Re-visiting the 1999 Hawk 200 Crash
They are not restrictions, but limits on effective performance. It's just the physics of it. To get technical, the ejection seat gun/rocket pack give the seat approximately a constant impulse. In practical terms, this means a set change in the velocity of the seat (say, 100mph change). If the seat is designed to go from zero to 100 mph with zero sink rate, then if there is already an aircraft sink rate of -20 mph (minus meaning downwards) an upright seat will go from -20 to +80 mph. Still a 100 mph change, but the first 20mph change was used to overcome the sink rate. Since the seat is moving more slowly upwards than designed after the gun/rockets fire, it won't get as high. If the aircraft is banked, some of the velocity change will be sideways, which is no use in an ejection above a flat surface. For example, with 30 degrees of bank, our seat will only gain 100*cos(30) = 86.6 mph upwards, so will therefore also not reach the desired maximum height for safe parachute opening.
The effects are cumulative. If the aircraft were sinking and banked as above, the vertical speed would go from -20 + 86.6 = + 66.6 mph. - a lot less than the + 100 mph with zero sink rate and bank (and you really don't want a number with 3 sixes in it!
).
The effects are cumulative. If the aircraft were sinking and banked as above, the vertical speed would go from -20 + 86.6 = + 66.6 mph. - a lot less than the + 100 mph with zero sink rate and bank (and you really don't want a number with 3 sixes in it!
).
Join Date: Mar 2011
Location: Did I Tell You I Was A Harrier Pilot
Posts: 79
Likes: 0
Received 1 Like
on
1 Post
A very sad event indeed.
Ninja'd by Fox3...
All modern zero-zero seats are just rockets that accelerate the pilot/seat combination to a speed whereby the chute will successfully open if ejection is initiated on the ground; watch the testing videos and you'll see that man-seat separation starts with an upward vector ie at max speed after rocket firing ceases.
A small bank angle on the ground (eg due to a gear collapse) will reduce the upward throw but will probably not prevent the chute from deploying successfully. The problem with high rates of descent is that the time from handle pull to the chute opening is something like 1.5 to 2.0 seconds (generic) and then the chute has to slow the pilot down enough so that a soft ground 'impact' can be achieved. During that time you can fall whilst decelerating quite a long way. The conservative rule of thumb is to eject when your height is above 0.1 x rate of descent (in feet per minute). So at 300 KIAS in the vertical (approx 30000 ft per min) the min safe ejection height will be 3000 ft AGL. The aircraft document set will contain specific details about rates of descent v heights for a successful ejection.
Ninja'd by Fox3...
All modern zero-zero seats are just rockets that accelerate the pilot/seat combination to a speed whereby the chute will successfully open if ejection is initiated on the ground; watch the testing videos and you'll see that man-seat separation starts with an upward vector ie at max speed after rocket firing ceases.
A small bank angle on the ground (eg due to a gear collapse) will reduce the upward throw but will probably not prevent the chute from deploying successfully. The problem with high rates of descent is that the time from handle pull to the chute opening is something like 1.5 to 2.0 seconds (generic) and then the chute has to slow the pilot down enough so that a soft ground 'impact' can be achieved. During that time you can fall whilst decelerating quite a long way. The conservative rule of thumb is to eject when your height is above 0.1 x rate of descent (in feet per minute). So at 300 KIAS in the vertical (approx 30000 ft per min) the min safe ejection height will be 3000 ft AGL. The aircraft document set will contain specific details about rates of descent v heights for a successful ejection.
DITYIWAHP is right about the time delays being very important too. In fact, on the Harrier, in the hover, the delay due to human reaction time is so critical that the advice used to be to eject immediately if there was any red warning caption. It may have been a harmless OXY caption, but in the around-a-second it took to look in and read an OIL caption or similar major engine problem, the aircraft would have built up enough sink rate to kill you, ejection or not.
In the Air Defence world, the sink rate calculation means that if are doing a 'post-hole' manoevre in air combat, going straight down supersonic, you are pretty much stuffed if you don't start recovery by 10,000 ft, as even the seat can't save you. Definitely not zero-zero.
In the Air Defence world, the sink rate calculation means that if are doing a 'post-hole' manoevre in air combat, going straight down supersonic, you are pretty much stuffed if you don't start recovery by 10,000 ft, as even the seat can't save you. Definitely not zero-zero.
Do a Hover - it avoids G
Join Date: Oct 1999
Location: Chichester West Sussex UK
Age: 91
Posts: 2,206
Likes: 0
Received 0 Likes
on
0 Posts
LJ
Thank you for your post 10.
The first para says it all and entirely accords with my understanding of the events surrounding the accident.
JF
Thank you for your post 10.
The first para says it all and entirely accords with my understanding of the events surrounding the accident.
JF
Do a Hover - it avoids G
Join Date: Oct 1999
Location: Chichester West Sussex UK
Age: 91
Posts: 2,206
Likes: 0
Received 0 Likes
on
0 Posts
I wrote an internal company memo after the first Hawk 200 accident way back in Feb 87. I would not change a word today. Sorry about the formatting.
Our Hawk 200 Accident
I have obtained a copy of the official accident report on the F20 display rehearsal accident, that happened in Canada en route to the Paris Air Show 1985. The report shows at least 10 remarkable similarities with our Hawk 200 accident.
1. Both pilots intended to pull up abruptly at high G in order to gain height, and then to obtain displacement from the runway by rolling as required, before turning back onto the runway heading.
2. Both pilots pulled the stick back when descending inverted, instead of when the aircraft was correctly banked.
3. Both reports discussed the effects of motion on the pilot as a likely cause of disorientation.
4. No fault was found with either aircraft.
5. Neither pilot had been given formal instruction on combating the effects of G, even though it is now available.
6. Both pilots were well practised and current in the routine.
7. The weather was ideal on both occasions.
8. No transmissions were made by either pilot associated with the final stages of the flight.
9. Neither pilot tried to eject although both could have done after the display sequence had first gone wrong.
10. The manoeuvres of both aircraft could be established by film or flight recorder.
I have copied the report widely in the hope that it will help senior management associated with this year's Paris participation appreciate the many different things that can be done to assist our display pilots to fly effective but safe displays. I am taking this opportunity to list below some points for discussion. I am sure others will be able to think of many more.
• Ensure that the display is properly developed, have it agreed and then fixed. Keep the pilot current.
• Obtain the best available advice on the effects of high G and rapid rolling because these are potentially greater with the latest breed of aircraft. If the best aeromedical advice referred to above recommends training on a centrifuge, do it.
• A ban on general test flying and navigation equipment, not needed for the display, being taken into the cockpit by the pilot.
• Formally establish a team to assist the display pilot, consisting of:
a. Another pilot.
b. A Flight Test engineer to acquire, process and log data on all
flights and make the records available as soon as possible.
(Video,Film, ADR, Voice etc)
C. The crew chief on the aircraft.
d. A marketing representative with the responsibility for all liaison with customers/press/company VIPs and to assist as the point of contact with the display team for all admin aspects of the rehearsals and actual displays. This person will enable the other members of the team to concentrate on executing the displays.
Only in exceptional circumstances should a rehearsal or display be flown without the full team being present.
Our Hawk 200 Accident
I have obtained a copy of the official accident report on the F20 display rehearsal accident, that happened in Canada en route to the Paris Air Show 1985. The report shows at least 10 remarkable similarities with our Hawk 200 accident.
1. Both pilots intended to pull up abruptly at high G in order to gain height, and then to obtain displacement from the runway by rolling as required, before turning back onto the runway heading.
2. Both pilots pulled the stick back when descending inverted, instead of when the aircraft was correctly banked.
3. Both reports discussed the effects of motion on the pilot as a likely cause of disorientation.
4. No fault was found with either aircraft.
5. Neither pilot had been given formal instruction on combating the effects of G, even though it is now available.
6. Both pilots were well practised and current in the routine.
7. The weather was ideal on both occasions.
8. No transmissions were made by either pilot associated with the final stages of the flight.
9. Neither pilot tried to eject although both could have done after the display sequence had first gone wrong.
10. The manoeuvres of both aircraft could be established by film or flight recorder.
I have copied the report widely in the hope that it will help senior management associated with this year's Paris participation appreciate the many different things that can be done to assist our display pilots to fly effective but safe displays. I am taking this opportunity to list below some points for discussion. I am sure others will be able to think of many more.
• Ensure that the display is properly developed, have it agreed and then fixed. Keep the pilot current.
• Obtain the best available advice on the effects of high G and rapid rolling because these are potentially greater with the latest breed of aircraft. If the best aeromedical advice referred to above recommends training on a centrifuge, do it.
• A ban on general test flying and navigation equipment, not needed for the display, being taken into the cockpit by the pilot.
• Formally establish a team to assist the display pilot, consisting of:
a. Another pilot.
b. A Flight Test engineer to acquire, process and log data on all
flights and make the records available as soon as possible.
(Video,Film, ADR, Voice etc)
C. The crew chief on the aircraft.
d. A marketing representative with the responsibility for all liaison with customers/press/company VIPs and to assist as the point of contact with the display team for all admin aspects of the rehearsals and actual displays. This person will enable the other members of the team to concentrate on executing the displays.
Only in exceptional circumstances should a rehearsal or display be flown without the full team being present.
JF
Wise words mate. It always really saddens me when highly respected and competent aviators 'buy the farm' when we all know they are more than capable of flying the manoeuvre in a less pressured environment. After Graham's accident, the next I was witness a couple of years later was Ted Girdler's sad demise off of the beach at Eastbourne. At the time I was probably at the peak of aviation skills as both an A2 OCU instructor and also on the BBMF. To see such magnificent individuals waste their lives in this way was sobering indeed.
We should all use this to be more wise after their untimely demise to try and stop it happening next time. I always think that financial pressure and aviation is a far greater risk than the human factor alone. Skill cannot always save us and luck is definately on the side of those that have astonished audiences at airshows/displays in the past. Sadly for Graham and Ted their luck ran out.
LJ
Wise words mate. It always really saddens me when highly respected and competent aviators 'buy the farm' when we all know they are more than capable of flying the manoeuvre in a less pressured environment. After Graham's accident, the next I was witness a couple of years later was Ted Girdler's sad demise off of the beach at Eastbourne. At the time I was probably at the peak of aviation skills as both an A2 OCU instructor and also on the BBMF. To see such magnificent individuals waste their lives in this way was sobering indeed.
We should all use this to be more wise after their untimely demise to try and stop it happening next time. I always think that financial pressure and aviation is a far greater risk than the human factor alone. Skill cannot always save us and luck is definately on the side of those that have astonished audiences at airshows/displays in the past. Sadly for Graham and Ted their luck ran out.
LJ
differing a/c types and 'loaded vs unloaded' rolls
Some of the previous posters have suggested that had the type been a Lightning or Jaguar or similar then the accident MIGHT have been avoidable, so without complicating my questions due to the gate positioning -
1. So is it correct that a more classically swept or delta would be able to hold a higher alpha over the straighter Hawk wing, with a proportional increase in induced drag?
2. At this specific point in the routine I understand the extra thrust of those types would mean that they had excess thrust available to overcome or balance the drag of high alpha but the Hawk couldn't due to having less thrust - they could have 'powered through' the drag?
3. I've seen the phrase mentioned on here that the 'Barrel roll' has claimed lots of pilots and is an underestimated manouver, - is there any specific reason why proximity to the ground being an obvious one?
Thanks in advance.
1. So is it correct that a more classically swept or delta would be able to hold a higher alpha over the straighter Hawk wing, with a proportional increase in induced drag?
2. At this specific point in the routine I understand the extra thrust of those types would mean that they had excess thrust available to overcome or balance the drag of high alpha but the Hawk couldn't due to having less thrust - they could have 'powered through' the drag?
3. I've seen the phrase mentioned on here that the 'Barrel roll' has claimed lots of pilots and is an underestimated manouver, - is there any specific reason why proximity to the ground being an obvious one?
Thanks in advance.
Just a desire to gain a better understanding of what happened, why it happened, at what point the maneuver went wrong, and how the resultant crash could have been avoided.
3. I've seen the phrase mentioned on here that the 'Barrel roll' has claimed lots of pilots and is an underestimated manouver, - is there any specific reason why proximity to the ground being an obvious one?
If you are not inverted at the top a barrel roll you will loose height, the problem that causes depends upon how much altitude you have to play with. The solution is simple, you just roll wings level.
As I said its a surprise that this accident happened and perhaps reflects military pilot training.
Really? You want to go there?! Let's see where this goes
I mean see where what goes? It can't go anywhere because how I've explained a barrel roll is how it is. The end. The picture at the "top" needs to be fully inverted. If it doesn't then if height loss could be an issue then stop pulling and rolling wings level is your friend.
You see it differently??
Pitts
I don't doubt your understanding of the barrel roll. I am calling into question your apparent disdain for military pilot training. I am also questioning your need to criticise a guy who made a fatal error. I'm sure if you'd been there you could have taught him to do it better and we wouldn't be having this conversation.
I'm guessing that you are well versed in aerobatic manoeuvres from your handle. Are you equally well versed in fast jet handling?
Do I really need to continue?
BV
I'm guessing that you are well versed in aerobatic manoeuvres from your handle. Are you equally well versed in fast jet handling?
Do I really need to continue?
BV
Sorry Bob but you misunderstand me. There is no disdain for military pilots and far from it. That's said there is little value to be gained from making some false god from military fast jet pilots, RAF and/or associates. In the end there by the grace of God go us all. We can all err, make mistakes, whatever, we could just as easily be talking spinning accidents with T67's couldn't we??
As for criticising the pilot in question I'm sorry but in the end (and sad to say) if he understood a barrel roll he wouldn't be dead that's the only conclusion. If by saying that it causes deep offence or upset then it doesn't change the fact. I'm not sure what my experience of a fast jet or otherwise changes that element.
As for criticising the pilot in question I'm sorry but in the end (and sad to say) if he understood a barrel roll he wouldn't be dead that's the only conclusion. If by saying that it causes deep offence or upset then it doesn't change the fact. I'm not sure what my experience of a fast jet or otherwise changes that element.
Pitts
I would think it safe to say that he understood a barrel roll - the pilot in question was a graduate of the Empire Test Pilots' School (ETPS), the very first Brit to fly the F117 Stealth Fighter (well before it was publically acknowledged), he flew Hunter, Hawk, Tornado, Jet Provost, Jaguar and a myriad of others including small aerobatic aircraft. As I understand it he was flying a display routine at low level in front of a crowd with tight display restrictions that he hadn't practiced very much.
Did he understand the barrel roll? - absolutely, as an ETPS graduate he could probably write you 10,000 words on the subject. Could he fly it safely? On a good day, yes, however he was probably having a bad day. He had been tasked at short notice to put something together - a pseudo role-demo come display without the normal full work up process. He paid for it with his life (and sadly someone else's).
Overall, Graham Wardell was a exceptionally skilled pilot who had a very bad day at the office...
I think that is why you have got BV's back up!
LJ
I would think it safe to say that he understood a barrel roll - the pilot in question was a graduate of the Empire Test Pilots' School (ETPS), the very first Brit to fly the F117 Stealth Fighter (well before it was publically acknowledged), he flew Hunter, Hawk, Tornado, Jet Provost, Jaguar and a myriad of others including small aerobatic aircraft. As I understand it he was flying a display routine at low level in front of a crowd with tight display restrictions that he hadn't practiced very much.
Did he understand the barrel roll? - absolutely, as an ETPS graduate he could probably write you 10,000 words on the subject. Could he fly it safely? On a good day, yes, however he was probably having a bad day. He had been tasked at short notice to put something together - a pseudo role-demo come display without the normal full work up process. He paid for it with his life (and sadly someone else's).
Overall, Graham Wardell was a exceptionally skilled pilot who had a very bad day at the office...
I think that is why you have got BV's back up!
LJ
The following users liked this post:
Hello Leon. I wasn't trying to pick a fight, the OP asked why it happened and at what point it went wrong and I was just explaining that in simple terms.
I’m sure Graham Wardell was a legend behind the stick. I’m sure he was a lovely guy and I mean and meant no offence to his memory, to those guys who knew him, worked with him and so on, but the thing that killed him wasn’t type experience, fast jet experience, crowd line, display restriction or role demo experience.
The thing that killed him is that at some point in that display the picture was wrong, he didn’t recognise it and as you say sadly he and someone else paid for it with their lives.
You say he understood a barrel roll, could write 10000 words on the subject as an ETPS graduate. Given all of that to some it may seem therefore that the humble barrel roll would hold no challenge, however whilst we wish to pay due respect to that experience and ability you have to reflect on what happened on the day.
I’m not sure what his process was for the display but in that part of the sequence the picture should have looked wrong and there would be a plan? That's normal. We can dress it how we like but in the end the mistake was simply not recognising that the picture was wrong and that pulling wasn’t going to save the situation.
I guess that is what I meant by saying he didn’t understand a barrel roll.
Does anyone have the official report into the accident as I’ve not seen it and I’d be interested to see how it was framed officially.
I’m sure Graham Wardell was a legend behind the stick. I’m sure he was a lovely guy and I mean and meant no offence to his memory, to those guys who knew him, worked with him and so on, but the thing that killed him wasn’t type experience, fast jet experience, crowd line, display restriction or role demo experience.
The thing that killed him is that at some point in that display the picture was wrong, he didn’t recognise it and as you say sadly he and someone else paid for it with their lives.
You say he understood a barrel roll, could write 10000 words on the subject as an ETPS graduate. Given all of that to some it may seem therefore that the humble barrel roll would hold no challenge, however whilst we wish to pay due respect to that experience and ability you have to reflect on what happened on the day.
I’m not sure what his process was for the display but in that part of the sequence the picture should have looked wrong and there would be a plan? That's normal. We can dress it how we like but in the end the mistake was simply not recognising that the picture was wrong and that pulling wasn’t going to save the situation.
I guess that is what I meant by saying he didn’t understand a barrel roll.
Does anyone have the official report into the accident as I’ve not seen it and I’d be interested to see how it was framed officially.
Pitts
Yeah, but, no, but...If he had flown the routine a few more times at 5,000ft base height then he may have made the same mistake a couple of times (having dished out at 4,500ft) and corrected it. When flying a fast jet the margins for error are far less - having flown Pitts, Extras, Chippies and a few aerobatic gliders in my time, compared to a fast jet it feels like a knife fight in a telephone box! If you bury the nose to 90 nose down at 250kts in a Hawk you will need at least 4,000ft to pull out without smacking into the ground or having to change your g-pants for clean ones. In a Tornado make that closer to 6-8,000ft!
Compare that to a Pitts then at 90 nose down at 180kts (no idea of Vne!) I would guess you need about 1,000-1,500ft? Have you ever flown low level aeros in your Pitts, the ground can seem awfully close as you max perform to meet your minimum stipulated CAP403 height?
As Fox 3 pointed out better than I, he was in 'coffin corner' as he let the nose drop below gate height. Even Martin Baker's finest couldn't save him once he started pulling hard to the heavy buffet.
I agree that he 'porked it' on the practice day and even more so on the day of his demise. He fully understood the discussion about the 'loaded roll' with the other Display Team that he discussed it with. Indeed they were absolutely gutted when he crashed and felt dreadful that he did it again. Sadly, he did it again - but how many civvy aero pilots debrief their sequence and then go on to make the same mistake again as they refly a compex series of manoeuvres according to their Aresti notes? You're spot on me old with 'to err is to be human'.
BTW, never seen the accident report. One wonders if it was 'sat on' due to the commercial involvement and as it was mil registered jet in a foreign country then it wouldn't have been AAIB material in 1999 either.
My other lasting memory of the event was I had an overwhelming urge to run towards the fireball; goodness knows why, as there was nothing I could do. The lass from the local embassy, who was standing next to me, fainted - that gave me something else to distract me and stop me being a silly-arse in trying to run to the fireball!
LJ
Yeah, but, no, but...If he had flown the routine a few more times at 5,000ft base height then he may have made the same mistake a couple of times (having dished out at 4,500ft) and corrected it. When flying a fast jet the margins for error are far less - having flown Pitts, Extras, Chippies and a few aerobatic gliders in my time, compared to a fast jet it feels like a knife fight in a telephone box! If you bury the nose to 90 nose down at 250kts in a Hawk you will need at least 4,000ft to pull out without smacking into the ground or having to change your g-pants for clean ones. In a Tornado make that closer to 6-8,000ft!
Compare that to a Pitts then at 90 nose down at 180kts (no idea of Vne!) I would guess you need about 1,000-1,500ft? Have you ever flown low level aeros in your Pitts, the ground can seem awfully close as you max perform to meet your minimum stipulated CAP403 height?As Fox 3 pointed out better than I, he was in 'coffin corner' as he let the nose drop below gate height. Even Martin Baker's finest couldn't save him once he started pulling hard to the heavy buffet.
I agree that he 'porked it' on the practice day and even more so on the day of his demise. He fully understood the discussion about the 'loaded roll' with the other Display Team that he discussed it with. Indeed they were absolutely gutted when he crashed and felt dreadful that he did it again. Sadly, he did it again - but how many civvy aero pilots debrief their sequence and then go on to make the same mistake again as they refly a compex series of manoeuvres according to their Aresti notes? You're spot on me old with 'to err is to be human'.
BTW, never seen the accident report. One wonders if it was 'sat on' due to the commercial involvement and as it was mil registered jet in a foreign country then it wouldn't have been AAIB material in 1999 either.
My other lasting memory of the event was I had an overwhelming urge to run towards the fireball; goodness knows why, as there was nothing I could do. The lass from the local embassy, who was standing next to me, fainted - that gave me something else to distract me and stop me being a silly-arse in trying to run to the fireball!
LJ