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RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 1 /nn
Aerodynamics Group
Applied Aerodynamics Conference
Basic Aerodynamics Applied to Airline Flyingto Improve Fuel Efficiency/Payloads and Safety
:Hugh DIBLEY FRAeS, FRIN, MCILT
formerly BOAC/BA Airbus Toulouse
(Busy slides for reading without audio!)
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 2 /nn
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 3 /nn
Hugh Dibley’s Main Aviation Activities
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 4 /nn
Pilots’ Role – To Carry Maximum Payload at Minimum Cost
Main factors – Pre-flight and In-FlightPilot’s operational effect on economy and the environment
Linear “holding” en-route versus Circular Holding at destinationOne-stop versus Non-stop flights to save fuel
Commander or Technician just complying with procedures?How much Need for Aerodynamic Knowledge?
How to cope with unexpected Black Swan events?
Practical Example of ATC Needing Aerodynamic KnowledgeControllers have asked to Stall / Go supersonic
Future Air Traffic Systems expect to involve Pilots in separation
Loss of Control In-flight now Cause of Most Passenger FatalitiesLack of pilot aerodynamic/system knowledge considered a factor
Example of accidents leading to US Law to Train for Stall Recovery
Hence formation of - RAeS Flight Simulation Group ICATEE(International Committee for Aircraft Training in Extended Envelopes)
Training for LOCI – Prevention and Recovery on Simulators & Aircraft
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 5 /nn
Simplified Aircraft Flight Profile – for a Single Aircraft
Single aircraft
Efficiency is reduced by the need for ATC to separate aircraft to
avoid conflicts then merge again for landing
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 6 /nn
Need to React with ATC which must Separate Aircraft then Merge to Land
ATC Sectors in South East England, UK ATC Sectors Los Angeles, USA
ATC often have to take aircraft away from their optimum route and altitude to separate aircraft safely.
The distance between aircraft, and loss of efficiency, depends upon the navigational accuracy of the total system – could vary from 3 miles under radar to 120 miles en-route. Latest navigation systems can reduce en-route space to 5 miles.
ATC is split into separate centres, sometimes determined nationally, and liaison between centres can reduce efficiency.
During descent aircraft may have to cross points between centres at specific altitudes thus flying level rather than following an efficient continuous descent with idle thrust.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 7 /nn
As aircraft approach their destination, ATC must merge aircraft into a stream to the runway to achieve the most efficient landing rate.
At present this is usually achieved by ATC giving aircraft headings and speeds to fly at low levels which stretch the approach path while aircraft are placed in sequence at the required spacing for the type causing extra fuel consumption and noise over the ground.
New Air Traffic Management Systems will merge aircraft into their landing sequence earlier in the flight, and allow more efficient descents with idle thrust leading to quieter Constant Descent Approaches with no periods of level flight.
The complexity of the process to merge traffic efficiently can be seen from the aircraft tracks into Schiphol airport at Amsterdam and simulations of the Paris arrival routes.
Simulation of Paris Arrivals
Need to React with ATC which must Separate Aircraft then Merge to Land
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 8 /nn
Prime Requirement – Sound Knowledge of Take-off Performance Principles
To Take-off at the Maximum Allowable Weight for the Conditions
Maximize Take-off Weight
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 9 /nn
Carry Minimum Safe Fuel Reserves to Maximize Payload
Cost of Extra Fuel which can reduce Payload
On long sectors extra fuel displaces payload thus losing revenue - loss is extreme on very long sectors when the tanks are already full and the only way to fly further is to reduce the passenger load/weight.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 10 /nn
Cost of carrying Extra Fuel – Not Restricting PayloadBurnt at app 3% per hour
Carrying extra fuel over the minimum flight plan fuel always involves as penalty due to the extra weight burnt at 3% per hour.
The actual cost of extra fuel depends on the relative cost of fuel between the departure and destination airfields. If the fuel is cheap enough at the departure airfield it can be worthwhile carrying/tankering extra fuel into the destination.
However the effect of the extra weight on the aircraft must be considered – extra landing distance, possible extra brake wear and use of reverse thrust, reduced maximum cruise altitude, etc.
This decision is best made by the crew on the day who need to know the cost of extra fuel for the most economic judgement. For example:
HKG-NGO Save $127/tonne – definitely worth tankering.LHR-BRU Save $1/tonne – not worth tanking for fuel price alone.
HKG-DEL Cost £1/tonne – extra fuel could be cheap insurance if delays en route were likely.
NGO-HKG Cost £206 – cost of extra fuel prohibitive.
Many companies do not publish Fuel Price Differentials but just tell crews when to “tanker” fuel, which may not be efficient.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 11 /nn
Cruise – Crews Need to be Aware of Aircraft Performance Crews should be have a good knowledge of the performance of their aircraft such as:
Optimum speeds for minimum cost, minimum fuel, etc and the penalties for flying away from the normal/recommended speeds.
Maximum altitudes for the aircraft weight and air temperature – All engines (provided by the FMS) and if limited by engine thrust of airframe buffet (not shown by FMS). Engine(s) Out altitude which may not be shown by the FMS with all engines running and be only available from graphs which are difficult to read quickly.
Crews have climbed the latest aircraft with modern FMS above the maximum recommended altitude and had to descend again.
Some aircraft have become upset with total loss of control.
Cruise Speed & Fuel Consumption Relationship Engine Out Altitudes may
only be available on graphs
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 12 /nn
Cruise – Crews Need to be Aware of Aircraft Performance
Higher Air Temp maylimit ceiling by thrustthus have to descend
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 13 /nn
Cruise – Crews Need to be Aware of Aircraft Performance
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 14 /nn
Cruise – Crews Need to be Aware of Aircraft Performance A320 70T FL330 Speed Range - Low Speed to High Speed Buffet/Mmo
Speed range at 1 G in level flight
Some aircraft can climb to “Coffin Corner”[not A320] DON’T GO THERE
Speed range at 1.5 G in Steep turn
FMGC Max Buffet Limit 1.3 G[A320 300 fpm Climb limited]
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 15 /nn
Cruise – Crews Need to be Aware of Aircraft Performance Table showing Boeing 747 Freighter Performance. All Engines & Engines Out
All Engine Max Altitude aerodynamically limited - Low Speed Buffet close to Cruise IAS
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 16 /nn
Cruise – Crews Need to be Aware of Aircraft Performance Table of Airbus A320 All Engines and Engine Out information – easier to access than FMS. All Engines Max Altitude is always limited by Climb Thrust. Available after FMS failure.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 17 /nn
Correct Descent from Cruise Altitude EssentialCrews can still have to calculate/monitor descent mentally
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 18 /nn
Reduction of True Air Speed at Low Altitude at the same Indicated Air Speed causes increase
in fuel consumption and flight time
Descending early wastes fuel and time, can expose aircraft to icing conditions and more
aircraft traffic, makes more noise, etc
Descent – Large opportunity for Fuel Savings – or Wastage
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 19 /nn
Descent – Large opportunity for Fuel Savings – or WastageTHERE IS NO TRADE BETWEEN FUEL & TIME DUE TO A POOR DESCENT
Summary of Penalties Cause by Poorly Executed Descents:
(Written in 1973 – some of us were worried about the environment then….)
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 20 /nn
Descent – Large opportunity for Fuel Savings – or WastageCircular slide rule primarily designed to help crews follow an efficient flight idle descent profile to comply with an ATC clearance such as to cross 23 DME XYZ at 8,000ft at 250kts.
Direct DME-Altitude checks are available throughout to verify on the profile. A fixed gradient of 400ft per mile above 10,000ft is suitable for IAS of 300-340kts according to aircraft weight, and 300ft per below 10,000ft for 250kts IAS after an 8 mile nm deceleration.
Checking the profile mentally, normally by 300ft per mile, requires regular computation of an equation, such as at 50 DME:(50-8-23) x 300 = 5,700 + 8,000 = 13,700ft
In a survey BOAC B747 pilots estimated their efficiency was improved by at least 10 miles when using the computer, covering the cost of the 2 provided on each aircraft in 1 flight.
Besides minimising fuel burn and noise, following this profile improves safety by keeping the aircraft well clear of the ground into nearly all airfields.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 21 /nn
Descent – Large opportunity for Fuel Savings – or Wastage
This linear computer has the altitude and sink rate on an elastic scale which can set gradients from 250ft per mile for slow speed descents or when in a tailwind up to 600ft per mile suitable for high speeds on a light aircraft into headwinds of 200kts. Could provide smoother descents than A340 FMGEC but not worth the effort for reduced engine changes.
Aircraft FMS now fly efficient descents, but if taken off the planned route by ATC pilots can be back to calculating the best profile using mental arithmetic.
United Airlines nearly bought the circular computer but while the fixed gradient was suitable 747s & DC10s, DC9s found it too steep and B727s too shallow for their high speeds.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 22 /nn
7. Approach – Critical for Fuel Savings & Noise ReductionApproach is the phase of flight after descent when the aircraft is decelerated and configured by extending flaps for the final approach.
Ideally it is a short period of continuous descent.
ATC may need to give headings and speeds while aircraft are merged into a landing stream, when flaps and landing gear must be extended as late as possible to minimise the extra fuel burnt.
The baseline of the table giving comparative fuel consumption is when cruising at FL370/37,000ft.
Minimum fuel is consumed while descending which shows that long slow descents with idle thrust are the most fuel efficient.
Maximum noise and fuel consumption, 400% more than at cruise altitude, is when flying level with flaps and gear extended (500% on a B747), but reduced when descending on the final glidepath even with the extra drag of full landing flap.
This demonstrates that level flight should be resisted if possible and that level flight with flaps and gear extended should avoided at all costs.
Baseline Cruising at 37,000ft
Minimum Fuel Consumption
Maximum Fuel Consumption
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 23 /nn
7. Approach – Critical for Fuel Savings & Noise ReductionThis shows that city life need not be disturbed significantly if aircraft are flown level with minimum flap setting above 3,000ft, preferably at least 5,000ft, before descending on the glideslope to the runway with gear up until about 1,500ft to be established for landing by 1,000ft. (On Airbus aircraft the gear can be extended at 800ft, like the Space Shuttle, but this is not the approved procedure.)
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 24 /nn
7. Approach – Critical for Fuel Savings & Noise ReductionOne operator into London Heathrow required the flaps and gear extension to be confirmed in the Initial Approach Checklist which was completed when leaving the entry points to the London area, so the aircraft could fly with the gear extended for up to 60 miles.
With the extra drag of the gear and flaps the aircraft would descend steeply and then fly at low altitude across central London making conversation impossible when over flying.
Aircraft noise disturbance over central London was a significant factor in the 1971 decision that the third London airport should be built 100km East of London on the Essex/North Sea coast, but this project was terminated after the 1973-4 fuel crisis.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 25 /nn
7. Approach – Critical for Fuel Savings & Noise ReductionTo try and reduce the extreme levels of noise over central London this article was published in the GAPAN Journal of March 1974 (Appendix A in the CEAS paper and at www.Dibley.eu.com.) Suggesting that crews should ideally fly a continuous descent from the entry point to intercept the runway glideslope and extend the landing at about 1,500ft to be stabilised in the landing configuration by 1,000ft.
The idea was accepted by UK NATS and after input from Lufthansa who were proposing their similar Managed Drag Procedure, Constant Descent Approaches were started into LHR in 1975. DMEs were installed to give crews continuous distance to the runway paid for by the Department of Trade who was responsible for Noise Abatement.
However CDAs into LHR were not implemented as well as hoped as the procedure has yet to be included in the manufacturers operating manuals. While local operators are proficient less regular visitors will tend to descent early to intercept the glideslope from below.
Similar CDAs can be flown into airports like JFK - immediately reducing noise on the approach.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 26 /nn
7. Approach – Critical for Fuel Savings & Noise ReductionThe type of CDA introduced into London and the Netherlands can give worthwhile noise reductions from 10 to 25 miles from the runway with no additional technology, and are being implemented in other airports such as Sacramento.
However at busy airports merging aircraft into an efficient sequence for the approach can be more difficult with aircraft trying to fly CDAs.
Future ATM systems due in service by about 2010 will allow efficient CDAs from cruise altitude, but procedures using parts of this system are already operating in some areas as described later.
UPS have been integrating their own aircraft flying CDAs into Louisville, which is possible because UPS is the only operator there at night.
Similarly because of their relatively low level of traffic the Swedish aviation authority LFV have been developing “Green” 4D trajectories flying CDAs into Stockholm Arlanda, both locally from and across the Atlantic.
However crews can still make savings using their own initiative.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 27 /nn
8. Crews Can Save Fuel/Time by Choosing Approach/Runway
Approach tracks into busy airports can be structured with a long lead in for bad weather, and some are flown automatically to follow agreed noise routes.
When traffic and weather permits, crews should be allowed to fly shorter visual approaches
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 28 /nn
Past Examples of Operational Fuel SavingsExample of 8% Immediate
Fuel Saving by Crews
Flight data recording showed that an aircraft fleet was not operating efficiently.
A fuel economy newsletter listed the flight segments and what how much extra fuel was being burnt / could be saved by a better operation.
The total extra burn was possibly 26% but this was unlikely to be saved as not all items would occur on one leg.
After crews were made aware of the penalties and some changes in procedures an 8% saving was achieved immediately.
Departure/arrival procedures in italics are not optimised in current operations.
1979 prices
Potential Fuel Saving 26%
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 29 /nn
Past Examples of Operational Fuel Savings
Crew Fuel Monitoring GraphsTop – Cost of Extra Fuel UpliftedCentre – Cost of Extra Fuel BurntBottom – Crew’sTotal Extra Cost
A contract was secured because the crews’ more efficient operation saved 13% fuel compared to the previous operator which covered the crews’ cost.
A cargo operator became profitable by, amongst other savings, increasing payloads by reduced fuel reserves and improved fuel consumption.
The Fuel Monitoring Graphs show how individual crew performance can vary and affect the profitability of an airline.
The top graph shows the cost of carrying extra fuel based on the Sector Fuel Price Differential.
The centre graph shows the cost of extra fuel burnt in flight, perhaps by non optimum operation of the aircraft – descending early, configuring for approach too soon, etc.
The bottom graph shows the total of the two. The difference between the extremes is over U$400 per sector which for a year could total U$100Ks.
Such information must obviously be used sensitively and only be used for encouragement.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 30 /nn
Current Operational Fuel Savings follow the Same Principles
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 31 /nn
Primarily due to Shortage of Runway Capacity
Approach controllers need a reserve of aircraft to be able to sequence aircraft in efficiently to maximise LHR’s single runway landing rate.
If Cruising at Normal Speed En Route then Circling at Destination –Fuel burnt while circling/holding is wasted – XX% on a short flight
Reducing Speed En Route to Lose the Time Spent Circling –Can eliminate fuel wastage.
Passenger delays in immigration due bunching in abnormal weather –Can be due to shortage of runway capacity....
We need more capacity else business will go to AMS, CDG, FRA , MUC
Linear Versus Circular Holding for DelaysWhy Regular Circular Holding At LHR
(10-20 mins holding considered normal to UK ATC?)
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 32 /nn
Fuel Economy on Long Haul Flights
Can fly 14,500km/9,000miles7,800 nautical miles
Bristol to Perth Australia
A380 Range Capability
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 33 /nn
Fuel Economy on Long Haul Flights
Bristol-Perth
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 34 /nn
Fuel Economy on Long Haul FlightsFlight Bristol – Perth Australia14,500km/9,000 statute miles
Flying Close to Colombo – about half wayFlight Time approx 18 hours
Fuel carried for Colombo–Perth is burnt at 4% per hour Bristol-Colombo
Therefore about an extra 35% fuel can be required for a non-stop flight on a high take-off weight aircraft capable of flying the 9,000 miles non stop.
A lighter aircraft designed to fly with the same payload but with a range of only 4,500 miles will save more fuel.
This was illustrated in the next slides by Dr John Green’s 2008 paper for Greener By Design, presented to the RAeS Toulouse Branch -
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 35 /nn
Options for reducing fuel burn per passenger-km
The Bréguet range equation
Fuel burn per tonne-kilometre
X
R
1X
Rexp022.1
W
W1
X
1
RW
W
P
E
P
F
where X = HηL/D H = calorific value of fuel η = overall propulsion efficiency L/D = lift/drag ratio
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 36 /nn
Effect of design range and operating range on payload-fuel efficiency
0
1000
2000
3000
4000
5000
6000
7000
8000
0 5000 10000 15000 20000 25000
Range (km)
PF
E (
km
)
maximum payload
design payload
maximum payload maximum passenger load
A
D
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 37 /nn
Effect of design range on fuel burn for long-distance travel
Design range
km
Payload tonne
Mission fuel
tonne
Reserve fuel
tonne
Max TOW tonne
OEW tonne
Fuel for 15,000km
tonne
15,000 25.9 120.3 13.5 300.0 140.3 120.3
Travelling 15,000km in one hop or three
Revision of earlier GBD estimates:Correction published in August 2006 issue of the Aeronautical Journal
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 38 /nn
Design range
km
Payload tonne
Mission fuel
tonne
Reserve fuel
tonne
Max TOW tonne
OEW tonne
Fuel for 15,000km
tonne
15,000 25.9 120.3 13.5 300.0 140.3 120.3
5,000 25.9 20.4 5.4 120.0 68.4 61.1
Travelling 15,000km in one hop or three Revision of earlier GBD estimates: Correction published in August 2006 issue of the Aeronautical Journal
Recent research shows the value of building an efficient 4,000nm aircraft
Raj Nangia further suggests refuelling rather than landing en route.
Effect of design range on fuel burn for long-distance travel
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 39 /nn
Commander or Technician just complying with procedures?How much Need for Aerodynamic Knowledge?
Beyond 10-9
Discovered in Australia, not accepted as Swan for decades
Theory byNassim Nicholas Taleb
Work focuses on problems of randomness and probability.
Criticized the risk management methods used by the finance industry and warned about
financial crises
to produce
a technically competent Commander who is capable
of fulfilling the basic Flight Operations task to
Carry Maximum Payload at Minimum Cost(safe, fuel efficient, quiet, kind to aircraft-engines, good service, etc)
and is capable of handling a Black Swan Event
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 40 /nn
Dealing with Black Swans
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 41 /nn
Considered by many to be a major Black Swan Event
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 42 /nn
Other Black Swans?Examples of Crew actions saving loss of life :
Eric Gennotte’s crew landed a A300 B4 with no hydraulics using differential engine thrust alone after hit by missile at Baghdad
Captain Peter Burkill retracted the 777 flaps to reduce drag thus avoiding fences before the runway when engines lost thrust on final approach into LHR
Captain Sullenberger started the APU out of sequence to keep the A320 powered normally when ditching in the Hudson
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 43 /nn
Other Black Swans?Examples of Failures requiring Considerable Crew Activity :
After an A380 engine 2 uncontained failure, while the aircraft was being flown manually, Richard de Crespigny’s crew had to action 53 ECAM messages taking some 50 minutes to complete. It took the 5 man crew some 2 hours to prepare the aircraft for landing. When on the ground they still had matters to resolve – engine 2 could not be shut down, wheels brakes reached 900°C.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 44 /nn
Another Example when the crew judged that the aircraft automatic ECAM System
(Electronic Centralised Aircraft Monitor)was better to be ignored as they had more information – a burning smell
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 45 /nn
Practical Example of ATC Needing Aerodynamic Knowledge1. BDA-JFK
Headwind 100 ktsFL350
Headwind 30 ktsFL410 B747 M.85/265 kts IAS, Speed 460 kts
DC8 M.82/280 kts IAS, Speed 380 kts
As the B747 was overtaking the DC8 -
in order to provide separation for descent –
The ATC controller requested the B747 to reduce speed by 60 kts.
(ATC normally use IAS when applying speed control.)
In which case the B747 would have stalled!
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 46 /nn
Practical Example of ATC Needing Aerodynamic Knowledge2. LHR-JFK
FL350
FL390 B747 M.85/265 kts IAS overtaking a 707
B707 M.82/280 kts IAS
In order to provide continued separation during descent –
the ATC controller asked the B747 what high speed could be maintained during descent - 747 replied M.89/390kts and was cleared to descend to FL150 at the high speed.
When passing FL370 the controller asked for the 747’s speed – given as M.89/285kts IAS.
The controller replied “But you said you could descend at 390kts”
390kts IAS is supersonic at FL370!
In one month ATC had requested to stall and go supersonic!
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 47 /nn
In Future Pilots may Maintain Separation from Other Aircraft
Example of Aircraft Navigational Display showing Other Aircraft, which can be used for Separation Assistance by the crew.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 48 /nn
“Future” ATM Fuel Savings Achieved NOW - USAUPS are already using their own ABESS (Airline Based En-Route Sequencing
and Spacing) system to enable their crews to fly efficient CDAs into Louisville.
No holding /circling like at LHR!
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 49 /nn
UPS Operations Control uses ABESS to Sequence & Merge aircraft during Cruise
Communication systems & Displays in UPS aircraft then allow crews to manage their own FDMS (Flight Deck Merging & Spacing) during an idle thrust descent.
“Future” ATM Fuel Savings Achieved NOW - USA
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 50 /nn
Considerable reductions in Noise and Fuel have made by the UPS ABESS & FDMS systems, enabling their crews to fly efficient CDAs into Louisville.
“Future” ATM Fuel Savings Achieved NOW - USA
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 51 /nn
“Future” ATM Fuel Savings Achieved NOW - EuropeIn Sweden flights have been flying “Green” 4D trajectories
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 52 /nn
2 pilots & Flight Engineer
2 pilots
Accidents due to Loss Of Control In-flight
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 53 /nn
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 54 /nn
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 55 /nn
LOC Accidents – Pinnacle - Bombardier CL-600-2B19 Failed to monitor AP Vertical Speed Mode climbing to FL410,
Speed reduced to stall which was not recovered. Should be prevented by improved knowledge of aerodynamics and thus use of automatics – (Some authorities say crews mustn’t VS mode as don’t understand!Has to be used routinely when climbing fast in busy airspace to avoid unnecessary ACAS/collision avoidance warnings.)Could have been recovered by better knowledge of aerodynamics and full stall recovery training? Avoided by proper crew discipline.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 56 /nn
LOC Accidents – American 587 – Airbus A300-600
ex JFK October 2001 Copilot applied full rudder travel both ways after passing through B747 wake vortex, thus exceeding the designed loads of the vertical stabiliser/fin which broke off.Crews had been trained to use rudder in an upset and flight simulators’ roll control response modified to require this – against the advice of both major aircraft manufacturers. Indicates the need for upset recovery training to be according to the manufacturer’s recommendations, otherwise negative training can result.
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 57 /nn
LOC Accidents –
Colgan Air - Bombardier DHC-8-40012th February 2009
Crew airspeed monitoring lapsed – due to fatigue? Had discussed possibility of tailplane icing – Reacted as per training video to retract flaps & pull aft stick? Should have been prevented by........ Could have been recovered by training/knowledge for type?
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 58 /nn
Colgan Air Bombardier Accident into Buffalo
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 59 /nn
Colgan Air Bombardier Accident into Buffalo
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 60 /nn
Families of passengers killedIn the Colgan Airways Accident
into Buffalo Lobbied congress to
Pass a LawRequiring Stall Training
For All Airline Pilots
Colgan Air Bombardier Accident into Buffalo
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 61 /nn
US Law
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 62 /nn
US Law
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 63 /nn
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 64 /nn
RAeS Flight Simulation Group Conference June 2009About Training at the Edge of the Normal Envelope
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 65 /nn
This led to the formation of the RAeS Flight Sim GroupInternational Committee for Aviation in Extended Envelopes
ICATEE
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 66 /nn
Aerodynamic Knowledge Needed for Pilots To Avoid/Recover from Upsets?
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 67 /nn
Aerodynamic Knowledge Needed for Pilots To Avoid/Recover from Upsets?
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 68 /nn
Aerodynamic Knowledge Needed for Pilots To Avoid/Recover from Upsets?
Includes Stall Warning and Stick Pusher
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 69 /nn
Aerodynamic Knowledge Needed for Pilots To Avoid/Recover from Upsets?
But in Icing – aircraft may stall before the warning/stick pusher
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 70 /nn
Aerodynamic Knowledge Needed for Pilots To Avoid/Recover from Upsets?
Vn Diagram to know if G limits have been exceeded
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 71 /nn
Upset Recovery Training in a Full Flight Simulator
But Current Motion Systems have limitations replicating accelerations felt beyond normal passenger service...
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 72 /nn
Development of Simulation
Current motion platform used in most simulators
5. Motion Systems
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 73 /nn
Development of Simulation
Angular motions are sensed in humans by canals in the inner ear
5. Motion Systems
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 74 /nn
compute aerodynamic coefficients
compute aerodynamic
compute aerodynamic
convert axes stability to body
and moment
forces
moments convert axes
stability to body
compute linear accelerations
compute angular accelerations
compute
compute Euler compute DCM
convert axes body to Euler
convert axes body to stability
atmospheric model
P',Q',R'
P,Q,R
Ps,Qs,Rs
L,M,N
engine forces
, M P,Q,R
e0,e1, e2,e3
inceptors
,M Xp,Zp
Lp,Mp,Np
Xs,Ys,Zs Xb,Yb,Zb
U',V',W'
U,V,W
Ps,Qs,Rs
Vc
inceptors
' '
and moments
U,V,W
Vx,Vy,Vz Pn,Pe,h
Ls,Ms,Ns
,M
Vc, Vc,
parameters
Development of Simulation
The inputs to the motion platform are calculated by the Equations of Motion
5. Motion Systems
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 75 /nn
Development of Simulation
As movement is limited, platform motion must be washed out ready for next event
Centrifuges are needed for high G acceleration (seen only in civil aircraft rejected takeoffs)
5. Motion Systems
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 76 /nn
1g
Development of Simulation
Acceleration sense available from motion platform
5. Motion Systems
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 77 /nn
1g
Development of Simulation
Acceleration sense available from motion platform
5. Motion Systems
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 78 /nn
1g
Development of Simulation
Acceleration sense available from motion platform
5. Motion Systems
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 79 /nn
1g
Development of Simulation
Acceleration sense available from motion platform
5. Motion Systems
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 80 /nn
1g
1g * Sin 20° = 0,34 g
1g * Cos 20° = 0,94g
20°
Development of Simulation
Acceleration sense available from motion platform
5. Motion Systems
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 81 /nn
Upset Recovery Training in a Full Flight Simulator
Instructor Operating Stations will have to include extra information to assess the crew’s performance
and to ensure that limits have not been exceeded,
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 82 /nn
The US DoT FAA Draft AC 120-STALL of 14 Dec 2011
– Stall and Stick Pusher Training contains comprehensive reminders about the
limitations of flight simulators, and the responsibilities of instructors to make students
aware of the lack of realism in the relevant areas.....
Upset Recovery Training in a Full Flight Simulator
Instructors must advise crews about motion realism
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 83 /nn
Upset Recovery Training in a Full Flight Simulator
Instructors must advise crews about motion realism
FAA Draft AC December 14th 2011 – Page 20
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 84 /nn
Upset Recovery Training in an Aircraft is RecommendedTo be part of a Commercial Pilot’s Initial Qualification
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 85 /nn
Reducing LOC-I Accidents
1998 & 2004 AURTA addressed Recovery
2008 version introduced prevention
A vital factor is to make crews aware of the hazards
“Prevention is Prime”
Hence the ICATEE’sUpsetPreventionRecoveryTrainingAid
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 86 /nn
ICAO’s Recent Pronouncement in UP&RT
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 87 /nn
MCC Courses
All airline pilots must pass a Multi-Crew Cooperation Course
These concentrate on the fact that:We all make mistakes,We should admit our mistakes/we were wrongWe must help each other work together for the common good – of not having an accident.
MCC Courses should be compulsory for bankers!
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 88 /nn
Equation/Formula for the Meaning of Life?
Attraction force to be the dream?
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 89 /nn
RAeS Applied Aerodynamics Conference - Hugh DIBLEY : “Aerodynamics Applied to Airline Operations” 18 th July 2012 90 /nn
Thank you
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