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-   -   AAIB investigation to Hawker Hunter T7 G-BXFI 22 August 2015 (https://www.pprune.org/rumours-news/591713-aaib-investigation-hawker-hunter-t7-g-bxfi-22-august-2015-a.html)

RetiredBA/BY 10th Mar 2017 07:47

I suggest 2 sheds and Lemain look up the aviation definition of altitude. It relates to MSL.
Height relates to a specified ground level !

Confusing the two could be lethal particularly when used in safety altitude, safety height context!

Lemain 10th Mar 2017 08:34

Hi RetiredBA -- I think you're being a little bit mean-spirited. I was trying to answer Hebog's question (9th March at 1303) and from his/her profile it looks as though they are not a pilot but someone who has a personal connection with this tragedy.

Hebog asked whether the pilot would have had to do mental arithmetic if there was a discrepancy in his altimeter. I thought that introducing the concept of 1013, Regional QNH, Airfield QNH, QFE etc would just confuse. So I stuck to the fundamentals - an altimeter is little more than a barometer with a knob. I hope that my simplified explanation won't have "lethal" consequences and in any case if Hebog isn't a pilot he'll probably have a few flying lessons before he flies solo.

I was unable to answer his post in full perhaps you could have a look and see if you can help.

2 sheds 10th Mar 2017 09:09

My point entirely, RetiredBA!

Ian W 10th Mar 2017 09:53


Originally Posted by Cows getting bigger (Post 9700825)
Where is this mythical Jet Provost that could actually achieve 305KIAS from a slowly descending turn at sea level?

Probably not pertinent to this thread but the JP Mk4 would do that easily, indeed it would do it in level flight with no problem. 440KIAS below 10,000ft very nice to fly BAC Jet Provost ? Jet Aircraft Museum unfortunately not too many left.

kenparry 10th Mar 2017 10:17


440KIAS below 10,000ft
It's a long time since I flew a JP, but my recollection is that the IAS limit was way below that, maybe around 330kt. ISTR that the JP3 was good for about 270kt full throttle at lowish level, the JP4 about 300kt.

dsc810 10th Mar 2017 11:40

This aircraft had in it a RR Avon Mk 122 giving 7600lb thrust ....so says the report.

Can those who have been giving comparable Hunter performance figures on here from their experience for loops etc tell us whether they were flying the T7 two seater variant or were they flying the single seater fighter variants and whether it had the higher rated Avon 200 series at around 1000lbs thrust in it when there were flying it.

Otherwise we are comparing apples and pears....

RetiredBA/BY 10th Mar 2017 12:25

Ian W: No JP 4 I ever flew could get anywhere near that. KP,s estimate sounds about right!
Lemain, Perhaps I came over a little strong.
However, many years ago I was a CAA IMC examiner (and an RAF IRE) and was frequently disappointed at the poor understanding by ppl holders of altimetery, something I tried to correct. I still hear of height and altitude being confused and their exact meaning being misunderstood.

Parson 10th Mar 2017 12:48

Oh dear - we are on a PROFESSIONAL PILOTS rumour network and we are debating the difference between altitude and height :ugh:

PDR1 10th Mar 2017 12:51

Surely not - that would be the altitude of insanity...

G0ULI 10th Mar 2017 13:34

Not to mention that QFE/QNH on that day was 1013 HPa or mbar!

sika hulmuta 10th Mar 2017 13:52

dcs810,

I presume you are referring to my posts. Same engine, mine was a single seat aircraft though. Although the 2 seater reputedly has a better performance than the single seaters due to area ruling. It always seemed to have an advantage in combat anyway and burn slightly less fuel.

Apples with apples here, give or take a few pounds of weight. That is what doesn't make sense as AH is no fast jet novice, and very able to fly this benign aircraft. But at the end the picture must have been very wrong.

I know others have seemingly excluded the possibility, but incapacitation of some sort is the only reason I can see.

Wetstart Dryrun 10th Mar 2017 14:49

Sika, a while back you asked 2 telling questions.

Why the early pull-up? - Maybe used to 6000ft runways, so a bit of compensation to centralise the display? Maybe the plan for the skewed loop was to apex a mile or so on the run-in and skew it on the way down with the arena in sight, noting the crowd line, display line and crowd centre, diving nicely over the fence ready for the next manoeuvre. Seems more likely than a bent pull-up with the field out of sight.

I think the crux question is why, on this pull-up, blind-sided and belly up to the airport, did he decide to throw away the planned manoeuvre, roll 90deg away from the 1000,s of people watching, get the field back in sight with possibe manoeuvre room and then float over the top at 100kts ish, which is about the slowest comfortable (?) speed to avoid a hammerhead or similar?

My best answer to this is the pilot recognised it was going wrong (engine power variation) and this was his best effort at an escape manoeuvre. Enough has been said about hours on type, currency, recency. A hunter flopping out of the vertical deserves respect and the escape manoeuve you described would be a hunter expert version, flying to vertical down, gaining speed and then pulling is the safer version if you have spare height.

I accept I have moved into speculation. Sorry, but this theory ,to me, explains controlled, albeit badly flown, flight path. More logical than the wrong aircraft or totally losing SA

Sorry again

John Farley 10th Mar 2017 14:54

Homsap

I am sorry it I did not make myself clear. I am sure he knew he was in a Hunter but that does not rule out selecting the wrong data base in one’s head. You may have much more experience than me of flying multiple types, but back in the old days MOD(PE) had me cleared for multiple types and 10 in one month was not uncommon. I certainly had to watch it. Fingers can slip on lists and so on.

nevillestyke 10th Mar 2017 16:27


Originally Posted by Parson (Post 9701761)
Oh dear - we are on a PROFESSIONAL PILOTS rumour network and we are debating the difference between altitude and height :ugh:

Not to mention elevation!

Homsap 10th Mar 2017 20:26

john Farley.....

I should say I and others have the highest regard for you as a test pilot. Can on only claim only thirty types and not as a test pilot, but I am an UK ATPL.

But I am very experienced in human factors, and I accept or understand as a test pilot being clearded by MOD (PE) for multiple types and ten types per month, might cause issues, in my opinion as both a pilot and psychologist, but not by way of criticism of you, I have difficulties with the thesis that AH thought he was in a JP, entry speed, and power setting, do not match, and the escape upon gate height was not met, escape was not excuted.

I made a previous reference to the A330 test flight fatality at Toulouse by NW chief test pilot, multiple flights on the same day, different types, on a near identical flight decks and business meetings. He was overloaded the types were similar.

Finally, and with all respect to you, John, if you had issues with up to ten types per month as a full time test pilot, if AH was flying an Airbus fulltime and JP Hunter, Hunter and RV8 very much part time, would that flag up issues.

H Peacock 10th Mar 2017 22:52


My best answer to this is the pilot recognised it was going wrong (engine power variation) and this was his best effort at an escape manoeuvre. Enough has been said about hours on type, currency, recency. A hunter flopping out of the vertical deserves respect and the escape manoeuve you described would be a hunter expert version, flying to vertical down, gaining speed and then pulling is the safer version if you have spare height.
Are you saying the Shoreham Hunter flopped out of the loop? I don't believe AH ever attempted an escape. Been mentioned before, but you'd never want to escape from a loop by putting the nose vertically down to gain speed, then pulling out. Speed may be very slow at the top, but you don't need to wait for another 90deg of the loop. Nose 10-40 deg below the horizon will suffice. Speed building rapidly - roll upright then ease out of the dive.

H Peacock 10th Mar 2017 22:55

JP 3A has a Vne of 350kts.
JP 5A has a Vne of 400kts.

Machinbird 11th Mar 2017 01:51

A-LOC, G-LOC
 
It is with some trepidation that I enter into this lovely discussion "dog fight" however I will throw my thoughts out there for consideration.

First, I am a former USN fast jet pilot and have pulled a lot of high g maneuvers and have a "feel" for the subject. ;)
My opinion on the initial Shoreham accident thread was that the pilot had experienced a disorienting physiological event during the pull up and in the subsequent mental recovery phase was confused and not thinking properly when he initiated the pull through.

A quick search in the medical literature brought this possibly relevant bit:

Only one previous study has assessed almost loss of consciousness (A-LOC) in operational fighter pilots, reporting an incidence rate of 14%. Research also indicates that 8-13% of pilots have experienced G-induced loss of consciousness (G-LOC). A-LOC can be as insidious as G-LOC due to the associated altered state of awareness and relative incapacitation time, making it a significant risk factor in the high +Gz environment. Royal Australian Air Force (RAAF) pilots currently fly the F/A-18 and Hawk 127, producing +Gz accelerations up to +7.5 Gz, which places these pilots at risk of both A-LOC and G-LOC.
METHODS:

A survey was administered to 100 active RAAF fighter pilots requesting information on G-induced visual and cognitive disturbances, A-LOC symptoms, and G-LOC. Details regarding type of aircraft, flying maneuvers performed and mission outcome were also sought.
RESULTS:

There were 65 RAAF fighter pilots who completed the survey (age 20-53 yr, height 168-193 cm, weight 64-110 kg, jet hours 30-5700 h). Of these pilots, 98% indicated they had experienced at least one visual or cognitive disturbance in the high G environment: gray-out 98%; black-out 29%; and A-LOC symptoms 52%, including abnormal sensation in limbs, disorientation, and confusion. There were 9% who indicated they had experienced G-LOC (50% were the pilot flying the aircraft).
Source link https://www.ncbi.nlm.nih.gov/pubmed/15892551

In my current occupation, I get to work brutally long days and micro-sleeps were a common hazard on the drive home. One interesting phenomena I noted was that following a microsleep event, my mental navigation plan was gone from memory and had to be re-created. If similar loss of plan applies to A-LOC experiences, it would create several seconds of confusion as the victim regains his bearings and re-creates the plan. Perhaps more research is needed on A-LOC to determine if a similar loss of plan effect exists.

For those who might be concerned about my microsleep experiences, I now have a strategy that has been effective in preventing further such experiences. (A cup of strong coffee immediately before the drive home.)

sika hulmuta 11th Mar 2017 06:59

I agree with John Farly and Machinbird. I can easily see a physiological event of some sort happening, and during a recovery awareness phase, selecting the wrong "database" could easily occur.

It would explain much.

Tay Cough 11th Mar 2017 07:39


Originally Posted by sika hulmuta (Post 9702525)
I agree with John Farly and Machinbird. I can easily see a physiological event of some sort happening, and during a recovery awareness phase, selecting the wrong "database" could easily occur.

It would explain much.

It would. I remain concerned as to why there is barely a passing mention of anything "medical" in the final report.


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