Classic British Flight Sim

I believed I HAD read the report incorrectly when you said that Nigel

Re the break up..
I'm not sure mate to be honest. If it had started twisting and turning rather than a flat stall, it's possible that forces were put on the airframe in places not intended to withstand such loading and she was full of fuel too. Must have been absolutely terrible for the poor souls onboard who would have known their end was near :-(

ATB

DaveB :tab:

I took a look at an appendix which is also available on the AAIB site which shows several charts and graphs including the Flight Recorder print out. Obviously, I know nothing whatsoever about interpreting one of these, but it appears to show that the maximum altitude reached during the flight was 1788 feet at which point the droop was retracted at 170 kias and the a/c fell 500 feet in about 16 secs during which time the stick push operated three times and the autopilot disengaged automatically. The stick push was actually working in that the nose had dropped to around level flight and speed increased to 193 kias. When the stick push was manually disengaged the nose-up pitch attitude went from 3.5 to 31.3 in 4 seconds. During the same time the IAS dropped from 193 to 54 and impact was 16 seconds after that. If I've interpreted it correctly the aircraft was falling like a brick with a nose-up attitude of at least 31 degrees and very little forward momentum. Which is what Leif said, I think.

Whatever happened in those final few seconds doesn't bear thinking about. It was horrible and I feel a deep sadness for those poor people.

Ian

This accident carried with it a huge amount of speculation, because of the crew room row beforehand , which was one of the reasons for the very lengthy public inquiry which followed. This was chaired not by a layman , but by Mr Justice Geoffrey Lane who was a distinguished former bomber and coastal command pilot. All the time one sees particular aspects of this and other less well informed reports picked out in isolation . Two, at least , of these occur in this thread. First, there is no credible evidence whatsoever of a mid-air breakup. This is not, to my knowledge, ever mentioned in the Lane report. Secondly, and more importantly, the suggestion by Julie Key that premature retraction of droops ( or in fact slats in the Trident 1 case) was known to occur without crew intervention was exhaustively examined in the inquiry, and rejected. A BEA F/O had voiced the theory - before the accident be it noted - that this could happen, and thus after the accident the possibility was very carefully tested. It was found that the interlock preventing retraction could indeed be overcome - but only when the hydraulic systems were not powered up i.e. when the aircraft was not under power on the ground - and thus the theory, though interesting, was not in fact borne out in practice.

This was a tragic accident, and not the last of its kind - the Lufthansa 747 at Nairobi was similar ( although there the droops were never selected at all) , and the Washington Potomac crash and also a DC9 takeoff crash were very similar, and I feel that for the sake of all concerned, it is probably time to lay this to rest

cstorey wrote:This was a tragic accident, and not the last of its kind - the Lufthansa 747 at Nairobi was similar ( although there the droops were never selected at all) , and the Washington Potomac crash and also a DC9 takeoff crash were very similar, and I feel that for the sake of all concerned, it is probably time to lay this to rest

Everything you say is correct, as per the AAIB report. But the reason that we are discussing this accident and not the others is because it was a very high profile incident involving a classic British aircraft (which many of us older members have flown on) and involved a very human story rather than pure mechanical failure. Many of us at the time felt deeply affected by it and it's memory has stayed with us. Despite several of us being interested in doing so, it sounds like you are saying that you don't think we should discuss it any further. I'm a bit puzzled as to why.

Ian

Sorry Ian is correct - the AF B737 accident at DCA had NOTHING to do with slats flaps or other devices - It was purely pilot error
in that the crew DID not identify EPR/TAT probes had iced over due to prolonged ground time in extremly inclement weather.
The DC9/MD80? accident I believe your referring to was the crash at Stapleton in the late 70s early 80s again in very inclement weather and was again attributed to failure to return to the deice pad prior to takeoff. The Staines accident was as Ian says
engraved on too many of the older members here memories. No offence but younger members have not been subjected to
the loss of life in accident like that - Safety today is what it is BECAUSE of accidents like GARPI and the two other accidents
mentioned here, we now teach CRM , and the cavalier "lets get this home" attitude will get you one thing in todays airline
enviorment......unemployed, not thankfully dead

I'll take my soap box with me

Leif

Leif - you are quite right about the Potomac incident, my mistake. The DC9 was the Northwest accident at Detroit 16.8.87 . Like others , I remember the day of Staines very well - I had been flying at the time for only about 5 years and the sense of shock was very unpleasant, as it was also in the THY DC10 crash just under 2 years later. That accident claimed the father of a friend. I just have a nasty feeling that there is a rather ghoulish interest in accidents which is not all that healthy. Having said that, I still read the AAIB bulletins monthly , and for some time after I left flying I used to receive the CHIRP bulletins from the CAA, which I devoured greedily partly because they often had amusing reports in them such as when Britannia was taken through an active danger area , but I suppose my excuse was that I had a professional interest in it.It's just my personal opinion, but I wish we concentrated on happier aspects of flying

Chris

Sorry to come in late on this one. Didn’t notice the thread.

My interest in this matter is that the small factory that I ran was situated at Unit 11, Staines Central Trading Estate, which was in the middle of Staines and a mere 600 yards from the crash site. The aircraft, which had levelled out from a turn, was directly in line with this factory. It occurred on a Sunday afternoon and so no staff were working. However, if the Trident had carried on for a further 5-6 seconds, it would have come down in the middle of Staines with unimaginable additional loss of life.

Regarding the break-up in flight theory, lay eyewitnesses are notoriously wide of the mark, especially on aviation matters. The fact is, as Leif has mentioned, the Trident was in a deep stall condition in which there are relatively minor loads applied to the airframe. It is, essentially, falling like a brick and no aerodynamic loads are going to exceed its design limits, whatever control inputs are applied.

The fact is that the droops had been retracted (I understood that it was the flaps that should have been retracted if only partially (I’ll have to seek Peter’s advice on this)) – but the retraction of the of the droops at a speed 60 kts below the manual figure had a disastrous effect on the airflow over the wing. At that angle of attack, re-selection of the droops would have immediately un-stalled the wing. Tragically, this did not happen.

Ralph

You would think that this lesson was well learnt....? Anyone remember the Dc-9 "racing the Storm" CRA should and would have saved the day then.....?

IIRC it was a AA flight......

Leif....correct me on this fella...?

Tony

Tony,

CRA, IIRC, AA?

I know we live in a world of acronyms but sometimes I am completely bewildered. I know we old ginks are a pain.

Ralph

LOL......American Airlines = AA......
IIRC = If I remember correctly........
CRA = Thinks its to do with Cockpit mangaement and co-pilot and pilot questionning each others actions....

;-)

Tony