The 1972 Trident accident at Staines - Part 1

GARPI - 18 June 1972

Feb 02, 2023

Over 50 years have passed since the fateful Sunday afternoon of 18 June 1972 when British European Airways (BEA) Trident 1C (Registration GARPI - Callsign Bealine 548) crashed soon after take-off from London Heathrow Runway 28R. The planned destination was Brussels. Following a stall1, the aircraft descended and broke up on impact in a field at Staines - to the south-west of Heathrow. All 118 people aboard the aircraft were killed.

The crash time was approximately 1611 and the stall occurred around 36 seconds earlier. The aircraft carried flight data recording (FDR)2 but Cockpit Voice Recording (CVR) was not installed. In 1972, radio communication with ATC was recorded but air traffic control radar was not recorded and so the flight path was deduced.

In view of both the gravity of the disaster and public concern, the government decided to set up a public inquiry and the Lord Chancellor was invited to appoint a Commissioner and Assessors. A High Court Judge (Mr Justice Lane) was appointed as Commissioner and the Assessors were the aeronautical engineer Sir Morien Morgan and Captain J W Jessop - Managing Director of Northeast Airlines (UK).3

The Air Accident Investigation Branch provided evidence to the inquiry which sat for 33 days in London from 20 November 1972 to 25 January 1973. There were 13 sets of legal representatives including the Attorney-General Sir Peter Rawlinson QC MP (1919-2006). Evidence was given by 67 witnesses.

The Inquiry issued its report in April 1973 - 4/1973 G-ARPI, 18 June 1972 - GOV.UK (www.gov.uk)

Emergency response

The Inquiry report states that from time 1620 onwards there was a rapid build-up of Police and other rescue services. The crash site was sufficiently inaccessible to prevent all but the most persistent sightseers from reaching it. “The Police were successful in controlling spectators, and contemporary reports that the presence of the public impeded rescue services were not borne out by the facts. All rescue services acted with commendable despatch.”4

We know that a young boy called a nurse (Frances Castledine) who lived nearby. She attended the scene. A passing ambulance also attended the scene. Other emergency services then began to arrive.

Air traffic control

The inquiry report has little to say about ATC other than saying YES in answer to a question about whether the service operated efficiently. There is no radio transcript included in the report.

Normal practice was that Heathrow Tower would instruct a departing aircraft to contact “London Radar” and we know that the aircraft did so and was instructed to climb to Flight Level 60 and squawk 6615. That climb instruction was acknowledged although the reply was a brief “Up to 60.” The squawk was not read back.

If the aircraft displayed the assigned transponder code (6615) then it would presumably have appeared on the radar controller’s screen. Beyond this it is not safe to surmise. Did the aircraft continue to display the code? At what point did the radar controller realise that the aircraft had descended and crashed? What did the controller do when it became clear that the aircraft was no longer airborne? How could the radar controller have quickly alerted supervisors to the situation so that they could take appropriate action (e.g. alerting rescue services)?

Weather

Weather at Heathrow was - Surface wind 210 degrees at 17 knots. Rain. 8/8 cloud5 at 1000ft and some lower cloud.

During the take-off, the crosswind component was therefore approximately 16 knots from the aircraft’s left.

The inquiry report notes that a cold front was approaching the airport and was about 30 miles away. There was “considerable turbulence.” The report also notes that “at crucial times the aircraft was in cloud and the crew had no visual reference.”

Wind velocity normally6 changes with height. In this case the likelihood was that the direction became more westerly and the speed increased.

In Captain Jan Bartelski’s7 book - “Disasters in the Air” - it is stated that a “Pan Am captain and IFALPA All Weather Landing Expert, who took off that afternoon in a Boeing 747 for New York, reported that he experienced the worst turbulence for many a year.” Bartleski does not say the time of this departure. It is also unclear whether Captain Key was aware of this (or similar) reports. Nonetheless, it seems fair to believe that an experienced pilot such as Captain Key would have known that some degree of turbulence would be present during the departure and climb out.

The pilots

The Trident operated with three pilots.

The Captain was Stanley Key (age 51) - an experienced pilot who held an Airline Transport Pilots Licence with some 15,000 hours experience including 4000 hours in command on Tridents. In the right-hand seat was Second Officer Jeremy Keighley (age 22) who held a Commercial Pilots Licence with Instrument Rating and had flown just 29 hours as second pilot on the Trident. The third pilot - (sat in the centre but behind the pilots flying) - was Second Officer Simon Ticehurst (age 24) who also held a Commercial Pilots Licence with Instrument Rating and had 1400 hours including 750 hours on Tridents. A fourth BEA employee - Captain John Collins - occupied the so-called “jump seat” (or observer seat) to the rear of the flight deck. He was not a crew member.

We do not know what Captain Key thought about having the least experienced of the two in the right-hand seat. However, for reasons connected with training, S/O Keighley was qualified to fly as second pilot but not as third. S/O Ticehurst was qualified to act as either P2 or P3.

The report states (Page 3) that Captain Key was the handling pilot and then comments

The phrase “in the particular conditions” appears to refer to the weather - rain with crosswind and low cloud. It seems a reasonable conclusion that Captain Key would have elected to handle the take-off rather than ask the minimally experienced second officer, with whom he had not flown before, to be the handling pilot.

The Trident wing

In the 1970s, the Trident was in many ways a sophisticated aeroplane design. Powered by three rear-mounted Rolls-Royce Spey low-bypass turbofans the aircraft had a swept wing and T-tail - Hawker Siddeley Trident. The wing was designed for high speed flight (around 500 kts at cruising altitude) but it produced relatively limited lift at lower speeds making it necessary to build in lift-enhancements.

The wing had trailing edge flaps to increase lift when at lower speeds (i.e. take-off and climb-out and also on approach to landing). Further, “leading edge droop flaps” were built in to the wing to increase the camber of the wing and reduce the stalling speed.8 The lower the stalling speed the better especially in phases of flight where airspeed is relatively low.9

Image: Droop flap shown in red.

Stall warning

Warning of an imminent stall was given by a built-in stick-shaker. If the stall occurred then the “stick pusher” would literally push the control column forward so as to push the aircraft’s nose down. The stick-pusher could be overridden (“dumped”) by the pilot selecting the override lever located to the left side of the central control pedestal.

Activation of the stick-pusher disengaged the autopilot.

The take-off and climb out

The aircraft taxiied at 1603 and, at 1606, ATC issued a Dover One Standard Instrument Departure. Take-off clearance was given at 1606:53. There was a short delay to enable the crew to attend to a technical issue. Take-off clearance was given a second time at 1608:24. Brakes-off time was about 1608:30.

The Inquiry report sets out the standard BEA procedure for take-off and climb-out but also notes that the actual sequence of events was “very different” -

The following data is from the Report Appendices - G-ARPI_Append.pdf (publishing.service.gov.uk).10 The data is taken from the aircraft's flight data recording.

1608:30 - Brakes off

1609:33 - autopilot was engaged with the Indicated Airspeed (IAS) at 170 kts. (The report comments about this early engagement of the autopilot. I cover that in Part 2).

1609:44 - left turn commenced - IAS still 170 kts.

1610:03 - trailing edge flaps were selected up at start of noise abatement - IAS 168 kts. The flaps fully retracted by 1610:13. At this point ATC instructed “548 climb to Flight Level 60 squawk 6615” - and that was acknowledged by the Captain who said “Up to 60”

1610:24 - aircraft in a left turn at 1772 ft above the airfield - IAS 162 kts with a left-hand bank angle of 21.4 degrees. At this moment, the leading edge droops were selected up.

1610:26 - the autopilot disengaged - stick shake and the first stick push activated. Height 1788 ft.

1610:32 - the droops had fully retracted.

1610:33 - second stick push - IAS 177kts - height 1562 ft.

1610:36 - third stick push - IAS 182 kts - height 1403 ft

1610:37 - stick-push ‘dump’ operated - IAS 187 kts - height 1360 ft

From the first stick push onwards the aircraft was descending and speed increasing. The last reliable speed and height data were at time 1610:39 when the IAS was 193 kts and height 1276 ft. Impact was at 1611.

From time 1610:26 at height 1788 feet to impact was only 34 seconds. That is an average descent rate of approximately 3155 feet per minute.

Hence, we see that the initial climb speed was below the 177 kts required. The droops were retracted when the aircraft was in a left turn flying at IAS 162 kts and at height 1772 ft. The BEA procedure was not to retract droops in a turn and the procedure also required IAS 225 kts with the aircraft 3000ft or above and established in the en-route climb.

The key question for the inquiry was therefore WHY had the aeroplane handling differed so markedly from the BEA standard procedure. This is looked at in Part 2 of this Viewpoint. For now, two other points can be noted.

a) Cockpit Voice Recording

CVR had been implemented in Australia and the USA by the mid-1960s. BOAC Boeing 747s were fitted with CVR.

Proposals were put forward by UK government in 1969 but met with opposition including what the inquiry report called “misgivings” by the British Airline Pilots Association (BALPA). A working party was set up in 1970, reported in 1971 and recommended that “future aircraft” (i.e. certificated after 1971) be fitted with a large capacity flight data recorder and cockpit voice recording.

The Inquiry noted that the investigation could not know what was passing between crew members by way of orders, comment or exclamation. A CVR might have established why the droop lever was moved, who moved it, and crew reaction afterwards. Consequently, the Inquiry recommended CVR for all civil passenger-carrying aircraft of more than 27,000 kgs all up weight. The inquiry stated that - “The time has come for expedition.”

In December 1972, the CAA put forward amendments to legislation but these were not planned to come into force until 1 January 1975.

b) Noise abatement procedures

On a personal note, in 1964 I was briefly at Heathrow as part of my ATC training. I stayed not far from Hounslow West Tube Station - (then the end of the Piccadilly line).11 Aircraft noise, especially from the first generation jet aircraft12, was (to say the least) considerable and, most of the time, Hounslow was underneath approaches for westerly landings at Heathrow. It was little wonder that noise abatement became a highly-sensitive political issue but the idea of having to fly with reduced thrust on take-off and climb-out was not welcomed by some aircrew of the day who saw it as a reduction in safety margins.

The Inquiry report stated -

Noise - Overview | Civil Aviation Authority (caa.co.uk)

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