Air North Brasilia Crash in Darwin (Merged)
BSB, it want overeading. It was the minimum indicated airspeed as such on the indicator (actually is 40).CAIS or Calibrated IAS. OR
A FDR channel "error" brought over into the animation.
A FDR channel "error" brought over into the animation.
Moderator
Like the EMB120 animation, there is a large amount of left bank immediately before the LOC
Unless the AFM says different, one can presume that the book Vmca is based on 5 degrees favourable bank for any conventional multi.
Realworld Vmc ramps up rapidly (and not linearly) as bank reduces and then goes the "wrong" way. The departure can be much faster than that arising from just letting the speed slowly come back trying to maintain height.
Include both reducing speed and bank going away from 5 degrees favourable .. and one is in for a very rapid and unpleasant roller coaster ride ... albeit only for a very short time ...
Back near Vmc, one pegs 5 degrees favourable bank like one's life depends on it .. which very well may be the case.
If that means a concurrent descent, so be it .. better to belly in right way up than corkscrew into the ground, upside down nose first ... and, if caught out in the situation and faced with a departure, it may be necessary to reduce thrust on the operating motor(s) to reduce Vmc .. allowing control if not performance.
Unless the AFM says different, one can presume that the book Vmca is based on 5 degrees favourable bank for any conventional multi.
Realworld Vmc ramps up rapidly (and not linearly) as bank reduces and then goes the "wrong" way. The departure can be much faster than that arising from just letting the speed slowly come back trying to maintain height.
Include both reducing speed and bank going away from 5 degrees favourable .. and one is in for a very rapid and unpleasant roller coaster ride ... albeit only for a very short time ...
Back near Vmc, one pegs 5 degrees favourable bank like one's life depends on it .. which very well may be the case.
If that means a concurrent descent, so be it .. better to belly in right way up than corkscrew into the ground, upside down nose first ... and, if caught out in the situation and faced with a departure, it may be necessary to reduce thrust on the operating motor(s) to reduce Vmc .. allowing control if not performance.
Checkee pull nose up too high. Speed loss.
In other threads, we still have "experts" (Xsperts) advocating "simulating" engine failures by chopping the mixture in pistons, or turning the fuel off.
Just in the last three days, I was talking to a quite well known instructor/ATO ---- who had little or no understanding of the changes of Vmca, depending on the bank angle.
I guess we will continue with a steady stream of fatalities in EFATO training, until we catch up with the rest of the world ----- and teach commonsense training techniques, and not blind "compliance".
Tootle pip!!
PS: Re. "compliance", a former Darwin FOI is now Bankstown based.
Small but relevant column on Australian Aviation website
:
Airnorth crash highlights importance of simulators — ATSB | Australian Aviation Magazine
Not the ex-seneca FO from China Southern, he'll be re-writing the AGK syllabus next!
:Airnorth crash highlights importance of simulators — ATSB | Australian Aviation Magazine
PS: Re. "compliance", a former Darwin FOI is now Bankstown based.
Last edited by Sarcs; 25th Feb 2012 at 05:40.
Join Date: Jun 1999
Location: Australasia
Posts: 362
Likes: 0
Received 0 Likes
on
0 Posts
Vmca as published can be very misleading
Vmca is a static speed. It is established in testing with asymmetric power/thrust set by incremental decreases in speed until one of the limiting parameters is met.
Because it is static and determined from a higher initial speed, it has some direct relevance to the Queenair video of slowly bleeding off the speed until LOC occurs. Well and good.
However, there is no element that accounts for sudden engine failure, slow rudder reaction or existing bank angle. The speed at which one of the limiting parameters will be met in the dynamic case will be much higher than the published static figure. There may be little margin, if any, between the target V2 and the dynamic Vmin if you have a sudden failure just after liftoff or at the start of a go-around. And in those cases, the priority is on control before climb.
The propeller related issues of loss of blown lift and discing exacerbate the dynamic issues substantially - I nearly lost a Conquest some 12-14 knots above the published Vmca during a practice engine failure in the GA, despite quite minimal reaction time as I saw the initiation begin. It seemed to take forever for the full rudder and full aileron to stop the roll and yaw, let alone bring it back to a sensible place.
JT: I seem to remember that, while certification standards limit the bank angle to "no greater than 5 degrees", the optimum is around 3 degrees.
And as for the good old V2 issue: it is a target speed from below (ie when accelerating), it is not the best anything (just the lowest speed at which the OEM can meet the minimum certification gradient) and, if you have already got it, V2+10 to V2+15 gives a much better gradient.
Stay Alive,
Because it is static and determined from a higher initial speed, it has some direct relevance to the Queenair video of slowly bleeding off the speed until LOC occurs. Well and good.
However, there is no element that accounts for sudden engine failure, slow rudder reaction or existing bank angle. The speed at which one of the limiting parameters will be met in the dynamic case will be much higher than the published static figure. There may be little margin, if any, between the target V2 and the dynamic Vmin if you have a sudden failure just after liftoff or at the start of a go-around. And in those cases, the priority is on control before climb.
The propeller related issues of loss of blown lift and discing exacerbate the dynamic issues substantially - I nearly lost a Conquest some 12-14 knots above the published Vmca during a practice engine failure in the GA, despite quite minimal reaction time as I saw the initiation begin. It seemed to take forever for the full rudder and full aileron to stop the roll and yaw, let alone bring it back to a sensible place.
JT: I seem to remember that, while certification standards limit the bank angle to "no greater than 5 degrees", the optimum is around 3 degrees.
And as for the good old V2 issue: it is a target speed from below (ie when accelerating), it is not the best anything (just the lowest speed at which the OEM can meet the minimum certification gradient) and, if you have already got it, V2+10 to V2+15 gives a much better gradient.
Stay Alive,
And to add to that, it (Vmca) is interpolated from LOC events at higher altitudes because no-one is dumb enough to intentionally find out what it is at low altitude.
And as for the good old V2 issue: it is a target speed from below (ie when accelerating), it is not the best anything (just the lowest speed at which the OEM can meet the minimum certification gradient) and, if you have already got it, V2+10 to V2+15 gives a much better gradient.
The engine was failed at about V2 + 15 (+/- about 5 knots). I slowed the aircraft to VFS (VySE) which was in this particular aircraft V2 + 10, and maintained it. The FO started calling 'speed'. I replied 'checked'. Once through AA the checkie paused the sim and told me that he wanted to see me maintain V2.
I told him that I would only maintain V2 if I was slower than it, and needed to accelerate to achieve it. If I were faster than V2 I would maintain that speed up to VFS (VySE) and if I were faster than VFS, I'd reduce to VFS.
Well this didn't go down to well. I was subsequently berated and told that I was required to maintain V2 until AA as this was the certification requirements of 20.7.1b. I replied that V2 was the TOSS, not a target speed for climb. I.e the minimum speed you could safely maintain to remain in control of the aircraft. You'd be daft to slow to V2 if you already had a margin of speed above it and a positive climb gradient
Tuns out I was right.......but I had to take some heat from it.
Join Date: Sep 2007
Location: Oz
Posts: 55
Likes: 0
Received 0 Likes
on
0 Posts
This got me into a heated position with a check captain during a cyclic check.
The engine was failed at about V2 + 15 (+/- about 5 knots). I slowed the aircraft to VFS (VySE) which was in this particular aircraft V2 + 10, and maintained it. The FO started calling 'speed'. I replied 'checked'. Once through AA the checkie paused the sim and told me that he wanted to see me maintain V2.
I told him that I would only maintain V2 if I was slower than it, and needed to accelerate to achieve it. If I were faster than V2 I would maintain that speed up to VFS (VySE) and if I were faster than VFS, I'd reduce to VFS.
Well this didn't go down to well. I was subsequently berated and told that I was required to maintain V2 until AA as this was the certification requirements of 20.7.1b. I replied that V2 was the TOSS, not a target speed for climb. I.e the minimum speed you could safely maintain to remain in control of the aircraft. You'd be daft to slow to V2 if you already had a margin of speed above it and a positive climb gradient
Tuns out I was right.......but I had to take some heat from it.
The engine was failed at about V2 + 15 (+/- about 5 knots). I slowed the aircraft to VFS (VySE) which was in this particular aircraft V2 + 10, and maintained it. The FO started calling 'speed'. I replied 'checked'. Once through AA the checkie paused the sim and told me that he wanted to see me maintain V2.
I told him that I would only maintain V2 if I was slower than it, and needed to accelerate to achieve it. If I were faster than V2 I would maintain that speed up to VFS (VySE) and if I were faster than VFS, I'd reduce to VFS.
Well this didn't go down to well. I was subsequently berated and told that I was required to maintain V2 until AA as this was the certification requirements of 20.7.1b. I replied that V2 was the TOSS, not a target speed for climb. I.e the minimum speed you could safely maintain to remain in control of the aircraft. You'd be daft to slow to V2 if you already had a margin of speed above it and a positive climb gradient
Tuns out I was right.......but I had to take some heat from it.
I replied that V2 was the TOSS, not a target speed for climb.
V2 means the initial climb out speed which is not less than the take-off
safety speed, it is not TOSS!!
safety speed, it is not TOSS!!
Unfortunatley I am with your checkie on this one.
Green Goblin's take on it is exactly the same as mine, and what I would have done if the engine quit at a speed above V2. Mr Boeing says if you are still in the second segment climb and already have speed greater than V2 when an engine quits, maintain that speed to the usual acceleration height etc etc. I don't have the manual with me, but seem to recall anything up to V2 + 15 is OK, assuming you already have that speed at time of failure. If you are faster, slowly come back to V2+15, by delaying the reduction of pitch (i.e. don't increase pitch just to get a lower speed).
What about 'improved climb' graphs and the performance benefits of climbing out above V2 min? V2 min is indeed sacred, but only if you haven't yet got it, you must get to it to have any guarantee of climb performance with an engine out, and of course to provide margin above Vmca. Unless the failure is introduced at V1 or at latest Vr, chances are the aircraft will be through V2 by the time the effects of a failure kick in. If you are already above V2, you can and usually should stay with what you have.
Engine failures in training should be introduced at various speeds - not just V1 or Vr - to reinforce this allowable flexibility. When training in real aircraft (as opposed to simulators) appropriate buffers should be built in - like assuming higher weights and V speeds for those higher weights.
What about 'improved climb' graphs and the performance benefits of climbing out above V2 min? V2 min is indeed sacred, but only if you haven't yet got it, you must get to it to have any guarantee of climb performance with an engine out, and of course to provide margin above Vmca. Unless the failure is introduced at V1 or at latest Vr, chances are the aircraft will be through V2 by the time the effects of a failure kick in. If you are already above V2, you can and usually should stay with what you have.
Engine failures in training should be introduced at various speeds - not just V1 or Vr - to reinforce this allowable flexibility. When training in real aircraft (as opposed to simulators) appropriate buffers should be built in - like assuming higher weights and V speeds for those higher weights.
Last edited by Mach E Avelli; 26th Feb 2012 at 07:11.
Join Date: Aug 2010
Location: Round the corner
Age: 61
Posts: 98
Likes: 0
Received 5 Likes
on
3 Posts
Guys, at the end of the day take the hypothetical plumb from your mouths and take a minute to reflect on the fact that the two aviators involved were, believe it or not, just like you.
How about a bit of respect. Does an extended net postmortem achive anything?
This industry has definately, definately changed.
Moderators?
How about a bit of respect. Does an extended net postmortem achive anything?
This industry has definately, definately changed.
Moderators?
Quote:
This got me into a heated position with a check captain during a cyclic check.
The engine was failed at about V2 + 15 (+/- about 5 knots). I slowed the aircraft to VFS (VySE) which was in this particular aircraft V2 + 10, and maintained it. The FO started calling 'speed'. I replied 'checked'. Once through AA the checkie paused the sim and told me that he wanted to see me maintain V2.
I told him that I would only maintain V2 if I was slower than it, and needed to accelerate to achieve it. If I were faster than V2 I would maintain that speed up to VFS (VySE) and if I were faster than VFS, I'd reduce to VFS.
Well this didn't go down to well. I was subsequently berated and told that I was required to maintain V2 until AA as this was the certification requirements of 20.7.1b. I replied that V2 was the TOSS, not a target speed for climb. I.e the minimum speed you could safely maintain to remain in control of the aircraft. You'd be daft to slow to V2 if you already had a margin of speed above it and a positive climb gradient
Tuns out I was right.......but I had to take some heat from it.
Interesting theory GG, how do you go passing an IRT or prof check doing that?
Quote:
I replied that V2 was the TOSS, not a target speed for climb.
V2 means the initial climb out speed which is not less than the take-off
safety speed, it is not TOSS!!
Unfortunatley I am with your checkie on this one.
This got me into a heated position with a check captain during a cyclic check.
The engine was failed at about V2 + 15 (+/- about 5 knots). I slowed the aircraft to VFS (VySE) which was in this particular aircraft V2 + 10, and maintained it. The FO started calling 'speed'. I replied 'checked'. Once through AA the checkie paused the sim and told me that he wanted to see me maintain V2.
I told him that I would only maintain V2 if I was slower than it, and needed to accelerate to achieve it. If I were faster than V2 I would maintain that speed up to VFS (VySE) and if I were faster than VFS, I'd reduce to VFS.
Well this didn't go down to well. I was subsequently berated and told that I was required to maintain V2 until AA as this was the certification requirements of 20.7.1b. I replied that V2 was the TOSS, not a target speed for climb. I.e the minimum speed you could safely maintain to remain in control of the aircraft. You'd be daft to slow to V2 if you already had a margin of speed above it and a positive climb gradient
Tuns out I was right.......but I had to take some heat from it.
Interesting theory GG, how do you go passing an IRT or prof check doing that?
Quote:
I replied that V2 was the TOSS, not a target speed for climb.
V2 means the initial climb out speed which is not less than the take-off
safety speed, it is not TOSS!!
Unfortunatley I am with your checkie on this one.
Mr Boeing says if you are still in the second segment climb and already have speed greater than V2 when an engine quits, maintain that speed to the usual acceleration height etc etc.
Betaman,
With all due respect, your reply typifies what is wrong with the "compliance" approach to training and checking.
I am reminded of the vehement opposition of the AFAP, at the time, to offset tracking. That offset tracking would prevent collisions in the event of all too common ATC mistakes, was not in dispute.
The AFAP opposition was entirely based on the CAO detailing tracking standards, and the rather stupid argument that, if a pilot was offset tracking, he was not "complying" with the CAO.
Conceptually, The Green Goblin is spot on , but you want to haggle with definitions, when he wants to fly his aircraft in accordance with the AFM ----- which is also a legal requirement, so I'll see your CAO, and raise you a regulation, CAR 138 ---- non-compliance with which is a strict liability offense with up to a 50 point penalty.
What The GG described would, I am willing to bet,be in conformity with the AFM and the manufacturer's training manual for his aircraft.
However, far more important is the fact, obviously unknown to you (or GG's check pilot) that we dropped pulling the nose up to get back to V2, after the American Airlines DC-10 loss at Chicago, many years ago.
Obviously, minimum climb gradients must be achieved at the nominated V2, but the performance of most transport aircraft, these days, will meet CAO 20.7.1b at a speed anywhere between V2 and V2+25 or more, at the chosen T/O flap setting.
The whole lesson of Chicago was that, in the event of Engine Fire, Severe Damage or Separation, you don't reduce speed or change configuration until you have a damned good idea of the situation and possible outcome.
In the Chicago DC-10 accident, the aircraft was controllable at V2+10, the pilot flying reduced to V2, and everybody died.
As this accident happened something like 30 years ago, and all the Boeing and Douglas ( and, I think, Lockheed) AFMs were amended as a result of NTSB recommendations, taken up by the FAA ----- and very promptly actioned, I am pleased to say, by Qantas, which was not fazed by the "imperative of compliance", at the cost of potentially losing an aircraft.
As a very wise former Director of Aviation Safety at CASA (Leroy Keith) once said:
"A compliant organisation is not necessarily a safe organization , a non-compliant organisation is not necessarily an un-safe organisation".
The subtlety of this view ( particularly given the shambolic state of regulation and standards in Australia) is clearly lost on all too many in the Australian aviation industry, within and without CASA.
Tootle pip!!
With all due respect, your reply typifies what is wrong with the "compliance" approach to training and checking.
I am reminded of the vehement opposition of the AFAP, at the time, to offset tracking. That offset tracking would prevent collisions in the event of all too common ATC mistakes, was not in dispute.
The AFAP opposition was entirely based on the CAO detailing tracking standards, and the rather stupid argument that, if a pilot was offset tracking, he was not "complying" with the CAO.
Conceptually, The Green Goblin is spot on , but you want to haggle with definitions, when he wants to fly his aircraft in accordance with the AFM ----- which is also a legal requirement, so I'll see your CAO, and raise you a regulation, CAR 138 ---- non-compliance with which is a strict liability offense with up to a 50 point penalty.
What The GG described would, I am willing to bet,be in conformity with the AFM and the manufacturer's training manual for his aircraft.
However, far more important is the fact, obviously unknown to you (or GG's check pilot) that we dropped pulling the nose up to get back to V2, after the American Airlines DC-10 loss at Chicago, many years ago.
Obviously, minimum climb gradients must be achieved at the nominated V2, but the performance of most transport aircraft, these days, will meet CAO 20.7.1b at a speed anywhere between V2 and V2+25 or more, at the chosen T/O flap setting.
The whole lesson of Chicago was that, in the event of Engine Fire, Severe Damage or Separation, you don't reduce speed or change configuration until you have a damned good idea of the situation and possible outcome.
In the Chicago DC-10 accident, the aircraft was controllable at V2+10, the pilot flying reduced to V2, and everybody died.
As this accident happened something like 30 years ago, and all the Boeing and Douglas ( and, I think, Lockheed) AFMs were amended as a result of NTSB recommendations, taken up by the FAA ----- and very promptly actioned, I am pleased to say, by Qantas, which was not fazed by the "imperative of compliance", at the cost of potentially losing an aircraft.
As a very wise former Director of Aviation Safety at CASA (Leroy Keith) once said:
"A compliant organisation is not necessarily a safe organization , a non-compliant organisation is not necessarily an un-safe organisation".
The subtlety of this view ( particularly given the shambolic state of regulation and standards in Australia) is clearly lost on all too many in the Australian aviation industry, within and without CASA.
Tootle pip!!
Moderator
Some observations, if I may ...
demanding that the nose be pulled up to reduce to V2
archaic thinking .. as others have observed
Vmca is a static speed ... there is no element that accounts for sudden engine failure, slow rudder reaction or existing bank angle.
Not quite the case.
For instance, current FAR 25 Vmca test requirements can be reviewed at AC 25-7B starting page 102.
The usual Vmca workup starts with the static Vmca (cf the typical pilot Vmca demonstration exercise). After this figure is determined, dynamic Vmca checks are made to ensure that the final figure published in the AFM covers both cases.
The speed at which one of the limiting parameters will be met in the dynamic case will be much higher than the published static figure
Not necessarily so but is covered in the AFM figure as above.
or at the start of a go-around
Different figure to that for takeoff and is established during certification
It seemed to take forever for the full rudder and full aileron to stop the roll and yaw, let alone bring it back to a sensible place.
This is a common observation unless the pilot has been through the wringer in sim training with the result that reactions are instinctive.
For instance, I recall (quite fondly) one endorsement crew (initial command ex 744 F/O and intake F/O) on the 732 during a contract training engagement many years ago.
The initial command chap hadn't ever really got on top of takeoff engine failures and, initially, was very underconfident. Not a good situation for that stage of his career. We fixed that problem late one night when (on the sly) we took one programmed session and hammered failures .. the next session was a spare and the techs let us continue on so the time ended up totalling around 6 hours as I recall.
To cut a long story short we made extensive use of freeze and reposition to concentrate on the difficult bits for both guys, working our way back to min weight, aft CG, min speed schedule takeoffs with the failure (a very impressive modelling of an historical large bird impact FDR trace - ie catastrophic seizure). By the end of the session, both guys could handle the failure with continued takeoff tracking the opposite end LLZ .. just about with their eyes closed. They toddled off home dead tired but with very large swelled heads and the rest of the endorsement program went pretty smoothly ...
As this particular operator made very extensive use of overspeed takeoffs and, as far as I could determine, only used low speed schedules for ferry flights from one coastal aerodrome .. and did all their sim training for the overspeed case, my contract colleagues and I were rather concerned for obvious reasons.
During the occasional checking/renewal sessions, I took to introducing the lowspeed case in play time .. where the pilots were prepared to have a looksee at the problem.
In just about every case, those who had a go at the critical case .. cold ... did the Braz sequence .. the sim, of course, was frozen shortly after the departure. All were able to get on top of the failure with a bit of explanation and several practice runs.
The point was the pilot responses had to be instinctive, near instantaneous, and quite aggressive to survive. I have no objective information as to just how the sim fidelity was for that exercise .. but it sure appeared realistic regardless of from which seat one saw it.
I think you did very well to survive your encounter, good sir.
standards limit the bank angle to "no greater than 5 degrees", the optimum is around 3 degrees
Static Vmca Standards impose a maximum favourable bank of 5 degrees. Given that the OEM would like to get the lowest Vmca possible .. as Vmca limits other certification considerations, a fence needs to be put around the paddock to maintain a level playing field. In addition, too much bank increases sideslip and, for such an exercise, too much of a good thing can be rather bad ...
Once the failure is sorted out and the aircraft gets to a sensible speed (somewhat higher than Vmca) the pilot can start worrying more about performance than control. It appears reasonably general, that optimum bank for climb performance is around 2-3 degrees regardless of Type. The only caveat is for some AH systems which can't tolerate steady small bank angles so, in general, the optimum is traded for the simpler by sacrificing a little performance and climbing wings level. Much easier for the pilot and the result is not all that different.
if you have already got it, V2+10 to V2+15 gives a much better gradient
The climb characteristic curve is a bit like an upturned cup .. with V2min well away from the top. Overspeed V2 provides a better climb gradient. Generally the top of the curve will be a moderate margin above V2min. Looking at routine overspeed schedules, the limit generally runs to V2min plus 20-30 to keep a check on ridiculous runway deltas.
Does an extended net postmortem achive anything?
If a bit of knowledge saves a crew next time .. I'd say that's a positive ... wouldn't you ?
we dropped pulling the nose up to get back to V2, after the American Airlines DC-10 loss at Chicago, many years ago.
Indeed .. and essential reading at NTSB AAR79-17. Although this mishap involved an asymmetric stall, the Industry recognised it as a wakeup call regarding pilot techniques during takeoff failures.
demanding that the nose be pulled up to reduce to V2
archaic thinking .. as others have observed
Vmca is a static speed ... there is no element that accounts for sudden engine failure, slow rudder reaction or existing bank angle.
Not quite the case.
For instance, current FAR 25 Vmca test requirements can be reviewed at AC 25-7B starting page 102.
The usual Vmca workup starts with the static Vmca (cf the typical pilot Vmca demonstration exercise). After this figure is determined, dynamic Vmca checks are made to ensure that the final figure published in the AFM covers both cases.
The speed at which one of the limiting parameters will be met in the dynamic case will be much higher than the published static figure
Not necessarily so but is covered in the AFM figure as above.
or at the start of a go-around
Different figure to that for takeoff and is established during certification
It seemed to take forever for the full rudder and full aileron to stop the roll and yaw, let alone bring it back to a sensible place.
This is a common observation unless the pilot has been through the wringer in sim training with the result that reactions are instinctive.
For instance, I recall (quite fondly) one endorsement crew (initial command ex 744 F/O and intake F/O) on the 732 during a contract training engagement many years ago.
The initial command chap hadn't ever really got on top of takeoff engine failures and, initially, was very underconfident. Not a good situation for that stage of his career. We fixed that problem late one night when (on the sly) we took one programmed session and hammered failures .. the next session was a spare and the techs let us continue on so the time ended up totalling around 6 hours as I recall.
To cut a long story short we made extensive use of freeze and reposition to concentrate on the difficult bits for both guys, working our way back to min weight, aft CG, min speed schedule takeoffs with the failure (a very impressive modelling of an historical large bird impact FDR trace - ie catastrophic seizure). By the end of the session, both guys could handle the failure with continued takeoff tracking the opposite end LLZ .. just about with their eyes closed. They toddled off home dead tired but with very large swelled heads and the rest of the endorsement program went pretty smoothly ...
As this particular operator made very extensive use of overspeed takeoffs and, as far as I could determine, only used low speed schedules for ferry flights from one coastal aerodrome .. and did all their sim training for the overspeed case, my contract colleagues and I were rather concerned for obvious reasons.
During the occasional checking/renewal sessions, I took to introducing the lowspeed case in play time .. where the pilots were prepared to have a looksee at the problem.
In just about every case, those who had a go at the critical case .. cold ... did the Braz sequence .. the sim, of course, was frozen shortly after the departure. All were able to get on top of the failure with a bit of explanation and several practice runs.
The point was the pilot responses had to be instinctive, near instantaneous, and quite aggressive to survive. I have no objective information as to just how the sim fidelity was for that exercise .. but it sure appeared realistic regardless of from which seat one saw it.
I think you did very well to survive your encounter, good sir.
standards limit the bank angle to "no greater than 5 degrees", the optimum is around 3 degrees
Static Vmca Standards impose a maximum favourable bank of 5 degrees. Given that the OEM would like to get the lowest Vmca possible .. as Vmca limits other certification considerations, a fence needs to be put around the paddock to maintain a level playing field. In addition, too much bank increases sideslip and, for such an exercise, too much of a good thing can be rather bad ...
Once the failure is sorted out and the aircraft gets to a sensible speed (somewhat higher than Vmca) the pilot can start worrying more about performance than control. It appears reasonably general, that optimum bank for climb performance is around 2-3 degrees regardless of Type. The only caveat is for some AH systems which can't tolerate steady small bank angles so, in general, the optimum is traded for the simpler by sacrificing a little performance and climbing wings level. Much easier for the pilot and the result is not all that different.
if you have already got it, V2+10 to V2+15 gives a much better gradient
The climb characteristic curve is a bit like an upturned cup .. with V2min well away from the top. Overspeed V2 provides a better climb gradient. Generally the top of the curve will be a moderate margin above V2min. Looking at routine overspeed schedules, the limit generally runs to V2min plus 20-30 to keep a check on ridiculous runway deltas.
Does an extended net postmortem achive anything?
If a bit of knowledge saves a crew next time .. I'd say that's a positive ... wouldn't you ?
we dropped pulling the nose up to get back to V2, after the American Airlines DC-10 loss at Chicago, many years ago.
Indeed .. and essential reading at NTSB AAR79-17. Although this mishap involved an asymmetric stall, the Industry recognised it as a wakeup call regarding pilot techniques during takeoff failures.
V speeds - Wikipedia, the free encyclopedia
Betaman and the like, I hope you learnt something tonight.
For the record, V2 is a TOSS, nothing more. It's not a magic speed that will fix all ones worries in an asymmetric situation. It's just the minimum speed you can fly to achieve certified climb gradients.
Which is why it's called the take of safety speed
Betaman and the like, I hope you learnt something tonight.
For the record, V2 is a TOSS, nothing more. It's not a magic speed that will fix all ones worries in an asymmetric situation. It's just the minimum speed you can fly to achieve certified climb gradients.
Which is why it's called the take of safety speed
Join Date: Jul 2010
Location: sydney
Posts: 1,469
Likes: 0
Received 0 Likes
on
0 Posts
John & greenie,
you guys are perhaps examples of "trainers" against "checkers".
Trainers teach...checkers just check and that is why some of this
"Bullsh...t" gets entrenched into our system.
It starts in GA where half qualified FOI's enforce their "opinions",
and massage their ego's, by forcing this sort of stuff into CAR 217 organisations. You cannot argue with them or reason with them, they are always "Right". A small CAR 217 organisation simply dosnt have the clout to pull them up..."comply with what I say" or you lose your accreditation, or suddenly become a " A not fit and proper person".
I failed a check ride for maintaining V2+10 instead of V2, have also been instructed that Full stalls must be conducted in a T tail jet, and stability augumentation must be turned off to practice stalling.
Actually I'm amazed more good pilots havnt been killed by these lunatics in charge of the asylum, and leadie am I right in that the BK FOI was the one the Skull reinstated after getting thrown out of Darwin?
you guys are perhaps examples of "trainers" against "checkers".
Trainers teach...checkers just check and that is why some of this
"Bullsh...t" gets entrenched into our system.
It starts in GA where half qualified FOI's enforce their "opinions",
and massage their ego's, by forcing this sort of stuff into CAR 217 organisations. You cannot argue with them or reason with them, they are always "Right". A small CAR 217 organisation simply dosnt have the clout to pull them up..."comply with what I say" or you lose your accreditation, or suddenly become a " A not fit and proper person".
I failed a check ride for maintaining V2+10 instead of V2, have also been instructed that Full stalls must be conducted in a T tail jet, and stability augumentation must be turned off to practice stalling.
Actually I'm amazed more good pilots havnt been killed by these lunatics in charge of the asylum, and leadie am I right in that the BK FOI was the one the Skull reinstated after getting thrown out of Darwin?
Absolutely spot on thorn bird! Except for this...
....I think your being over generous!
Especially when it comes to this individual:
Except for this...
It starts in GA where half qualified FOI's enforce their "opinions",
Especially when it comes to this individual:
and leadie am I right in that the BK FOI was the one the Skull reinstated after getting thrown out of Darwin?
Moderator
I failed a check ride for maintaining V2+10 instead of V2,
I guess that, sometimes, one has to play the game. However, the fault probably lay with the operator (and, perhaps, OEM) for not generating a more liberal SOP in the Ops Manual.
have also been instructed that Full stalls must be conducted in a T tail jet
Stall protocols are another major concern when it comes to the operational standards side of the table not always having much of an idea of what the certification folks did in the first place.
The certification flight test standards have varied over the years so that aircraft A and aircraft B might well have had different techniques applied in the stall certification.
One example comes to mind - a well-known flight test organisation used to use a particular light twin for TP training. This particular Model was certificated by approach to the stall only, rather than pulling into the developed stall.
Apparently, during one course, a USAF trainee proposed that it might be interesting to check out the developed stall .. whereupon the aircraft flicked into an inverted spin.
Food for thought ?
Lesson is .. before making it up on the run, do some homework on the certification standards and techniques relevant to the aircraft via TCDS, Design Standards, ACs, etc.
stability augumentation must be turned off to practice stalling.
I presume we are talking SAS stuff here ? Given that the usual reason for SAS is to fix a deficient stability characteristic found during certification testing, AFM admonitions MUST be observed lest the pilots find themselves in a pickle beyond their knowledge limits.
For instance, the same flight test organisation used to use a well-known (different) twin for training. This particular aircraft incorporated a SAS to fix a very undesirable longitudinal static stability problem during the missed approach.
Consider the situation with the system deactivated .. you, as pilot, initiate an overshoot (not too different from stall recovery when you run up the thrust at the appropriate time) and, with an unintended reduction in speed, you find that you now have a runaway speed reduction unless you push forward aggressively - the reverse of what you expect normally with a stable aircraft where you have to put in a pull force to fly slower than trim speed.
Again, know what the story is for the aircraft prior to making it up on the run ...
I guess that, sometimes, one has to play the game. However, the fault probably lay with the operator (and, perhaps, OEM) for not generating a more liberal SOP in the Ops Manual.
have also been instructed that Full stalls must be conducted in a T tail jet
Stall protocols are another major concern when it comes to the operational standards side of the table not always having much of an idea of what the certification folks did in the first place.
The certification flight test standards have varied over the years so that aircraft A and aircraft B might well have had different techniques applied in the stall certification.
One example comes to mind - a well-known flight test organisation used to use a particular light twin for TP training. This particular Model was certificated by approach to the stall only, rather than pulling into the developed stall.
Apparently, during one course, a USAF trainee proposed that it might be interesting to check out the developed stall .. whereupon the aircraft flicked into an inverted spin.
Food for thought ?
Lesson is .. before making it up on the run, do some homework on the certification standards and techniques relevant to the aircraft via TCDS, Design Standards, ACs, etc.
stability augumentation must be turned off to practice stalling.
I presume we are talking SAS stuff here ? Given that the usual reason for SAS is to fix a deficient stability characteristic found during certification testing, AFM admonitions MUST be observed lest the pilots find themselves in a pickle beyond their knowledge limits.
For instance, the same flight test organisation used to use a well-known (different) twin for training. This particular aircraft incorporated a SAS to fix a very undesirable longitudinal static stability problem during the missed approach.
Consider the situation with the system deactivated .. you, as pilot, initiate an overshoot (not too different from stall recovery when you run up the thrust at the appropriate time) and, with an unintended reduction in speed, you find that you now have a runaway speed reduction unless you push forward aggressively - the reverse of what you expect normally with a stable aircraft where you have to put in a pull force to fly slower than trim speed.
Again, know what the story is for the aircraft prior to making it up on the run ...
Join Date: Jun 2011
Location: Downunda
Posts: 562
Likes: 0
Received 0 Likes
on
0 Posts
Actually I'm amazed more good pilots havnt been killed by these lunatics in charge of the asylum, and leadie am I right in that the BK FOI was the one the Skull reinstated after getting thrown out of Darwin?
Fortunately several Operators in DN voiced their concerns about this individual and he was subsequently transferred and some semblance of sanity returned.
Unfortunately a couple of our Checkies (one of which ended up becoming our CP) was tainted by his mantra, some of which defied all commonsense and the laws of physics .
Examples were-
(a) Sudden and vicious V1 cuts just as the aircraft was rotating (and they wondered why we were having multiple/un-explained torque rollbacks across the fleet);
(b) low level (200-300’ overwater or on takeoff) stickshaker climbs;
(c) sudden and un-warned emergency descents with full crew onboard;
(d) low level (200-300’ overwater) steep turns with foggles on and sometimes with full crew onboard ( one of the checkies said that this was a regulator requirement, even though it was contrary to SOPs and company Ops manuals);
(e) demonstrating x-wind technique by keeping the down-wind mains in the air for an extended amount of time (FDR recorded 17.5 seconds), this manoeuvre nearly had the aircraft departing the runway and the sudden hard braking resulted in a skidmark over 100m long with the result that two main tyres were destroyed (this incident led to the checkie losing his approval and being demoted). The list of examples is by no means exhaustive.
All those operators in the Sydney basin beware of this individual, if he his assigned to oversee your ops and you value your business and the safety of your employees’ then demand to have someone else!
Last edited by 004wercras; 27th Feb 2012 at 01:21. Reason: K impact
How about a bit of respect. Does an extended net postmortem achive anything?