AAIB investigation to Hawker Hunter T7 G-BXFI 22 August 2015
Wiggy. Later in the report it also states:
"The rpm at pull up (derived from the spectrum analysis of the action camera audio) was 7,530 audio, which reduced to less than 6,800 audio, possibly as low as 6,500 audio during the upward half of the manoeuvre and was increased transiently to 7,210 audio. It was 7,010 audio at the apex. This was contrary to the pilot’s declared nominal power setting of increasing to full power at or shortly after the pull-up. The throttle was not visible on the video and so it is not possible to confirm whether the rpms were pilot selected or due to an engine malfunction."
The number of variations in engine RPM (from the graph in the report) during the manoeuvre do not make sense. I know of no one that continually and deliberately moves the throttle(S) around that much during a loop ("bent" or otherwise), particularly pre-apex.
"The rpm at pull up (derived from the spectrum analysis of the action camera audio) was 7,530 audio, which reduced to less than 6,800 audio, possibly as low as 6,500 audio during the upward half of the manoeuvre and was increased transiently to 7,210 audio. It was 7,010 audio at the apex. This was contrary to the pilot’s declared nominal power setting of increasing to full power at or shortly after the pull-up. The throttle was not visible on the video and so it is not possible to confirm whether the rpms were pilot selected or due to an engine malfunction."
The number of variations in engine RPM (from the graph in the report) during the manoeuvre do not make sense. I know of no one that continually and deliberately moves the throttle(S) around that much during a loop ("bent" or otherwise), particularly pre-apex.
Pittsextra,
No, I don't. Not from what I'm reading in the body of the report. There are too many significant findings in the body of the report that are not reflected in the summary. Known instrument failures/malfunctions/miscallibrations and issues with the engine fuel control leading to very significant rpm reductions during the manoeuvre are all potential causal factors. In fact, I think they know the summary is incomplete as there are a number of issues where they have stated that they may report further on certain issues later. That smacks of an incomplete investigation.
No, I don't. Not from what I'm reading in the body of the report. There are too many significant findings in the body of the report that are not reflected in the summary. Known instrument failures/malfunctions/miscallibrations and issues with the engine fuel control leading to very significant rpm reductions during the manoeuvre are all potential causal factors. In fact, I think they know the summary is incomplete as there are a number of issues where they have stated that they may report further on certain issues later. That smacks of an incomplete investigation.
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So the pilot enters the manouvre at 185ft, his minimun height should have been 500ft, Entry speed 305 kts, should have been 350 kts, so at the point of entry things are no going well and negligent. Then full power is not applied, then the pilot fails to meet his target height of 4000ft and speed is 105 kts. In interview the pilot does not know the speed for the escape manouvre. Not really convinved that he had confused the speeds and safety gates between the JP3/5 and the Hunter, surely he knew what aircraft type he was flying. The report states he couldn't recall anything after the Wednesday before the accident, but while being treated at the accident site, he was lucid and reported feeling unwell prior to the flight. Yet this fact can not be established. Again if he felt unwell why did he continue with the display?
It will be interesting what the Police's next move will be. I would imagine he has tranfered his aircraft, cars and house into his wife's name by now,
It will be interesting what the Police's next move will be. I would imagine he has tranfered his aircraft, cars and house into his wife's name by now,
Homsap
Regards AH's memories of the event and the hours/days around it, before calling "foul" you might want to Google the likes of Post-traumatic amnesia (PTA).
As for your final comment, harsh and uncalled for, to say the least.
Regards AH's memories of the event and the hours/days around it, before calling "foul" you might want to Google the likes of Post-traumatic amnesia (PTA).
As for your final comment, harsh and uncalled for, to say the least.
Homsap,
You seem either to be quoting the summary without reading the body of the report (which are very different) or you are being very selective and picking out bits that fit your assumptions.
Inform yourself before posting judgements, please.
Addendum regarding altitudes as an example (from the body of the report):
The rotational speed of air traffic control radar antennas is such that the information they receive is not updated sufficiently frequently for accurate tracking of aircraft that are continuously changing direction and speed.
Errors associated with aligning the recorded radar track with specific points on the ground include random errors and systematic errors. These vary for the different radar heads for a given aircraft track and complicate the mixing of positional data from different radar sources. Pressure altitude data, referred to as ‘Mode C’, from different recorded radar tracks can be more readily combined as this information is transmitted from the same aircraft's transponder.
Some of the Mode C altitude data was automatically flagged by the system as ‘Not-validated’, including a signi cant proportion of altitudes recorded during the accident display. However, this ‘Not-validated’ radar data appears reasonable when compared with the validated radar data and other evidence, such as the motion captured by imagery and results of photogrammetry analysis. Radar data validation is discussed further in Section 1.16.2.
You seem either to be quoting the summary without reading the body of the report (which are very different) or you are being very selective and picking out bits that fit your assumptions.
Inform yourself before posting judgements, please.
Addendum regarding altitudes as an example (from the body of the report):
The rotational speed of air traffic control radar antennas is such that the information they receive is not updated sufficiently frequently for accurate tracking of aircraft that are continuously changing direction and speed.
Errors associated with aligning the recorded radar track with specific points on the ground include random errors and systematic errors. These vary for the different radar heads for a given aircraft track and complicate the mixing of positional data from different radar sources. Pressure altitude data, referred to as ‘Mode C’, from different recorded radar tracks can be more readily combined as this information is transmitted from the same aircraft's transponder.
Some of the Mode C altitude data was automatically flagged by the system as ‘Not-validated’, including a signi cant proportion of altitudes recorded during the accident display. However, this ‘Not-validated’ radar data appears reasonable when compared with the validated radar data and other evidence, such as the motion captured by imagery and results of photogrammetry analysis. Radar data validation is discussed further in Section 1.16.2.
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Indeed, it is covered in the report, Pozidrive, you are right. Too many others jumping to conclusion without reading the report.
For a year and a half now, people have been complaining about how long it's taken to publish. Now it's here, they seem unwilling to read it.
For a year and a half now, people have been complaining about how long it's taken to publish. Now it's here, they seem unwilling to read it.
Pozi,CM
I will give you the benefit of the doubt if you read what I wrote and confirm you understand.
The report identifies vapour, aparently from the wing tank area. The trail I refer to is from the fuselage/jetpipe and is visible in video online.
I will give you the benefit of the doubt if you read what I wrote and confirm you understand.
The report identifies vapour, aparently from the wing tank area. The trail I refer to is from the fuselage/jetpipe and is visible in video online.
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Wiggy...
I accept that he may later have suffered from from memory loss at a latter date, not least as he was placed into an induced coma.
I do not think my comments are harsh, if a pilot of a commecial flight crashed a aircraft as a result not abiding to DA/DH, approach speeds, or the regulated speed say below 10,000 feet, and as a result eleven people died, wouldn't we be calling it both professionally negligent and criminal.
Likewise, had the pilot been given too much morphine at the crash scene and died as result, wouldn't his family be calling the paramedics negligent and be suing the ambulance service.
But in fairness to the pilot, and putting aside any action by the police or CAA against him, whether he is in the right or wrong, I don't think anyone would want to carry the burden of guilt and in addition I would imagine 'on the balance of probabilty' through the civil court he will loose everything.
Again in saying I'm harsh, I do accept that in part the CAA are at fault as display authorision process is way out of date, which was the case in both this accident, the Gnat crash and others. Likewise you would think the local planning authority in conjunction with airports and the CAA, could place exclusion zones when displays take place, rather wasting their time investigating or persecuting people for illicit garden decking,etc..
Courtney Mil....
I think we all see things in a different way, and the 'selective' way I put it was as the events in terms of an error chain within say a few minutes, he may have misread the altimeter or ASI, or thought he was in a JP we will never know, as for the non application of power which might have been human error, if not had the engine malfunctioned, in any event in planning the display, I would hope the pilot might have had 'an escape plan' in the event of an engine or instrument failure at any stage of his display.
I accept that he may later have suffered from from memory loss at a latter date, not least as he was placed into an induced coma.
I do not think my comments are harsh, if a pilot of a commecial flight crashed a aircraft as a result not abiding to DA/DH, approach speeds, or the regulated speed say below 10,000 feet, and as a result eleven people died, wouldn't we be calling it both professionally negligent and criminal.
Likewise, had the pilot been given too much morphine at the crash scene and died as result, wouldn't his family be calling the paramedics negligent and be suing the ambulance service.
But in fairness to the pilot, and putting aside any action by the police or CAA against him, whether he is in the right or wrong, I don't think anyone would want to carry the burden of guilt and in addition I would imagine 'on the balance of probabilty' through the civil court he will loose everything.
Again in saying I'm harsh, I do accept that in part the CAA are at fault as display authorision process is way out of date, which was the case in both this accident, the Gnat crash and others. Likewise you would think the local planning authority in conjunction with airports and the CAA, could place exclusion zones when displays take place, rather wasting their time investigating or persecuting people for illicit garden decking,etc..
Courtney Mil....
I think we all see things in a different way, and the 'selective' way I put it was as the events in terms of an error chain within say a few minutes, he may have misread the altimeter or ASI, or thought he was in a JP we will never know, as for the non application of power which might have been human error, if not had the engine malfunctioned, in any event in planning the display, I would hope the pilot might have had 'an escape plan' in the event of an engine or instrument failure at any stage of his display.
Last edited by Homsap; 3rd Mar 2017 at 14:45.
Originally Posted by Homsap
I think we all see things in a different way, and the 'selective' way I put it was as the events in terms of an error chain within say a few minutes, he MAY have misread the altimeter or ASI, or THOUGHT he was in a JP we will never know, as for the non application of power which MIGHT HAVE BEEN HUMAN ERROR, if not had the engine malfunctioned, in any event in planning the display, I would hope the pilot might have had 'an escape plan' in the event of an engine or INSTRUMENT FAILURE [which he may not have known about] at any stage of his display.
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If you feel you don't need to base your assumptions on the entire report, or just can't be bothered to read it, then you are missing a LOT of facts.
I'll spell it out...
There are basic flight safety points to be deduced from the evidence presented in the summary. They are obvious to any professional aviator (as we both are/were) especially those trained to instruct/supervise/authorise (I was, I assume you were too).
Those basic lessons are both obvious and timeless - the detail does absolutely nothing to mitigate them in anyway whatsoever. It merely offers a much richer and deeper level of understanding of the actual events and contributing factors. Note also I refer ONLY to basic/general (or high level, if you prefer) lessons - not one word about blame, or how the contributing factors combined to create the outcome.
If you don't know what general lessons I refer to, I'm slightly shocked and can only wonder at your agenda, since I believe your knowledge of airmanship, flight safety and human factors to be at least as good as mine.
Maybe I'm wrong about that.
And now I'll depart and leave discussion those that want to debate the detail, comforted in the knowledge that regulations regarding air displays will be both strengthened and more rigorously enforced, thank goodness.
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Well,I've read it all. My thoughts:
AH may have pulled the trigger, but the system both manufactured and gave him the gun.
Entry to the manoeuvre has been demonstrated to be outside of normal parameters. This includes busting the base height of 500ft.
Some possible technical issues (engine RPM and altimeter). Note that the possible altimeter error would have displayed a value lower than actual. There's also evidence that the pilot had altered thrust demand during the loop manoeuvre during previous displays.
Continuing the loop from an apex of 2700ft was unachievable.
More interestingly and probable far more wide-reaching:Some possible technical issues (engine RPM and altimeter). Note that the possible altimeter error would have displayed a value lower than actual. There's also evidence that the pilot had altered thrust demand during the loop manoeuvre during previous displays.
Continuing the loop from an apex of 2700ft was unachievable.
Questionable DA/DAE procedures/process.
Maintenance and maintenance (regulatory) oversight was lacking.
Lack of understanding about who owned the 'risk' at air displays.
Poor, occasionally non-existent, safety management at many levels.
Summing-up my initial, most worrisome, thoughts in a sentence - The air display scene lacked effective oversight and suffered from ingrained and institutionalised denial. Maintenance and maintenance (regulatory) oversight was lacking.
Lack of understanding about who owned the 'risk' at air displays.
Poor, occasionally non-existent, safety management at many levels.
AH may have pulled the trigger, but the system both manufactured and gave him the gun.
There is a vapour trail from the jet pipe area at a couple of points during the flight (e.g. at about 4 seconds in this compilation https://www.youtube.com/watch?v=Mr4POEBz81s)
From memory, does the Hunter not have a fuel vent pipe in that genreal area?
Originally Posted by TOFO
There are basic flight safety points to be deduced from the evidence presented in the summary.
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I will also be reading the report from cover to cover, but I fear it will be difficult to aviod confirmation bias while reading. At least I will try my best to approach the report with an open mind, even though we all "know" what happened. 
There are too many significant findings in the body of the report that are not reflected in the summary. Known instrument failures/malfunctions/miscallibrations and issues with the engine fuel control leading to very significant rpm reductions during the manoeuvre are all potential causal factors.
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As an ex Hunter pilot I shall read the full report before making any significant comment.
At the moment I will merely limit myself to saying the machine will happily loop at sea level at 300 kts and ISA, and gain height at the display weight. 350 kts is not required, and indeed may not be desirable if keeping the display tight is a priority.
At the moment I will merely limit myself to saying the machine will happily loop at sea level at 300 kts and ISA, and gain height at the display weight. 350 kts is not required, and indeed may not be desirable if keeping the display tight is a priority.