Post-V1 abort after bird-strike destroyed Kalitta 747F
12-25-2008, 07:55 AM
#21
Gets Weekends Off
Joined APC: Aug 2006
Posts: 3,931
Talking about the future...Not any previous accident.....
In a bad situation I hope I make the choice to stop above V1 if it is THE choice required to save the day. I'm assuming the situation is clear enough make that choice...It may not be.
I know there will be lots of folks to answer to so that choice will be very difficult indeed.
In a bad situation I hope I make the choice to stop above V1 if it is THE choice required to save the day. I'm assuming the situation is clear enough make that choice...It may not be.
I know there will be lots of folks to answer to so that choice will be very difficult indeed.
12-25-2008, 08:01 AM
#22
Permanent Reserve
Joined APC: Aug 2007
Posts: 1,677
Originally Posted by AerisArmis
And I will point out to you that, with the exception of one guys asking an unanswered question of a block rep, none of the subsequent posts were about, nor mentioned FedEx. So what exactly is your beef? That?
You can thank Albie (post #20, paragraph 1-2) for weakening your argument.
No beef, just an observation. This is not the crud table at the O-club -
no need to defend your "turf".
All I'm saying, is start a new thread, rather than hijack an existing one.
It doesn't cost anything, which should be of note to all you captains.
Merry Christmas and Happy Hanukkah!!!
12-25-2008, 08:20 AM
#23
Gets Weekends Off
Joined APC: Sep 2006
Position: In the Purple Haze
Posts: 321
Originally Posted by Albief15
Whale....I remember reading in ground school about the fact that just about all the jets that have continued past V1 would have been better off. Can you think of any (rare) examples where the opposite was the case? How about any of you flex/pro instructors?
So...back to whale and you other smart guys who've been flying these big beasts a lot longer than me...I'm interested in your thougts on the go/no go decisions.....
So...back to whale and you other smart guys who've been flying these big beasts a lot longer than me...I'm interested in your thougts on the go/no go decisions.....
Good to hear from you! Merry Christmas my friend... I don't know of any aircraft that has rejected after V1 and had a positive outcome vs. dealing with the situtation in the air and returning to the airport or alternate.
V1 is simply that: The speed at which the decision is made to continue or reject. There is no grey area regarding this. V1 speed takes into account many factors that I previously described. The heavier the aircraft the more important due to mass; V1/VR speeds are likely to have a wider spread as the aircraft reaches MGTW. If the reject occurs after V1, the chances of safely stopping are nil. As in the previous post, the crew rejected 8 seconds after V1; that is just wrong and this crew will most likely be held accountable.
Windshear scenarios are probably the worst situations where a pilot would choose to reject but according to flight testing, and numerous data recovered from accident scenes the only way to reject is below V1; at V1 you go! In a situation with windshear, it is recommended that you do not rotate until the last 2000' so that you can gain additional a/s when the windshear is encountered. However, situations like this are not likely to occur in advanced aircraft now with the aids such as predictive w/s, field Doppler radar and PIREP's from other pilots. The Captain must use all available information in the decision as to takeoff or wait. But V1 is still V1; the speed at which the aircraft will reject or continue the takeoff roll.
Whale
12-25-2008, 08:37 AM
#24
Gets Weekends Off
Joined APC: Jun 2006
Position: C-172 FO
Posts: 468
Originally Posted by MD10PLT
I'm still trying to get my hand around this civilian TOLD. In the AF we had both a decision speed and a refusal speed. Typically the decision speed meant just that--go or no-go, but the refusal speed was the speed you could accelerate to and still stop by the end of the runway. Quite often the RS was well above DS, giving a guy the option of aborting above DS (had to be a really good reason).
Doesn't look like the civilian world has anything like a RS, it all seems to be calculated based on what is the max TOGW for a given runway and critical engine failure speed. Wonder if a RS would be good to know.
Doesn't look like the civilian world has anything like a RS, it all seems to be calculated based on what is the max TOGW for a given runway and critical engine failure speed. Wonder if a RS would be good to know.
V1 can be either a Decision Speed or a Refusal Speed. If the TOGW equals MTOGW limited by Runway (As referred in the civilian sector), than it is in fact a refusal speed (speed upon which an acft can accelerate, loose an engine, and either abort or continue the takeoff within the confines of the runway) not to be greater than max braking or tire limit speed, and not less than ground minimum control speed.
In the case where TOGW exceeds MTOGW limited by runway, FAR's say no takeoff is allowed.
In the last case where TOGW is less than MTOGW limited by runway. V1 is defined by your company, a low number favors brakes and repair, a higher number favors pilots as they are USUALLY go minded. I hope this last one is not confusing. It is a safe scenario and the FAA approves.
Another thing I've noticed lately, is that everyone wants to GO all the time without regard for VMCG or what loosing an engine does to your takeoff ground roll (big increase) so I've heard a lot of pilots define there own V1 where they say "above 100 knots we take it airborne regardless of what the problem is" - This is a flawed approach.
Now Kallitta did the exact opposite of this in aborting past V1.
12-25-2008, 09:05 AM
#25
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Joined APC: Aug 2006
Posts: 3,931
Originally Posted by Whale Pilot
I don't know of any aircraft that has rejected after V1 and had a positive outcome vs. dealing with the situtation in the air and returning to the airport or alternate.
V1 is simply that: The speed at which the decision is made to continue or reject. There is no grey area regarding this. V1 speed takes into account many factors that I previously described. The heavier the aircraft the more important due to mass; V1/VR speeds are likely to have a wider spread as the aircraft reaches MGTW.
If the reject occurs after V1, the chances of safely stopping are nil.
As in the previous post, the crew rejected 8 seconds after V1; that is just wrong and this crew will most likely be held accountable.
Windshear scenarios are probably the worst situations where a pilot would choose to reject but according to flight testing, and numerous data recovered from accident scenes the only way to reject is below V1; at V1 you go! In a situation with windshear, it is recommended that you do not rotate until the last 2000' so that you can gain additional a/s when the windshear is encountered. However, situations like this are not likely to occur in advanced aircraft now with the aids such as predictive w/s, field Doppler radar and PIREP's from other pilots. The Captain must use all available information in the decision as to takeoff or wait. But V1 is still V1; the speed at which the aircraft will reject or continue the takeoff roll.
Whale
V1 is simply that: The speed at which the decision is made to continue or reject. There is no grey area regarding this. V1 speed takes into account many factors that I previously described. The heavier the aircraft the more important due to mass; V1/VR speeds are likely to have a wider spread as the aircraft reaches MGTW.
If the reject occurs after V1, the chances of safely stopping are nil.
As in the previous post, the crew rejected 8 seconds after V1; that is just wrong and this crew will most likely be held accountable.
Windshear scenarios are probably the worst situations where a pilot would choose to reject but according to flight testing, and numerous data recovered from accident scenes the only way to reject is below V1; at V1 you go! In a situation with windshear, it is recommended that you do not rotate until the last 2000' so that you can gain additional a/s when the windshear is encountered. However, situations like this are not likely to occur in advanced aircraft now with the aids such as predictive w/s, field Doppler radar and PIREP's from other pilots. The Captain must use all available information in the decision as to takeoff or wait. But V1 is still V1; the speed at which the aircraft will reject or continue the takeoff roll.
Whale
How 'bout accidents where the crew continued, legally mind you, and subsequently crashed when they could have stopped??
I admit standardization and simplicity is important, in both the method and terminology. So important that the system as implemented will save lives and is superior. No argument there. You are correct, there is no grey area in that system. Following the rules will in almost all cases save lives and equipment.
But you've continued further and made more absolute statements. No methodology is perfect in all situations. There is a compromise in certain conditions.
In all likelihood, modern pilots will never have a situation that encourages a stop above V1. So the point is probably moot. But that does not mean, for example, a 757 on a 12K runway at low elevation in cool weather can't stop above V1 and stop safely.
Never say never.
Not worth shooting me on this....I am just the messenger...Unless you can't resist.
I know high speed rejects are dangerous.
I'm not talking about the typical situations our system targets.
Just giving thought to a once in a lifetime bad event.
Last edited by Gunter; 12-25-2008 at 09:30 AM.
12-25-2008, 09:20 AM
#27
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Joined APC: Sep 2006
Position: Retired
Posts: 3,717
Originally Posted by Gunter
How 'bout accidents where the crew continued, legally mind you, and subsequently crashed when they could have stopped??
I admit standardization is important, in both the method and terminology. So important that the system as implemented will save lives and is superior. No argument there. You are correct, there is no grey area in that system. Following the rules will in almost all cases save lives and equipment.
But you've continued further and made more absolute statements. No methodology is perfect in all situations. There is a compromise in certain conditions.
In all likelihood, modern pilots will never have a situation that encourages a stop above V1. So the point is probably moot. But that does not mean, for example, a 757 on a 12K runway at low elevation in cool weather can't stop above V1 and stop safely.
Never say never.
I admit standardization is important, in both the method and terminology. So important that the system as implemented will save lives and is superior. No argument there. You are correct, there is no grey area in that system. Following the rules will in almost all cases save lives and equipment.
But you've continued further and made more absolute statements. No methodology is perfect in all situations. There is a compromise in certain conditions.
In all likelihood, modern pilots will never have a situation that encourages a stop above V1. So the point is probably moot. But that does not mean, for example, a 757 on a 12K runway at low elevation in cool weather can't stop above V1 and stop safely.
Never say never.
We're taught NEVER make the decision to abort after V1. In the simulator, if you do it, you will surly end up off the end of the runway, and I don't care if you're an empty MD-11 or Airbus, both of which have great auto-brakes and powerful spoilers/reversers. You will end up off the end, if for no other reason than the sim instructor wants to make the point that you NEVER abort after V1. Having said that, as an example, if you were flying an A-300 and after V1 you lost both engines, well...... you'd probably try for a stop, and rightly so. But, in a "normal" situation, with at least one engine performing correctly, it's best to get it in the air and sort it out then. "Modern" pilots, who have gone through a "modern" flight school, will probably NEVER make the decision to abort above V1, in a "normal" situation. Thankfully.
JJ
And by the way, Merry Christmas.
12-25-2008, 09:21 AM
#28
Retired Doug herder
Joined APC: Mar 2005
Position: Former DC8 73 Capt DHLAirways/Astar. Retired
Posts: 424
I agree with Whale. In Transport Category jets, prior to V1, you can stop. After V1, you go. Period. Especially in Heavy jets. If you begin to deviate from SOP with a crew, it is going to cause confusion and a lack of coordinated action in the cockpit. There are very few things that are going to bring a Heavy jet down if you decide to keep going after V1, get airborne, clean it up, deal with it, and come back around and land in an orderly fashion. I'm glad no one was injured, but I'm really scratching my head over why they waited so long after V1 to decide to stop, then when they did, they didn't deploy the reversers or spoilers? (And yes, I know that accel/stop is not predicated on use of reversers. But obviously you want everything going for you that you can.) There isn't a lot of room for overrun at EBBR on any runway. They had to know they would go off the end and in the ditch...
12-25-2008, 09:29 AM
#29
Gets Weekends Off
Joined APC: Jul 2007
Position: Gear Monkey
Posts: 3,191
I agree there are no "absolutes".
In my years of doing very short field ops in austere environments, I learned the Capt must carefully consider what "monsters" lie just off the runway and plan/brief accordingly.
....is the overrun and beyond, clear, long, with few hazards? .
....or, as someone else mentioned, like Anderson (Guam) where there's a 200 ft drop off into the ocean?
...once airborne, is the terrain flat --- allowing plenty of time to accelerate, clean up and climb?
...or, terrain that would require immediate manuevering, and perhaps even a turn into a dead engine(s).
How does Vmcg apply in your jet in terms of accelearting towards a flying airspeed with an outboard inoperable.
There are scenarios in the C-130 community where you brief going, but also brief that you are going to slightly retard a symmeterical good engine (to the failed one) to allow the plane to maintain runway centerline while doing so.
That's highly counterintuitive at first --- and very, very important to brief ahead of time, or the CoPilot and FE will be very confused that your saying "we're going", but then pulling back one of the good engines.
While keeping the jet on the prepared surface (either on takeoff or a subsequent emergency landing) is always the desired outcome, one could find themselves in a case where neither is possible --- and then they have to chose which "monster" they would rather face, and at what speed/altitude they want to face it.
In my years of doing very short field ops in austere environments, I learned the Capt must carefully consider what "monsters" lie just off the runway and plan/brief accordingly.
....is the overrun and beyond, clear, long, with few hazards? .
....or, as someone else mentioned, like Anderson (Guam) where there's a 200 ft drop off into the ocean?
...once airborne, is the terrain flat --- allowing plenty of time to accelerate, clean up and climb?
...or, terrain that would require immediate manuevering, and perhaps even a turn into a dead engine(s).
How does Vmcg apply in your jet in terms of accelearting towards a flying airspeed with an outboard inoperable.
There are scenarios in the C-130 community where you brief going, but also brief that you are going to slightly retard a symmeterical good engine (to the failed one) to allow the plane to maintain runway centerline while doing so.
That's highly counterintuitive at first --- and very, very important to brief ahead of time, or the CoPilot and FE will be very confused that your saying "we're going", but then pulling back one of the good engines.
While keeping the jet on the prepared surface (either on takeoff or a subsequent emergency landing) is always the desired outcome, one could find themselves in a case where neither is possible --- and then they have to chose which "monster" they would rather face, and at what speed/altitude they want to face it.
12-25-2008, 10:13 AM
#30
Gets Weekends Off
Joined APC: Nov 2005
Position: 777 FO
Posts: 931
[QUOTE=DLax85;525270]
There are scenarios in the C-130 community where you brief going, but also brief that you are going to slightly retard a symmeterical good engine (to the failed one) to allow the plane to maintain runway centerline while doing so.
That's highly counterintuitive at first --- and very, very important to brief ahead of time, or the CoPilot and FE will be very confused that your saying "we're going", but then pulling back one of the good engines.
QUOTE]
I know that technique is used, but I wouldn't let folks brief it up as a plan. If you absolutely NEED to reduce the opposite outboard to maintain directional control, OK, but keep in mind you have reduced power, like you said. Vmca in the Herc is defined as max power on all operating engines with max rudder deflection. Once you reduce the power on the opposite engine, Vmca is no longer valid and you're not really sure of what you've got. If spaghetti leg guys couldn't get enough rudder in there, then you may have to reduce an outboard engine or get the other pilot to help with the rudder - otherwise keep it at max power, IMO. Reducing power in that situation could just allow you to crash straight ahead.
There are scenarios in the C-130 community where you brief going, but also brief that you are going to slightly retard a symmeterical good engine (to the failed one) to allow the plane to maintain runway centerline while doing so.
That's highly counterintuitive at first --- and very, very important to brief ahead of time, or the CoPilot and FE will be very confused that your saying "we're going", but then pulling back one of the good engines.
QUOTE]
I know that technique is used, but I wouldn't let folks brief it up as a plan. If you absolutely NEED to reduce the opposite outboard to maintain directional control, OK, but keep in mind you have reduced power, like you said. Vmca in the Herc is defined as max power on all operating engines with max rudder deflection. Once you reduce the power on the opposite engine, Vmca is no longer valid and you're not really sure of what you've got. If spaghetti leg guys couldn't get enough rudder in there, then you may have to reduce an outboard engine or get the other pilot to help with the rudder - otherwise keep it at max power, IMO. Reducing power in that situation could just allow you to crash straight ahead.
