747 Crash At Brussels
Join Date: Sep 2007
Location: Brussels
Posts: 145
Likes: 0
Received 0 Likes
on
0 Posts
The report is not yet published.
It will be here :
Service public fédéral Mobilité et Transports - Intranet FR
Go to "Air", then "Rapports d'enquête accidents aériens"
The reports are in English.
It will be here :
Service public fédéral Mobilité et Transports - Intranet FR
Go to "Air", then "Rapports d'enquête accidents aériens"
The reports are in English.
Join Date: May 2004
Location: Bear Island
Posts: 598
Likes: 0
Received 0 Likes
on
0 Posts
V1 vs V1
Core developing subject here is whether it is an option to abort after the V1 we accept as being the go/no go.
We are trained that V1 means go go go .. fly the aircraft, get out of the danger zone, accelerate, go to after takeoff / climb / abnormal /emergency checklists, and use the copious amounts of fuel on board to rationalise the next decisions using FORDIC or the like as a guide to an agreed set of subsequent actions... it works.
That is a reliable set of options under 99.9% of circumstances that most pilots will face in their entire career.
The remaining 0.1% of everyone's career distills to a very minor possible percentage.. ergo, follow the procedures !
We cannot be trained for that infinitesimal chance, if we were, it would de-program us from responding to a more likely set of occurrences... result would be more over-runs, and quite possibly more fatalities.
BUT ..is there something in the idea that when one is flying an airframe full of freight, that one knows or feels that saving one selves in an lower energy overrun situation is preferable to a high energy and unsustainable situation once airborne ?
I did once have a grossly overloaded aircraft thanks to the Royal Mail getting confused between pounds and kilos .. so many moons ago that all I can remember was chronic pitch instability and a marked reluctance to climb, it did however concentrate the mind somewhat.
Pallets and freight can shift, or its placement can be very incorrectly planned whilst pax generally do not vary to the same degree.
The crisis in confidence becomes where do you actually discover the problem flying freight ? well how about V1 and it's not just a cozy cut like in the sim.
My understanding is that there were performance planning rather than load planning issues here .. but in terms of psyche ?
TR
We are trained that V1 means go go go .. fly the aircraft, get out of the danger zone, accelerate, go to after takeoff / climb / abnormal /emergency checklists, and use the copious amounts of fuel on board to rationalise the next decisions using FORDIC or the like as a guide to an agreed set of subsequent actions... it works.
That is a reliable set of options under 99.9% of circumstances that most pilots will face in their entire career.
The remaining 0.1% of everyone's career distills to a very minor possible percentage.. ergo, follow the procedures !
We cannot be trained for that infinitesimal chance, if we were, it would de-program us from responding to a more likely set of occurrences... result would be more over-runs, and quite possibly more fatalities.
BUT ..is there something in the idea that when one is flying an airframe full of freight, that one knows or feels that saving one selves in an lower energy overrun situation is preferable to a high energy and unsustainable situation once airborne ?
I did once have a grossly overloaded aircraft thanks to the Royal Mail getting confused between pounds and kilos .. so many moons ago that all I can remember was chronic pitch instability and a marked reluctance to climb, it did however concentrate the mind somewhat.
Pallets and freight can shift, or its placement can be very incorrectly planned whilst pax generally do not vary to the same degree.
The crisis in confidence becomes where do you actually discover the problem flying freight ? well how about V1 and it's not just a cozy cut like in the sim.
My understanding is that there were performance planning rather than load planning issues here .. but in terms of psyche ?
TR
Join Date: May 1999
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
All the old footle tootle about V1.
Fact is, the TO data V1 generally assumes a balanced field. Most take offs, it is not a balanced field. So V1 will only be V1 when you are at max weight for that runway. (Yes yes I know - I am talking about the general case.)
Don't believe me? Look up V1 for max weight for any runway you are familiar with, then look up V1 at 3/4 that weight. Lo and behold, V1 at the lighter weight is less than the V1 at max weight.
You obviously require more runway to do an accelerate stop at a higher weight.
Stopping assumes the wheels and brakes and everything work as advertised. True. However, continueing makes a few assumptions too. The propeller has in fact feathered. The engine is still in it's mountings. The cowlings are attached as per when we taxied and nothing large is sticking through them. The gear has retracted, all of it, and the doors as well. The flaps are in the TO position both sides, and the leading edges ditto. Etc ad nauseum.
The point being, it is better to hit the overrun at fifty knots than the scenery up the road at two fifty.
You can easly stop right up to runway-limited V1, guys, no troubles at all. Just don't stuff about. The engineers and the test pilots have got it right.
Fact is, the TO data V1 generally assumes a balanced field. Most take offs, it is not a balanced field. So V1 will only be V1 when you are at max weight for that runway. (Yes yes I know - I am talking about the general case.)
Don't believe me? Look up V1 for max weight for any runway you are familiar with, then look up V1 at 3/4 that weight. Lo and behold, V1 at the lighter weight is less than the V1 at max weight.
You obviously require more runway to do an accelerate stop at a higher weight.
Stopping assumes the wheels and brakes and everything work as advertised. True. However, continueing makes a few assumptions too. The propeller has in fact feathered. The engine is still in it's mountings. The cowlings are attached as per when we taxied and nothing large is sticking through them. The gear has retracted, all of it, and the doors as well. The flaps are in the TO position both sides, and the leading edges ditto. Etc ad nauseum.
The point being, it is better to hit the overrun at fifty knots than the scenery up the road at two fifty.
You can easly stop right up to runway-limited V1, guys, no troubles at all. Just don't stuff about. The engineers and the test pilots have got it right.
Join Date: May 2001
Location: UK
Posts: 71
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Accident Report
3.2. Cause and contributing factors.
The accident was caused by the decision to Reject the Take-Off 12 knots
after passing V1 speed.
The following factors contributed to the accident;
o Engine Nr 3 experienced a bird strike, causing it to stall. This
phenomenon was accompanied by a loud bang, noticed by the crew.
o The aircraft line up at the B1 intersection although the take-off
parameters were computed with the full length of the runway.
o The situational awareness of the crew,
o Less than maximum use of deceleration devices.
o Although the RESA conforms to the minimum ICAO requirement, it
does not conform to the ICAO recommendation for length.
The accident was caused by the decision to Reject the Take-Off 12 knots
after passing V1 speed.
The following factors contributed to the accident;
o Engine Nr 3 experienced a bird strike, causing it to stall. This
phenomenon was accompanied by a loud bang, noticed by the crew.
o The aircraft line up at the B1 intersection although the take-off
parameters were computed with the full length of the runway.
o The situational awareness of the crew,
o Less than maximum use of deceleration devices.
o Although the RESA conforms to the minimum ICAO requirement, it
does not conform to the ICAO recommendation for length.
In a nutshell, after a birdstrike on #3, Capt rejected 12 knots after V1 with not a great deal of runway left and nobody applied spoilers or reverse thrust.
