British European Airways Flight 548
 Flight deck of a BEA Trident | |
| Accident summary | |
|---|---|
| Date | 18 June 1972 |
| Type | Deep stall – aircraft misconfiguration caused by pilot error |
| Site | Staines, England |
| Passengers | 112 |
| Crew | 6 |
| Injuries | 0 |
| Fatalities | 118 |
| Survivors | 0 |
| Aircraft type | Hawker Siddeley Trident 1C |
| Operator | British European Airways |
| Tail number | G-ARPI |
| Flight origin | London Heathrow Airport |
| Destination | Brussels Airport |
British European Airways Flight 548 (BE 548) was a Hawker Siddeley Trident 1C airliner, registration G-ARPI, operating as a British European Airways (BEA) scheduled commercial passenger flight from London Heathrow Airport to Brussels, Belgium. At 16:11 Greenwich Mean Time (GMT) on Sunday, 18 June 1972, less than three minutes after departing from Heathrow, the aircraft crashed near the town of Staines, killing all 118 persons on board. The accident became known as the Staines disaster, and was the worst air disaster in Britain until the Pan Am Flight 103 bombing over Lockerbie, Scotland in 1988.
The primary findings of the public inquiry, based on data recovered from the flight data recorders, were that the crash resulted from a deep stall caused by the captain's errors in failing to maintain the correct airspeed and configuring the aircraft's high-lift devices correctly and that the crew failed to monitor the airspeed and aircraft configuration. Secondary factors including pilot incapacitation and the low experience level of the co-pilot were also noted. The process and findings of the inquiry were considered highly controversial among British pilots and the public.
Recommendations from the public inquiry led to the mandatory requirement for cockpit voice recorders to be installed on British-registered airliners. One recommendation, amongst others, was that greater caution should be exercised in allowing off-duty flight crew members to occupy flight deck seats.
On 18 June 2004 two memorials in Staines were dedicated to those who died in the accident.
Industrial relations background
The International Federation of Air Line Pilots' Associations (IFALPA) had declared Monday 19 June 1972 (the day after the accident) as a worldwide protest strike against aircraft hijacking which had become commonplace in the early 1970s. Support was expected, but the British Air Line Pilots Association (BALPA) nevertheless organised a confidential postal ballot to ask its members at BEA whether or not they wanted to strike. Because of the impending strike action, air travellers had amended their plans to avoid disruption, and as a result Flight BE 548 was full, despite the service operating on a Sunday, traditionally a day of light travel.
BALPA was also in an industrial dispute with BEA, concerning issues of pay and working conditions. The dispute was highly controversial, with those in favour being mainly younger pilots, and those against mostly older pilots. A group of 22 BEA Trident co-pilots known as Supervisory First Officers (SFOs) were already on strike, citing their low status and high workload. To compensate for a temporary shortage of fully qualified co-pilots, SFOs were instructed to occupy only the third flight deck seat of the Trident and to act in the capacity known as "P3", involving operating the aircraft’s systems and assisting the captain (known as "P1" on the BEA Trident fleet) and the co-pilot (known as "P2") who between them handled the aircraft. In other airlines and aircraft, the job of BEA Trident SFO/P3s was usually performed by flight engineers. As a result of being limited to the P3 role, BEA Trident SFOs/P3s were denied experience of aircraft handling, a measure which led to loss of pay, which they resented. In addition, their status led to a regular anomaly: experienced SFO/P3s could only assist while less-experienced co-pilots actually flew the aircraft.
Captain Key's outburst
Tensions and hazards resulting from the positions in which BEA Trident SFOs and young co-pilots were placed came to a head shortly before the accident. On Thursday 15 June, a captain complained vociferously that the inexperienced co-pilot whom he had been assigned "would be useless in an emergency". Upset, the co-pilot committed a serious error on departure from Heathrow. The mistake was noted and remedied by the SFO, who later related the event to his colleagues as an example of avoidable danger. This event became known among BEA pilots as the "Dublin Incident".
A mere hour and a half before the departure of BE 548, its rostered captain, Stanley Key, was involved in a quarrel in the BEA crew room at Heathrow’s Queen’s Building with a First Officer named Flavell. The subject of Key's outburst was the threatened strike which Flavell supported and Key opposed. Both of Key's flight deck crew members on BE 548 witnessed the altercation, and another bystander described Key’s outburst as "the most violent argument he had ever heard". Shortly afterwards Key apologised to Flavell, and the matter seemed closed. Key’s robustly anti-strike views had won him enemies in the weeks before the accident, and graffiti directed personally against him had appeared on the flight decks of BEA Tridents, including Papa India. The graffiti found on Papa India's P3 desk was analysed by a handwriting expert during the investigation to determine who might have written it, but this could not be determined and the public inquiry members eventually dismissed it as irrelevant.
Operational background
The aircraft operating Flight BE 548 was a Hawker Siddeley Trident Series 1 short- to medium-range three-engined airliner. This particular Trident was one of twenty-four de Havilland DH.121s ordered by BEA in 1959, and with the constructor's number 2109 it was registered to the corporation as G-ARPI in 1961. By the time of the aircraft's first flight on the 14 April 1964 the company had become Hawker Siddeley Aviation, and Papa India was delivered to BEA on 2 May 1964.
While technically advanced, the Trident (and other aircraft with a T-tail arrangement) had potentially dangerous stalling characteristics. If its airspeed was insufficient, and particularly if its high-lift devices were not extended at the low speeds typical of climbing away after take-off or of approaching to land, it could enter a deep stall (or "superstall") condition from which recovery was practically impossible.
The danger first came to light in a near-crash during a 1962 test flight when de Havilland pilots Peter Bugge and Ron Clear were testing the Trident's stalling characteristics by pitching its nose progressively higher, thus reducing its airspeed: "After a critical angle of attack was reached, the Trident began to sink tail-down in a deep stall." Eventually it entered a flat spin, and a crash "looked inevitable", but luck saved the test crew. The incident resulted in the Trident being fitted with an automatic stall warning system known as a "stick shaker", and a stall recovery system known as a "stick pusher" which automatically pitched the aircraft down in order to build up speed if the crew failed to respond to the warning.
