Pacific South West Airlines Flight 1771, 7 December 1987
Pacific South West Airlines (PSA) flight 1771 was a scheduled commercial passenger flight from Los Angeles Airport (LAX) to San Francisco Airport (SFO). The background to this event was a large US operator had recently purchased and taken over the smaller Pacific South West Airlines operation. An ex-employee, David A Burke, a ticketing agent from the PSA operation, had recently been dismissed for theft of receipts. The events on Flight 1771 that transpired that day became well known in the aviation community as a hijack/murder/suicide occurrence, killing all occupants onboard in addition to destroying the aircraft. This flight was on a British Aerospace 146-200, a regional jet aircraft powered by four Textron Lycoming engines (LF-502 power plants). This aircraft can carry up to 100 passengers in various cabin configurations. The aircraft is a T-tail design, and the short single-aisle cabin results in passengers sitting in 5 or 6 abreast.
On 7 December, Burke purchased a ticket for PSA flight 1771 to travel to SFO to meet with his previous manager, under the pretence of regaining his employment with PSA. Flight 1771 was a PSA British Aerospace 146-200 aircraft: an example of this general aircraft type is illustrated in Figure 8.2.
Burke boarded this flight knowing that his ex-manager would commute from SFO to LAX and back. At the time of Burke's dismissal, Burke had failed to surrender his USAir employee credentials (e.g. ID badge, etc.). Burke used these employee credentials to bypass the normal domestic passenger security checks, as he was armed with a Magnum handgun revolver. In-flight, Burke wrote a threatening letter on an airsick bag, believed to be for his exmanager, although it is not known if the ex-manager received it prior to his homicide.
The size of the flight deck on this type of aircraft is very small, as shown in Figure 8.3, with seating for only three occupants, namely the Captain, First Officer and an observer, where the observers' seat is immediately behind the centre pedestal, in front of the flight deck door. The passenger cabin and the cockpit are only separated by a small boarding area (indicated in Figure 8.3).
It is surmised that Burke went to the aircraft lavatory to load the handgun, as the door to the toilet was heard opening/closing on the CVR before the events unfolded. Burke shot the ex-manager twice in the passenger cabin, which was overheard by the flight crew who relayed this information to АТС. A crew member immediately went to the front of the aircraft, opened
British Aerospace 146/RJ100 series aircraft. (Paul Spikkers.)
Drawing of 146-200 Flight Deck and forward cabin.
the flight deck door and then entered and said to the pilots, 'we have a problem.' The Captain replied to her ‘what’s the problem?' At this point Burke shot the cabin crew member dead, and said, ‘I'm the problem.' All of the audio was recorded by the CVR. Both pilots were then shot and either incapacitated or killed. The CVR indicated increasing levels of wind noise, consistent with a steep nose-down pitch attitude of around 70 degrees.
The plane descended at very high speed, at some points exceeding the speed of sound. None of the passengers were able to prevent the steep descent, and a final bullet was recorded being discharged at this time, again recorded by the CVR. The victim of this shooting is believed to be PSA's Chief Pilot, who was also a passenger on the flight. The aircraft impacted onto a hillside in the Santa Lucia Mountains at very high speed with tremendous energy. There were no survivors, and the devastation was such that 27 of the 38 passengers could not be identified due to the total carnage of the crash.
As a direct result of this hijack/homicide/suicide event, several policy changes took place. Airport security was changed to require all employees including the pilots, engineers, cabin crews, etc., to undergo the same security screening and checks as passengers. Another corporate policy change was from large organisations, to forbid travel by multiple board-level executives on the same flight, as various organisations lost multiple employees on that flight.
Silk Air 185, 19 December 1997
Silk Air flight 185 was a scheduled flight from Jakarta, Indonesia to Changi airport in Singapore. On 19 December 1997, the flight operated using a Boeing 737-300 series aircraft, carrying 97 passengers and seven crew on an 80-minute regional flight, the track being illustrated in Figure 8.4. This aircraft crashed into the Musi River in Indonesia, killing all 104 souls onboard. The NTSB investigation cites suicide by the captain, resulting in a murder- homicide event for all other occupants.
The aircraft was commanded by Captain Tsu Way Ming, a 41 year-old former Singapore military pilot, and First Officer Duncan Ward, 23-year-old New Zealander. The early phase of the flight was uneventful, and the aircraft reached the cruise altitude of 35,000 ft at around 15:53 hrs (local). At 16:05 hrs, the CVR stopped recording - which is a very unusual event as switching off this device requires an occupant to manually pull the circuit breakers, usually located in the overhead panel above the pilots. At 16:11 hrs, the DFDR then stopped recording. Again, this is a very unusual situation that requires a person to pull the circuit breaker in the overhead panel. Because there is very little CVR or DFDR recorded evidence of the final moments, it
SilkAir's MI 185 Jakarta to Singapore flight route, showing the intended route and the actual track. (NTSC.)
is surmised that the F/O Ward was either locked out of the flight deck or incapacitated by Capt. Tsu.
At 16:12 hrs, the aircraft entered a near-vertical dive. The extreme forces acting on the aircraft from the descent caused parts of the aircraft to detach prior to impact. The aircraft hit the water at almost supersonic speeds, resulting in parts of the aircraft being embedded 15 feet below the bottom of the riverbed. The extremely high energy impact caused the whole structure, including the occupants, to disintegrate upon impact, with absolute carnage ensuing. None of the bodies of the passengers or crews were complete, and only six of the occupants were positively identified in the crash debris. The final moments of the flight and crash site are shown in Figure 8.5.
The investigation of this event was controversial. The crash investigation comprised of multiple organisations from Indonesia, USA (NTSB), Singapore and Australia. The final report was overwritten by the Indonesian Chairman, contradicting NTSB views that the evidence was consistent with a deliberate
SilkAir's final moments and crash site on the Musi River, Indonesia. (NTSC.)
manipulation of the flight controls, most likely by the Captain. The report noted that the captain had recent financial losses exceeding $1.2 million and, in the weeks leading up to the event, the Captain had obtained a sizable life insurance policy of around $600,000. Furthermore, the day of the event coincided with a previous experience where he lost four Singapore Air Force acquaintances during his military flight training. Financial difficulty and the gain from a fraudulent life insurance claim was one possible motive for a murder/suicide homicide event for this flight.
One potential area of system failure that was identified from the accident investigation, and other historical B737 events in the USA, involved the hydraulic servo valve that is fitted to the vertical stabiliser of the B737 series aircraft. Under certain flight conditions, it was found that the aircraft's vertical surface could move to its full deflection extremity, potentially causing a rudder reversal situation. Parker Flannifin (USA), the Original Equipment Manufacturer (OEM) of these valves, lost a legal challenge raised by three families of the relatives of this SilkAir flight. A Los Angeles Court of Appeal in 2004 found that the valve manufacturer, Parker Flannifin, was liable and awarded damages of $43.6 million.
Egypt Air 990, 31 October 1999
Egypt Air flight 990 was a scheduled flight from Los Angeles International airport with a planned technical stop to refuel at JFK, New York, before the final journey to Cairo International Airport, Egypt. The aircraft associated with this event on 31 October 1999 was a Boeing 767-300 carrying 217 occupants, of which 203 were passengers and 14 were crew members. Because the flight was a long-haul scheduled operation, the airline rostered an active crew of a captain and a first officer. In addition, a relief crew comprised of another captain and first officer for the cruise phase of the flight. The usual procedure for the airline at the time was for the active crew to fly the aircraft for four to five hours before being relieved by the second crew. The second sector flight leg from JFK New York to Cairo International Airport, Egypt, is shown in Figure 8.6, including the location of the crash site in the Atlantic Ocean, some 60 miles from Nantucket Island. Shortly After departing JFK New York at 01:20 hrs (local), at around 20 minutes into the flight the relief First Officer Gameel Al-Batoui entered the flight deck and demanded
Egypt Air 990 second sector flight track outbound JFK to Cairo and crash site. (Egyptian CAA.) to change the flight roster arrangements. The active First Officer initially disagreed, but later acquiesced with Al-Batoui's demands, as Al-Batoui was more senior and experienced.
The aircraft climbed to the cruise altitude of 33,000 ft, and at around 01:49 hrs it is believed that Captain El-Habashi visited the lavatory, leaving F/O Al-Batoui alone at the controls. At this point, the CVR picked out Al-Batoui saying 7put my trust in god.' Then autopilot was disconnected with Al-Batoui saying 7 rely on God'. A nose-down elevator attitude was inputted by Al-Batoui, followed by the engine power levers being retarded and the engines throttled back. In this very steep descent, a zero-G nose over forward pitch was encountered, followed by an excessive descent speed, beyond the Velocity Never Exceed values. At around this point, Captain El-Habashi was able to re-enter the flight deck to try and recover the desperate situation. Electrical power was lost. Captain El-Habashi tried in vain to slow the descent by pulling back on the control column and applying engine power, asking Al-Batoui what he had done, but as the engines had been shut down, this action was not successful. The FDR indicated that the elevator circuits became disconnected at this time, because at least 50 pounds of force were applied to the separate elevator circuits. The B767 elevator control system is illustrated in Figure 8.7, showing the two separate cable circuits, the yokes
B767 elevator control system including components. (NTSB.)
B767 elevator control recorded by the DFDR in the final moments of the crash. (NTSB.)
and the disconnect unit (that is included in Figure 8.7, described as the 'control columns override mechanism').
The purpose of a disconnect is to allow one elevator to function should one side of the circuit become jammed or stuck, which would give some nose attitude control in the most extreme of conditions, such as this event. However, the disconnect condition would also imply that both elevators are not being moved together in unison, such as one control being pulled while the other is being pushed. The evidence for this unusual control of the elevators in the final moments of the flight is provided from the DFDR, shown in Figure 8.8.
The event can be considered to have very strong 'indications' of a pilot- induced homicide/suicide event from the above physical evidence, although the investigation findings differed dramatically between the Egyptian civil aviation report (June 2001) and the NTSB report (March 2002). The NTSB report findings state that the fateful nose-down attitude that occurred when F/O Al-Batoui was alone in the Flight deck was not caused from a failure in the elevator control system or any other airplane failure. While investigation opinions may differ between states, the weight of evidence (from sources including the CVR and DFDR) suggests that F/O Al-Batoui deliberately caused the crash. From calmly stating the phrase 'I rely on God' (74 seconds before the start of the decent and during the dive), to switching-off the engines and countering the Captain's desperate attempts to level the aircraft.
The F/O's actions regarding the 'probable cause' of the crash has never been established in either accident reports.