Hawker Hunter down at Shoreham
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FWIW, in Canada:
I think any pilot would agree that pitch of more than 30 degrees would be an abnormal attitude.
“aerobatic manoeuvre”“aerobatic manoeuvre” means a manoeuvre where a change in the attitude of an aircraft results in a bank angle greater than 60 degrees, an abnormal attitude or an abnormal acceleration not incidental to normal flying;
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I don't agree for one!
It all depends on what you are doing/flying.
I used to display something where we were not cleared to carry out aerobatics but we would get 60 degrees nose down at 200'
Airbus 30 degrees up is abnormal. F22, not so much.
I think people are getting hung up on irrelevancies.
I don't know, though I have my suspicions, what went wrong with this display, but I guarantee that the problem was not lack of energy during the pull up due to having to climb to 500'
I have not flown the Hunter but I strongly suspect it has enough power to maintain speed with 30 degrees nose up.
It all depends on what you are doing/flying.
I used to display something where we were not cleared to carry out aerobatics but we would get 60 degrees nose down at 200'
Airbus 30 degrees up is abnormal. F22, not so much.
I think people are getting hung up on irrelevancies.
I don't know, though I have my suspicions, what went wrong with this display, but I guarantee that the problem was not lack of energy during the pull up due to having to climb to 500'
I have not flown the Hunter but I strongly suspect it has enough power to maintain speed with 30 degrees nose up.
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If you're at >100 feet at any sort of decent speed in a fast jet if you apply power and pull back in any sort of meaningful way by the time you hit 30 degrees of pitch you'll already be well above 500 feet....
The people saying this a/c was "flying too low" must be talking only of the end of the manoeuver. Because if my understanding is correct, it certainly wouldn't appear to be an accurate description of the entry
I would humbly suggest that insufficient 'pitch rate' in the early stages of the second half of the manoeuver is quite likely to provide a clue? At this point in time, if the reasons for that are indeed known, they certainly have not been made public.
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=4468 I would humbly suggest that insufficient 'pitch rate' in the early stages of the second half of the manoeuver is quite likely to provide a clue?.
If there was plenty of energy available at the top, then a higher 'pitch rate' is possible. But in a low energy state at the apex, the aircraft needs to be gently nursed over the top to allow the speed to recover with the aid of gravity and thrust. Any attempt to increase the 'pitch rate' prematurely will cause a massive rise in drag and loss of lift, and make matters worse.
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Aerobatic or not?
Close to the edge of the topic but pitch or bank limits are now ALLWAYS the identifier for aeros, for example manouervring for an attack or photographic run are exceptions to that rule, there may be others
Pitch
Someone I knew very well died in a similar accident to this one. The report found that prior to rolling inverted the pitch up was less than intended (due to a hazy horizon over the sea) which dictated entry altitude and thus left him with insufficient room to pull thorugh as intended.
He was very experienced indeed and had been a member of that famous jet aerobatic team. Even the best of us can get caught out on the day and at low level, mistakes carry a heavy penalty.
He was very experienced indeed and had been a member of that famous jet aerobatic team. Even the best of us can get caught out on the day and at low level, mistakes carry a heavy penalty.
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Can somebody point me to the document (CAA, EASA, ICAO etc) in which aerobatics is defined as exceeding 30 deg pitch?
http://www.caa.co.uk/docs/33/CAP%204...l%20events.pdf
7.6 Close formation flying is further classified into Basic, Intermediate and Advanced (Aerobatic) categories. The categories are defined as:
Basic - Gentle formation manoeuvring where the bank angle should be limited to approximately 30 degrees and the pitch angle to 30 degrees. Formation manoeuvring should be smooth and progressive.
Intermediate- snip
Advanced - snip
Basic - Gentle formation manoeuvring where the bank angle should be limited to approximately 30 degrees and the pitch angle to 30 degrees. Formation manoeuvring should be smooth and progressive.
Intermediate- snip
Advanced - snip
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There are some "definitions" of aerobatics or at least "clarifications" in the document at:
https://www.caa.co.uk/docs/2628/2013...2007SERA02.pdf
there are also some mentions in the document at:
https://www.caa.co.uk/docs/620/20100...mentsCRDb2.pdf
However there are no specifically quoted pitch or bank angles for aerobatic manoeuvres though in the first document specific aerobatic manoeuvres are quoted.
I did not see any definitions at Aerobatics either!
https://www.caa.co.uk/docs/2628/2013...2007SERA02.pdf
there are also some mentions in the document at:
https://www.caa.co.uk/docs/620/20100...mentsCRDb2.pdf
However there are no specifically quoted pitch or bank angles for aerobatic manoeuvres though in the first document specific aerobatic manoeuvres are quoted.
I did not see any definitions at Aerobatics either!
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Has anyone considered the weather to be a possible factor yet. The weather may appear to be benign but what is actually happening to an airmass is often unseen. Summer weather often produces unseen thermals, rising columns of warmed air with associated areas of sinking air. This often produces sea-breeze fronts near the coast and sometimes moving well inland. On the coastal side of a sea-breeze front there can be very large areas of sinking air, such areas going up to several thousand feet where the entire air mass may be going downwards at several hundred feet a minute. Suppose the airmass is descending at 300 fpm (not unusual) and an aircraft within it can perform a loop in 20 seconds and finishing at 100' agl it will have lost an extra 100' so end up at ground zero. Do display pilots factor this possibility into their displays.
I was not there and have not seen the weather reports, but if there were lots of fluffy cumulus clouds visible inland but none over the airfield and out to sea then there is a possibility that there was a large mass of descending air in the area, particularly if an unseen front had only recently passed through. The passage of such an invisible front would be normally be indicated by a change of wind direction along with the line of cumulus clouds moving further inland. Of course, in many instances there will be no cumulus but there will still be thermals and still be a hidden front with its associated large area of descending air.
Another possibility, if the wind is from a northerly direction, is wave effect caused by the hills to the north. Again, there may be visual clues from wave clouds but not always. Again, these can produce very large areas of both rising and descenting air in the order of hundreds of feet per minute.
I was not there and have not seen the weather reports, but if there were lots of fluffy cumulus clouds visible inland but none over the airfield and out to sea then there is a possibility that there was a large mass of descending air in the area, particularly if an unseen front had only recently passed through. The passage of such an invisible front would be normally be indicated by a change of wind direction along with the line of cumulus clouds moving further inland. Of course, in many instances there will be no cumulus but there will still be thermals and still be a hidden front with its associated large area of descending air.
Another possibility, if the wind is from a northerly direction, is wave effect caused by the hills to the north. Again, there may be visual clues from wave clouds but not always. Again, these can produce very large areas of both rising and descenting air in the order of hundreds of feet per minute.
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Kudos to Ka -2b Pilot for raising the question that should first come to mind.
Highly localized downdrafts are far from an unknown phenomenon at coastal boundaries, as he says and can be accentuated by topographic features. There were at least two hills in the immediate vicinity of 200ft. With the tolerances required for the manoeuvre even localized 20/ft sec winds would erase the margin of safety implied by the visuals in 20 secs, i.e. the manoeuvre gets squashed to the ground.
Yet there is little discussion along this obvious first line of inquiry.
Highly localized downdrafts are far from an unknown phenomenon at coastal boundaries, as he says and can be accentuated by topographic features. There were at least two hills in the immediate vicinity of 200ft. With the tolerances required for the manoeuvre even localized 20/ft sec winds would erase the margin of safety implied by the visuals in 20 secs, i.e. the manoeuvre gets squashed to the ground.
Yet there is little discussion along this obvious first line of inquiry.
Originally Posted by AmuDarya
Kudos to Ka -2b Pilot for raising the question that should first come to mind.
Highly localized downdrafts are far from an unknown phenomenon at coastal boundaries, as he says and can be accentuated by topographic features. There were at least two hills in the immediate vicinity of 200ft. With the tolerances required for the manoeuvre even localized 20/ft sec winds would erase the margin of safety implied by the visuals in 20 secs, i.e. the manoeuvre gets squashed to the ground.
Yet there is little discussion along this obvious first line of inquiry.
Highly localized downdrafts are far from an unknown phenomenon at coastal boundaries, as he says and can be accentuated by topographic features. There were at least two hills in the immediate vicinity of 200ft. With the tolerances required for the manoeuvre even localized 20/ft sec winds would erase the margin of safety implied by the visuals in 20 secs, i.e. the manoeuvre gets squashed to the ground.
Yet there is little discussion along this obvious first line of inquiry.
As for sink in the lee of a hill, 12 knots down would be more typical of wave rotor in the mountains. And this time the hill is to the north and the wind south-easterly
Last edited by aox; 10th Sep 2015 at 10:21.
I've done a lot of paragliding in the Shoreham area, and know the local sea breeze setup quite well; I was also at the show. I never saw any sign at all of a sea breeze setting up, even later in the afternoon. The only wind I was aware of was the ESE breeze mentioned in the AAIB bulletin, which seemed to decrease over the course of the afternoon.
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The discussion is moving into what was my gut instinct when I was told the sad news and watched the video.
My initial feelings were that a combination of weather factors could have either created the situation or compounded some other marginal problem or deviation from plan:
- tailwind component during the bottom of the manoeuvre
- warm humid air impacting performance and lift to some degree
- orographic effects
- and perhaps fuel load.
WB
My initial feelings were that a combination of weather factors could have either created the situation or compounded some other marginal problem or deviation from plan:
- tailwind component during the bottom of the manoeuvre
- warm humid air impacting performance and lift to some degree
- orographic effects
- and perhaps fuel load.
WB
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Here is the weather for most of the relevant times, perfect conditions for an air display.
FC 22/08/2015 17:00-> TAF EGKA 221700Z NIL=
FC 22/08/2015 13:57-> TAF EGKA 221357Z 2215/2219 11010KT CAVOK
PROB30 TEMPO 2217/2219 12015G25KT=
FC 22/08/2015 11:00-> TAF EGKA 221100Z 2212/2219 12010KT CAVOK
PROB30 TEMPO 2217/2219 12015G25KT=
FC 22/08/2015 08:03-> TAF EGKA 220803Z 2209/2218 VRB03KT CAVOK
BECMG 2209/2212 12010KT=
FC 22/08/2015 08:01-> TAF EGKA 220801Z 2208/2215 VRB03KT CAVOK
BECMG 2209/2212 12010KT=
FC 22/08/2015 05:00-> TAF EGKA 220500Z NIL=
FC 22/08/2015 02:00-> TAF EGKA 220200Z NIL=
SA 22/08/2015 13:50-> METAR EGKA 221350Z 11010KT CAVOK 25/17 Q1012=
SA 22/08/2015 13:20-> METAR EGKA 221320Z 11010KT CAVOK 25/17 Q1013=
SA 22/08/2015 12:50-> METAR EGKA 221250Z 11011KT CAVOK 25/17 Q1013=
SA 22/08/2015 12:20-> METAR EGKA 221220Z 12012KT CAVOK 24/17 Q1013=
SA 22/08/2015 11:50-> METAR EGKA 221150Z 11011KT CAVOK 23/17 Q1014=
SA 22/08/2015 11:20-> METAR EGKA 221120Z 11011KT CAVOK 23/17 Q1014=
SA 22/08/2015 10:50-> METAR EGKA 221050Z 12010KT CAVOK 22/17 Q1014=
SA 22/08/2015 10:20-> METAR EGKA 221020Z 13008KT CAVOK 22/18 Q1014=
SA 22/08/2015 09:50-> METAR EGKA 220950Z 12010KT CAVOK 22/17 Q1014=
Unless some kind of freak, unrecorded weather phenomenon suddenly and momentarily occurred of sufficient magnitude to affect the performance of a jet fighter such as the T7, weather not a factor.
FC 22/08/2015 17:00-> TAF EGKA 221700Z NIL=
FC 22/08/2015 13:57-> TAF EGKA 221357Z 2215/2219 11010KT CAVOK
PROB30 TEMPO 2217/2219 12015G25KT=
FC 22/08/2015 11:00-> TAF EGKA 221100Z 2212/2219 12010KT CAVOK
PROB30 TEMPO 2217/2219 12015G25KT=
FC 22/08/2015 08:03-> TAF EGKA 220803Z 2209/2218 VRB03KT CAVOK
BECMG 2209/2212 12010KT=
FC 22/08/2015 08:01-> TAF EGKA 220801Z 2208/2215 VRB03KT CAVOK
BECMG 2209/2212 12010KT=
FC 22/08/2015 05:00-> TAF EGKA 220500Z NIL=
FC 22/08/2015 02:00-> TAF EGKA 220200Z NIL=
SA 22/08/2015 13:50-> METAR EGKA 221350Z 11010KT CAVOK 25/17 Q1012=
SA 22/08/2015 13:20-> METAR EGKA 221320Z 11010KT CAVOK 25/17 Q1013=
SA 22/08/2015 12:50-> METAR EGKA 221250Z 11011KT CAVOK 25/17 Q1013=
SA 22/08/2015 12:20-> METAR EGKA 221220Z 12012KT CAVOK 24/17 Q1013=
SA 22/08/2015 11:50-> METAR EGKA 221150Z 11011KT CAVOK 23/17 Q1014=
SA 22/08/2015 11:20-> METAR EGKA 221120Z 11011KT CAVOK 23/17 Q1014=
SA 22/08/2015 10:50-> METAR EGKA 221050Z 12010KT CAVOK 22/17 Q1014=
SA 22/08/2015 10:20-> METAR EGKA 221020Z 13008KT CAVOK 22/18 Q1014=
SA 22/08/2015 09:50-> METAR EGKA 220950Z 12010KT CAVOK 22/17 Q1014=
Unless some kind of freak, unrecorded weather phenomenon suddenly and momentarily occurred of sufficient magnitude to affect the performance of a jet fighter such as the T7, weather not a factor.
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There has been some very interesting speculation in the last page or so here, but I doubt most of you have much concept of how small the influence of the weather phenomena you're discussing is on a fast jet. I'm sorry to say that your lack of understanding has taken you up a blind alley. Sea breezes, down draughts and inversions can pretty safely be discounted as serious threats to fast jet aeros.
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There has been some very interesting speculation in the last page or so here, but I doubt most of you have much concept of how small the influence of the weather phenomena you're discussing is on a fast jet. I'm sorry to say that your lack of understanding has taken you up a blind alley. Sea breezes, down draughts and inversions can pretty safely be discounted as serious threats to fast jet aeros.
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This pilot almost got away with his manoeuvre. If he'd had another couple of hundred feet, it would have just been another 'interesting' clip on youtube. There are many clips there of near misses (and non misses) with the terra firma, usually by well trained military pilots flying a variety of modern fighters. It can happen to the best of pilots in the best aircraft. And it regularly does....
If he'd smacked it into some farmland, there would have been a great deal less fuss, but it would have been the same accident as far as the nuts and bolts of what caused it are concerned. I suspect calls for 'something to be done' would be just as absent as they were after the recent Gnat accident.
Heaven forbid that the findings of the AAIB should be anticipated, but I'd happily bet my next months wages that this was just exactly what it appears to be.
Not the first by a long way, or the last.
Barring the odd unfortunate occurrence, like this one, the 'system' has done a damn good job of protecting those near to, and attending, Airshows for decades. Quite a few decades...Has everything to be zero risk?
Precisely nothing needs to be done, apart from the CAA resisting the urge to kneejerk the very much attended and enjoyed UK Airshow scene into another 'elf 'n safety, hard hat zone.
If he'd smacked it into some farmland, there would have been a great deal less fuss, but it would have been the same accident as far as the nuts and bolts of what caused it are concerned. I suspect calls for 'something to be done' would be just as absent as they were after the recent Gnat accident.
Heaven forbid that the findings of the AAIB should be anticipated, but I'd happily bet my next months wages that this was just exactly what it appears to be.
Not the first by a long way, or the last.
Barring the odd unfortunate occurrence, like this one, the 'system' has done a damn good job of protecting those near to, and attending, Airshows for decades. Quite a few decades...Has everything to be zero risk?
Precisely nothing needs to be done, apart from the CAA resisting the urge to kneejerk the very much attended and enjoyed UK Airshow scene into another 'elf 'n safety, hard hat zone.
@AtomKraft
Well, I very much hope it is.
People seem to be forgetting that this "stunt" (and I use the word quite deliberately), killed 11 people, all of whom were where they were on their legitimate business and had every right to believe they were safe, and that some prune was not about to drop 10 tons of fuel filled aircraft on top of them.
The accident was foreseeable and preventable. The CAA's almost immediate reaction by restricting this kind of display was not "knee-jerk" reaction, but a belated recognition that it is not acceptable to put the general public at risk for the pleasure of a few.
As a fellow human being, I wish the pilot a speedy recovery, but he, and all those in the approval chain behind this very obviously dangerous manoeuvre must expect to bear the cost, judicial and otherwise.
Not the first by a long way, or the last.
People seem to be forgetting that this "stunt" (and I use the word quite deliberately), killed 11 people, all of whom were where they were on their legitimate business and had every right to believe they were safe, and that some prune was not about to drop 10 tons of fuel filled aircraft on top of them.
The accident was foreseeable and preventable. The CAA's almost immediate reaction by restricting this kind of display was not "knee-jerk" reaction, but a belated recognition that it is not acceptable to put the general public at risk for the pleasure of a few.
As a fellow human being, I wish the pilot a speedy recovery, but he, and all those in the approval chain behind this very obviously dangerous manoeuvre must expect to bear the cost, judicial and otherwise.
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'fast jet'
There has been some very interesting speculation in the last page or so here, but I doubt most of you have much concept of how small the influence of the weather phenomena you're discussing is on a fast jet. I'm sorry to say that your lack of understanding has taken you up a blind alley. Sea breezes, down draughts and inversions can pretty safely be discounted as serious threats to fast jet aeros.