King Air B200 crash, Iceland August 2013
Discussion
Zulu 10 said:
JuniorD said:
She is pretty offensive though! I can't image what it would be like to spend five hours in the flight deck with a person such caustic attitude.
In which case trying imagining that you’re in an Albert having to make a tactical approach to some strip in the middle of nowhere that’s hot and high, and overlooked by even higher ground that was still held by the good guys at the time of morning briefing, but they're not responding on the assigned freq, and the weather’s closing in, and fuel’s marginal etc….Need I go on? Possibly not, but caustic or not she sounds like exactly the sort of person with whom, in a tight spot, you really would want to share a cockpit.
In which case I would have the harpy dumped out over the zone and await the inevitable, immediate surrender of the enemy.
There's no doubt in my mind (although I may of course, be wrong) that he simply flew it into the ground. As I said in the first post, most likely looking at his mates at the drag strip to see if they were watching rather than flying the plane.
It looks (to me at least) as though he changes the control inputs very slightly, just before it goes in, which at a guess is when the F/O brought his attention to the fact that they were about to hit the deck and he tried to avoid the, by that point, inevitable outcome.
The only reason it has any roll rate when the majority of the airframe hits the ground is because the wing has hit the ground, up until that point, its not doing anything special at all.
It looks (to me at least) as though he changes the control inputs very slightly, just before it goes in, which at a guess is when the F/O brought his attention to the fact that they were about to hit the deck and he tried to avoid the, by that point, inevitable outcome.
The only reason it has any roll rate when the majority of the airframe hits the ground is because the wing has hit the ground, up until that point, its not doing anything special at all.
WOW!
dr gn had what I perceived to be a snide dig at my post (he's done it before) and I 'bit' slightly (note to self: Try not to post late at night when tired). As a result we have pages of people leaping to defend dr gn and impugn my character (with some rather childish name calling). Aside from the fact that I would imagine dr gn to be perfectly capable of standing up for himself, that says far more about the commentators that it does about either me or dr gn.
Oh mighty internet keyboard warriors the lot of you.
But I digress...
Do I think it stalled? Possibly. The bottom line is that we only have a very short amount of footage of the crash and not what preceded it, nor can we say with any accuracy what the airspeed of the a/c is nor the G applied prior to impact. However the a/c goes in left wing low but relatively 'flat' with regards to pitch and with a fair rate of descent. I can see no sign of the pilot trying to raise the wing, nor any 'yug' in pitch to avoid the ground. Having spent a lot of my career flying around at low level, and with a decent regard for the fact that Terra Firma generally wins any argument, that leads me to suspect that there may be another factor here (other than a complete lack of awareness of the proximity to the ground) preventing any attempt at avoidance. Pilots generally 'yug' when they get that close to the ground!
If the pilot can not raise the wing that begets the question, why? Possibly he/she has run out of control authority or possibly the wing has stalled. If the wing has stalled then he/she is never going to get the nose up.
We do know from the statements that the Pilot had been apparently 'showboating' having gone around from a landing attempt at a nearby airfield so there may well have been some mis-handling prior to the crash that might have lead to a manoeuvre (accelerated) stall. For the non-aircrew here it is worth pointing out that the steady state stall speed increases by a factor of the sq rt of the G applied. In a 60 degree AoB turn the stall speed increases by nearly 50% (a factor of 1.4).
However it is just as possible that this was a case of mis-handled asymmetric following a loss of power leading to a loss of control.
Another possibility (which I am starting to favour having looked at the video again) is a fin-stall with a possible rudder hard-over. Showboating using rudder reversal(s) would give the same symptoms (dependent upon a/c type). I don't have experience of the King Air but the Jetstream (similar configuration) certainly would fin-stall and rapidly drop a wing if you mis-handled (mis-footed?) the rudder. The only way to recover was to trade height for airspeed, so you didn't do it close to the ground.
Alternatively it was merely poor piloting and lack of awareness that lead to the ground reaching up and smiting them.
dr gn had what I perceived to be a snide dig at my post (he's done it before) and I 'bit' slightly (note to self: Try not to post late at night when tired). As a result we have pages of people leaping to defend dr gn and impugn my character (with some rather childish name calling). Aside from the fact that I would imagine dr gn to be perfectly capable of standing up for himself, that says far more about the commentators that it does about either me or dr gn.
Oh mighty internet keyboard warriors the lot of you.
But I digress...
Do I think it stalled? Possibly. The bottom line is that we only have a very short amount of footage of the crash and not what preceded it, nor can we say with any accuracy what the airspeed of the a/c is nor the G applied prior to impact. However the a/c goes in left wing low but relatively 'flat' with regards to pitch and with a fair rate of descent. I can see no sign of the pilot trying to raise the wing, nor any 'yug' in pitch to avoid the ground. Having spent a lot of my career flying around at low level, and with a decent regard for the fact that Terra Firma generally wins any argument, that leads me to suspect that there may be another factor here (other than a complete lack of awareness of the proximity to the ground) preventing any attempt at avoidance. Pilots generally 'yug' when they get that close to the ground!
If the pilot can not raise the wing that begets the question, why? Possibly he/she has run out of control authority or possibly the wing has stalled. If the wing has stalled then he/she is never going to get the nose up.
We do know from the statements that the Pilot had been apparently 'showboating' having gone around from a landing attempt at a nearby airfield so there may well have been some mis-handling prior to the crash that might have lead to a manoeuvre (accelerated) stall. For the non-aircrew here it is worth pointing out that the steady state stall speed increases by a factor of the sq rt of the G applied. In a 60 degree AoB turn the stall speed increases by nearly 50% (a factor of 1.4).
However it is just as possible that this was a case of mis-handled asymmetric following a loss of power leading to a loss of control.
Another possibility (which I am starting to favour having looked at the video again) is a fin-stall with a possible rudder hard-over. Showboating using rudder reversal(s) would give the same symptoms (dependent upon a/c type). I don't have experience of the King Air but the Jetstream (similar configuration) certainly would fin-stall and rapidly drop a wing if you mis-handled (mis-footed?) the rudder. The only way to recover was to trade height for airspeed, so you didn't do it close to the ground.
Alternatively it was merely poor piloting and lack of awareness that lead to the ground reaching up and smiting them.
Ginetta G15 Girl said:
Another possibility (which I am starting to favour having looked at the video again) is a fin-stall with a possible rudder hard-over. Showboating using rudder reversal(s) would give the same symptoms (dependent upon a/c type). I don't have experience of the King Air but the Jetstream (similar configuration) certainly would fin-stall and rapidly drop a wing if you mis-handled (mis-footed?) the rudder. The only way to recover was to trade height for airspeed, so you didn't do it close to the ground.
Is that when rolled over so the fin is near horizontal & being used with lots of rudder to keep the nose up - then the fin can stall the same way as a normal wing?I seem to recall doing it a few times with RC planes & most things scale up to full size aircraft ok.
Not exactly.
Fin-stall generally occurs at low-speed high Alpha (Angle of Attack) when there is significant side-slip (15-20 degrees). The critical component being the high degree of side-slip.
This large side-slip angle occurs because of a rapid yawing moment which is caused by:
1. Small but rapid rudder inputs .
2. Abnormally large rudder deflections.
3. Rapid rudder reversals.
As the a/c approaches the critical side-slip angle heavy fin buffet occurs. If the side-slip is allowed to go beyond the onset of buffet the outboard wing may stall owing to the fuselage masking the relative airflow. This will result in a loss of both lateral and directional stability. Furthermore, the nature of the high set tailplane (in the case of the Jetstream) means that it may be masked with a consequent loss of pitch authority.
The only way out of this is to kill the side-slip, but you can't control your way out because you have lost both directional and lateral stability. Ergo you need to increase speed to regain control (get the nose down). If you have lost pitch control you are going to need a lot of height to trade. Hence you don't want to do it close to the ground!
An awful lot of pilots are unaware of the fin-stall phenomenon and may not react fast enough to the buffet in which case it's 'Game Over'.
Fin-stall has killed a number of C-130 crews (Nov 71 at Little Rock, Jan 81 at Ramstein and Feb 92 at Evansville) and is suspected to be at the root of the loss of the American Airlines 587 Airbus A300 at JFK in Nov 01.
Fin-stall generally occurs at low-speed high Alpha (Angle of Attack) when there is significant side-slip (15-20 degrees). The critical component being the high degree of side-slip.
This large side-slip angle occurs because of a rapid yawing moment which is caused by:
1. Small but rapid rudder inputs .
2. Abnormally large rudder deflections.
3. Rapid rudder reversals.
As the a/c approaches the critical side-slip angle heavy fin buffet occurs. If the side-slip is allowed to go beyond the onset of buffet the outboard wing may stall owing to the fuselage masking the relative airflow. This will result in a loss of both lateral and directional stability. Furthermore, the nature of the high set tailplane (in the case of the Jetstream) means that it may be masked with a consequent loss of pitch authority.
The only way out of this is to kill the side-slip, but you can't control your way out because you have lost both directional and lateral stability. Ergo you need to increase speed to regain control (get the nose down). If you have lost pitch control you are going to need a lot of height to trade. Hence you don't want to do it close to the ground!
An awful lot of pilots are unaware of the fin-stall phenomenon and may not react fast enough to the buffet in which case it's 'Game Over'.
Fin-stall has killed a number of C-130 crews (Nov 71 at Little Rock, Jan 81 at Ramstein and Feb 92 at Evansville) and is suspected to be at the root of the loss of the American Airlines 587 Airbus A300 at JFK in Nov 01.
Edited by Ginetta G15 Girl on Thursday 9th January 14:20
Ginetta G15 Girl said:
dr gn had what I perceived to be a snide dig at my post (he's done it before)
True on both counts. It was meant to be more of a joke, but either way I apologise.Ginetta G15 Girl said:
and I 'bit' slightly (note to self: Try not to post late at night when tired). As a result we have pages of people leaping to defend dr gn and impugn my character (with some rather childish name calling).
This wasn't the intention of my initial comment, and I agree that posting things when tired or bored can be a very bad thing. Things can soon get out of hand.Ginetta G15 Girl said:
Aside from the fact that I would imagine dr gn to be perfectly capable of standing up for himself, that says far more about the commentators that it does about either me or dr gn.
For some inexplicable reason I have always been fascinated by aircraft, but I have never flown a real one. My assumptions were based on a limited knowledge of designing and flying my own model aircraft, and a significant technical interest in aircraft in general though my job. As I said I was/am genuinely interested in how and why scenarios like the one in the video develop.I can fully understand how someone who has a lot of experience in a particular field (you) can get irritated when someone who hasn't (me) makes a comment, but let's all remember - me included - that everyone is good at something, and a bit of give and take can go a long way. At the end of the day...it's just an internet forum.
And thanks for the explanation.
I'm not a pilot of flying expert but I have seen plenty of light aircraft in action and (perhaps relevant been too and met a number of Icelandic people)
As a generalization, they are nuts. I guess living on an icy, active volcano where beer is £10 and eating reindeer all day long will make you like that?
Call it whatever you like but based on the video alone you would have to call it a fly-past/showboating gone wrong. The exact aeronautical description is slightly unimportant for the passengers (RIP) but I think most people know you can't bank right over without loosing height and clearly they didn't have enough of it to start with :-)
Kudos to the marshal who starts off on the left and legs it towards the accident before anyone else blinks, good man.
As a generalization, they are nuts. I guess living on an icy, active volcano where beer is £10 and eating reindeer all day long will make you like that?
Call it whatever you like but based on the video alone you would have to call it a fly-past/showboating gone wrong. The exact aeronautical description is slightly unimportant for the passengers (RIP) but I think most people know you can't bank right over without loosing height and clearly they didn't have enough of it to start with :-)
Kudos to the marshal who starts off on the left and legs it towards the accident before anyone else blinks, good man.
Sort of.
'Top Rudder' is useful in keeping the nose up at 90 degrees AoB, eg in a slow roll or a hesitation roll. However it isn't used in a normal AoB turn (quite the reverse in fact, in-turn rudder is used to prevent any 'skid').
In a normal turn what you are doing is tilting the Lift Vector (which is perpendicular to the wing surface) by banking the a/c so as to provide a turning force. Vector resolution will show that you still have an upwards vector component but you now also have a sidewards vector component. In producing this sidewards component (the turning force) the upwards component must reduce.
If you then do nothing the a/c will start to descend (smaller upwards vector component of the Lift vs the unchanged weight of the a/c). You stop the a/c descending by increasing the total Lift. You do this by either increasing speed (add power) or by increasing Alpha (Angle of Attack) ie pulling back on the stick (thereby adding G), or both.
So it is perfectly possible to fly a level turn at relatively high angles of bank.
'Top Rudder' is useful in keeping the nose up at 90 degrees AoB, eg in a slow roll or a hesitation roll. However it isn't used in a normal AoB turn (quite the reverse in fact, in-turn rudder is used to prevent any 'skid').
In a normal turn what you are doing is tilting the Lift Vector (which is perpendicular to the wing surface) by banking the a/c so as to provide a turning force. Vector resolution will show that you still have an upwards vector component but you now also have a sidewards vector component. In producing this sidewards component (the turning force) the upwards component must reduce.
If you then do nothing the a/c will start to descend (smaller upwards vector component of the Lift vs the unchanged weight of the a/c). You stop the a/c descending by increasing the total Lift. You do this by either increasing speed (add power) or by increasing Alpha (Angle of Attack) ie pulling back on the stick (thereby adding G), or both.
So it is perfectly possible to fly a level turn at relatively high angles of bank.
I watched the video again and paused it, right at the end the pilot seems to yank the stick back - too late I might add.
The turn tightens right up and the plane mushes
Also the nose of the plane is pointing at the ground almost as soon as it goes overhead- from the cockpit that would be a windscreen full of green and black not blue.
Or am I mistaken?
The turn tightens right up and the plane mushes
Also the nose of the plane is pointing at the ground almost as soon as it goes overhead- from the cockpit that would be a windscreen full of green and black not blue.
Or am I mistaken?
Ginetta G15 Girl said:
Not exactly.
Fin-stall generally occurs at low-speed high Alpha (Angle of Attack) when there is significant side-slip (15-20 degrees). The critical component being the high degree of side-slip.
This large side-slip angle occurs because of a rapid yawing moment which is caused by:
1. Small but rapid rudder inputs .
2. Abnormally large rudder deflections.
3. Rapid rudder reversals.
As the a/c approaches the critical side-slip angle heavy fin buffet occurs. If the side-slip is allowed to go beyond the onset of buffet the outboard wing may stall owing to the fuselage masking the relative airflow. This will result in a loss of both lateral and directional stability. Furthermore, the nature of the high set tailplane (in the case of the Jetstream) means that it may be masked with a consequent loss of pitch authority.
The only way out of this is to kill the side-slip, but you can't control your way out because you have lost both directional and lateral stability. Ergo you need to increase speed to regain control (get the nose down). If you have lost pitch control you are going to need a lot of height to trade. Hence you don't want to do it close to the ground!
An awful lot of pilots are unaware of the fin-stall phenomenon and may not react fast enough to the buffet in which case it's 'Game Over'.
Fin-stall has killed a number of C-130 crews (Nov 71 at Little Rock, Jan 81 at Ramstein and Feb 92 at Evansville) and is suspected to be at the root of the loss of the American Airlines 587 Airbus A300 at JFK in Nov 01.
I know what you mean now, thanks. I knew that could occur, but I didn't realise the name for it.Fin-stall generally occurs at low-speed high Alpha (Angle of Attack) when there is significant side-slip (15-20 degrees). The critical component being the high degree of side-slip.
This large side-slip angle occurs because of a rapid yawing moment which is caused by:
1. Small but rapid rudder inputs .
2. Abnormally large rudder deflections.
3. Rapid rudder reversals.
As the a/c approaches the critical side-slip angle heavy fin buffet occurs. If the side-slip is allowed to go beyond the onset of buffet the outboard wing may stall owing to the fuselage masking the relative airflow. This will result in a loss of both lateral and directional stability. Furthermore, the nature of the high set tailplane (in the case of the Jetstream) means that it may be masked with a consequent loss of pitch authority.
The only way out of this is to kill the side-slip, but you can't control your way out because you have lost both directional and lateral stability. Ergo you need to increase speed to regain control (get the nose down). If you have lost pitch control you are going to need a lot of height to trade. Hence you don't want to do it close to the ground!
An awful lot of pilots are unaware of the fin-stall phenomenon and may not react fast enough to the buffet in which case it's 'Game Over'.
Fin-stall has killed a number of C-130 crews (Nov 71 at Little Rock, Jan 81 at Ramstein and Feb 92 at Evansville) and is suspected to be at the root of the loss of the American Airlines 587 Airbus A300 at JFK in Nov 01.
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