Date and time |
Aircraft |
Tuesday 25 July 2000 at 14 h 44[1] |
Concorde |
|
registered F-BTSC
|
Site of accident |
Owner |
La Patte d'Oie in Gonesse (95) |
Air France |
|
|
Type of flight |
Operator |
Charter flight Flight AFR 4590 |
Air France |
|
Persons on board |
|
Flight Crew: 3 Cabin Crew: 6 Passengers: 100 |
Summary:
During takeoff from runway 26 right at Roissy Charles de Gaulle Airport, shortly before rotation, the front right tyre of the left landing gear was damaged and pieces of the tyre were thrown against the aircraft structure. A major fire broke out under the left wing. Problems appeared shortly afterwards on engine N° 2 and for a brief period on engine N° 1. The aircraft was neither able to climb nor accelerate. The crew found that the landing gear would not retract. The aircraft maintained a speed of 200 kt and a radio altitude of 200 feet for about one minute. Engine n° 1 then stopped. The aircraft crashed onto a hotel at La Patte d'Oie in Gonesse.
|
People |
Equipment |
||
|
Killed |
Injured |
Uninjured |
|
Crew |
9 |
- |
- |
|
Passengers |
100 |
- |
- |
Destroyed |
Third parties |
4 |
6 |
- |
|
ORGANISATION OF THE INVESTIGATION
On Tuesday 25 July 2000 at around 14 h 50 UTC, the BEA was informed of the accident to a Concorde in the commune of Gonesse (95) after takeoff from Paris Charles de Gaulle. In accordance with Annex 13 to the Convention on International Civil Aviation and the law of 29 March 1999 relating to technical investigation of accidents and incidents in civil aviation, a technical investigation was launched. A Principal Investigator was nominated as Investigator-in-Charge.
In accordance with the provisions of Annex 13, a British accredited representative and two investigators from the AAIB, accompanied by several experts from BAE SYSTEMS and Rolls Royce, joined the investigation as representatives of the State of Manufacture, along with German (BFU) and American (NTSB and FAA) observers. Air France, EADS and SNECMA made numerous experts available to the BEA.
The Minister of Equipment, Transport and Housing established a Commission of Inquiry, in accordance with the law of 29 March 1999. This Commission has assisted the BEA in its work. Two meetings were held in the course of which the Commission was informed of the progress of the investigation. The Commission approved the process.
The Investigator-in-Charge established seven working groups to find and collate the information necessary for the investigation. The groups worked in the following specific areas:
- site and wreckage
- aircraft, systems and engines
- preparation and conduct of the flight, personnel information
- flight recorders
- aircraft performance
- witness testimony
- examination of previous events.
These groups have worked continuously since 27 July. Two plenary sessions of the working groups took place on the 3rd and 22 August to summarise the progress of the investigation.
All operations carried out at the site or on parts of the aircraft have been conducted in co-ordination with those responsible for the judicial investigation, in accordance with judicial procedures. The accident site and all parts of the aircraft are under the control of the judicial authorities. The majority of technical examinations have yet to be performed.
On 16 August, on the basis of the findings of the investigation, the BEA and its British counterpart the AAIB issued an initial safety recommendation.
The initial results from the investigation are contained in this report, which has been presented to, and approved by, the Commission of Inquiry.
1 - HISTORY OF FLIGHT
On Tuesday 25 July 2000 the Concorde registered F-BTSC, operated by Air France, took off from Paris Charles de Gaulle to undertake charter flight AFR 4590 to New York with nine crew members (3 FC, 6 CC) and one hundred passengers on board. The Captain was Pilot Flying (PF), the First Officer (FO) was Pilot Not Flying (PNF).
The total weights of the aircraft and of the fuel on board stated by the Flight Engineer (FE) at the time the aircraft started were 186.9 t and 95 t respectively. The speeds selected by the crew were V1: 150 kt, VR: 198 kt, V2: 220 kt.
At 13 h 58 min 27 s, the crew contacted ATC on the Flight data frequency and requested the whole length of runway 26 right for a takeoff at 14 h 30.
At 14 h 07 min 22 s, the controller gave startup clearance and confirmed runway 26 right for takeoff.
At 14 h 34 min 38 s, the Ground controller cleared the aircraft to taxi towards the runway 26 right holding point via the Romeo taxiway.
At 14 h 40 min 02 s, the Tower controller cleared 4590 to line up. At 14 h 42 min 17 s, he gave it takeoff clearance, and announced a wind from 090° at 8kt. The crew read back the takeoff clearance. The FE stated that the aircraft had used eight hundred kilos of fuel during taxiing.
At 14 h 42 min 31 s, the PF commenced takeoff. At 14 h 42 min 54 s, the PNF called one hundred knots, then V1 nine seconds later.
A few seconds after that, the right front tyre on the left main landing gear was destroyed, very probably after having run over a piece of metal. The destruction of the tyre resulted in large pieces of rubber being thrown against and damaging parts of the aircraft.
At 14 h 43 min 13 s, as the PF commenced the rotation, the controller informed the crew the presence of flames behind the aircraft. The PNF acknowledged this transmission and the FE announced the failure of engine n° 2. The recorded parameters show a momentary loss of power on engine n° 1 that was not mentioned by the crew. Eight seconds later the fire alarm sounded and the FE announced that he was shutting down engine n° 2. The fire alarm then stopped. The PNF drew the PF's attention to the airspeed.
At 14 h 43 min 30 s, the PF called for landing gear retraction. The controller confirmed the presence of large flames behind the aircraft.
At 14 h 43 min 42 s the fire alarm recommenced.
At 14 h 43 min 56 s, the PNF commented that the landing gear had not retracted and made several callouts in relation to the airspeed.
At 14 h 43 min 59 s, the GPWS alarm sounded several times. The FO informed ATC that they were trying for Le Bourget aerodrome. The recorded parameters then indicate a loss of power on engine n° 1. A few seconds later, the aircraft crashed onto a hotel at La Patte d'Oie in Gonesse at the intersection of the N17 and D902 roads.
2 - INJURIES TO PERSONS
Injuries |
Crew Members |
Passengers |
Others |
Fatal |
9 |
100 |
4 |
Serious |
0 |
0 |
0 |
Slight/None |
0 |
0 |
6 |
3 - DAMAGE TO AIRCRAFT
The aircraft was destroyed on impact.
4 - OTHER DAMAGE
The hotel that the aircraft crashed onto was destroyed.
5 - personnel INFORMATION
5.1 Flight Crew
5.1.1 Captain
Male, 54 years old
- Commercial pilot's licence n° 193067 issued 12 July 1967
- First class Commercial pilot's licence n° 208369 issued on 8 August 1969
- Airline transport pilot's TOP licence n° 195176 issued on 19 February 1976
- Last medical at the CPEMPN (Paris) on 5 May 2000
- IFR rating obtained 2 June 1969, valid until 31 August 2000
- B 727 rating on 4 December 1970
- A 300 rating on 24 April 1974
- B 737 rating on 13 December 1977
- Captain on 3 February 1983
- Pilot Instructor from 31 December 1985, valid until 30 June 2001
- A 320 rating on 18 November 1988
- A 340 rating on 27 February 1993
- Concorde rating on 16 August 1999, valid until 31 August 2001
- Pilot's competency check on 9 June 2000, valid until 31 August 2001
- CRM training course on 6 January 1994
- Line check planned for October 2000
- Base check on 4 February 2000
- Total flying hours: 13 477 of which 5 495 as Captain
- Flying hours on Concorde: 317 of which 284 as Captain
- Flying hours in the last six months: 177.91
- Flying hours in the last three months: 95.34
- Flying hours in the last thirty days: 23.86
5.1.2 First Officer
Male, 50 years old
- Commercial pilot's licence n° 411171 issued on 16 December 1971
- First class commercial pilot's licence n° 263672 issued on 9 October 1972
- Airline transport pilot's TOP licence n° 232079 issued on 2 February 1979
- Last medical at the CPEMPN (Paris) on 17 January 2000
- IFR rating valid until 31 December 2000
- Nord 262 rating on 31 March 1972
- Morane Saulnier 760 rating on 26 March 1972
- Caravelle rating on 1st June 1974
- A 300 rating on 16 November 1979
- Concorde rating on 10 January 1989, valid until 31 December 2000
- Pilot's competency check on 23 (S1) and 24 (S2) November 1999, valid until 31 December 2000
- CRM training course on 9 May 1994
- Line check 1st August 1999, valid until 31 August 2000
- C1 base check on 26 November 1999 valid until 31 December 2001
- Concorde Simulator Flight Instructor from 15 March 1999, valid until 31 March 2000
- Total flying hours: 10 035 of which 2 698 as FO on Concorde
- Flying hours as instructor: not calculated before 1997 at Air France
- Flying hours in the previous six months: 127.25
- Flying hours in the previous three months: 50.13
- Flying hours in the previous thirty days: 7.64
Note: The Captain's and First Officer's licences are covered by the FCL1 regulations (July 1999), the type rating renewing the licence as long as the medical certificate is valid. For those over 40 years of age, the medical certificate is valid for six months. Unlike the previous regulations, its validity runs from a specific date to a specific date rather than to the end of the month.
5.1.3 Flight Engineer
Male, 58 years old
- Flight Engineer's Licence n° 142568 issued on 22 March 1968, valid until 30 June 2001
- Last medical at the CPEMPN (Paris) on 20 June 2000
- Caravelle rating on 8 March 1968
- Falcon 20, rating on 27 March 1968
- B 727 rating on 4 January 1973
- B 737 rating on 28 February 1978
- B 747 rating on 29 May 1980
- B 747-400 rating on 3 November 1990
- Concorde rating on 28 February 1997, valid until 30 June 2001
- Total flying hours: 12 532 of which 937 as FE on Concorde
- Flying hours in the previous six months: 131.64
- Flying hours in the previous three months: 62.19
- Flying hours in the previous thirty days: 23.62
Note: the FE's licence is subject to the former regulations, as defined by the modified Order of 31 January 1981. The licence is valid for one year; the medical check-up is valid from the day of the check-up to the end of the same month the following year. The test and the medical check-up must be carried out in the same month.
5.2 Cabin crew
5.2.1 Cabin Services Director
Female, 36 years old
Qualifications:
- Initial training: Safety Certificate on 2 October 1986.
- Concorde professional aptitude certificate on 4 May 1992
5.2.2 Flight Attendants
Female, 36 years old
Qualifications:
- Initial training: Safety Certificate on 4 March 1991
- Concorde professional aptitude certificate in January 1999
Female, 49 years old
Qualifications:
- Initial training: Safety Certificate on 20 February 1978
- Concorde professional aptitude certificate in July 1990
Female, 27 years old
Qualifications:
- Initial training: Safety Certificate on 2 February 1996
- Concorde professional aptitude certificate in August 1999
Male, 32 years old
Qualifications:
- Initial training: Safety Certificate on 24 February 1993
- Concorde professional aptitude certificate in January 1999
Male, 38 years old
Qualifications:
- Initial training: Safety Certificate on 14 May 1990
- Concorde professional aptitude certificate in June 1997
6 - AIRCRAFT INFORMATION
6.1 Airframe
6.1.1 Information (see appendix 1)
- Manufacturers([2]): EADS / BAE SYSTEMS
- Type: Concorde type 1 - version 101
- Serial number: 3
- Registration: F-BTSC
- Entry into airline service on 24 October 1979
- Airworthiness Certificate issued on 23 December 1975, valid until 29 September 2002
- Flying hours up to 25 July 2000: 11989 hours and 4873 cycles
- Since type DO1 general overhaul on 1st October 1999: 576 hours and 181 cycles.
6.1.2 Maintenance
The aircraft had undergone a scheduled check AO1 in accordance with the approved maintenance programme. The check commenced on 17 July 2000 and was completed on the 21st. During the check, the left main landing gear bogie had been replaced in order to correct an acceptable deferred defect related to the under-inflation detection system.
Since the A check, the aircraft had undertaken four flights, on July 21, 22, 23 and 24. On the 24th, several maintenance operations had been carried out:
Problems |
Maintenance Actions |
Slight thrust surges in cruise at mach 2, with illumination of start pump warning light. |
Checks on both TCU's, replacement of the N1 limit amplifier, check on the EGT line, ground test OK. |
Brake overload warning light for wheel n° 4. |
Cable changed. |
Slow leak in blue hydraulic system in flight. |
Connecting joint on the artificial feel cylinder on the blue hydraulic system replaced. |
Tyre on wheel n° 5 worn. |
Wheel n° 5 replaced. |
The aircraft was originally planned as a reserve for 25 July. F-BVFA was planned to carry out scheduled flight 002 in the morning and F-BVFC to undertake Flight 4590. For maintenance reasons, there was an allocation change between F BVFA and F-BVFC. F-BVFA was finally declared unavailable during the night and the reserve aircraft, F-BTSC, was programmed in its place to carry out Flight 4590.
The aircraft was airworthy and there were no acceptable deferred defects for Flight 4590. Prior to the flight, the GARRETT pneumatic motor which activates the engine n° 2 secondary exhaust nozzle buckets, had been replaced. Tests had been carried out and they revealed no anomalies.
6.2 Landing Gear
6.2.1 General
The Concorde has a nose gear, an auxiliary gear situated at the rear of the fuselage and two main landing gears, each with a bogie with four wheels. The bogies are equipped with a system which detects under-inflation of a tyre and transmits a visual signal to the cockpit. This detection system is inhibited when the speed of the front wheels is less than 10 kt or when the indicated airspeed is above 135 kt.
6.2.2 Gear Retraction
Gear retraction is controlled electrically by the landing gear control lever situated on the pilot's panel (three-position lever: up, neutral, down) and is activated by hydraulic pressure from the Green circuit (see figure 1). The lever cannot be moved from the "neutral" position to the "up" position unless the left main landing gear shock strut is no longer compressed.
Conditions for gear retraction:
- The gear doors must be unlocked and open.
- The main and nose gears must no longer be compressed.
- The front wheels must be centred
- The main landing gear bogies must be perpendicular to the gear leg.
When all of the landing gear is locked in the "up" position, the gear doors close. During retraction of the main gear, the shock struts are retracted into the gear leg to allow them to fit in the gear well. The wheels are automatically braked when the gear selector is in the "up" position.
For the landing gear, the Yellow hydraulic circuit is used only if there is a failure in the Green circuit. The perpendicularity of the gear is ensured by two autonomous nitrogen-powered pneumatic actuators |
Figure 1 - Synoptic diagram of the main gear hydraulic system |
6.2.3 Braking
The brakes are manufactured by Dunlop. Braking is electrically controlled and is activated by hydraulic pressure from the Green circuit in normal conditions.
In case of failure in the Green circuit, an automatic switch allows the Yellow circuit to be used. In case of emergency braking, only the Yellow circuit is used in direct hydraulic liaison with the rudder bars.
|
|
|
Figure 2 - Synoptic diagram of main landing gear braking |
6.2.4 Deflectors
The deflectors are made of composite materials and fibreglass (to make them frangible) except for the bogie fasteners. Each deflector weighs around 4 kg and is located at the front of each main landing gear. Their function is to deflect water and spray to ensure it does not enter the engine air intakes. These deflectors were the subject of an optional Service Bulletin (SST 32-103 of 12/01/95 modified on 28/02/95) which proposed the insertion of two cables in the leading edge in order to retain pieces of the deflectors in case of failure. Air France did not apply the aforementioned Service Bulletin. |
|
6.2.5 Wheels and Tyres
The wheels were manufactured by Dunlop, and the tyres used by Air France were manufactured by Goodyear in the United States. No retread tyres have been used since 1997.
On the day of the accident, the main landing gear wheels and tyres on F BTSC were installed as follows:
Figure 3 (from above)
|
WHEEL P/N |
WHEEL S/N |
Position on aircraft |
Workshop issue date |
Date installed on aircraft |
TYRE S/N |
Number of cycles |
AHA1216 |
531 |
1 |
09/06/00 |
10/07/00 |
91510047 |
9 |
AHA1216 |
579 |
2 |
25/05/00 |
29/05/00 |
91831651 |
37 |
AHA1216 |
594 |
3 |
10/05/00 |
18/05/00 |
91801029 |
45 |
AHA1216 |
500 |
4 |
17/02/00 |
22/06/00 |
91831659 |
23 |
AHA1216 |
446 |
5 |
06/07/00 |
24/07/00 |
91560078 |
0 |
AHA1216 |
581 |
6 |
12/07/00 |
18/07/00 |
91570604 |
4 |
AHA1216 |
518 |
7 |
22/06/00 |
24/06/00 |
91870259 |
19 |
AHA1216 |
591 |
8 |
04/07/00 |
09/07/00 |
91930448 |
9 |
N.B. notation in bold type refers to left main landing gear.
6.3 Fuel
The signal from each fuel gauge is sent simultaneously to the corresponding indicator and to a totaliser. By design, error in measurement of the total fuel quantity must not exceed 5 % in extreme flight conditions, and the error in measurement on each of the tanks must not exceed 2 %. The quantity of fuel present in a tank can be considered to be correctly indicated when the reading is greater than zero. The quantity present cannot be presumed if the above does not apply.
Note: a general electrical power cut fixes the last indication supplied by the needles and masks the indications on the rollers with a flag. The failure of an electrical connection from a fuel gauge leads to an indication of zero on the corresponding indicator.
Before the accident flight, the tanks had been filled with jet fuel (Jet A1). An overfill of 300 litres, equivalent to a quantity of 237 kg had been added. In total, the quantity loaded was around 94 800 kg.
Note: the overfill procedure allowed loading of a maximum of 1 630 litres extra, compared to the quantities mentioned below.
The capacity of the thirteen tanks is presented in the table below. These represent maximum capacities without exceeding the level of the upper sensors.
Function |
Number |
Capacity (litres) |
Quantity (kg) |
Engine supply |
1 2 3 4 |
5 300 5 770 5 770 5 300 |
4 198 4 570 4 570 4 198 |
Main tanks |
5 6 7 8 |
9 090 14 630 9 350 16 210 |
7 200 11 587 7 405 12 838 |
Auxiliary tanks |
5A 7A |
2 810 2 810 |
2 225 2 225 |
Transfer tanks (balance) |
9 10 11 |
14 010 15 080 13 150 |
11 096 11 943 10 415 |
Total |
|
119 280 |
94 470 |
6.4 Engines
6.4.1 General
Power is supplied by four twin spool turbojets installed in pairs, each being equipped with a reheat, a variable area air intake and variable primary and secondary exhaust nozzle used to optimise performance. The secondary exhaust nozzle also incorporates the thrust reverser.
The n° 1 and n° 2 engines are respectively the outer and inner left engines, engines n° 3 and n° 4 the inner and outer right engines.
Manufacturers: Rolls Royce and SNECMA.
- Type: Olympus 593 MK 610-1428.
- Reheat provides 18 % extra thrust at takeoff.
|
n° 1 |
n° 2 |
n° 3 |
n° 4 |
Serial number |
CBE031 |
CBX115 |
CBE092 |
CBE051 |
Installation date |
03/02/2000 |
01/08/1999 |
14/06/2000 |
23/08/1999 |
Total hours |
11 200 |
9 158 |
8 394 |
11 670 |
Hours since installation |
342 |
576 |
84 |
576 |
Cycles since installation |
106 |
181 |
28 |
181 |
6.4.2 Contingency Mode
The contingency mode can be activated manually or automatically in the case of engine failure on takeoff. Thrust above the maximum takeoff thrust can then be provided by remaining engines. Automatic mode is activated when:
- The throttle levers move above the 10 % level,
- Reheat is activated on any engine,
- The take off monitor is armed,
- N2 on an engine goes below 58.6 %.
The power of the other three engines then increases automatically up to a level which may reach 105 % of N2.
6.4.3 Reheat Cutout
As soon as an engine's N1 falls below 75 %, reheat on that engine is disconnected. Reheat is re-activated when N1 exceeds 81 %.
6.4.4 Fire Protection
Fire detection on an engine is ensured by two loops which react to increases in temperature. They are made up of four components assembled in line so as to detect:
- A fire around the engine and/or
- A torch flame fire around the combustion chamber.
If only one loop detects a fire, the loop is indicated as faulty and has to be shut off by the crew. If both loops detect a fire, the Gong sounds and the appropriate red ENGINE warning light comes on in the Main Warning System (MWS) panel, followed by a flashing red warning light on the engine shutdown/fire handle of the corresponding engine and an aural warning (bell).
Pulling the engine shutdown/fire handle shuts:
- The air conditioning valve
- The hydraulic shutoff valve
- The LP and HP fuel supply valves
- The reheat fuel supply valve
- The fire doors.
The dual head extinguishers are activated by two push buttons located behind each engine shutdown/fire handle.
Note: the red warning light in the Main Warning System is also associated with alarms for low oil pressure, engine TCA overheat, and detection of liquid in the dry bays.
6.4.5 Engine Maintenance
Each engine consists of twelve modules whose maintenance is undertaken by Air France, by SNECMA Services or by GEAS. The final assembly is performed by GEAS. Tasks performed can be of three types: visual inspection, partial repair or major repair based on the Olympus Maintenance Manual.
Readings taken by the FE during supersonic flight of parameters such as EGT and FF assist in assessment of engine condition. The readings from these engines on previous flights have not revealed any malfunctions.
6.5 Weight and balance
6.5.1 Weight
The weights listed in the first table hereafter are those which were entered by the Dispatcher to establish the forecast weight, then the final weight. The second table shows the real weights as established by the investigation.
Computer-generated weight (kg) |
Phase 1 forecast |
Taxi weight |
Takeoff weight |
Corrected basic weight |
81 560 |
81 560 |
81 560 |
Baggage |
1 651 |
2 131 |
2 131 |
Fuel + taxiing |
93 400 + 2 000 |
92 936 + 2 000 |
92 936 |
Passengers |
8 253 |
8 253 |
8 253 |
EIC |
0 |
0 |
0 |
Total weight |
186 864 |
186 880 |
184 880 |
Real or noted weight (kg) |
Phase 1 forecast |
Taxi weight |
Takeoff weight |
Corrected basic weight |
81 560 |
81 560 |
81 560 |
Baggage |
1 651 |
2 525 (1) |
2 525 |
Fuel + taxiing |
39 730 ( before refuelling) |
94 853 |
93 853 (4) |
Passengers |
8 253 (2) 7 759 (3) |
8 253 (2) 7 759 (3) |
8 253 (2) 7 759 (3) |
EIC |
60 (5) |
60 |
60 |
Total weight |
|
187 251 (2) 186 757 (3) |
186 251 (2) 185 757 (3) |
(1) Nineteen items of baggage loaded on board were not taken into account, only 103 items appearing on the load sheet. There were 122 items of baggage loaded on board, with an average estimated weight of 20.7 kg each, making a total of 2 525 kg.
Note: these items of baggage had not been taken into account by the Gaétan system nor by the Baggage Reconciliation System (See paragraph 16.2).
(2)By applying the fixed average for passengers: one passenger = 84 kg, one child = 35 kg.
(3)By applying the fixed average for men and women: one man = 88 kg, one woman = 70 kg, one child = 35 kg.
Note: for holiday charter flights, it is also possible to use a fixed average of 76 kg per passenger.
(4)Allowing that the aircraft consumed a ton of fuel during taxiing.
(5)The EIC corresponds to 60 kg of newspapers.
6.5.2 Balance
The CG noted on the final load sheet gives a figure of 52.3 at Zero Fuel Weight and 54.2 for taxiing with fuel; this is the normal CG for a takeoff at maximum takeoff weight.
6.6 Takeoff Performance
The following parameters are used hereafter for performance calculations:
- QNH of 1 008 hPa
- temperature 19 °C
- a dry runway
- a CG of 54
The Operating Manual provides the maximum structural weights:
- for taxiing 186 880 kg
- at takeoff 185 070 kg
Since the wind readings at different test points show a light and variable wind, the calculations are made with calm wind conditions.
Note: the takeoff limitations evaluation gives a maximum performance weight of 186.7 tons. With this weight and the associated speeds (V1, V2, VR), the second segment limitation and the tyre limitation have to be taken into account. The higher the aircraft speed on takeoff, the further the second segment limitation is pushed back. However, this speed is further limited by the constraints imposed by the tyres.
At the maximum structural weight at takeoff, the calculations provide the following values:
- V1: between 139 and 162 kt (the crew selected 150 kt)
- VR: 199 kt
- V2: 220 kt (1.125 VZRC)
- Three-engine trim: 12.9°
The Flight Manual provides the following zero rate of climb (VZRC) figures.
VZRC (kt) 185 t |
3 engines |
2 engines |
Gear retracted |
193 |
262 |
Gear extended |
205 |
>300 |
Note: the notion of VZRC is important for Concorde. It is the cruising threshold speed, which allows the aircraft to remain in level flight at zero rate of climb. On a thrust/speed diagram, VZRC is located at the intersection of the thrust available curve and the thrust required curve. These points represent an unstable condition. Furthermore, these speed values are highly influenced by the actual weight of the aircraft.
Ground and air minimum control speeds:
-VMCA = VMCG = 132 kt on three engines,
-VMCA = VMCG = 157 kt on two engines.
Takeoff runway length required and takeoff distance required (Flight Manual):
-TORA = 3 370 metres
-TODA = 3 700 metres
Note: These distances are regulated distances taking into account the failure of one engine.
A calculated simulation can be performed based on these parameters and a serviceable aircraft with four engines operating. Since it is not possible to know the exact weight at brake release (because of utilisation of the average passenger weights, for example), the maximum structural weight at takeoff (185.070 kg) is used for the calculations.
The results of this simulation are as follows (rounded figures):
- V1 is reached 1 150 m, or 33 s, after brake release
- VR is reached 2 070 m, or 43 s, after brake release
- V2 is reached 2 700 m, or 48 s, after brake release
- The wheels leave the ground 2 600 m after brake release
- The distance run to reach 35 feet is 2 950 metres
For all of these values, the influence of an increase in weight of one ton was examined and found to be negligible.
7.1 General Situation at 12 h 00
7.1.1 At Altitude
At level 500 hPa (around 5 500 m), a depression associated with a pocket of cold air (temperature < -16 °C) was centred over the Gulf of Gascony. It was moving from the southwest towards the northeast and arrived over the Paris region during the night. It was associated with the rear of the disturbance covering the southwest of the country.
An analysis of the meteorological situation at 12 h 00, performed using the Météo-France, Aladin model, with a mesh of 0.1° at heights of 100, 200 and 500 m above the ground, showed a small anti-cyclonic cell centred on the Seine et Marne which was moving north-east at forecast times of 15 h 00 and 18 h 00. Because of its progression, this cell maintained an easterly flow over the whole Paris region during the afternoon.
7.1.2 On the Ground
A succession of low-pressure areas stretched from La Coruna to Leningrad. At midday one of these low-pressure areas was centred over the Poitou and Auvergne regions and was moving northeast. In front of its warm front, in the cool wet air left by the previous day's disturbance, the cloud cover was essentially made up of cumulus and stratocumulus with little vertical development.
This slightly subsiding intermediate zone had a weak pressure gradient. Consequently, it produced variable winds of less than 10 kt, locally calm.
7.2 Situation at the Aerodrome
After the dispersal of morning mist at around 10 h 00, the increase in temperatures provided visibilities and ceilings which removed any operating restrictions on the aerodrome.
At 14 h 43, visibility was 15 km, the sky was cloudy with 2/8 Cu at 540 m, 2/8 Cu at 720 m and 5/8 SC at 1 020 m. The temperature was 19 °C and the humidity 74 The average wind at the threshold of runway 26 was 090°/3 kt and 320°/3 kt at the threshold of runway 08.
At 14 h 44, the average wind at the threshold of runway 26 was 020°/3 kt and 300°/3kt at the threshold of runway 08.
Note: wind measurements are taken every half a second and averaged over two minutes.
Between 14 and 15 h, the surface wind varied in strength at the two thresholds between calm and 9 kt and between 330° and 170° in direction. The runway was dry.
7.3 Documents Supplied to the Crew
The meteorological dossier supplied to the crew consisted of wind and temperature charts with forecasts at flight levels 300, 390 and 530 at 12h and 18 h, two TEMSI charts for the north Atlantic between flight levels 250 and 360 for the same times and TAF, METAR and SIGMET reports valid for the destination and alternate aerodromes.
Not applicable.
9.1 Radar Track
In order to obtain a precise position of the aircraft on the runway, the track was based on data from the AVISO system, the digitising system for the analogue ground radar.
BEA/ADP Image
N.B: the numbers on the track refer to chapter 11.
9.2 Telecommunications
Flight AFR 4590 was contacted successively on the following frequencies:
-ATIS on 126.175 MHz
-Flight data on 126.65 MHz
-Traffic on 123.6 MHz
-Ground on 121.8 and 121.975 MHz
-Loc South on 120.9 MHz
Relevant communications are mentioned below.
9.2.1 ATIS
The "XRay" recording at 12 h 10 included:
-Takeoff runways 27 and 26 right
-Runway 27 LDA 2 630 metres
-TORA 2 900 metres
-ASDA 2 900 metres
-TODA 2 900 metres
-Wind 350°/ 7 kt
-Temperature 16 °C
-QNH 1008
The "Yankee" recording at 13 h 50 included:
-Takeoff runways 27 and 26 right
-Runway 27 LDA 2 630 metres
-TORA 2 900 metres
-ASDA 2 900 metres
-TODA 2 900 metres
-Wind 010°/ 4 kt
-Temperature 19 °C
-QNH 1008
9.2.2 Flight Data Frequency
At 13 h 58, the crew requested "Concorde for New York on Echo 26 we need the whole length of 26 right"
At 14 h 07, the controller confirmed ".plan for 26 right .", the crew read back ". on 26 right .".
9.2.3 Ground Frequency
At 14 h 34, the controller said "Air France 45 90, good morning, taxi to holding point 26 right via Romeo" then added ". do you want Whisky 10 or do you want taxiway Romeo". The crew confirmed "we need the whole runway". The controller replied "OK so you're taxiing for Romeo, Air France 45 90". The crew read the information back.
9.2.4 Loc South Frequency
At 14 h 40 min 02 s, the controller transmitted "45 90 line up 26 right", then crew replied "we line up and hold on 26 right, 45 90".
At 14 h 42 min 17 s, the controller said"45 90 runway 26 right wind 090 8 kt cleared for takeoff ", the crew replied"45 90 takeoff 26 right".
At 14 h 43 min 13 s the controller stated". 45 90 you have flames . you have flames behind you". The crew acknowledged this transmission.
At 14 h 43 min 28 s, a transmission, whose source could not be identified, was made on the frequency "it's really burning and I'm not sure it's coming from the engines ".
A 14 h 43 min 31 s, the controller confirmed "45 90 you have strong flames behind you"and he continued ". as you wish you have priority for a return to the field". The crew acknowledged this transmission.
A 14 h 44 min 05 s, the controller transmitted "Fire Service Leader err . the Concorde I don't know his intentions get into position near the southern parallel runway" then "Fire Service Leader correction the Concorde is returning on runway 09 in the opposite direction". The crew then transmitted "we're trying for Le Bourget."
A 14 h 45 min 10 s, the controller told the Fire Service Leader "The Concorde has crashed near Le Bourget Fire Service Leader".
A 14 h 46 min 09 s, the controller announced "For all aircraft listening I will call you back shortly we're going to get ourselves together and we're going to recommence takeoffs".
A 14 h 55 min 47 s, an aircraft informed the controller ".there is smoke on runway 26 right, there's something burning apparently, for information ."
A 14 h 57, a runway vehicle (Flyco 9) told the controller "there's tyre"then "pieces of tyre which are burning".
10 - AERODROME INFORMATION
10.1 General
Paris Charles de Gaulle Aerodrome currently has one northern runway 09/27 and two southern parallel runways 08/26. Work was being carried out on the north runway, from 15 June to 17 August 2000, and its available length was reduced during this period of time from 3 600 to 2 700 metres, its width being unchanged at 45 metres.
Runway 08L/26R (26 right) is 4 215 m long and 45 m wide. Runway 08R/26L is 2 900 m long and 60 m wide.
Runway 26R has 600 m of tarmac followed by 7.5 metre square concrete slabs, its threshold being at an altitude of 312 feet.
The aerodrome has two fire fighting centres, a north RFFS and a south RFFS. Each centre is able to mobilise the men and equipment required for a Category 9 airport such as Paris Charles de Gaulle.
10.2 Runway Inspections
ADP Note 10/AD/98 specifies three daily inspections in addition to the lighting inspection: before 7 h 00, around 14 h 00 and around 21 h 00 local time.
On 25 July at around 04 h 30 (local time), an inspection of the runway was performed in two passes by a flyco runway inspection vehicle. Nothing was reported.
At around 14 h 30, a partial inspection of the runway was performed by a flyco vehicle in the vicinity of taxiway W2 following suspicion of a bird strike.
Between 14 h 35 and 15 h 10, an exercise with several fire service vehicles took place on runways 26 right and 26 left. To allow for this exercise, the runway inspection planned for 15 h 00 was delayed.
11 - FLIGHT RECORDERS
11.1 Recorder Types and Readout
Two flight recorders were installed on board F-BTSC, in addition to a Quick Access Recorder (QAR) which was also interrogated to assist in the investigation.
The flight recorders were found at the accident site by a technical investigator four hours after the accident. They were recovered as soon as conditions at the site permitted. They were placed under seal and taken to the BEA by two police officers.
Cockpit Voice Recorder (CVR)
- Make: Fairchild
- Type number: 93-A100-83
- Serial number: illegible
The CVR was opened, read out and a copy of the recording made during the night of the 25/26 July.
The outer casing of the CVR showed signs of exposure to fire and impact damage. The serial number was illegible because of marks left by fire. Nevertheless, the CVR's thermal protection had functioned and the tape was found intact inside its protective box.
In the following days, a transcript of the entire length of the recording was made. The validation of the identity of the voices of the crewmembers was made with Air France Concorde pilots. Access to the recording was then limited to relevant members of some of the working groups, as well as members of the Commission of Inquiry.
Flight Data Recorder (FDR)
- Make: Sundstrand
- Type number: 981-6009-011
- Serial number: 3295
Since the equipment normally used for the readout of this type of recorder at the BEA was temporarily unavailable, the recorder was taken to the Bretigny Flight Test Centre by a police officer, in accordance with the agreement between the two organisations. The recorder was opened during the night of the 25/26 July, in the presence of two BEA investigators.
The outer casing of the FDR was damaged by impact and showed signs of exposure to fire. After the protective box was opened, the following was noted:
- The tape wind mechanism appeared to be in good condition
- The tape was in position, not stuck to the read and record heads
- There were black marks on the tape and various mechanisms
- The read and record head cables were stuck at the level of the protective box joint, some black marks being visible there inside the casing.
The tape, after extraction, was cleaned with distilled ethyl alcohol. It was strengthened at one point where the beginnings of a tear had been observed.
Readout of the whole of the tape, with simultaneous synchronisation of the signal being read out, was performed with Sundstrand IAE (Incident Analysis Equipment) (PN 960-0145-002).
Because of the condition of the tape, readout of the recording was of medium quality, and this caused a certain loss of signal synchronisation. This first readout made a preliminary analysis possible, but it was decided to seek better quality data at the same time, either by reading out the QAR or by a new readout of the FDR tape with digitisation of the signal so as to improve synchronisation by using algorithms appropriate to a poor quality signal.
QAR
- Make: Dassault
- Model: EQAR F6217
- Type number: 1374-100-000
- Serial number: 290
The QAR is an unprotected recorder. It contains a copy of the FDR data on a magneto-optical disc and is used by Air France for flight analysis. The write procedure for the disc uses three backup memories whose role is to stock data sent by the Flight Data Acquisition Unit (FDAU) until such time as the vibration conditions detected by an internal accelerometer in the QAR are favourable for writing on the disc. The memories are volatile and must remain powered for the information they contain to be conserved.
The data readout was performed on 1st and 2nd August at Elancourt by personnel from Thomson CSF, the manufacturer of the QAR, in the presence of a judicial expert and a BEA investigator.
The QAR's box was crushed and the magneto-optical disc was deformed. The memory card, visible through the half torn-off casing, seemed to be in good condition. It was therefore decided to concentrate the work on this card. Two of the three memories had been torn off at impact. The third was still in place and was powered.
Tests were performed on check sample cards so as to define a method of data extraction, since this operation had never been carried out before. The method used was to connect a parallel power supply to the memory so as to be able to transfer it from its card to a receiver card. An uninterrupted series of zeros had first been written onto the two other memories of the receiver card.
The content of the third memory could thus be read out and a copy of the disc was given to the BEA. After analysis, it appeared that the parameters of the accident flight were present on the only one of the three memories which had remained powered. The quality of the recording, because of the technology used, was excellent and there was no de-synchronisation. It was not therefore necessary to try to read out the magneto-optical disc nor to proceed with further acquisition work on the FDR tape signal.
11.2 CVR Readout
A synchronisation of the CVR recording was performed with the radio-communications recording (UTC time) and with the FDR recording.
Ground test were performed on Concorde using a recorder of the same type. A spectral analysis comparison of the recordings helped identify the sound of certain selectors and alarms.
In collaboration with a researcher from the Institute of Sound and Vibration Research in Southampton (GB) an attempt was made to detect, on the sound recording, possible noises of impacts on the aircraft structure by demodulation of the onboard power supply frequency (400 Hz). This technique proved fruitless.
A transcription of the last five minutes of the recording is attached in appendix 2. Of the thirty minutes on the CVR, the following points are of note:
N.B.: the numbers (1, etc.) refer to positions on the track in 9.1 and in appendix 5.
14 h 13 min 13 s, FE "so total fuel gauge I have ninety-six four with ninety-six three for ninety-five on board".
14 h 13 min 46 s, FO "fire protection", FE "tested".
14 h 14 min 04 s, FO "ZFWZFCG", FE "so I have ninety-one nine and fifty-two two".
14 h 14 min 17 s, Captain "the reference speeds so V1 one hundred fifty, VR one hundred ninety-eight, V2 two hundred twenty, two hundred forty, two hundred eighty, it's displayed on the left ".
14 h 14 min 28 s, FO "Trim", Captain "it's thirteen degrees".
14 h 14 min 53 s, Captain "Then the lever is at fourteen and you'll have an N2 of ninety-seven and a bit ", FE "ninety-seven".
14 h 22 min 22 s, Captain "right we're going to do one hundred eighty-five one hundred that's to say we're going to be at the . structural limits", "structural err fifty-four per cent balance (*) see".
14 h 39 min 04 s, Captain "So the takeoff is . at maximum takeoff weight one hundred eighty tons one hundred which means four reheats with a minimum failure N2 of ninety-eight", "Between zero and one hundred knots I stop for any aural warning the tyre flash", "tyre flash and failure callout from you right", "Between one hundred knots and V1 I ignore the gong I stop for an engine fire a tyre flash and the failure callout", "after V1 we continue on the SID we just talked about we land back on runway twenty-six right".
14 h 40 min 19 s, Captain "How much fuel have we used ?" FE "We've got eight hundred kilos there".
14 h 41 min 09 s, FE "Brake temperatures checked one hundred fifty .".
14 h 42 min 31 s, Captain "top".
1 14 h 42 min 54 s, FO "one hundred knots".
14 h 42 min 57 s, FE "four greens".
2 14 h 43 min 03 s, FO "V1".
Of 14 h 43 min 07 s to 14 h 43 min 13 s, various noises which have not been identified at this stage of the investigation
3 14 h 43 min 13 s, message from the controller informing them of flames at the rear, read back by the FO.
14 h 43 min 20 s, FE "Failure eng. failure engine two".
4 14 h 43 min 22 s, fire alarm
14 h 43 min 24 s, FE "cut engine two".
14 h 43 min 25 s, Captain "engine fire procedure" and one second later, end of fire alarm
14 h 43 min 27 s, FO "Watch the airspeed the airspeed the airspeed".
5 14 h 43 min 30 s, Captain "Gear on retract".Over the following eight seconds, the crew mentioned the landing gear several times.
14 h 43 min 42 s, Fire alarm.
14 h 43 min 46 s, Captain "(are you) cutting engine two there".
14 h 43 min 48 s, FE "I've cut it".
14 h 43 min 49 s, FO "the airspeed".
6 14 h 43 min
56 s, FO "the gear isn't retracting".
Between 14 h 43 min 59 s and 14 h 44 min 03 s, three GPWS alarms are heard and at the same time the FO says "the airspeed".
7 14 h 44 min 14 s, FO "Le Bourget Le Bourget"then a few seconds later 8 "negative we're trying for Le Bourget".
14 h 44 min 31 s, end of the recording.
11.3 FDR Readout
11.3.1 The Flight
The recordings were decoded with the aid of documents provided by Air France and EADS. Four hundred parameters were recorded. Some of these parameters posed validation problems, in particular for their neutral or reference values. The SAT recording was invalid.
The previous flights, supplied by the Air France flight analysis service, were analysed for the purpose of validation and comparison.
Graphs derived from the recorded parameters for the whole of the flight are shown in appendix 4. Details of some significant parameters are listed below.
The following tables show the recorded values of certain parameters. For a given generated time, the associated parameters are values sampled at a specified moment in the course of the corresponding second. This indication does not appear in the tables. In addition, only the parameters of one engine are recorded each second. Thus, the parameters of each engine appear only every four seconds.
N.B.: The numbers (1, etc.) refer to the track shown in 9.1 and in appendix 5.
1 100 kt callout, generated time 97585
CAS: 100 kt
Control Column: 0.4°
Trim: 0.4°
Heading: 270°
Rudder bar: - 0.6° (right)
Lateral acceleration: between - 0.04 and 0.01
Longitudinal acceleration: 0.27
Engine |
Time |
N1 |
N2 |
EGT |
FF t/h |
P7 |
n° 4 |
97585 |
93.16 |
102.83 |
723.6° |
20.27 |
40.19 |
n° 1 |
97586 |
94.10 |
102.63 |
750° |
21.57 |
41.08 |
n° 2 |
97587 |
93.96 |
103.04 |
750° |
21.49 |
41.21 |
n° 3 |
97588 |
89.94 |
102.83 |
763.7° |
22.11 |
42.39 |
2 one second after the V1 callout, generated time 97595
CAS: 151 kt
Control Column: 0.4°
Trim: 0.4°
Heading: 269°
Rudder bar: - 1.8 (right)
Lateral acceleration: between - 0.05 and - 0.04
Longitudinal acceleration: 0.28
Engine |
Time |
N1 |
N2 |
EGT |
FF t/h |
P7 |
n° 2 |
97595 |
94.54 |
103.13 |
756.8° |
22.34 |
42.49 |
|
n° 3 |
97596 |
89.88 |
102.77 |
769.5° |
22.92 |
43.47 |
n° 4 |
97597 |
93.84 |
102.83 |
730.5° |
21.23 |
41.96 |
n° 1 |
97598 |
94.51 |
102.54 |
755.9° |
22.54 |
42.89 |
3 flames reported by the controller, generated time 97604
CAS: 188 kt
Control column: - 3.8°
Trim: 1.3 (up)
Heading: 267°
Rudder bar: - 6.4 (right)
Lateral acceleration: between - 0.11 and - 0.17
Longitudinal acceleration: 0.16
Engine |
Time |
N1 |
N2 |
EGT |
FF t/h |
P7 |
n° 3 |
97604 |
90.12 |
102.74 |
756.8° |
23.33 |
44.11 |
|
n° 4 |
97605 |
94.16 |
102.89 |
769.5° |
21.67 |
42.88 |
n° 1 |
97606 |
86.95 |
98.58 |
730.5° |
18.28 |
38.04 |
n° 2 |
97607 |
48.69 |
73.30 |
755.9° |
0.95 |
17.30 |
4 radio altitude positive, generated time 97614
CAS: 201 kt
Control column: 0.6°
Trim: 12.8° (up)
AOA: 13.35°
Heading: 270°
Rudder bar: - 16.4 (right)
Radio altitude: 6 ft
Engine |
Time |
N1 |
N2 |
EGT |
FF t/h |
P7 |
n° 1 |
97614 |
50.77 |
74.77 |
480.5° |
1.32 |
17.54 |
|
n° 2 * |
97615 |
57.07 |
77.52 |
446.3° |
3.48 |
19.54 |
n° 3 |
97616 |
90.67 |
102.69 |
770.5° |
22.97 |
43.72 |
n° 4 |
97617 |
94.72 |
102.92 |
732.4° |
21.47 |
42.33 |
*: engine fire warning
5 request to retract landing gear, generated time 97621
CAS: 199 kt
Control column: 0.5°
Trim: 11.1°(up)
AOA: 12.27°
Heading: 266°
Rudder bar: - 11.9 (right)
Radio altitude: 100 ft
Engine |
Time |
N1 |
N2 |
EGT |
FF t/h |
P7 |
n° 4 |
97621 |
94.66 |
104.12 |
758.8° |
23.87 |
44.08 |
|
n° 1 |
97622 |
91.08 |
100.9 |
648.4° |
14.22 |
41.04 |
n° 2 |
97623 |
15.97 |
33.9 |
320.3° |
0 |
13.78 |
n° 3 |
97624 |
90.97 |
103.89 |
801.8° |
25.67 |
45.16 |
6 non retraction of gear noted, generated time 97647
CAS: 211 kt
Control column: 1.7°
Trim: 9.3°(up)
AOA: 11.89° then 13.28°
Heading: 271°
Rudder bar: - 12.5 (right)
Radio altitude: 182 ft
Engine |
Time |
N1 |
N2 |
EGT |
FF t/h |
P7 |
n° 2 |
97647 |
6.27 |
13.92 |
235.4° |
0 |
13.37 |
|
n° 3 |
97648 |
91.64 |
104.00 |
796.9° |
25.60 |
45.21 |
n° 4 |
97649 |
95.13 |
104.21 |
762.7° |
23.82 |
43.65 |
n° 1 |
97650 |
94.92 |
103.54 |
758.8° |
22.43 |
42.57 |
From generated time 97649 to generated time 97653, GPWS "Whoop Whoop Pull Up" alarm.
7 FO "Le Bourget Le Bourget", generated time 97665
CAS: 208 kt
Control column: 1.9°
Trim: 10.6°(up)
AOA: 12.08°
Roll: - 2.57° then - 4.69° (to the left)
Heading: 270°
Rudder bar: - 18.1 (right), Mechanical mode
Radio altitude: 199 ft
Engine |
Time |
N1 |
N2 |
EGT |
FF t/h |
P7 |
n° 4 |
97665 |
95.01 |
104.18 |
758.8° |
23.67 |
43.82 |
|
n° 1 |
97666 |
43.56 |
81.36 |
855.5° |
3.64 |
15.01 |
n° 2 * |
97667 |
5.60 |
12.92 |
182.6° |
0 |
13.88 |
n° 3 |
97668 |
90.91 |
103.68 |
793.9° |
25.52 |
44.97 |
*: engine fire warning
8 message "negative we're trying for Le Bourget", generated time 97673
CAS: 181 kt
Control column: 7.6°
Trim: 16.5°(up)
AOA: 19.52°
Roll: - 38.82° then - 40.93° (left)
Heading: 238°
Rudder bar: - 22.5° (right), Mechanical mode
Radio altitude: 300 ft (1)
Engine |
Time |
N1 |
N2 |
EGT |
FF t/h |
P7 |
n° 4 |
97673 |
95.13 |
104.21 |
757.8° |
23.22 |
42.53 |
|
n° 1 |
97674 |
25.17 |
51.39 |
640.6° |
0 |
14.35 |
n° 2 * |
97675 |
5.19 |
12.30 |
168.9° |
0 |
14.05 |
n° 3 |
97676 |
91.41 |
103.98 |
798.8° |
24.55 |
42.33 |
*: engine fire warning
9 four seconds before the end of the recording, generated time 97677
CAS: 136 kt
Control column: 3.4°
Trim: 13.2°(up)
AOA: 25.15°
Roll: - 95.58° then - 108.17°(left)
Heading: 193°
Rudder bar: - 28.3 (right), Mechanical mode
Radio altitude: 459 ft (1)
Engine |
Time |
N1 |
N2 |
EGT |
FF t/h |
P7 |
n° 4 |
97677 |
96.39 |
104.62 |
764.6° |
22.90 |
40.04 |
n° 1 |
97678 |
20.04 |
42.60 |
585.9° |
0 |
13.71 |
n° 2 * |
97679 |
5.13 |
11.98 |
164.1° |
0 |
14.02 |
n° 3 |
97680 |
55.11 |
80.60 |
776.4° |
14.63 |
17.75 |
*: engine fire warning
(1) the radio-altimeter readings are no longer representative due to the extreme roll attitude of the aircraft.
11.3.2 Engines
This paragraph presents a preliminary explanation of the engine parameters. Note that these parameters are recorded every four seconds.
Note: Data on engine speed (N1 for the LP turbine and N2 for the HP turbine) presents a lag relative to the theoretical value. This lag is identical for all four engines. We may consider that it represents of an error in the recorded values.
The initial acceleration values of the engines and their behaviour during the initial phase of the takeoff (up to 97602) are normal on all four engines. From time 97603 onwards, significant changes appear in the parameters of engines 1 and 2. Speed, temperature and flow parameters indicate deceleration. Within the limitations of sampling error, this behaviour appears simultaneously on both engines. Initially engine 2 is more affected than engine 1. Engine 1's parameters return to normal values from generated time 97626.
In the CVR recording, the FE announces engine 2 cut off. A noise similar to an engine shutdown/fire handle being pulled is then heard. The change in the parameters of engine 2 confirms the shut down of the engine. This engine's parameters then appear to be normal for an engine windmilling in these flight conditions.
From time 97620 onwards, the parameters of engine 3 then of engine 4 behave in a manner consistent with a switch from "Take Off" to "Contingency" modes. From time 97626 onwards, after the initial problem, the parameters of engine 1 also show engine speeds consistent with a change to "Contingency" mode. The fuel flow, primary exhaust nozzle area and P7 pressure are consistent with reheat operating on these engines.
From time 97654 onwards, the parameters of engine 1 indicate a deceleration and an increase in EGT. From time 97680 onwards, the parameters of engine 3 and then engine 4 indicate a sharp deceleration.
11.3.3 Track
The aircraft's track (see appendix 5) was calculated by integrating the airspeed and magnetic heading parameters, by positioning the first and last points of their known or estimated position. A reasonable approximation of the ground track was thus obtained. Bearing in mind the method used, the tolerance is of the order of about a dozen metres at the ends of the track. It is at its greatest in the middle of the track (around a hundred metres).
12.1 The Runway
Various debris and marks were found on the runway after the accident (see drawing in appendix 3). They are identified in the following by the grid number of the concrete slab where they were found, the distances being measured in relation to the eastern end of the tarmac part of the runway (see section 10). Thus, for example, an element identified at Slab 180 level was found 1 950 m from the point of origin (600 + 180 x 7.5). Debris was also found under the aircraft's flight path.
Note: the point at which the brakes were released is located between 65 and 85 m from the beginning of the runway.
12.1.1 Water Deflector
Parts of the water deflector of the left main landing gear were found between Slabs 139 and 166, that is 1 642 to 1 845 m from the beginning of runway 26 right, more precisely at 139, 149, 151, 157 and 166. The parts found did not include metallic parts.
Part found at Slab 166 level: right part of the deflector
12.1.2 Pieces of Tyre
Pieces of tyre from the Concorde were found at slab levels 146, 152, 166, 180, 186 and 187. The parts found at Slab 152 level (a piece measuring 100 x 33 cm and weighing more than 4 kg) and that found at Slab 180 level fitted together. Visual inspection revealed a transverse cut about 32 centimetres long.
Piece of tyre at Slab 180 levelPiece of tyre at Slab 152 level
12.1.3 Piece of Metal
Piece found at Slab 152 level
A strip of metal about 43 centimetres long, bent at one of its ends, was found on the runway shoulder at Slab 152 level. Its width varies from 29 to 34 mm and it has drilled holes, some containing rivets, similar to the Cherry aeronautical type. The holes are not at regular intervals.
On visual inspection, the piece appeared to be made of light alloy, coated on one side with epoxy primer (greenish) and on the other side with what appeared to be red aircraft mastic for hot sections (RTV 106). It did not appear to have been exposed to high temperature.
This piece was not identified as part of the Concorde.
12.1.4 Structural Element
A ribbed structural part measuring about 30 x 30 cm was found at Slab 160 level. It was white on the external side and dark on the ribbed side. It came from the aircraft's No. 5 fuel tank. It showed no signs of impact damage.
Part found at Slab 160 level |
|
12.1.5 Brake Servo Valve Case
|
An alloy part, identified as the brake servo valve case, from the left main landing gear, was found at Slab 175 level. This part was sooted and had clearly been overheated. It had impact deformation.
Part found at Slab 175 level |
12.1.6 Piece of Concrete and Signs of Explosion
Signs of an explosion and a piece of concrete torn from the runway were found at the Slab 181 level. The piece of concrete was about one centimetre thick, 10 centimetres wide and 25 to 30 centimetres long. Found intact, it was later broken in two.
12.1.7 Lighting
The runway edge light at the Slab 293 level (about 2 800 m from the origin) was broken and small pieces of the light were found nearby. Ground marks showed that this light was broken by the Concorde's left main landing gear.
12.1.8 Tyre tracks
Irregular marks made by the left landing gear were noted up to the broken light (around 2 800 metres).
After this point, the marks became intermittent then disappeared at about 2 830 m from the runway threshold.
|
From Slab 161 level to Slab 232 level, that is between 1 807 and 2 340 m, the mark of a flat tyre with an incomplete tread was observed.
This mark was parallel to the runway axis (at about 3.8 m) then diverged at about 2 200 metres.
When this mark disappeared at about 2 340 m, its displacement from the centreline was about 8 m. This corresponded to the right front tyre of the aircraft's left landing gear.
Mark left by the left truck and broken light |
12.1.9 Soot Deposit
Traces of soot, produced by incomplete combustion of kerosene, were apparent on the runway 1 860 m onward from the origin (Slab 168). These were large and dense up to 2 300 m and then became less dense and rich in carbon up to taxiway S4, at 2 770 metres. The traces, which were on average 7 m wide, were initially centred on the damaged wheel ground mark and progressed to a position corresponding to the far left of the aircraft.
Slab 202
A further sooted area was apparent after taxiway S4 up to the broken edge light.
Slab 290
Between Slabs 310 and 340
The grass was burnt adjacent to the runway edge, between 2 902 and 3 165 metres. This area, also featuring soot deposits, indicated that there was an extensive flame after the aircraft became airborne.
12.2 Between Runway 26 Right and the Site of the Accident
In the 1 000 m after the end of the runway, along the extended centreline, the following elements were identified:
. a piece of fire-damaged fuel tank,
. the tail cone anti-collision light,
. a severely fire-damaged inspection panel from the wing lower surface,
. seven inspection panels identified as coming from the upper surface of the left wing dry bay, with no signs of fire,
From 1 000 to 2 500 m after the end of the runway:
. an inspection panel identified as also coming from the upper surface of the left wing dry bay, showing no signs of fire,
. a fire-damaged piece of duct,
. fire-damaged structural parts that appear to have come from the aircraft tail cone.
Burn marks on the ground were visible where certain items of debris were found, particularly where the tar had melted adjacent to items found on the roofs of buildings in the freight zone. A wheat field was damaged by fire 2 500 m from end of the runway.
Beyond this point, the following was noted:
. two hydraulic shutoff valves, one damaged by fire,
. two lower inspection panels from the engine nacelle, one melted, the other intact,
. debris from the wings, in particular fuel tank parts,
. a fire-damaged hydraulic line.
Leading up to the crash site, many small pieces of metal, honeycomb components, pieces of riveted structure and parts of the rear fuselage, were found. Most of these parts show traces of fire and their distribution was continuous along the aircraft's track.
12.3 The Accident Site
12.3.1 Description of Site and Plan
The crash occurred south-west of Paris Charles de Gaulle airport at about 9 500 m from the threshold of runway 26R in a level area. The altitude of the area is 400 feet. The wreckage was at the intersection of the N17 and the D902 roads.
BEA/IGN/FLEXIMAGE image Aerial photo of the accident area
The crash site was divided into a grid. The various areas were referenced to this grid.
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Map showing aircraft wreckage distribution at the crash site
Aerial view showing grid
Examination of the site showed that the aircraft had struck the ground on heading 120° left, with little horizontal speed. After the impact, it broke and spread generally to the south, with the aircraft upright.
The wreckage was extensively burnt. Only the front parts of the aircraft, found mainly in areas C3, D4 and Z4 escaped the ground fire, together with a few pieces of the fuselage scattered over the site. Most of the wreckage, with the exception of the cockpit, remained within a rectangle measuring a hundred metres long by fifty metres wide (areas CB2, D3 and E3).
Signs of ground impact were found to the north of the site at the intersection of areas A and B. There was a row of trees about three metres high, oriented east to west, then a crater at the bottom of which was rear tank No. 11. Pieces of engine air intake were found half-buried at A3 and signs of ground impact were apparent at A3 and CB2-North. Wheel N° 6 was embedded in the ground.
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Ground impact marks |
