Interesting AAIB reccomendation

[Check Airman]

Caught this (http://www.flightglobal.com/articles/2008/01/10/220738/inquiry-reveals-challenger-604-design-flaw.html) today on Flight International. I've pasted the interesting bit below.

http://www.flightglobal.com/articles/2008/01/10/220738/inquiry-reveals-challenger-604-design-flaw.html

A safety recommendation in the report relates to the training of controllers to consider the balance of risk involved in directing an aircraft with impaired controls or power over major conurbations, rather than vectoring them to airports away from urban areas.

While I appreciate the concern for those on the ground, I hope this doesn't mean that one day, a crew requesting vectors to the nearest airport will be sent to a lower population risk location, instead of the nearest runway.

[The Nr Fairy]

It's not the first time this recommendation, or something similar, has been made.

For those interested, the original report is on the AAIB web site (http://www.aaib.dft.gov.uk/publications/formal_reports/1_2008_vp_bjm.cfm).

The other report which springs to mind is the one relating to a freighter near London where the aircraft was vectored over western London when low on fuel (if memory serves right), but I can't find it at the moment. When I find it I'll post a link.

[turn right 5 degrees]

As far as I am concerned it's the Captain's call, I might suggest an alternative airfield (that looks suitable) if you are in an emergency situation but if you want to go to Heathrow or any other airfield I will do my best to assist you.

The AAIB recommends that controllers be trained in keeping aircraft in distress away from built up areas but who will carry the can if we direct you to EGSS and you end up in the middle of Bishops Stortford but would have made EGLL?


TR5D

[doubleu-anker]

Have to agree with the AAIB on this. If the thing is going to crash then let it crash in an unpopulated area if possible.

Are the airlines using such low fuel reserves now that the A/C cant make Stansted from west London?

[turn right 5 degrees]

Neither of these were to do with fuel if you read the reports, the Evergreen had power problems and the Challenger had control problems, both crews electing Heathrow as the most suitable. If the Evergreen had been directed to EGSS it could well of ended up in NE London.

TR5D

[Capt H Peacock]

So what happens when an aircraft inbound to Heathwick with an emergency is refused permission to land?

We already get the 'wouldn't you really rather go elsewhere' speech read out to us, courtesy of the beancounters and lawyers I imagine.

Of course the Captain has the ultimate authority - and flight safety is paramount (Yawn):hmm:, but an incident that blocks the runways at Gatrow looks bad on News 24 and could adversely impact on retail operations!!

[p7lot]

For all of you in any doubt...when I call "I have control"
I have control of the aircraft.

[doubleu-anker]

Remember the B747 out of AMS in the early '90's that lost control, crashed and took about another 50 innocent victims with it.

[frontlefthamster]

Economics and many other factors, all in society's control, have brought us airports in highly populated areas. :ugh:

Aircraft crash near airports. :(

A sensible commander, with time and fuel on his hands, may make a decision to divert to a remote airport, if faced with problems likely to cause catastrophe. Equally, he might deem it appropriate to carry on towards a populous area on the grounds that he has insufficient fuel or height to go elsewhere, or he wants to be going somewhere he's familiar with. I hope that the decisions made in future are sound, and we don't repeat the AMS accident - or see worse - here, but if we do, ultimately, it will be my first two paragraphs above to which we, as a society, should refer in the first instance. :hmm:

[ACARS]

Quote from article - It was diverted to London Heathrow because Farnborough's runway was not long enough for a flapless approach, and carried out a safe landing there.

Is this normal SOP for an aircraft to fly to a destination knowing that in a partilcuar configuration (flapless in this case) it can't land.

Just curious....

[Check Airman]

Have to agree with the AAIB on this. If the thing is going to crash then let it crash in an unpopulated area if possible.

Well you don't know that it's going to crash now do you? That's why you declare the emergency to prevent the crash. FYI, the challenger didn't crash.

[doubleu-anker]

"Well you don't know that it's going to crash now do you?"

Quiet right. The poor Captain of the B747 that crashed at AMS probably had the same thought. Unfortunately he did crash.

Without speaking ill of the dead, he was offered and accepted a runway that approached over a build up area, the city of AMS.

20/20 hindsight is easy but the authorities in that case should have had that a/c vectored to a remote military base with sufficient r/w length.

[blimey]

Yes of course he should have been sent to some remote, totally unfamiliar base with probably poor aids and little crash cover. :hmm:

[His dudeness]

"Without speaking ill of the dead, he was offered and accepted a runway that approached over a build up area, the city of AMS."

I think it ain´t easy to find unpopulated areas in the Netherlands. Anyhow, these poor guys LOST CONTROL, so they could have ended up anywhere even if vectored to some place else.
The whole thing is highly theoretical IMO. And would you like to have a full 47 or a A380 crashlanding at a place like Biggin Hill (I know its not a "suitable" airfield, just exaggarating a bit) ? With, maybe, 3 firefighters present?

[esa-aardvark]

My background is Space not Air, but I happen to remember some details on this.A colleague was part of the investigating team . I remember that he told me that things were by no means simple. The aircraft could have landed back
at Schiphol quite quickly on an alternative runway, but for traffic management reasons was routed back to Schiphol, on whatever runway I don't remember.
Alternative thought about was a landing straight ahead into the polder
(sorry I don't remember the name) which would have been a bit of an environmental problem. In the end the loss of control occurred
when the flaps were lowered for landing, then it was discovered that
asymmetric deployment occurred after the game was well & truly over.
Somewhat similar to the DC10 a few years earlier.

John

[Mad (Flt) Scientist]

Is this normal SOP for an aircraft to fly to a destination knowing that in a partilcuar configuration (flapless in this case) it can't land.


For normal commercial jet ops (ignoring Part 91 for now) you have to plan to use only 60% of the available runway for the "non failure" case; that gives a 67% distance margin available for any failures. That means any failure which cauises a landing distance increase of more than 67% means your initial planned distance is shorter than your failure required distance. So if your planned runway was marginal, you might no longer be able to land.

The 67% factor gives a margin for most failures, but there will be cases where it's not enough.

The Challenger landing distance factor was 75% for the case in question, per the AAIB report.

[BOBBLEHAT]

It's worth remembering that ATC rarely get the full story over the R/T. I know for a fact that this was the case in both the challenger and the Evergreen incidents. The challenger incident was used in controller training exercises for ATCO's in the London TMA as a good example of handling an incident and even includes a letter of thanks to ATC from the captain.

[TheOddOne]

So what happens when an aircraft inbound to Heathwick with an emergency is refused permission to land?

We already get the 'wouldn't you really rather go elsewhere' speech read out to us, courtesy of the beancounters and lawyers I imagine.

Capt Peacock,

If you've declared an Emergency, then you WON'T be refused permission to land, even though it is known that you will block the runway upon arrival.

When I was at LHR & LGW, we had 'Message A' which we could ask ATC to recite to the crew of an inbound a/c that might block the runway (particularly critical at LGW). This politely asked crews to consider diverting to a less busy, suitable runway. Such an animal no longer exists. I think we had Stansted in mind, but that's almost as busy as LGW some days. I think what finally knocked it on the head for this concept was The Virgin A340 with the hung MLG on 27L at LHR. There wasn't an issue about it's ability to fly, but certainly as was shown it's ability to land. In this case, I believe landing at Heathrow was the right thing to do, all the RFFS on tap etc even though it meant complete chaos for 48 hours and knock-on for days and days. I'm not sure that 'Message A' even exists in MATS part I or II any more.

I think 'Mesage A' was partly a beancounter thing but also from our point of view an Ops desire to keep the show on the road and the runway open.

TheOddOne

[Jetscream 32]

I will never forget Tims answer in the V340 when they asked hime to div to MSE with the hung gear...... firm but polite.....!!!:E

[False Capture]

Jetscream 32,

So what did he say?:confused: