EgyptAir Crash: Safety Experts Voice Fears Over Flight 804 Evidence
WSJ - By Daniel Michaels in Frankfurt, Tamer El-Ghobashy in Cairo and Robert Wall in London
Updated May 23, 2016 6:05 p.m. ET
Aviation-safety experts are voicing concerns that Egypt may be mishandling debris collected from the downed EgyptAir plane, potentially compromising evidence that could help determine why the Airbus Group SE A320 crashed.
Forensic and chemical analysis of aircraft wreckage can yield vital information for investigators to glean how and why a plane went down. Such findings are particularly crucial when investigators lack access to a plane’s flight recorders, known as black boxes, which typically provide the most comprehensive information about what occurred on board on a flight.
EgyptAir Flight 804 plunged into the Mediterranean Sea on May 19 during a flight from Paris to Cairo with 66 people on board.
Crash investigators are battling not just a lack of data, but also conflicting information about the last seconds of flight. Greek officials Thursday said the plane veered off course before its demise. Ehab Azmi, chairman of the Egyptian air-navigation service, on Monday disputed that sequence, saying contact with the plane was lost abruptly while still at its cruising altitude.
The Egyptian navy has been scooping plane debris and body parts out of the water while the search continues for the main wreckage.
People in close contact with the investigation are concerned that potentially vital evidence is being compromised. Photographs released by Egypt’s military of the salvage operation show personnel handling items without wearing protective clothing, and placing them on unprotected surfaces.
This could threaten the investigation, the people said, because forensic investigators will analyze debris for chemical residue of explosives, fire or smoke. Military personnel who are in contact with weapons or ammunition can be exposed to similar chemical residue and inadvertently transfer it to any debris they handle. Lubricants and other nonmilitary items on ships can contain the same chemicals used to produce explosives and jeopardize chemical analysis of the debris.
Egypt’s military declined to comment on the recovery process, referring questions to the country’s civil aviation ministry. A spokesman for the ministry said concerns over contamination are without merit. He said the military’s recovery teams were accompanied by aviation ministry experts, whom he described as search "veterans” who comply with the standards that govern such operations.http://www.wsj.com/articles/egyptair-crash-safety-experts-voice-fears-over-flight-804-evidence-1464036919
MASK MAN ON pb:
-- AUTO – a signal is automatically sent to open thepassenger mask doors when the cabin altitude exceeds 14,000 feet.
-- Selected – manually sends a signal to deploy masks.
PASSENGER SYS ON light – illuminates white when either an automatic or manual signal has been sent to deploy the passenger masks.
CREW SUPPLY pb – controls the crew oxygen low pressure supply valve:
-- ON (lights out) – the supply valve is open, and low pressure oxygen is supplied to the masks.
-- OFF (white) – the supply valve is closed.
-- Used in response to the Avionics Equipment Ventilation Computer (AEVC) sensing smoke in the avionics compartment.
-- The BLOWER and EXTRACTpbs are placed to the OVRD (override) position inaccordance with ECAM procedure.
-- This closes the inlet valve, stops the blower fan, and isolates the cargo under floor and aircraft skin heat exchanger.
-- Conditioned air is provided by the air conditioning system through an air conditioning inlet valve.
-- The extract fan draws the conditioned air through the avionics compartment, and expels it through the small internal flap within the closed extract valve.
Some notes Regarding ACARS messages...
00:26Z 3044 ANTI ICE R WINDOW
00:26Z 561200 R SLIDING WINDOW SENSOR
00:26Z 2600 SMOKE LAVATORY SMOKE
00:27Z 2600 AVIONICS SMOKE
00:28Z 561100 R FIXED WINDOW SENSOR
00:29Z 2200 AUTO FLT FCU 2 FAULT
00:29Z 2700 F/CTL SEC 3 FAULT
Source Document: A319/A320 Technical Notes
An extraction fan draws air from the cabin through the lavatories and galleys and exhausts it near the outflow valve. The extraction fan runs continuously when electrical power is available.
My observation -> If there is smoke in the cabin, it will be drawn into the lavatories to the smoke detector. Smoke source not necessarily in the lavatory.
In Smoke Configuration the main bus bars are shedded. Same as emergency electrical configuration except that the fuel pumps are connected upstream of the GEN 1 line contactor. 75% of equipment is shed, all that is remained is supplied from the CBs on the overhead panel.
• A smoke detector in the air extraction duct detects smoke in the avionics compartment. If smoke is detected for more than 5 min it can be cleared but remains latched. A dual FCU reset on ground can de-latch it.
• One smoke detector is in each lavatory. It sends signals to an SDCU (Smoke Detection Control Unit) which in turn sends signals to the FWC and CIDS.
• Flight control surfaces are electrically controlled and hydraulically activated.
• The stabilizer and rudder can be mechanically controlled.
• There are seven Flight Control Computers:
o Two ELACs
• Normal elevator and stabilizer control.
• Aileron control.
o Three SECs
• Spoiler control.
• Standby elevator and stabilizer control.
o Two FACs
• Electrical rudder control.
• Also, there are two FCDC (Flight Control Data Concentrators) which acquire data from the ELACs and the SECs and send it to the CFDS and EIS
SEC 3 – Controls Spoiler 2.
If a SEC fails, its spoilers are retracted.
• The Speedbrake is made up of spoilers 2, 3 and 4.
• Extension is inhibited if:
o SEC 1 and SEC 3 have faults.
Flight Control - Mechanical Backup
• Mechanical backup happens in the case of a complete loss of electrical power.
• Pitch is controlled manually using the THS. (Trimmable Horizontal Stabilizer)
• Lateral control is through the rudders.