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-   -   Citation Incident at Leeds (https://www.pprune.org/biz-jets-ag-flying-ga-etc/417506-citation-incident-leeds.html)

Daifly 7th Jun 2010 19:29

Citation Incident at Leeds
 
Anyone know any more?

BBC News - Two rescued as aircraft overshoots Leeds airport runway

doublesix 7th Jun 2010 22:03

CLDVRVR AND REDSNAIL

I can't see the relevance of your sarcastic comments. Please explain?

Chinchilla.612 7th Jun 2010 22:17

I used to fly that aeroplane, and know the owner........afraid I don't see the same funny side you guys seem to about this :=

baron_rouge 7th Jun 2010 22:48

I witnessed the incident from the Multiflight side of the airfield and it was definitely no laughing matter. The Citation was just airborne when the decision was made to abort so was travelling at around Vr and the pilot immediately put down on the runway (14). I'm not going to speculate on why he aborted rather than go around as only the pilot knows the full circumstances and it's a matter for the AAIB. We all know that a good landing is one you can walk away from so the good news is that nobody was injured.

DX Wombat 7th Jun 2010 23:11

Engine fire - one person I spoke to said flames were clearly visible coming from the aircraft and no, I didn't put the idea into his head, he volunteered the information as he had seen it happen.* Lots of bits of debris all over the 34 threshold. Aircraft now roosting in a tree in the 32 undershoot. I'm really pleased the two on board got out safely.
* Baron-rouge - he probably had a better view than you did as he was parked on the elevated section of old road next to the cemetery at the end of 32.

fastjet45 8th Jun 2010 07:46


"I witnessed the incident from the Multiflight side of the airfield and it was definitely no laughing matter. The Citation was just airborne when the decision was made to abort so was travelling at around Vr and the pilot immediately put down on the runway (14)."
Hate to say it; but if he was airborne and therefore past V1 why on earth did he consider landing again, wonder what was briefed prior to departure? were was he trained to land back on the runway after V1? :eek:

BigNumber 8th Jun 2010 08:08

I don't think it our place to assess or make a 'morning coffee' analysis of the situation the crew faced.

Only the crew can possibly know the situation that they faced. I'm sure they will let the relevant authority know in time.

I am certain that there will be a compelling reason that they followed their course of action. Frankly none of us know anything at all other than a 'hear say' interpretation of what might have been half seen perhaps.

Neon Circuits 8th Jun 2010 08:14

#2 and #3, use of so called 'comedy' is not appropriate, funny or welcome.

Reject after V1/VR? They were probably using the same value for both, perhaps they considered that they were light, on fire, plenty of runway? Depends if they rotated, all speculation please wait for AAIB.

Uncle Wiggily 8th Jun 2010 08:47


got to be a consideration if light, on fire, plenty of runway
Maybe I'm not reading your post correctly, but after V1 is reached there is no decision to be made because you are getting airborne regardless. Prior to V1 you can abort and safely bring the aircraft to a stop, but to say to yourself after V1, "gee it still looks like we have more than enough runway, lets disregard that V1 call and keep the jet on the runway" defeats the whole purpose of assigning a V1 speed to your takeoff/data calculations. I can't imagine something written like that in this comapny's SOP's, lol.

Anyhow, I'm sure I misread your post.

bingofuel 8th Jun 2010 09:07

There was an incident many years ago when an HS748 disgorged the right hand turbine blades through the wing just after take off, resulting in an uncontrolled fire on the wing.

The Capt put it down on the remaining runway in front of him.

If I recall correctly, the investigation concluded that had he tried to fly a circuit to land the wing would have burned through and detached. It was concluded his actions saved lives.

There is always an exception to the rule.

Lets stop the speculation and wait for some FACTS.

Trim Stab 8th Jun 2010 09:19


Maybe I'm not reading your post correctly, but after V1 is reached there is no decision to be made because you are getting airborne regardless. Prior to V1 you can abort and safely bring the aircraft to a stop, but to say to yourself after V1, "gee it still looks like we have more than enough runway, lets disregard that V1 call and keep the jet on the runway" defeats the whole purpose of assigning a V1 speed to your takeoff/data calculations.
The FMS's that I have used on Citations (Collins 3000 and UNS-1) both calculate V1 and Vr by working out what values give a balanced take off for the aircraft weight, temps and pressures. The TODA is not a parameter that is used in the calculation. If departing from a very long runway, it is thus technically possible to abort after V1 and land back on the runway.

Uncle Wiggily 8th Jun 2010 09:51

TrimStab:

Interesting. So, what was your procedure/decision once V1 was announced?

Thanks

fastjet45 8th Jun 2010 09:58


The FMS's that I have used on Citations (Collins 3000 and UNS-1) both calculate V1 and Vr by working out what values give a balanced take off for the aircraft weight, temps and pressures. The TODA is not a parameter that is used in the calculation. If departing from a very long runway, it is thus technically possible to abort after V1 and land back on the runway.
:eek: So after V1 then VR how much runway have you used whilst airborne? how much runway is left? how much runway do you need to land and stop depending on how fast you are now going? I think you need to study performance again! of course TODA is a parameter V1 on a performance A aircraft is there for a reason; accelerate to and stop in the remaining distance or exceed V1 and continue to get airborne safely in the remaining distance to 35ft.

CL300 8th Jun 2010 10:20


To best of my knowledge and information given by training providers and manufactures there has never been an instance were it was necessary to make such a decision due to an engine fire on a multi engined civil jet aircraft, they are designed to fly after such a failure.
Falcon 20 in LBG, Concorde at CDG, the only 2 that spring to my mind...
It is generally safer to take the problem in the air... uncontained fire/engine failure is not anywhere in certification...This is one of the reason , there is still pilots in flightdeck..

hawker750 8th Jun 2010 10:23

It is very clear that nobody on this thread knows much about what V1 is. V1 can be a range of speeds depending on what you want it to tell you. Most small jets use V1=VR because it is convenient. All this tells you is that at V1 you can stop or go safely. Most small jets will use the same speeds (V1/VR) regardless of whether they are taking off from a 6000 ft runway or a 16000 ft runway, so in a sense TODA does not come into the equation. It only comes in if the runway length is limiting and the MTOW has to be regulated.
As to whether it is safe to land back after VR or abhorts after V1, the V1 speed will not tell you this information, only that the plane will safely continue. Great research has gone into this subject and concluded in no uncertain fashion that stopping close to V1 is not an advisable course of action. Why people continue to do so is a mystery, in light jets probably a throw back to light piston engine flying when flying on one (or nil) engines was not a very heatlthy thing to do close to the ground.
May I suggest similar to the citation ex Biggin where proper procedures and SOP's were not in place or followed?

Chinchilla.612 8th Jun 2010 10:31

Fastjet45,
I think what Trim Stab was getting at was that the V speeds calculated from the FMS on that aircraft type do not account for runway length (except in so much as highlighting if the TODR is greater than the TODA). If you have a particularly long runway, you could in theory still have room to land ahead......but personally I would not be keen to do so. I do not get the impression Trim Stab was suggesting he would abort after V1, just that at the right airport it could be possible.

To answer your other points at Vr they should have used somewhere around 3000' of runway (rough figure). Once airborne the remaining runway is decreasing at a little over 200fps. If fully configured for landing (which they wouldn't be) it should be possible to stop in around 3000-3500' of runway. If I remember rightly, Leeds is a little over 7000' in length? So there could be something like 2 or 3 seconds while airborne to reconfigure if you wanted to land ahead successfully at Leeds in that aircraft?
Only approximate figures and depends how high they went before trying to land again, so please don't get too fixated on them.
Chinchilla.

Trim Stab 8th Jun 2010 10:33


http://images.ibsrv.net/ibsrv/res/sr...milies/eek.gif So after V1 then VR how much runway have you used whilst airborne? how much runway is left? how much runway do you need to land and stop depending on how fast you are now going? I think you need to study performance again! of course TODA is a parameter V1 on a performance A aircraft is there for a reason; accelerate to and stop in the remaining distance or exceed V1 and continue to get airborne safely in the remaining distance to 35ft
You should read my post again - I said "technically" it is possible if the runway is long enough. I did not say that it was an advisable procedure. Neither did I claim that TODA is not part of a performance calculation - I merely pointed out that Citation FMS's that I have used do not use it in their calculations.

On a VLJ not many runways are limiting and there are plenty of runways where you could actually get airborne, and still safely land back on the runway. At somewhere like Ramonskoye (18000ft runway) you could probably do it three times in a light CJ3.

fastjet45 8th Jun 2010 11:16


On a VLJ not many runways are limiting and there are plenty of runways where you could actually get airborne, and still safely land back on the runway. At somewhere like Ramonskoye (18000ft runway) you could probably do it three times in a light CJ3.
Trim Stab

The whole point of my previous arguments: "probably do it three times"

V1 is a calculated figure, along with all the other performance criteria required before departure so that in the event of such a situation the crew have the best chance possible of executing the correct procedure instead of guessing. SOP's :ugh:

Trim Stab 8th Jun 2010 11:25

Really? So if you took off at Ramskoye in a CJ3, and had an engine fire just after V1, you would continue, and try to climb and do a circuit to return to the threshold, even though you had some 17000ft of runway directly in front of you?

As I said, the FMS's on the CJ do not take into account the TODA, and there are occasions where, with a bit of experience, you can take V1=Vr.

fastjet45 8th Jun 2010 11:48

Trim Stab


Really? So if you took off at Ramskoye in a CJ3, and had an engine fire just after V1, you would continue, and try to climb and do a circuit to return to the threshold, even though you had some 17000ft of runway directly in front of you?
Yes I would;
Because at that moment in time I and my crew would be in a position that we have been trained for, we would be following the manufactures SOP, we would have ensured that all the performance parameters had been met to operate safely from V1 to a landing, we would be in a position to deal safely with the emergency and inform ATC in a timely manor to ensure emergency services were at the correct point to meet us, we would have had time to brief the passengers accordingly, shall I go on?


As I said, the FMS's on the CJ do not take into account the TODA, and there are occasions where, with a bit of experience, you can take V1=Vr.
As I said before; how do you know if there is enough runway left, it depends how high you where, how fast you were going, what configuation you were in, do you brief such an event to your crew?
Were does a bit of experience start? and when do you become experienced enough to start guessing?


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