and PREDICTED LDG FUEL (the predicted quantity of fuel remaining on
landing). This is based on the data entered together with data
predictions from software algorithms provided to the DYNAMIC module
from a MANAGEMENT software module. Note, it is usual practice to
fuel an aircraft to some quantity less than that proposed on the
OFP, to allow for adjustments in fuelling calculations by the
captain, for example allowing more up-to-date information on cargo
weight and passenger numbers. This depends upon an airline policy
and aircraft type, but may be OFP minus 3 tonnes for example. The
total calculated fuel requirement for the flight is the standby
fuel figure (that initial fueling amount) plus the additional
amount added at the ramp as a result of calculations--this is the
ADJ RAMP FUEL, being the total desired fuelling level determined at
the ramp.
[0055] The above algorithms incorporate safeguards based on
regulatory requirements which ensure that the minimum fuel needed
to satisfy these requirements is carried.
[0056] The algorithms take into account the fuel required to start
the main engines 2, the fuel used by the aircraft's auxiliary power
unit (APU) 1, the fuel used during taxiing to runway R1 and from
runway R2, the fuel expected to be used in flight and the fuel used
on landing.
[0057] The captain has discretion to increase the quantity of fuel
actually uplifted to the aircraft, as in the prior art based on
printed operational flight plans, but the interactive software
incorporated in the DYNAMIC module enables him to calculate the
implications of this--for example the amount of the additional fuel
that will be expended simply in carrying its own weight. The
required fuel is uplifted from a bowser 4.
[0058] Information required by the captain's computer is received
via e.g. a WiFi network from a server computer in (for example) the
terminal T1, as indicated by wireless signal Si from antenna 3 on
the terminal which is received by a further antenna 3 on the
aircraft. All the network signals are preferably encrypted.
[0059] It should be noted that the DYNAMIC module as well as the
other software modules are preferably all run on the server
computer and that the captain's computer acts as a thin client,
providing the user interface and the basic network communication.
Accordingly the further data as well as the operational flight plan
data can be received and processed by the server and the results
transmitted (within signal S1) to the captain's laptop via the WiFi
network. The input from the captain at the user interface during
the processing of the further data is transmitted to the server
over the WiFi network. Thus the network link between the flight
deck computer and the server in terminal 1 is bidirectional.
[0060] The aircraft then takes off (A') flies (A'') to the
destination and lands (A''') at runway R2 at the destination. After
taxiing to the destination terminal T2 is completed, the captain
notes the actual fuel remaining (LDG FUEL) and compares it with the
predicted value (PREDICTED LDG FUEL) calculated by the DYNAMIC
module. This and related data are communicated via antennae 3 of
the WiFi network to a further computer in terminal T2, using a
further software module, COMPLETE. Assuming the fuel consumption
prediction was accurate, this provides further confidence in the
system and enables the algorithms to be fine-tuned if
necessary.
[0061] Further detail is given below.
[0062] Referring to FIG. 2, the relationship between the software
modules M is shown. The arrows depict information flow (single
direction or bidirectional) between the modules.
[0063] The modules (termed Fuel Matrix modules) are as follows:
i) Fuel Matrix DYNAMIC
[0064] This is a core application utilised by the captain of the
aircraft as the main application during pre-flight duties to assist
the flight deck with recommended fuel uplifts in line with company
policies. It requires OFP data field entries (automatic or manual)
together with responses to extra fuel considerations to present
recommended fuel figures. To assist, related historical facts are
provided from the HISTORICAL module and live data is available from
the LIVE module. Typically, the time taken by the captain for data
entry is 90 seconds. The calculation machine predominately operates
within this application with inputs from/changes to the Fuel Matrix
MANAGEMENT module tailoring these calculations.
ii) Fuel Matrix COMPLETE
[0065] This is a core application utilised during post-flight
duties to record actual fuel factors to enhance the Fuel Matrix
LIVE and Fuel Matrix HISTORICAL modules. The average data field
entry time is 45 seconds. This module is primarily for use in data
collation/distribution within the software suite.
iii) Fuel Matrix MANAGEMENT
[0066] This is a core application utilised only by specialist
airline administrators to define a generic or route specific
benchmark and offer optimisation and standardisation. This
application inputs data for and/or modifies the algorithms utilised
in the DYNAMIC module. In this manner the DYNAMIC application can
be fine tuned to influence results and fuel cost savings. The
MANAGEMENT module also provides control for the other modules, with
the exception of the COMMUNITY module.
iv) Fuel Matrix LIVE
[0067] This is an add-on application utilised by the flight crew
immediately before fuelling to view user-defined live data to
assist with extra fuel considerations. When the captain or other
members of the flight crew are answering the extra fuel
consideration questions in the FUEL MATRIX dynamic application,
they can check on live data i.e. most recent reports of holding at
destinations, weather encountered and avoided on routes, runways in
use and other information relevant to fuel consumption for their
particular flight. This module can be customised by different users
or airlines.
v) Fuel Matrix HISTORICAL
[0068] This is an add-on application utilised by the flight crew to
view user-defined facts derived from previous flight statistics to
assist with extra fuel considerations. When the flight crew are
answering the extra fuel consideration questions in the Fuel Matrix
DYNAMIC application and reviewing recommended fuel loads, they can
check on historical data to build confidence in the results of the
fuel calculation such as predicted arrival fuel and anticipated
holding times for example. This module can be customised by
different users or airlines.
vi) Fuel Matrix COMMUNITY
[0069] This is an add-on website chat forum application utilised by
pliots/management/air traffic controllers and others to stimulate
fuel cost saving and monitoring discussions (threads) with simple
user-friendly functionality. The website can provide aviation news,
fuel prices, chat forums, information on fuel related issues and
the like and feeds information to the MANAGEMENT module.
vii) ADD-ON Modules
[0070] Further modules M' may be developed in the future and the
MANAGEMENT module is arranged to communicate with such modules.
[0071] Referring to FIG. 3, a start-up screen on the captain's
laptop is shown. He will normally log in (by clicking on button B1
with the laptop mouse) and then select the DYNAMIC module by
clicking on button B5. However buttons B2 to B4 provide access to
the LIVE, HISTORICAL and COMMUNITY modules which may be accessed to
provide background information for working with the DYNAMIC module
during the fuel calculation. The COMPLETE module is selected using
button B6 after touchdown at the destination. The MANAGEMENT module
typically contains the algorithms upon which the key calculations
and reference factors rely. This is preferably only accessible by
company systems administrators authorized to access this module and
may be selected with button B7, if needed.
[0072] Referring to FIGS. 4 and 5, the MANAGEMENT module, which
would normally be operated by specialist administrators on the
ground, can operate either with generic definable parameters (FIG.
4) which are not tied to any particular route or with
route-specific definable parameters (FIG. 5) if these are available
in running the fuel calculation algorithms. The latter provides
enhanced accuracy.
[0073] Referring to FIG. 4, the MANAGEMENT module includes data
entry boxes for the aircraft type, the hourly fuel consumption of
APU 1 (FIG. 1) the time taken to start the engines 2 (in minutes)
the fuel required to start the engines, the fuel consumption per
minute during taxiing and the date of the current version of the
module. These data entry boxes are shown at the head of the screen.
In addition, as shown at the right of the screen, there are data
entry boxes for the CRZD factor (the percentage that must be added
to the manufacturer's nominal fuel consumption for the aircraft
type to take into account the degradation in fuel consumption of
the particular aircraft being flown, due to e.g. dents in its
fuselage which impair its aerodynamic performance), STAT RMF
(statistical remaining fuel) and STAT CONT (statistical contingency
fuel). STAT RMF and STAT CONT may be used to feed into planned
landing fuel (PLF) calculations which illustrates to the flight
crew the fuel they can expect to carry on landing at the
destination and can be calculated in various ways. For example, PLF
can be calculated assuming all planned flight fuel is used plus an
amount of the remaining contingency fuel (CONT) multiplied by a
contingency factor (cf); or multiplying the adjusted ramp fuel
value by the statistical remaining fuel value (STAT RMF); or
assuming all planned flight fuel is used plus an amount of the
remaining contingency fuel (CONT) multiplied by a contingency
factor (cf) and multiplied by a statistical contingency factor
(STAT CONT). Typically, all three will be calculated and the lowest
will be displayed as PLF value to the flight crew. As more data
becomes available, the statistical factors become more reliable and
the PLF will be more accurate.
[0074] The MANAGEMENT module also utilizes, for example, six
independent parameters GP1 to GP6 which are associated with
respective fuel quantities which collectively make up the total
fuel requirement from running the APU 1, starting the engines 2,
taxiing from terminal T1, take-off from runway R1, the flight to
the destination, holding above the destination, landing on runway
R2 and taxiing to terminal T2.
[0075] Each of the above parameters GP1 to GP6 is associated with a
contingency value CONT GP1 to CONT GP6 respectively (certain values
of which are listed in column C1 in FIG. 4) and these represent
additional weights of fuel which must be carried in order to
satisfy contingencies such as the need to avoid bad weather and the
like. Collectively, CONT GP1 to CONT GP6 represent the total
additional fuel required to satisfy all recognised
contingencies.
[0076] Importantly, GP1 to GP6 are modified in dependence upon
answers to certain questions Q1 to Q6 (described below in relation
to FIG. 6) presented by the DYNAMIC module to the captain on his
laptop screen (his user interface). The effect is shown in columns
C2, C3 and C4. The parameter number is shown in column C2, the
yes/no answer (Y/N) is shown in column C3 and the effect in terms
of extra fuel is shown in column C4. For example, referring to the
first row (question Q1) in C2, C3 and C4, if the answer to question
Q1 is "No" then GP2 is raised by 1000 kg. No values are given for
the final row (Q6) because this is unused in the presently
described embodiment--extra fuel considerations may be further
defined and a relevant question or questions inserted here.
[0077] Thus contingency fuel is analysed by contingency and
adjusted in response to answers to simple questions given by the
captain immediately before fuelling.
[0078] Column C5 and column C6 show certain relationships between
contingency fuel values ("CONT LIMIT") and a contingency factor
("CONT FACT"). For example if the contingency fuel is greater than
2000 kg, then the contingency factor is 0.5. If the contingency
fuel is only 600 kg, then the contingency factor is unity. The
contingency factor is a probability factor utilised in an algorithm
for calculating the probable weight of fuel remaining on landing at
the destination.
[0079] The text entry boxes in columns C1 to C4 can be filled in by
the administrator. Selection buttons B at the foot of the screen
allow the administrator to perform the operations indicated on
those buttons.
[0080] Referring now to FIG. 5, if route-specific parameters are
available then they are used. For example if a route involves
flying over water, slightly different fuel consumption may result.
This can be taken into account using route-specific parameters.
[0081] It will be noted that the screenshot of FIG. 5 shows the
aircraft registration code (in this case G-ABCD), the flight number
("FLT NBR") and the destination ("DEST") code (in this case EGKK)
which are not included in the generic screenshot of FIG. 4.
Otherwise the screenshots are similar, and in particular, columns
c1 to c4 relate to the answers to questions Q1 to Q6 in the same
manner as columns C1 to C4 relate to the answers to these
questions, although the values entered by the administrator in the
text entry boxes of c4 differ from the corresponding values in
C4.
[0082] The constraints represented in columns c5 and c6 are
comparable to those of columns C5 and C6 (FIG. 4) respectively.
[0083] FIG. 6 shows the information presented interactively to the
captain by the DYNAMIC module as he determines the quantity of fuel
to uplift (load onto) the aircraft, this quantity being known as
the "adjusted ramp fuel" and indicated as "ADJ RAMP FUEL" namely
53.5 metric tonnes in this example.
[0084] The top left-hand region of the screen shows "OFP DATA,"
namely the flight number ("FLT NBR") and aircraft registration code
("AC/REG"), the destination ("DEST"), the expected fuel consumption
("TRIP") for the flight itself (i.e. take-off to landing but
excluding taxiing, excluding starting up the engines 2 and
excluding 30 minutes running the APU 1) the fuel required ("T/O
FUEL") for the flight itself at take-off (i.e. fuel required minus
TAXI fuel requirement), the degradation in fuel consumption
performance during flight, expressed as a percentage of the nominal
fuel consumption of that aircraft type, for the particular aircraft
("CRZ DEG") and the estimated zero fuel weight ("EZFW") and
estimated take-off weight ("ETOW") which is equal to EZFW+T/O FUEL.
The actual zero fuel weight on take-off ("AZFW") is not known at
the time of preparation of the OFP, is not included in the OFP, and
therefore is not OFP data. However, once this parameter is known,
it is entered by the captain in the AZFW box.
[0085] Finally, the OFP section includes boxes MS and PS for the
deletions and additions of fuel respectively per 1000 kg of fuel
subtracted from or added to the T/O FUEL value. For example if the
AZFW were 3,000 kilograms less than the EZFW, and this resulted in
a reduction in the calculated fuel requirement of 1,000 kilograms,
a further reduction 173 kilograms could be made to take into
account the saving in fuel otherwise required to carry the 1000 kg
of fuel to the destination.
[0086] The EXTRA FUEL CONSIDERATIONS section of the screenshot
shows an example of six questions Q1 to Q6 with (in the case of Q1)
an associated text entry box and in case of Q2 to Q5 YES/NO
buttons. These questions are as follows:
[0087] PARKING TO ACTIVE RWAY: The expected taxiing time (in
minutes) to the active runway R1 (FIG. 1) which may differ from the
taxiing time to the runway assumed in the operational flight plan
(OFP) as a result of a last-minute change to the runway selected,
e.g. as a result of a change in wind or as a result of noise
abatement procedures;
[0088] ATTAIN YOUR PLANNED FLS? Are the flight levels (defining
altitudes of different sections of the flight) specified in the OFP
going to be attained?--they may not be as a result of Air Traffic
Control restrictions, other aircraft already occupying the
requested flight levels, etc, after generation of the OFP. A change
in flight level can change the calculations for fuel consumption
requirements for the flight.
[0089] ANTICIPATE DEST HOLDING? Is holding anticipated at the
destination (e.g. as a result of air traffic congestion, bad
weather, earlier delays, etc)? [0090] HOLDING FOR +10 MINS:
Assuming an affirmative answer to the previous question, is the
holding period expected to be greater than 10 minutes?
[0091] DEST WX NEAR MINMAS? Is bad weather (possibly necessitating
a landing at an alternate airport) expected at the destination?
[0092] LVP IN FORCE? Are low visibility procedures in force?
[0093] In this example, Q6 and its associated answer button are
greyed out because it is known that such procedures are not in
force--so the question is assumed answered in the negative.
[0094] The captain can access real time live data via has laptop
(e.g. weather conditions en route, waiting times at destination
airport, etc), using the LIVE module (which, in common with the
other software modules, is preferably run on the remote server).
Additionally he is made aware of historical statistical data (e.g.
typical holding times) relevant to the sector by the HISTORICAL
module. These sources of information inform his answers to the
above questions.
[0095] In response to the captain's answers to questions Q1 to Q6
between boarding the aircraft and fuelling, and in response to the
captain selecting the CALC button B to confirm these answers, the
DYNAMIC module runs a set of algorithms to calculate the following
(as an example) in the CALCULATED FINAL FIGURES box:
[0096] ADJ RAMP FUEL: the adjusted ramp fuel value, i.e. the weight
of fuel in tonnes required to be uplifted to the aircraft A from
the bowser 4 at the ramp position;
[0097] TRIP: the amount of fuel in tonnes required for the flight,
i.e. while the aircraft is airborne, and
[0098] TAXI: the amount of fuel in kilograms required for taxiing
to the runway R1.
[0099] The pilot can accept the resulting figures (by selecting the
ACCPT button B) and upload the fuel, or can reject the resulting
figures (by selecting the REJCT button B). The latter choice brings
up a further screen (not shown) giving the opportunity to override
the calculated values, but if the manually selected values are
outside safe limits, the DYNAMIC module displays an appropriate
warning message.
[0100] All of the captain's decisions regarding fuel uplift are
recorded electronically on the OFP which is retained after the
flight to meet legal requirements. Optionally, this data may also
be retrieved by the airline management for monitoring of flying
efficiency and the effect of the decisions of the Captain may be
reviewed to identify flawed decisions, requirement for training
etc, as a management tool.
[0101] The screenshot of FIG. 6 also includes a HISTORICAL FACTS
section which displays the EXPECTED HOLDING (time)--in this case 8
minutes and the PREDICTED LDG (landing) FUEL (in tonnes). The
former figure is generated by the HISTORICAL MODULE and the latter
is generated by the DYNAMIC MODULE.
[0102] Examples of the algorithms run by the various modules will
now be described in general terms, before describing the screenshot
of FIG. 7 which is generated by the COMPLETE application after
landing at the destination.
[0103] The algorithms are typically run in three stages as follows:
[0104] i) In a preliminary step the route is checked to see whether
route-specific definable parameters are available--if not then
generic definable parameters are used (see the screenshots of FIGS.
4 and 5). Units are converted to metric if necessary. [0105] ii)
The following main algorithms are run: [0106] ctaxi (to calculate
the fuel required for taxiing) [0107] arf (to calculate the
adjusted ramp fuel) [0108] ctf (to calculate the trip fuel i.e.
fuel consumption during the flight including take-off and landing)
[0109] plf (to calculate the planned landing fuel i.e. the fuel
remaining on landing) [0110] iii) To complete the process, a fuel
saving value and/or a carbon dioxide reduction value are calculated
and a safety check is run to ensure that the fuel carried and
take-off and landing weights are within safe limits.
[0111] Optionally, a further step iv) may be incorporated, either
by incorporation in the process above or by using a separate
module, in which various calculations that are currently carried
out, e.g. in respect of Tankering, Cost Index, Re-Clearance and
Alternate Airport Selection and/or Optimum Route Selection, using
only Fuel Cost and Time parameters may be advantageously refined,
for example by using, in addition, carbon trading or
emissions-trading information. Such calculations may form an
independent module or be incorporated into the plf algorithm. This
optional step is set out in more detail below using Tankering as an
example to demonstrate the application. Accordingly, in an example
of a further step, Tankering Fuel calculations may be carried out
(this may be included in the plf algorithm). Some airlines include
in fuelling calculations implications of the varying fuel costs at
different locations, because the planned flight comprises more than
one leg, e.g. from A landing at B and flying on to land at C. For
example, where the fuel cost at a destination airport (B) is
significantly higher than the starting airport (A), the OFP may
direct additional fueling to save costs, even allowing for the fuel
burn required to carry the extra fuel to the destination (B) to
enable onward flight to destination (C) without purchasing more
fuel. This is a procedure known as Tankering. The method and
apparatus of the present invention may also allow for a Tankering
procedure to be implemented in the most efficient manner so that
any Extra Fuel may be uploaded allowing for calculated requirements
for Tankering Fuel. By using, for example, the LIVE module,
up-to-date relative fuel cost data may be provided, and the cost
efficiency of the Tankering procedure maximized to that particular
flight using a further algorithm provided, for example, by the
DYNAMIC module (or a separate TANKERING module). Furthermore, the
LIVE module may provide access to up-to-date carbon trading or
emissions-trading information, and such data included in the
Tankering Fuel calculation, in particular in the fuel burn
associated with Tankering, the cost not only of the purchase of the
fuel but also the carbon trading cost of Tankering fuel-burn. A
Tankering calculation can be provided as part of the method and
system of the invention described hereinbefore or as a separate
module.
[0112] Additionally, there is provided in a further aspect of the
invention a system for the calculation of the optimum
cost-efficient amount of Tankering fuel for an aircraft flight from
a pre-determined departure point to a pre-determined destination
point, the system comprising a programmed computer arranged to
determine a Tankering fuel-burn rate for said flight on the basis
of operational flight plan data and further data relevant to fuel
consumption for that instance of the flight, said computer
configured to receive input data on cost of fuel at departure and
destination and carbon trading costs associated with the flight and
configured to calculate from said Tankering fuel burn rate and said
input data an optimum Tankering fuel load for the flight.
[0113] In a still further aspect, there is provided a method for
the fuelling of an aircraft with Tankering fuel for a flight from a
pre-determined departure point to a pre-determined destination
point, wherein the fuel requirement for the flight is determined,
an optimum Tankering fuel load is determined by Tankering fuel
calculation software from a calculated Tankering fuel-burn rate,
the differential cost of fuel at the destination point and the
departure point and the carbon trading cost of Tankering fuel-burn
for the flight, said Tankering fuel-burn rate being determined on
the basis of operational flight plan data and further data relevant
to fuel consumption for that instance of the flight, and
subsequently fuel to meet said fuel requirement and a determined
optimum amount of Tankering fuel is uplifted to the aircraft under
the control of the user.
[0114] Tankering fuel is defined here as the amount of extra fuel
required at departure point to achieve a certain amount of extra
fuel remaining at the destination (destination-Tankered fuel). That
is, the Tankering fuel is equal to the destination-Tankered fuel
plus the Tankering fuel-burn (that is, the fuel burn associated
only with carrying extra Tankering fuel).
[0115] Preferably, the same data sources and calculations used to
determine a fuel requirement for a flight is adapted and used to
determine the Tankering fuel-burn.
[0116] With reference to the algorithms referred to above for the
purpose of putting the invention into effect according to one
embodiment involving defined steps i), ii) and iii), steps i) and
iii) do not require further explanation. The algorithms of step ii)
are given by way of Example below. Generic or route-specific
parameters available to the algorithms are shown in italics and
variables entered on screen (see the above discussion of the
screenshots) by the captain or flight crew or calculated by a
preceding algorithm from such entered variables are shown in
bold.
EXAMPLE
[0117] ctaxi Algorithm
ctaxi=(apuf.times.0.5)+esf+((tt-est).times.tf) [0118] ctaxi is the
total fuel consumption involved in taxiing. [0119] apuf is the
hourly fuel consumption of the APU 1. The 0.5 figure represents the
assumed half-hour run time of the APU. [0120] esf is the fuel
required to start the engines 2. [0121] tt is the taxiing time and
is entered by the captain/flight crew (see question Q1 in FIG. 6).
The HISTORICAL algorithm of FIG. 6 provides historical data,
adjusted for seasonal changes, for this parameter which can be used
to guide the answer to question Q1. [0122] est is the time taken
for the engines to start, normally 1 to 2 minutes. [0123] tf is the
rate of fuel consumption during taxiing.
arf Algorithms 1) and 2)
[0123] [0124] 1) Required code: zfwdiff (zero fuel weight
difference)=(AZFW-EZFW)/1000 [0125] (The divisor of 1000 converts
from kilograms to tonnes)
[0126] If zfwdiff positive then.times.zfwdiff by PS=PSzfw
[0127] If zfwdiff negative then.times.zfwdiff by MS=MSzfw
[0128] (MS and PS are shown in the OFP DATA section of FIG. 6).
[0129] (cg1 and cg2 etc are contingency groups, which control fuel
additive questions--if there is a high CONT, there will be answers
that do not require an additive question) [0130] If CONT.ltoreq.cg1
then
[0131] if Q5=Yes then tof5=p5
[0132] (see question Q5 and CONT in FIG. 6) [0133] If
CONT.ltoreq.cg2 then
[0134] if Q1=No then tof1=p1
[0135] if Q2=Yes then tof2=p2
[0136] if Q3=Yes then tof3=p3 [0137] (see questions Q1 to Q3 in
FIG. 6)
[0138] If CONT.ltoreq.cg3 [0139] Q4=Yes then tof4=p4 [0140] if CRZ
DEG=P then tofcrzd=crzd.times.crzdf.times.CONT
[0141] (CRZ DEG is cruise degradation--a cruise degradation figure
is applied to an aircraft to account for the variation in fuel burn
as a result of age and imperfections. The higher the value
attributed to CRZ DEG, the more likely it is to have a small fuel
additive to account for it). [0142] 2) Required code: newtof (new
take-off fuel)=tof ((+PSzfw) or
(-MSzfw))+tof1+tof2+tof3+tof4+tof5+tof6+tofcrzd [0143] (thus newtof
is the New Take-Off Fuel weight i.e. the actual weight of fuel at
take-off) arf=newtof+ctaxi
ctf Algorithms
[0143] [0144] Required code: atow (actual take-off
weight)=AZFW+newtof [0145] Required code: towdiff (take-off weight
difference)=(ATOW--ETOW)/1000
[0146] If towdiff positive then.times.towdiff by PS=PStow
[0147] If towdiff negative then.times.towdiff by MS=MStow [0148]
ctf=TRIP ((+pbtow) or (-mbtow))
[0149] (AZFW, ETOW and TRIP are given in the OFP data section of
FIG. 6).
plf Algorithms
[0150] Required code: cf (contingency factor) (this defines the
contingency factor: it is assumed that a small amount of CONT
(contingency fuel) may be used up on a flight and a large portion
should be expected, typically, to remain unused; i.e. if the CONT
fuel is expected to be less than or equal to a defined contingency
limit (e.g. c11) then a first contingency factor applies to
cf-relevant calculation, if not then the same test is carried out
relevant a further contingency limit associated with a further
contingency factor, until the appropriate contingency factor is
determined).
[0151] If CONT.ltoreq.c11 then cf=cf1 or
[0152] If CONT.ltoreq.c12 then cf=cf2 or [0153] If CONT.ltoreq.c13
then cf=cf3 or [0154] If CONT.ltoreq.c14 then cf=cf4 or [0155] If
CONT.ltoreq.c15 then cf=cf5 [0156]
plf=arf-ctf-ctaxi-tof1-tof2-tof3-tof4-tof5-tof6-((CONT-tofcrzd).times.cf)
(this defines predicted landing fuel=adjusted ramp fuel--calculated
trip fuel--calculated taxi fuel--[fuel additives]--expected used
part of contingency fuel) [0157] or [0158] *plf=arf.times.srmf
[0159] or [0160]
*plf=arf-ctf-ctaxi-tof1-tof2-tof3-tof4-tof5-tof6-((CONT-tofcrzd).times.sc-
ont)
[0161] *These possibilities involving statistically derived
parameters srmf and scont can be used when sufficient data has been
collated by the COMPLETE MODULE.
[0162] Referring now to FIG. 7, when the aircraft has landed at its
destination, the COMPLETE module is run to acquire, either manually
from the flight crew or automatically from aircraft instruments,
the FLIGHT DATA and ACTUAL FUEL FACTORS shown. The latter
correspond to the (with hindsight) correct answers to questions Q1
to Q6 of FIG. 6. This information is saved (by selecting a button
B) and fed to the HISTORICAL, MANAGEMENT and LIVE modules (FIG. 2)
for current and future reference.
* * * * *