Egypt A320 over Mediterranean on May 19th 2016, fire on board, traces of explosives found

Last Update: October 30, 2024 / 09:52:07 GMT/Zulu time

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Incident Facts

Date of incident
May 19, 2016

Classification
Crash

Airline
Egypt Air

Aircraft Registration
SU-GCC

Aircraft Type
Airbus A320

ICAO Type Designator
A320

On Oct 30th 2024 Egypt's Civil Aviation Authority released their final report concluding the probable causes of the crash were:

The aircraft flight path was uncontrollable as the aircraft and the flight crew were severely affected by fire and smoke. This resulted from the effects of the explosive materials located at the forward galley just behind the rear section of the cockpit. The aircraft crashed into the sea.

Contributing factors

- The fire/smoke event took place very quickly and flight crew were disabled.

- Several aircraft systems failure.

- Explosion resulted in oxygen flow in the cockpit, which enriched the fire/ smoke.

The prosecution had formed an investigation committee who analysed:

The prosecution formed a committee headed by a forensic evidence expert and included two experts, an aviation expert and a forensic medicine expert. This committee will be referred to as the triple committee in the following context.

The triple committee issued a report which included the following:

- Some parts of the wreckage found shows signs of varying severity of damage, dents, and declining, and some of them showed traces of mechanical stress and thermal effects, which could have occurred as a result of the explosion of explosive materials. These parts are from the direct rear part of the aircraft’s cockpit, which contains the food preparation area in the upper part (the galleys) and a water closet (lavatory). These traces indicate that this area was exposed to a pressure wave from the inside to the outside. They were found to be free of any traces of explosive materials. This can be explained due to the presence of those parts in seawater for some time before they were recovered.

- The presence of a leaking sound under pressure near the location of the mic number (3) installed on the back of the cockpit on the rear right side, is likely to be the result of a broken oxygen pipe passing near the food preparation area (the galley) located behind the cockpit of the aircraft next to the fuselage frame number 12.

- A fire can take place after oxygen leaks with the existing contents if there is a heat source. The fire continues until the oxygen runs out, which explains the absence of significant fire traces.

- The presence of the pilot alone in the cockpit after noticing the fire and directing the First officer to take the fire extinguisher and exit the cockpit, and that the pilot had difficulty breathing action.

- The triple committee concluded : Passing an explosive package containing two explosive substances (TNT and DNT), according to chemical analyzes of the Forensic Medicine Authority, into the crew’s meal carts, which are placed in the food preparation area “the galley” directly in the back area of the cockpit of the aircraft, and detonating it after a certain elapsed time, leading to a deficiency in that area and breaking of the oxygen line pipe, passing near that area behind the galley area, resulting in a leak in the oxygen cylinder in the cockpit and starting fire as a result of the availability of (oxygen - the contents of the place - a suitable heat source from the site of the explosion). The fire ends when the oxygen cylinder runs out, which leads to the absence of oxygen in the cockpit, resulting in the formation of toxic carbon monoxide gas, which combines with blood hemoglobin to form a carboxyhemoglobin compound, which causes lethargy and loss of consciousness that may lead to death.

The prosecution thus wrote this Memorandum:

The Egyptian Prosecution’s memorandum submitted to the investigation committee on 28/11/2023.

The prosecution Memorandum recognized the report of the Forensic Medicine Authority, that proved by conducting chemical tests and analysis on the parts of the wreckage and recovered human remains that traces of the explosive substances 2, 4, 6-trinitrotolene (TNT), 3-nitrophthalic acid, and 4, 6-dinitrotolene (DNT explosive) were found. In addition to material traces that can be considered from the detonation products, the explosive compounds were stuck into the bodies of the passengers and to the solid objects used in the manufacture of the plane, which indicates that this material was released at a high speed as a result of the explosive wave associated with the explosion, and it sprayed on the passengers and the body of the plane and led to its collapse and the death of all persons on board.

The investigation considered three different scenarios:

A) Fire/Smoke started in the cockpit at the F/O side and enriched by oxygen leak.

B) Fire/ smoke started outside the cockpit due to explosive materials located at the galley just aft of the rear section of the cockpit.

C) Fire and smoke due to explosive materials located at the galley just aft of the rear section of the cockpit, the high energy and pressure generated from the explosion propagated affecting the right hand side oxygen system.

The investigation analysed for scenario A)

- This scenario could be consistent with the hissing sound heard in the CVR at 00:25:24.

However if there was a leak in the oxygen system, then the oxygen cylinder would have been depleted in a shorter time, which is not compatible with hissing sound time period heard in the CVR recording.

- Since this scenario assumes that the fire/smoke was originated in the cockpit and enriched by oxygen leak, then it was expected that the fire extinguishers should have been used. However there is no evidence in the CVR that a fire extinguisher was used inside the cockpit to fight the fire.

Hence this evidence makes this scenario inconsistent with CVR contents.

- The "lavatory smoke" warning was recorded in the FDR at 00:26:14 (50 seconds after the first hissing sound) preceding the "avionics smoke" warning which was recorded at 00:27:00 (96 seconds after the 1st hissing sound).

Since the air saturated with smoke in the cockpit is extracted into the avionics ventilation system thus suggesting to trigger "Avionics smoke" warning prior to "lavatory smoke", which is not the case.

This scenario is inconsistent with smoke warnings.

- This scenario assumes that the fire started and continued at the right hand side of the cockpit, However and based on the wreckage examination/analysis:

a) It has been proven that there were thermal effects that affected the aircraft’s cabin parts, components and contents, as well as the human remains of the victims that were on board in the cabin.

b) Wire insulations in part no.31 (which are most sensitive to heat effects) were intact. Leading to the conclusion that the temperature was not high enough to affect wire insulation. This highly suggest that the fire did not originate in the cockpit.

These evidences make this scenario inconsistent with wreckage examination results.

Based on the examination report dated 28/11/2016 of the remains of the victims, the forensic results concluded that the cause of accident and the death of persons was attributed to injuries associated with an explosion of highly explosive materials and the aircraft crash as a result of the explosion with TNT material and the presence of burn marks on some of the human remains that were subjected to examination and some of the small solid parts stuck in them was confirmed. In addition, and based on the triple committee report, the presence of thermal effects on the wreckage were indicated.

This scenario is inconsistent with the forensic Medicine Authority studies/results and the triple committee report.

This scenario did not identify the source of ignition.

Based on the above information, scenario No.1 can be ruled out.

The investigation analysed for scenario B)

- This scenario is inconsistent with the hissing sound heard in the CVR at 00:25:24.

- This scenario is consistent with the fact that "lavatory smoke" warning was recorded in the FDR at 00:26:14.

- Since the anti-hijack camera is designed to be activated for 5 minutes starting from entry request, and the timing between the entry of the cabin crew member and the call “fire” was detected after less than two minutes (1min: 47sec). Hence it can be concluded that the fire statement was based on viewing through the anti-hijack camera.

- After the cabin crew member entered the cockpit, the first officer asked her to confirm the cabin crew number onboard by asking "you are four... Right??" So probably the first officer was looking back while he was speaking with her when he saw the fire or smoke on the anti-highjack camera LCD located above the third occupant’s seat. Above information strongly suggest that the fire was originated in the area outside the cockpit and within the range of the anti-high jacking camera.

- Based on the wreckage examination/analysis, it has been proven that there were thermal effects that affected the aircraft’s parts, components and contents, as well as the human remains of the victims that were on board. These evidences make this scenario consistent with wreckage examination results.

- Reference to ELT, the ELT transmitted a signal at 00:36:59. The aircraft was still traced by radar returns meaning that the aircraft was still in the air. This indicates that the aircraft was subjected to very high G loads (at least 2.0 in the axial direction). This scenario is consistent with the ELT information with the assumption that there was another explosion after the first explosion.

- Based on the examination report dated 28/11/2016 of the remains of the victims, the forensic results concluded that the cause of accident and the death of persons was attributed to injuries associated with an explosion of highly explosive materials and the aircraft crash as a result of the explosion with TNT material and the presence of burn marks on some of the human remains that were subjected to examination and some of the small solid parts stuck in them was confirmed. In addition, and based on the triple committee report, the presence of thermal effects on the wreckage were indicated. This scenario is consistent with the forensic Medicine Authority studies/results and the triple committee report.

- This scenario clearly identifies the source of ignition.

Based on the above information and because of inconsistency with the hissing sound, scenario No.2 can be ruled out.

The investigation analysed for scenario C):

Fire/ smoke started outside the cockpit and eventually fire and smoke propagated to the cockpit from the right hand side. The explosion and the oxygen flow enriched fire were the causes of the accident.

- This scenario clearly identifies the source of ignition.

- The heat energy generated by the explosion set fire to the aircraft components including forward galley and surroundings.

- Explosion in the galley area behind the cockpit propagated to the cockpit affecting the right hand side oxygen system and might have opened the first officer left oxygen box door while the oxygen mask emergency knob set to emergency position leading to oxygen flow, resulting in the hissing sound.

- Based on FDR and CVR correlation, the cockpit crew announced fire 44 seconds prior to lavatory smoke warning and 90 seconds prior to avionics smoke warning indicating that the fire originated outside the cockpit before triggering the smoke warnings. This evidence makes this scenario consistent with FDR and CVR correlation.

- In order for the smoke to be dense enough to trigger the lavatory smoke warning while the lavatory door is closed (was closed to allow the cabin crew to access the cockpit), the smoke outside the door must go through the door grills to get to the smoke sensor, therefore taking into account the time and the density needed, then the triggering event should have occurred before the activation of the lavatory smoke warning.

- Based on the CVR and sequence of events, the cockpit door was closed at the beginning of the hissing sound then it was opened supported by captain’s order to close it. This suggests that the female cabin crew fled the cockpit. There was no evidence of any firefighting activities inside the cockpit. This supports that fire was originated outside the cockpit.

- There was no call from cabin to inform cockpit crew of any developing situation outside the cockpit, indicating that the fire/smoke was sudden and strong that the cabin crew didn't have a chance to communicate it to the cockpit.

- Some of the cabin wreckage parts were exposed to thermal effects suggesting fire originated outside the cockpit.

- The 5 wreckage parts that are adjacent to each other and surround the area of the FWD galley at door 1R (FWD fuselage RHS); condition suggest internal overpressure.

- Based on the wreckage examination/analysis, it has been proven that there were thermal effects that affected the aircraft’s parts, components and contents, as well as the human remains of the victims that were on board. These evidences make this scenario consistent with wreckage examination results.

- Trolleys are housed in the forward galley back to back with 120VU panel. The trolleys are back to back where the connectors supplying the failed computers are adjacent to each other and concentrated in the lower right hand side area of the 120 VU panel. This evidence makes this scenario consistent with the location of the connectors of failed computers.

- ARINC Raw Data messages support that the heat source propagated from the galley and affected the cockpit right side, as Lavatory smoke warning preceded Avionics smoke warning. This evidence makes this scenario consistent with ARINC Raw Data messages.

- Based on FDR and ELT analysis, there might have been another explosion:

+ The FDR indicated very high sudden acceleration G's at the last two seconds of the valid FDR recording (00:29:44, 00:29:45).

+ The ELT transmitted a signal at 00:36:59. The aircraft was still traced by radar returns meaning that the aircraft was still in the air. This indicates that the aircraft was subjected to very high G loads (at least 2.0 in the axial direction)

This scenario is consistent with FDR and ELT information with the assumption that there was another explosion after the first one.

- Based on the examination report dated 28/11/2016 of the remains of the victims, the forensic results concluded that the cause of accident and the death of persons was attributed to injuries associated with an explosion of highly explosive materials and the aircraft crash as a result of the explosion with TNT material and the presence of burn marks on some of the human remains that were subjected to examination and some of the small solid parts stuck in them was confirmed. In addition, and based on the triple committee report, the presence of thermal effects on the wreckage were indicated. This scenario is consistent with the forensic Medicine Authority studies/results and the triple committee report.

Based on the above information, scenario No.3 should be ruled in and the investigation committee adopt this scenario.