Crash at Shoreham Air show
Discussion
dr_gn said:
Pan Pan Pan said:
RichB said:
Pan Pan Pan said:
Dr Jekyll said:
RoverP6B said:
It wasn't a loop. Looks more like a Cuban to me.
I think it was a quarter clover.
people do like to exhibit their superior knowledge of aerobatics on here... Since Pistonheads is essentially a motoring forum, I also suggested that from the various videos of the incident, it `looked' like a high speed stall (possibly best described as the aerial equivalent of understeer) occurred at the bottom of the manouvre. Generally no problem if this occurs at high altitude, but unfortunately like any stall, it can be, when experienced at low level
Pan Pan Pan said:
These are genuine questions. Do you understand how aeroplanes fly, what a stall is, and what a high speed stall is? from your comment it `appears' that you do not.
I think the point is that if it did stall, as it certainly appears to have done, the stall only occurred because the pilot was trying hard to pull up because the aircraft was already too low. So the main cause/s of the accident had already happened.Whether it might have avoided the crash if it hadn't stalled is a secondary issue.
Pan Pan Pan said:
These are genuine questions. Do you understand how aeroplanes fly, what a stall is, and what a high speed stall is? from your comment it `appears' that you do not.
Supercilious much?Dr Gn is right, at the point the pilot realised that the manouevre wasn't going as planned, whether he pulled up so hard that the aircraft stalled is neither here nor there. I'm guessing there was a point of no return somewhere and the pilot missed it.
Point scoring to show off your credentials is better left to forums like pprune, IMHO. Here it just makes you look like a jerk.
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
RichB said:
Pan Pan Pan said:
Dr Jekyll said:
RoverP6B said:
It wasn't a loop. Looks more like a Cuban to me.
I think it was a quarter clover. people do like to exhibit their superior knowledge of aerobatics on here... Since Pistonheads is essentially a motoring forum, I also suggested that from the various videos of the incident, it `looked' like a high speed stall (possibly best described as the aerial equivalent of understeer) occurred at the bottom of the manouvre. Generally no problem if this occurs at high altitude, but unfortunately like any stall, it can be, when experienced at low level
To my eyes, the 'high speed stall' (if that's really what it was) near the bottom of the loop was a last chance panic reaction to an imminent crash that was primarily caused by errors made much earlier in the manouver. By the time the "stall" happened, it was pretty much irrelevant to whether the crash was going to happen or not. It might have affected how and where the aircraft impacted slightly, but that's about it.
dr_gn said:
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
RichB said:
Pan Pan Pan said:
Dr Jekyll said:
RoverP6B said:
It wasn't a loop. Looks more like a Cuban to me.
I think it was a quarter clover. people do like to exhibit their superior knowledge of aerobatics on here... Since Pistonheads is essentially a motoring forum, I also suggested that from the various videos of the incident, it `looked' like a high speed stall (possibly best described as the aerial equivalent of understeer) occurred at the bottom of the manouvre. Generally no problem if this occurs at high altitude, but unfortunately like any stall, it can be, when experienced at low level
To my eyes, the 'high speed stall' (if that's really what it was) near the bottom of the loop was a last chance panic reaction to an imminent crash that was primarily caused by errors made much earlier in the manouver. By the time the "stall" happened, it was pretty much irrelevant to whether the crash was going to happen or not. It might have affected how and where the aircraft impacted slightly, but that's about it.
It matters little what the manouvre itself actually was, other than that part of it consisted of a high speed descent (at which for high speed aerobatics, would be considered low level) but not what would be outside the norm for a display pilot at this type of event.
`If' the manouvre was initiated at insufficient height to safely complete it. (that is the first part of the HASELL checks required before carrying out any aerobatic manouvre, and which becomes even more critical where aerobatic manouvres are carried out at low level) the `possible' causes for this, could be multiple, but which may come to light following the AAIB`s investigations, but as I posted, the height at which the manouvre was initiated, was one of the key factors.
What the manouvre itself actually was, was not.
If sufficient height had been available, it is most `likely' that the incident would not have occurred, but also as posted earlier, from watching the various videos of the incident, the bottom of the manouvre `looked' like a high speed stall, which could, as you have suggested, be the result of split second, but as it turned out, too late control inputs intended to arrest the descent.
Pan Pan Pan said:
You possibly missed the part in my earlier post, which referred to the height at which the manouvre was initiated, being a key element in what happened.
It matters little what the manouvre itself actually was, other than that part of it consisted of a high speed descent (at which for high speed aerobatics, would be considered low level) but not what would be outside the norm for a display pilot at this type of event.
`If' the manouvre was initiated at insufficient height to safely complete it. (that is the first part of the HASELL checks required before carrying out any aerobatic manouvre, and which becomes even more critical where aerobatic manouvres are carried out at low level) the `possible' causes for this, could be multiple, but which may come to light following the AAIB`s investigations, but as I posted, the height at which the manouvre was initiated, was one of the key factors.
What the manouvre itself actually was, was not.
If sufficient height had been available, it is most `likely' that the incident would not have occurred, but also as posted earlier, from watching the various videos of the incident, the bottom of the manouvre `looked' like a high speed stall, which could, as you have suggested, be the result of split second, but as it turned out, too late control inputs intended to arrest the descent.
But if you're trying to work out whether something went wrong during the manoeuvre, knowing what the manoeuvre was supposed to be is fundamental. If something went badly wrong during the manoeuvre, the entrance height and speed might not have been a problem in themselves.It matters little what the manouvre itself actually was, other than that part of it consisted of a high speed descent (at which for high speed aerobatics, would be considered low level) but not what would be outside the norm for a display pilot at this type of event.
`If' the manouvre was initiated at insufficient height to safely complete it. (that is the first part of the HASELL checks required before carrying out any aerobatic manouvre, and which becomes even more critical where aerobatic manouvres are carried out at low level) the `possible' causes for this, could be multiple, but which may come to light following the AAIB`s investigations, but as I posted, the height at which the manouvre was initiated, was one of the key factors.
What the manouvre itself actually was, was not.
If sufficient height had been available, it is most `likely' that the incident would not have occurred, but also as posted earlier, from watching the various videos of the incident, the bottom of the manouvre `looked' like a high speed stall, which could, as you have suggested, be the result of split second, but as it turned out, too late control inputs intended to arrest the descent.
Dr Jekyll said:
Pan Pan Pan said:
You possibly missed the part in my earlier post, which referred to the height at which the manouvre was initiated, being a key element in what happened.
It matters little what the manouvre itself actually was, other than that part of it consisted of a high speed descent (at which for high speed aerobatics, would be considered low level) but not what would be outside the norm for a display pilot at this type of event.
`If' the manouvre was initiated at insufficient height to safely complete it. (that is the first part of the HASELL checks required before carrying out any aerobatic manouvre, and which becomes even more critical where aerobatic manouvres are carried out at low level) the `possible' causes for this, could be multiple, but which may come to light following the AAIB`s investigations, but as I posted, the height at which the manouvre was initiated, was one of the key factors.
What the manouvre itself actually was, was not.
If sufficient height had been available, it is most `likely' that the incident would not have occurred, but also as posted earlier, from watching the various videos of the incident, the bottom of the manouvre `looked' like a high speed stall, which could, as you have suggested, be the result of split second, but as it turned out, too late control inputs intended to arrest the descent.
But if you're trying to work out whether something went wrong during the manoeuvre, knowing what the manoeuvre was supposed to be is fundamental. If something went badly wrong during the manoeuvre, the entrance height and speed might not have been a problem in themselves.It matters little what the manouvre itself actually was, other than that part of it consisted of a high speed descent (at which for high speed aerobatics, would be considered low level) but not what would be outside the norm for a display pilot at this type of event.
`If' the manouvre was initiated at insufficient height to safely complete it. (that is the first part of the HASELL checks required before carrying out any aerobatic manouvre, and which becomes even more critical where aerobatic manouvres are carried out at low level) the `possible' causes for this, could be multiple, but which may come to light following the AAIB`s investigations, but as I posted, the height at which the manouvre was initiated, was one of the key factors.
What the manouvre itself actually was, was not.
If sufficient height had been available, it is most `likely' that the incident would not have occurred, but also as posted earlier, from watching the various videos of the incident, the bottom of the manouvre `looked' like a high speed stall, which could, as you have suggested, be the result of split second, but as it turned out, too late control inputs intended to arrest the descent.
It's pedantry really.
ie.
If you are driving a car and misjudge the speed for a bend, chances are you will understeer off into the scenery. So you could say that "understeer" was the cause of the accident, but of course the root cause was excessive speed!
In this case, it's fairly clear from the footage of the loop recovery that the initial recovery was at a reasonably mild loading, with a pretty gentle positive pitch gain. As it became clear to the pilot that insufficient altitude remained, it is also clear that they (as you would expect) pulled very hard indeed, putting the airframe on or over it's max wing loading to attempt to tighten the recovery as much as possible. The fact the pilot survived shows that the vertical RoD was actually fairly small as the airframe impacted the road, and the AOA was quite extreme (looking at the footage, the airframe is pitched very nose high, with the engines at, or spooling up to, full power)
As the pilot was pretty experienced in fast jets, there is a good chance he actually managed to get to the peak loading of the airframe in this last ditch "miss the ground" maneuver, and yes, there is a good chance that the wings of the plane very fully loaded and perhaps even overloaded (There is a slight wing drop and wiggle from the airframe during the last 2 secs, that suggest that one wing may have become fully "stalled", or that the AOA had reached a very unstable angle)
But that is all rather irrelevant. The simple fact is that by the time the pilot realised he was too low, there was insufficient altitude availible to complete the maneuver. The only other course of action would have been to aim nose down into a field and bang out! And NO pilot is ever going to do that. (just like if you come round a bend in the road, find a horse in the middle of the road, no driver ever deliberately steers into a field to miss it!)
IMO, it was a very close thing. Looking at the last second of the flight, and the trajectory of the aircraft (nose high, fully power, fully loaded), another 50 foot altitude and he would probably have made it........ ;-(
ie.
If you are driving a car and misjudge the speed for a bend, chances are you will understeer off into the scenery. So you could say that "understeer" was the cause of the accident, but of course the root cause was excessive speed!
In this case, it's fairly clear from the footage of the loop recovery that the initial recovery was at a reasonably mild loading, with a pretty gentle positive pitch gain. As it became clear to the pilot that insufficient altitude remained, it is also clear that they (as you would expect) pulled very hard indeed, putting the airframe on or over it's max wing loading to attempt to tighten the recovery as much as possible. The fact the pilot survived shows that the vertical RoD was actually fairly small as the airframe impacted the road, and the AOA was quite extreme (looking at the footage, the airframe is pitched very nose high, with the engines at, or spooling up to, full power)
As the pilot was pretty experienced in fast jets, there is a good chance he actually managed to get to the peak loading of the airframe in this last ditch "miss the ground" maneuver, and yes, there is a good chance that the wings of the plane very fully loaded and perhaps even overloaded (There is a slight wing drop and wiggle from the airframe during the last 2 secs, that suggest that one wing may have become fully "stalled", or that the AOA had reached a very unstable angle)
But that is all rather irrelevant. The simple fact is that by the time the pilot realised he was too low, there was insufficient altitude availible to complete the maneuver. The only other course of action would have been to aim nose down into a field and bang out! And NO pilot is ever going to do that. (just like if you come round a bend in the road, find a horse in the middle of the road, no driver ever deliberately steers into a field to miss it!)
IMO, it was a very close thing. Looking at the last second of the flight, and the trajectory of the aircraft (nose high, fully power, fully loaded), another 50 foot altitude and he would probably have made it........ ;-(
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
RichB said:
Pan Pan Pan said:
Dr Jekyll said:
RoverP6B said:
It wasn't a loop. Looks more like a Cuban to me.
I think it was a quarter clover. people do like to exhibit their superior knowledge of aerobatics on here... Since Pistonheads is essentially a motoring forum, I also suggested that from the various videos of the incident, it `looked' like a high speed stall (possibly best described as the aerial equivalent of understeer) occurred at the bottom of the manouvre. Generally no problem if this occurs at high altitude, but unfortunately like any stall, it can be, when experienced at low level
To my eyes, the 'high speed stall' (if that's really what it was) near the bottom of the loop was a last chance panic reaction to an imminent crash that was primarily caused by errors made much earlier in the manouver. By the time the "stall" happened, it was pretty much irrelevant to whether the crash was going to happen or not. It might have affected how and where the aircraft impacted slightly, but that's about it.
It matters little what the manouvre itself actually was, other than that part of it consisted of a high speed descent (at which for high speed aerobatics, would be considered low level) but not what would be outside the norm for a display pilot at this type of event.
`If' the manouvre was initiated at insufficient height to safely complete it. (that is the first part of the HASELL checks required before carrying out any aerobatic manouvre, and which becomes even more critical where aerobatic manouvres are carried out at low level) the `possible' causes for this, could be multiple, but which may come to light following the AAIB`s investigations, but as I posted, the height at which the manouvre was initiated, was one of the key factors.
What the manouvre itself actually was, was not.
If sufficient height had been available, it is most `likely' that the incident would not have occurred, but also as posted earlier, from watching the various videos of the incident, the bottom of the manouvre `looked' like a high speed stall, which could, as you have suggested, be the result of split second, but as it turned out, too late control inputs intended to arrest the descent.
I disagreed with that: As I commented, my assumption is that the "pull out phase" as you put it, was, contrary to what you wrote, pretty much irrelevant. Again, my assumption is that the cause of the accident was nothing to do with any kind of stall during this phase; once the pilot had committed to complete the manouver (i.e. not rolled out of the loop near the top), the outcome was a forgone conclusion simply becasue the top of the loop was too low.
The above may be completely wrong, as might 90% of the comments from most people on this thread, but I still fail to see how what I wrote indicated a lack of understanding of how aircraft fly and what stalls are. Can you explain why you drew those conclusions?
dr_gn said:
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
RichB said:
Pan Pan Pan said:
Dr Jekyll said:
RoverP6B said:
It wasn't a loop. Looks more like a Cuban to me.
I think it was a quarter clover. people do like to exhibit their superior knowledge of aerobatics on here... Since Pistonheads is essentially a motoring forum, I also suggested that from the various videos of the incident, it `looked' like a high speed stall (possibly best described as the aerial equivalent of understeer) occurred at the bottom of the manouvre. Generally no problem if this occurs at high altitude, but unfortunately like any stall, it can be, when experienced at low level
To my eyes, the 'high speed stall' (if that's really what it was) near the bottom of the loop was a last chance panic reaction to an imminent crash that was primarily caused by errors made much earlier in the manouver. By the time the "stall" happened, it was pretty much irrelevant to whether the crash was going to happen or not. It might have affected how and where the aircraft impacted slightly, but that's about it.
It matters little what the manouvre itself actually was, other than that part of it consisted of a high speed descent (at which for high speed aerobatics, would be considered low level) but not what would be outside the norm for a display pilot at this type of event.
`If' the manouvre was initiated at insufficient height to safely complete it. (that is the first part of the HASELL checks required before carrying out any aerobatic manouvre, and which becomes even more critical where aerobatic manouvres are carried out at low level) the `possible' causes for this, could be multiple, but which may come to light following the AAIB`s investigations, but as I posted, the height at which the manouvre was initiated, was one of the key factors.
What the manouvre itself actually was, was not.
If sufficient height had been available, it is most `likely' that the incident would not have occurred, but also as posted earlier, from watching the various videos of the incident, the bottom of the manouvre `looked' like a high speed stall, which could, as you have suggested, be the result of split second, but as it turned out, too late control inputs intended to arrest the descent.
I disagreed with that: As I commented, my assumption is that the "pull out phase" as you put it, was, contrary to what you wrote, pretty much irrelevant. Again, my assumption is that the cause of the accident was nothing to do with any kind of stall during this phase; once the pilot had committed to complete the manouver (i.e. not rolled out of the loop near the top), the outcome was a forgone conclusion simply becasue the top of the loop was too low.
The above may be completely wrong, as might 90% of the comments from most people on this thread, but I still fail to see how what I wrote indicated a lack of understanding of how aircraft fly and what stalls are. Can you explain why you drew those conclusions?
At present we have no way of knowing how this was done, bearing in mind that during high speed flight, altimeters tend to over read, being a pressure instrument (sometimes by as much as 300 ft), and that even the best conventional (non radar) altimeters have normal tolerances not better than +/- 30 ft. Alternatively the pilot may have just used visual cues to determine whether or not he had enough height to complete the manouvre. No one will know until the investigations are complete, (possibly not even then) and that wont be until next year at the soonest. So at present we have no way of knowing all the factors which lead to the incident.
As far as my comment regarding what happened at the bottom of the manouvre being the most important part, anything which changes an aircraft from being an allegedly intact viable flying machine to a piece of smoking wreckage would in my view be quite important.
As for asking if you understood what a stall was, either at low or high speed, it is the point at which any aircraft stops flying, and therefore also the point at which its pilot no longer has control over its trajectory, so I would rate that as being quite an important part of the manouvre.
A stalled aircraft is then no longer flying, any more than a house brick is `flying' regardless of what height it is falling from or what speed it is travelling at.
There are far too many unknowns regarding what actually happened at this point in time, for anyone to make definitive statements on what happened, I was commenting on what `I saw' in the various videos of the incident.
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
RichB said:
Pan Pan Pan said:
Dr Jekyll said:
RoverP6B said:
It wasn't a loop. Looks more like a Cuban to me.
I think it was a quarter clover. people do like to exhibit their superior knowledge of aerobatics on here... Since Pistonheads is essentially a motoring forum, I also suggested that from the various videos of the incident, it `looked' like a high speed stall (possibly best described as the aerial equivalent of understeer) occurred at the bottom of the manouvre. Generally no problem if this occurs at high altitude, but unfortunately like any stall, it can be, when experienced at low level
To my eyes, the 'high speed stall' (if that's really what it was) near the bottom of the loop was a last chance panic reaction to an imminent crash that was primarily caused by errors made much earlier in the manouver. By the time the "stall" happened, it was pretty much irrelevant to whether the crash was going to happen or not. It might have affected how and where the aircraft impacted slightly, but that's about it.
It matters little what the manouvre itself actually was, other than that part of it consisted of a high speed descent (at which for high speed aerobatics, would be considered low level) but not what would be outside the norm for a display pilot at this type of event.
`If' the manouvre was initiated at insufficient height to safely complete it. (that is the first part of the HASELL checks required before carrying out any aerobatic manouvre, and which becomes even more critical where aerobatic manouvres are carried out at low level) the `possible' causes for this, could be multiple, but which may come to light following the AAIB`s investigations, but as I posted, the height at which the manouvre was initiated, was one of the key factors.
What the manouvre itself actually was, was not.
If sufficient height had been available, it is most `likely' that the incident would not have occurred, but also as posted earlier, from watching the various videos of the incident, the bottom of the manouvre `looked' like a high speed stall, which could, as you have suggested, be the result of split second, but as it turned out, too late control inputs intended to arrest the descent.
I disagreed with that: As I commented, my assumption is that the "pull out phase" as you put it, was, contrary to what you wrote, pretty much irrelevant. Again, my assumption is that the cause of the accident was nothing to do with any kind of stall during this phase; once the pilot had committed to complete the manouver (i.e. not rolled out of the loop near the top), the outcome was a forgone conclusion simply becasue the top of the loop was too low.
The above may be completely wrong, as might 90% of the comments from most people on this thread, but I still fail to see how what I wrote indicated a lack of understanding of how aircraft fly and what stalls are. Can you explain why you drew those conclusions?
A stalled aircraft is then no longer flying, any more than a house brick is `flying' regardless of what height it is falling from or what speed it is travelling at.
Secondly, your assertion that a stall ..."is the point at which any aircraft stops flying, and therefore also the point at which its pilot no longer has control over its trajectory.." isn't strictly correct for a few reasons, the most obvious one being that several aircraft are able to controlled post-stall by a variety of means. Obviously this doesn't apply so much to the Hunter, but if you're making definitions covering "any" aircraft, then maybe it's you who needs to brush up on your theory?
dr_gn said:
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
RichB said:
Pan Pan Pan said:
Dr Jekyll said:
RoverP6B said:
It wasn't a loop. Looks more like a Cuban to me.
I think it was a quarter clover. people do like to exhibit their superior knowledge of aerobatics on here... Since Pistonheads is essentially a motoring forum, I also suggested that from the various videos of the incident, it `looked' like a high speed stall (possibly best described as the aerial equivalent of understeer) occurred at the bottom of the manouvre. Generally no problem if this occurs at high altitude, but unfortunately like any stall, it can be, when experienced at low level
To my eyes, the 'high speed stall' (if that's really what it was) near the bottom of the loop was a last chance panic reaction to an imminent crash that was primarily caused by errors made much earlier in the manouver. By the time the "stall" happened, it was pretty much irrelevant to whether the crash was going to happen or not. It might have affected how and where the aircraft impacted slightly, but that's about it.
It matters little what the manouvre itself actually was, other than that part of it consisted of a high speed descent (at which for high speed aerobatics, would be considered low level) but not what would be outside the norm for a display pilot at this type of event.
`If' the manouvre was initiated at insufficient height to safely complete it. (that is the first part of the HASELL checks required before carrying out any aerobatic manouvre, and which becomes even more critical where aerobatic manouvres are carried out at low level) the `possible' causes for this, could be multiple, but which may come to light following the AAIB`s investigations, but as I posted, the height at which the manouvre was initiated, was one of the key factors.
What the manouvre itself actually was, was not.
If sufficient height had been available, it is most `likely' that the incident would not have occurred, but also as posted earlier, from watching the various videos of the incident, the bottom of the manouvre `looked' like a high speed stall, which could, as you have suggested, be the result of split second, but as it turned out, too late control inputs intended to arrest the descent.
I disagreed with that: As I commented, my assumption is that the "pull out phase" as you put it, was, contrary to what you wrote, pretty much irrelevant. Again, my assumption is that the cause of the accident was nothing to do with any kind of stall during this phase; once the pilot had committed to complete the manouver (i.e. not rolled out of the loop near the top), the outcome was a forgone conclusion simply becasue the top of the loop was too low.
The above may be completely wrong, as might 90% of the comments from most people on this thread, but I still fail to see how what I wrote indicated a lack of understanding of how aircraft fly and what stalls are. Can you explain why you drew those conclusions?
A stalled aircraft is then no longer flying, any more than a house brick is `flying' regardless of what height it is falling from or what speed it is travelling at.
Secondly, your assertion that a stall ..."is the point at which any aircraft stops flying, and therefore also the point at which its pilot no longer has control over its trajectory.." isn't strictly correct for a few reasons, the most obvious one being that several aircraft are able to controlled post-stall by a variety of means. Obviously this doesn't apply so much to the Hunter, but if you're making definitions covering "any" aircraft, then maybe it's you who needs to brush up on your theory?
Pan Pan Pan said:
Please explain how a stalled hunter at the base of a manouvre with a high energy downward component is able to fly away from the ground?
You could equally ask how an unstalled hunter at the base of a manouvre with a high energy downward component is going to be able to fly away from the ground.RoverP6B said:
Not a Pitts, but I did learn power flight on Beagle Pups, both 100 and 150 variants, and my instructor was ex-Red Arrows QFI Ted Girdler, one of the finest pilots this country has ever produced.
A small world - he was my PPL CFI back in the early 90's. Another airshow loss sadly.Mave said:
Pan Pan Pan said:
Please explain how a stalled hunter at the base of a manouvre with a high energy downward component is able to fly away from the ground?
You could equally ask how an unstalled hunter at the base of a manouvre with a high energy downward component is going to be able to fly away from the ground.If the aircraft was not stalled, it would still be flying, and the wings would still be producing lift, whether that would be have been enough to avoid hitting the ground is what (hopefully) the investigations will determine.
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
dr_gn said:
Pan Pan Pan said:
RichB said:
Pan Pan Pan said:
Dr Jekyll said:
RoverP6B said:
It wasn't a loop. Looks more like a Cuban to me.
I think it was a quarter clover. people do like to exhibit their superior knowledge of aerobatics on here... Since Pistonheads is essentially a motoring forum, I also suggested that from the various videos of the incident, it `looked' like a high speed stall (possibly best described as the aerial equivalent of understeer) occurred at the bottom of the manouvre. Generally no problem if this occurs at high altitude, but unfortunately like any stall, it can be, when experienced at low level
To my eyes, the 'high speed stall' (if that's really what it was) near the bottom of the loop was a last chance panic reaction to an imminent crash that was primarily caused by errors made much earlier in the manouver. By the time the "stall" happened, it was pretty much irrelevant to whether the crash was going to happen or not. It might have affected how and where the aircraft impacted slightly, but that's about it.
It matters little what the manouvre itself actually was, other than that part of it consisted of a high speed descent (at which for high speed aerobatics, would be considered low level) but not what would be outside the norm for a display pilot at this type of event.
`If' the manouvre was initiated at insufficient height to safely complete it. (that is the first part of the HASELL checks required before carrying out any aerobatic manouvre, and which becomes even more critical where aerobatic manouvres are carried out at low level) the `possible' causes for this, could be multiple, but which may come to light following the AAIB`s investigations, but as I posted, the height at which the manouvre was initiated, was one of the key factors.
What the manouvre itself actually was, was not.
If sufficient height had been available, it is most `likely' that the incident would not have occurred, but also as posted earlier, from watching the various videos of the incident, the bottom of the manouvre `looked' like a high speed stall, which could, as you have suggested, be the result of split second, but as it turned out, too late control inputs intended to arrest the descent.
I disagreed with that: As I commented, my assumption is that the "pull out phase" as you put it, was, contrary to what you wrote, pretty much irrelevant. Again, my assumption is that the cause of the accident was nothing to do with any kind of stall during this phase; once the pilot had committed to complete the manouver (i.e. not rolled out of the loop near the top), the outcome was a forgone conclusion simply becasue the top of the loop was too low.
The above may be completely wrong, as might 90% of the comments from most people on this thread, but I still fail to see how what I wrote indicated a lack of understanding of how aircraft fly and what stalls are. Can you explain why you drew those conclusions?
A stalled aircraft is then no longer flying, any more than a house brick is `flying' regardless of what height it is falling from or what speed it is travelling at.
Secondly, your assertion that a stall ..."is the point at which any aircraft stops flying, and therefore also the point at which its pilot no longer has control over its trajectory.." isn't strictly correct for a few reasons, the most obvious one being that several aircraft are able to controlled post-stall by a variety of means. Obviously this doesn't apply so much to the Hunter, but if you're making definitions covering "any" aircraft, then maybe it's you who needs to brush up on your theory?
The point I was making in that reply - obviously I think - was that you questioned my knowledge of what a stall was, yet ironically you have just given your own incorrect definition of what stalls are when applied to "any aircraft".
So...to go back to my original question, cutting out all the interventing guff, what exactly did I write to cause you to think I don't know what a stall is?
Pan Pan Pan said:
Mave said:
Pan Pan Pan said:
Please explain how a stalled hunter at the base of a manouvre with a high energy downward component is able to fly away from the ground?
You could equally ask how an unstalled hunter at the base of a manouvre with a high energy downward component is going to be able to fly away from the ground.If the aircraft was not stalled, it would still be flying, and the wings would still be producing lift, whether that would be have been enough to avoid hitting the ground is what (hopefully) the investigations will determine.
It doesn't matter whether the wing was producing lift or not- what matters is whether the wing could produce sufficient lift; and if he stalled it near the bottom of the manoeuvre, this implies he was asking for more lift than the wing could produce.
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