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British Airways 9

Accident Case Study

In 1982 all of what happened to British Airways 9 was unknown in aviation, the crew did everything right and as a result there were no fatalities and the airplane, though damaged, was not destroyed. The flight took off at night just as Mount Galunggung had erupted. They flew through the volcanic dust at altitude where the lessons began:

  • Volcanic ash is very dry, abrasive, and fine. When the airplane entered the dust cloud the fine, dry dust electrified with static electricity and appeared to be St. Elmo's Fire.
  • The static makes radio communications difficult, if not impossible.
  • As the dry ash enters the hot engines, it becomes a sludge that collects onto the turbine blades, fouling the airflow and eventually causing them to compressor stall and shut down.
  • After the aircraft is forced to descend the engines cool and the sludge on the turbine blades break off, allowing the engines to be restarted.
  • The powder is so abrasive that the windscreen is sandblasted and very difficult to see through.

images

Photo: Dramatization, from May Day.

As Jack Diamond of the British Aviation Journal The Log puts it:

The job of the airline pilot in the early days of civil aviation was one in which character, skill and a dogged ability to stick to the task, under extreme pressure, were tested on an almost daily basis. Weather forecasting was rudimentary, navigation was based on fleeting glimpses of railway lines through ragged cloud and accurate landings on an ability to discern a dim line of gooseneck flares. The aircraft were subject to frequent technical failures and the engines had to be nursed with the sensitivity old stagecoach drivers used in handling an inexperienced team of four. Those who learned their trade during the war came through an even more deadly and unforgiving school. Nowadays, the modern generation of pilots sit in air-conditioned comfort, with reliable engines, navigating errors measured in yards rather than miles on aircraft which can land themselves, smoothly and accurately, in almost impenetrable fog.

We are the first generation of pilots who may go through a whole career without having a genuine emergency; many pilots have completed fifteen years flying without having suffered an engine failure. Although this is undoubtedly a blessing, it does beg the question, how will they behave if they are eventually put to the test?

Accident Report

I suppose you could argue this wasn't an "accident" at all and more properly fits into the category "incident." I am including it because it supports two articles I have in the works, one on professionalism and the other on the fine art of mind-reading. There is no official "accident report" that I know of. So much of what follows comes from a magazine article and book, shown below in the References.

  • Date: 24 June 1982
  • Type: Boeing 747-236B
  • Operator: British Airways
  • Registration: G-BDXH
  • Fatalities: 0 of 15 crew, 0 of 247 passengers
  • Aircraft Fate: Unknown
  • Phase: En route
  • Airport: (Departure) Kuala Lumpur International Airport (KUL/WMKK), Malaysia
  • Airport: (Destination) Perth Airport, WA (PER/YPPH), Australia

Narrative

We know today what the symptoms of engine failures due to volcanic ash ingestion are; we are cheered by the fact the engines will restart if shutdown properly after the aircraft descends to an altitude that allows the ash to break free. But this crew were the first and had no such knowledge. They worked together marvelously and brought their lessons home for the rest of us to be better armed.

images

Photo: Mount Galunggung erupting, Diamond, p. 14.

Click photo for a larger image

[Diamond, pp. 13-15]

  • Captain Eric Moody, Senior First Officer Roger Greaves and Senior Engineer Officer Barry Townley-Freeman.
  • The aircraft was laden with 247 passengers and 91,000 kg of fuel for the flight to Perth, the night was moonless, but clear, and the flying conditions were smooth. The en-route weather forecast was good and the crew expected an uneventful flight lasting 5 hrs. The flight crew ate their meal after settling into the cruise at 37,000 ft. This was supplemented by a tray of satay (a speciality of Malayan cookery). The crew had finished their meal by the time the aircraft was south of Jakarta on Airway B69.
  • Eric Moody had a quick look at the area ahead of the aircraft with the weather radar and picked up nothing more interesting than returns from the surface of the sea. He made his way aft and found that the crew toilet was occupied. He descended the stairs to the first class area and started a conversation with the forward purser Sarah Delana-Lea. Almost immediately he was called to the flight deck by Fiona Wright the Stewardess I. As he climbed the stairs he noticed puffs of 'smoke' billowing out from the vents at floor level and a smell which he described as 'acrid, or ionised electrical', such as one finds near sparks from electrical machinery. He entered the flight deck to find the windscreens ablaze with what appeared to be the most intense display of St. Elmo's fire he had ever experienced. Eric strapped himself into his seat and again looked at the weather radar. Nothing of significance was in view, but he was pleased that in his absence, the other two crew members had put on the seat belt signs and the engine igniters.
  • Roger then pointed out the side windows at the engine intakes which were glowing as if lit from within. The electrical discharges had a stroboscopic effect which gave the illusion that the fans were moving slowly backwards. At the same time the St. Elmo's fire on the windscreen had given way to a display of what looked like tracer bullets. All this happened so quickly that there was little time for discussion and Eric had been distracted by the display from what he considered to be the most important consideration, the smoke which appeared to have got into the air conditioning.
  • Before he could speak Barry called out "Engine failure number 4!" Eric immediately asked for the Engine Fire Drill, and the other two crew members carried it out. Roger believes the crew were helped by the fact that the problem compounded itself gradually. The slow build-up of danger ensured that they were not plunged instantly into an extreme situation. They became more alert and concentrated as the incident became more complex and at no time lost control of their reasoning processes. They were soon forced to face the full consequences of their problem by the voice of the Flight Engineer.
  • "Engine failure number 2 ... "
  • "Three's gone ... "
  • "They've all gone!"
  • Eric stared at the instrumentation in front of him and refused to accept the full impact of what had been said. "Four engines do not fail", was the refrain which dominated his thinking. He had practised a four engine failure detail on the simulator some months earlier and then, the assumption had been made that all generators would fail, leaving the aircraft on standby electrical power, fed from the aircraft batteries. This would have caused a failure of the co-pilot's instrumentation and much of the cockpit lighting. Yet the instrumentation all appeared to work and the auto-pilot remained in control. The display on the engine instruments was also very confusing as the instruments were a mixture of Smiths and General Electric, some which froze under power loss and some in which the needles dropped off the scale. There were also some amber lights indicating that engines had exceeded their maximum turbine gas temperatures. While he studied this confusing display, Eric heard Barry suggest that they shut the engines down. At the same time he noticed that the airspeed was decreasing. He put the auto-pilot into a gentle descent and turned to his co-pilot "OK Roger, put out a Mayday".
  • Eric then controlled the aircraft using the auto-pilot, while the other two carried out appropriate emergency drills. Both pilots shared the task of moving the engine start levers on different occasions. Because the auto-pilot remained in control, Eric had time to consider the likely cause of such a multiple failure: electrical? (check all circuit breakers): fuel? (turn on all pumps and cross feed cocks): icing? (turn on engine anti-icing). All the crew members, afterwards, felt that checklists, for such extreme emergencies, should contain every item for consideration and not leave anything to intuition. Although crew members will always exercise their initiative, it is better that they have trust, that the check list covers everything. The dominant feeling of the crew at this point was the question 'what have we cocked up?'
  • The first relights were attempted on engines 1, 2 and 3, but Eric decided, with the agreement of the crew, to attempt relights on the number 4 engine along with the others. (The number 4 engine fire handle had been pulled when the fire drill had been carried out).
  • At 26,000 ft. the cabin pressure warning horn sounded as the cabin climbed through 10,000 ft. The crew started to don their oxygen masks. When Roger removed his mask from the stowage it fell to pieces in his hand. The bayonet fitting came out of the supply pipe and the tubing disengaged itself from the mask. Eric was presented with an unenviable choice. Should he continue to descend as slowly as possible and have his co-pilot suffer the effects of anoxia, or should he increase the rate of descent till the aircraft was at a more survivable altitude. He chose the latter, and began an emergency descent.
  • However he decided not to extend the gear, as instructed in the flying manual, because it opened up the possibility of having to ditch the aircraft with gear extended, should it prove impossible to retract them. With hindsight it is now obvious that during gear extension, the hydraulic power from windmilling engines might not be powerful enough to move the gear and the flying controls at the same time. They had previously turned the aircraft on a Northerly heading back towards Jakarta and they decided that with a safety height of 10,500 ft in that area, they would turn back out to sea when the aircraft reached 12,000 ft. At this time the inertial navigation systems were giving a display of gibberish and were no use in fixing their exact position.
  • When they reached 20,000 ft. Eric retracted the flight spoilers and reduced the rate of descent. Ironically he noticed that Roger had, by then, managed to fit the oxygen mask together (a test of intelligence and manual dexterity while under extreme pressure).
  • At this point Roger noticed that his airspeed indication showed 320 kts whilst Eric's showed 270 kts. Eric thought that it was worth assuming that the higher figure was correct in case they had been attempting to start the engines while outside the relight envelope. Again they had no luck, although the fuel had been igniting behind the engines and treating those passengers with window seats to a view of, what appeared to be, four engines on fire. At about that time the cabin reached 14,000 ft. and the passenger oxygen masks were deployed. Eric decided it was time to have a word with them.
  • "Good evening ladies and gentlemen. This is your Captain speaking. We have a small problem. All four engines have stopped. We are all doing our damndest to get them going again. I trust you are not in too much distress."
  • It was about this point that Eric started to consider the awesome consequences of attempting a deadstick touchdown on the sea at night. His father had taken him, as a child, to Hythe pier to watch the flying boats land. He knew that flying boats did not fly at night because of the difficulty of judging height above water. He remembered, with some amusement, a training film made by British Airways which simulated a ditching at sea. The Captain playing the role (no actor) had used the phrase 'it's not our day' in passing the bad news on to the cabin crew. This reverie was interrupted by sounds of jubilation from the other two crew members as number 4 engine started. (This was the engine which had first run down and the success amply repaid Eric's gamble in trying to start it). The other three engines started, an almost interminable, 90 seconds later. They were at 12,000 ft.
  • They immediately requested a climb to a height which gave them more clearance over the high ground ahead of them and asked for clearance to Jakarta. They climbed to 15,000 ft. and at about this height there was a resumption of the St. Elmo's Fire. When the throttles were pulled back to level out the Number 2 engine surged continually. It felt as though it would shake the aircraft apart, so it was shut down, but not without great reluctance. At this point Eric suspected that the St. Elmo's Fire, above 15,000 ft, was somehow connected with the engine problems and concluded that the engines themselves were severely damaged. He decided to descend to get away from the strange atmospheric effects but resolved to leave the throttles in their present position and to control the aircraft speed and descent by the use of speedbrakes, flaps and undercarriage. This required a leap of the imagination as up till then they had strong suspicions that the engines had failed because of an oversight, or an error, by the crew. They were cleared to Jakarta Airport where the weather was fine, with calm wind and good visibility. The only added complication was that glide path information was not available for Runway 24.
  • While the aircraft was on the base log for runway 24 the crew had great difficulty in picking up any lights on the ground and, in particular, in picking out the runway lights. Eventually the runway was spotted to the right of the aircraft out of the co-pilot's side-window. When they lined up with the runway the lights again disappeared and the crew realised that their front windows were almost opaque. The final descent, to touch down, was made using the localiser, to stay on the centreline, and by peering through the outer edge of the left hand front window, which was still clear, Eric was just able to make out the lights of the VAS Is on the left of the runway. The other two crew members called out the radio altitude and DME distance to help in judging the descent. When they were over the runway the whole of the front windows were filled with a diffuse glare of light. This was comforting in that it proclaimed the general proximity of the runway, but the delay before the wheels touched down felt like minutes rather than seconds. The landing itself was smooth, Eric felt that the earth seemed to gather them up; downstairs in the cabin spontaneous cheers and clapping broke out from the passengers.
  • The crew taxied the aircraft off the runway towards the terminal building. The glare of light from the parking area again filled the front windows with a blinding glare. They decided to call it a day and parked the aircraft.

Analysis

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Photo: One of the engine intakes after the event, Diamond, p. 15.

Click photo for a larger image

[Diamond, pp. 15-16]

  • It was two days before the crew got confirmation of the cause of the incident. Barry was convinced that it was caused by an encounter with volcanic ash when he found his hands and clothes covered in a fine black dust as they waited for steps to be brought to the aircraft. When they got outside they found all the leading edges, engine nacelles and nose cone stripped of paint as if the aircraft had been sandblasted, as indeed in one sense it had. They had flown into the dust cloud from a volcanic eruption from Mount Galunggung which is positioned about 110 miles south east of Jakarta. The plume of ash started to become visible on satellite weather photographs, after the event.
  • The engines were the worst affected parts of the aircraft with the turbine blades having the most damage. The tips of the blades were ground away where they were blasted by the ash at high speed. The material of the ash was mostly silicate particles with a mean diameter of .075 mm. Apart from wearing away the high speed parts of the engine the 'silicacious refractory material sintered in contact with the hot metal fusing itself to the blades'. This is what happens inside steel furnaces. The changes in blade shape and size had serious effects on the efficiency of the engines with the number 4 engine (significantly the engine which ran down first) being the least damaged. Ash was also found in the pitot tubes which had caused the differing airspeed readings. In October 1984 ICAO issued a special report on the dangers of volcanic ash to aircraft, where it was pointed out that the incident on the 24th June 1982 was the ninth eruption of Mount Galunggung that year. The report found that prevention was better than cure, but suggested that any pilot who encountered such a problem should, altitude permitting, reduce thrust to zero, descend and leave the area as soon as possible. Consideration should be given to turning off engines and restarting them when clear of the ash and inside the relight envelope of the aircraft.
  • What can be learnt from the behaviour of the crew?

  • It would be comforting to think that this was an average crew and that a similar outcome would have emerged had others been flying the aircraft. If this be the case then British Aviation is indeed blessed with the standards of their pilots and flight engineers. If they were unexceptional crew members then it is obvious that they behaved in an exceptional way. They exhibited a quality which is described, best, by a word which is much loved by football managers, and the word is 'bottle'. This describes a sort of courage which is not of the gung-ho variety but the sort which causes someone to persist in an enthusiastic and inspiring manner when the odds for success look slim. Barry said that, had the aircraft landed in the sea, he would have still been trying to start engines as the fuselage touched the water. This is the sort of professionalism which passengers deserve to get from their flight crew.
  • Barry felt, very strongly, that check lists, which have to be used in such extreme emergencies, should contain every item of rel­evance to that emergency (perhaps in an expanded form in the Flying Manual) and suggests that the crew should read out, from the check-list, the items which are meant to be 'memory items'. When there are three concurrent drills to be carried out while one is "thinking through treacle", close adherence to a comprehensive checklist is the only way to guard against error.
  • heir efforts were successful because:
    1. One pilot ensured that while check-lists were being completed, the aircraft attitude and speed were always monitored (somebody minded the shop),
    2. the emergency was managed in a rational and safe manner,
    3. the emergency checklists were fully utilised.
    4. they continued to try to start the engines even though for 13 minutes there was no visible reward for their efforts,
    5. they used the auto-pilot to reduce work load so that, at least, one member of the crew could detach himself from the check-list and try and reason his way to a solution,
    6. where necessary they made bold decisions: trying to start No.4 engine and refusing to climb back into the cloud of ash, and
    7. they made full use of each crew member, aircraft system and landing aid, to ensure a safe landing.
  • This was an exercise in crisis management, the sort of thing which NATO spends much of its time studying. Any Captain finding himself in such an extreme situation must ensure that, at any particular moment, he clearly identifies the aspect of the problem which is most relevant to the safety of the aircraft and attempts to solve it. He must be able to delegate some responsibilities, and clear-minded enough to ignore those problems which are not an immediate danger to the aircraft. These priorities will change as time goes on so the pilot must guard against tunnel vision. This is an aspect of aviation which is not studied widely, although, in recent years, there have been five occasions when multi-engined aircraft lost all engine power.

Cause

Since there wasn't an official accident report, this listing of a cause comes a book written by another British Airways pilot, Captain Stanley Stewart.

[Stewart, p. 202] On the evening of 24 June, Mount Galunggung, the active volcano situ­ated on the south Java coast 100 miles (160 kilometres) south-east of Jakarta, had erupted violently. Giant plumes of ash and grit had been hurled eight miles (thirteen kilometres) into the air. The explosion had created a vast volcanic storm of thick, hot, sulphurous gases and high electrical activity. No aviation warning was given. North-easterly winds aloft at twenty-five to thirty knots had blown the plume across the path of BA 009 and it had been engulfed in ash. Flying through the hot grit at speed had the effect of sandblasting X-ray Hotel's leading edges and had stripped paint and caused the opaque surface on the windscreens and landing light covers. The dust had penetrated aircraft sensors such as pitot tubes which sense dynamic pressure to measure airspeed. The discrepancy in the airspeeds was the result. The engine nacelles, intakes and fans were shot-blasted and stripped clean. Erosion of the compressor blades had occurred and the ash, which was of a silicate material, had fused in contact with the hot metal of the combustion chambers and turbines. Deposits of fused volcanic ash up to half an inch in diameter were later discovered in all the engine tailpipes. The effect was sufficient to disrupt the airflow and was similar to dampening a blaze with sand. As a result the engines had flamed-out and all power had been lost. At 13,500 ft (4,115 m), X-ray Hotel had broken into clean air and the least damaged engine, number four, had roared into life. Subsequent climb to 15,000 ft (4,570 m) had taken them back into the ash cloud. It was a close escape which might have ended tragically had not the skill, coolness and persistence of the flight crew won the day. But the passengers and crew of BA 009 were lucky, too, for the aircraft only just emerged from the volcanic storm in the nick of time.

References

Cinder and Ash Hazards, Professional Pilot, August 2013, pgs. 86 - 90.

Diamond, Jack, Down to a Sunless Sea: The anatomy of an incident, The Log, April 1986

May Day: Falling From the Sky, Episode 27, Season 4, 22 April 2007 (British Airways 9)

Stewart, Stanley, Emergency: Crisis on the Flight Deck, 2013, Airlife Publishing, Ramsbury, Marlborough, England

Revision: 20180222
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