18^th June marks 45 years since a plane crash that changed the face of accident investigation. In 1972 British European Airways Flight 548 crashed shortly after take-off from Heathrow Airport, killing all 118 on-board.
The accident became known as the Staines Air Disaster, or the Papa India crash, and as of 2017 it remains the deadliest air accident (Lockerbie killed more people but was a terrorist incident) to take place in the United Kingdom.

To mark the anniversary I visited a memorial at the crash site and a nearby church which has a stained glass window in memory of the crash victims. I reflected not only on the tragically high loss of life, but also on the legacy of this crash.

In 1972 there was no legal requirement to carry a Cockpit Voice Recorder (CVR) on UK registered aircraft. Papa India did have a Flight Data Recorder (FDR) but like most aircraft at the time, it did not have a CVR, a factor that made investigating the crash particularly tricky.

The Accident Investigation Branch, the forerunner to the Air Accident Investigation Branch, was able to determine the immediate causes of the accident: a persistent speed error, the movement of the droop lever, the failure of the monitoring system, the failure of the crew to diagnose the reason for the operation of the stall prevention system and their failure to fly a recovery.

But what other factors had a role to play in the crash? Questions were raised as to whether the Captain was affected by a subtle medical incapacitation. Did inexperience play a role? Was it a case of inattention or distraction? Or did an ongoing industrial dispute over pay and conditions affect relations between the pilots?
The lack of a CVR meant that what actually happened in the cockpit on that day went to the grave with those onboard. It made it impossible to get a full understanding of the causes of the crash.

The accident report stated: “There is a danger of assuming that we have all the facts before us and that the only problem is to assemble them in the right order. Had we had the benefit of a cockpit voice-recorder this might have been true. As it were there may well be some vital piece of information missing which would, if known, change the whole picture.”

Recommendations from a public inquiry in to the accident included increased training to help pilots recognise subtle incapacitation in their colleagues, closer co-operation between the Civil Aviation Authority and British airlines and an urgent call for mandatory installation of Cockpit Voice Recorders on all British-registered civil passenger-carrying aircraft of more than 27,000 kg (60,000 lb.) all-up weight.

The report explained the need for CVRs as follows:

“This accident has shown that data as to the height, speed, attitude and movement of controls of the aircraft, however valuable as eliminating any suggestion of mechanical failure, do not always provide as full a picture as possible. The investigator is still left in the dark as to what was passing between the crew members by way of orders, comment or exclamation.”

The recommendation resulted in their fitting becoming mandatory on larger British-registered airliners from 1973.

It’s fair to say that BALPA had been concerned about the introduction of voice recorders up until this point but this accident changed a lot of people’s minds. Their fitting has changed accident investigation beyond recognition and we must remain vigilant to ensure all cockpit recordings are there to aid flight safety.
For pilots any accident or tragedy is devastating. But it would be further devastating if lessons were not learnt to help improve technology, training and regulation to ensure similar accidents cannot be repeated. That’s why pilots support the vital work of the AAIB and believe investigators must be able to carry out their painstaking work freely.

Pilots continue to warn against any premature or unhelpful release of accident information beyond the accident investigation. We believe such releases jeopardise the current excellent safety culture, could impede the accident investigation and add to the distress of victims and their families.

The Papa India crash was a catalyst for a vital improvement in cockpit recording and helped build the open safety culture in aviation. The public inquiry report in to Papa India’s crash put it like this:

“There must be some area of uncertainly in every accident, but the more these areas can be reduced the greater the prospect of eliminating a possibility of recurrence.”

As the pilots of today prepare for another busy summer, they do so in the knowledge that aviation today is safer because of the lessons of the past. So although there were no voice recorders on board Papa India 45 years ago, from the ashes of the crash rose a new voice. It’s the voice of a safety culture that is still keeping flights safe today.