Hawker Hunter down at Shoreham

[cwatters]

someone asked this question and suggested that the Queen should create a civilian version of the Victoria Cross to be awarded on an occasion like this.

One already exists. It's called the George Cross. It ranks alongside the VC.

https://en.wikipedia.org/wiki/George_Cross

One was awarded to..

Barbara Jane Harrison, an air stewardess on BOAC Flight 712, who died on 8 April 1968 after helping many passengers escape from an onboard fire at Heathrow Airport.

Aside: The VC can also be awarded to civilians but it's for gallantry in the presence of the enemy.

[Cows getting bigger]

Pace

Already and understandably so the CAA have made knee jerk legislation with no evidence to back up that legislation banning vintage aircraft from flying aerobatic displays and who knows what further restrictions will be placed on airshows as further evidence unwinds ?

Err, terminology please. The CAA have not made any form of legislation, they are not empowered by the Government to do so. They have put in place temporary measures and will review as necessary.

Let's look at this another way. A Gnat and a Hunter, both operated on Permits to fly, both based at North Weald, crash within a couple of weeks of each other. Now, I've no real visibility of how many 'vintage' jets there are out there, nor do I know how many operators, engineering organisations etc support these jets. To date, no one has presented any evidence of technical malfunction, or not. We, the great unwashed, simply don't know.

Personally, I think the measures are, to use your word, understandably prudent.

[keewee]

Credit due

Credit is due after this tragic incident to all responding personnel & authority. There is a plethora of paperwork & practice that goes into responding to an incident such as this & training is key.
At the blunt end the emergency response - outstanding. The back-up to that (e.g. PA announcements etc) - superb. To the bereaved & their families, support - give thanks.
Now let AAIB etc do their job. No one is not affected by events such as this & the amazing thing that comes out of such tragedy is the intricate way it is dealt with to do justice where possible to all those affected.
Credit to all involved in due process.

[Ranger One]

Originally Posted by Cows getting bigger

Err, terminology please. The CAA have not made any form of legislation, they are not empowered by the Government to do so. They have put in place temporary measures and will review as necessary.

Let's look at this another way. A Gnat and a Hunter, both operated on Permits to fly, both based at North Weald, crash within a couple of weeks of each other. Now, I've no real visibility of how many 'vintage' jets there are out there, nor do I know how many operators, engineering organisations etc support these jets. To date, no one has presented any evidence of technical malfunction, or not. We, the great unwashed, simply don't know.

You only have to follow the breadcrumbs and see where they lead.

We've had two incidents in recent weeks, one involving a Gnat, the other a Hunter.

Look at what they have not done; they haven't brought in any temporary restrictions on airshow *venues*, on the *nature* of displays that may be performed, on the *display line* or box, or on *who* may perform aeros, in terms of hours or qualifications. Their concerns clearly are not in any of these areas.

Instead, they've grounded Hunters, and confined all other vintage jets, and *only* jets, to low-energy manoeuvres. To me, that says pretty damn clearly that they must Know Something, and their primary suspicion IS in the technical/maintenance/airworthiness area - of Hunters specifically, and vintage jets in general.

Otherwise, there would be no logic whatsoever in permitting (say) a P-38 to perform any aeros they like, but restricting (say) a Vampire to flypasts; the consequences of either landing on your head are equally dismal.

[Widger]

AAIB Special Bulletin on Hawker Hunter T7, G-BXFI


https://www.gov.uk/government/news/a...nter-t7-g-bxfi

[strake]

He held a valid Display Authorisation (DA), issued by the UK CAA, to
display the Hawker Hunter to a minimum height of 100 ft during flypasts and 500 ft during
Standard3
category aerobatic manoeuvres.

and then
commenced a descending left turn to 200 ft amsl, approaching the display line at an angle
of about 45º. The aircraft then pitched up into a manoeuvre with both a vertical component
and roll to the left, becoming almost fully inverted at the apex of the manoeuvre at a height
of approximately 2,600 ft amsl.

The press appear to have focused on these two aspects.

[slf99]

AAIB report

As per the AAIB report, and their comments about "no abnormal indications have been identified", can anyone comment as to whether 100KIAS at the apex of a loop inverted at 2,600 feet is a good or bad place to be in a Hawker Hunter attempting a loop?

[clareprop]

commenced a descending left turn to 200 ft amsl, approaching the display line at an angle
of about 45º. The aircraft then pitched up into a manoeuvre with both a vertical component
and roll to the left, becoming almost fully inverted at the apex of the manoeuvre at a height
of approximately 2,600 ft amsl.

It would appear that this is the key comment from the initial report. If I understand correctly, the loop was entered at around 200ft. I would ask those who know if that is within acceptable licensed parameters.

[yellowbobbyjet]

In display flying, an aerobatic manoeuvre is defined as more than 30 degrees pitch or more than 60 degrees roll. (CAP403) It is common to climb from approved flypast height to aerobatic height in a fluid motion before commencing the full manoeuvre. As long as the pitch attitude has not exceeded 30 degrees by the aerobatic minimum then, the aerobatic manoeuvre has not commenced below the minima. Flying in this way would give an additional margin to the pilot, while keeping the display flowing. Whether or not this manoeuvre was flown in this way is not clear from the initial AAIB report.

The headline in The Mail cannot be justified until they have made a much fuller analysis of the manoeuvre.

[9 lives]

It is common to climb from approved flypast height to aerobatic height in a fluid motion before commencing the full manoeuvre.

Yes but....

Depending upon the thrust available and power to weight ratio, that climb to the aerobatic entry altitude at 29 degrees pitch up, could be consuming energy which really should be saved for the maneuver. I Am far from a Hunter pilot, but any low performance propeller aerobatic aircraft I have ever flown requires a loop entry from either level flight, or a slight descent, or it will get mushy over the top. If mushy over the top, you're having to surrender altitude to gain airspeed down the back of the loop, or else you may pull too much with the ground rush, and mush semi stalled all the way down the back side of the loop, leveling at a much lower altitude than intended. Mushing down the back of a loop, because you did not accelerate to the flying speed you'll need to pull the required G, will consume a lot of altitude.

I'm confident that these factors are considered during the planning of the performance, I'm hopeful that pilots are entering the planned maneuver with the momentum they need, stored in speed.

[PrivtPilotRadarTech]

Yeah, I'm not a former RAF flying instructor, but I can read what one has to say:

David Learmount, a former pilot and RAF flying instructor, claimed the crash would not have happened if the plane had started at a higher altitude.
'If he had been 500 feet when he entered the manoeuvre and done exactly the same thing 11 people would be alive today.'

That the pilot survived the impact tells me that he almost made it. I would add that perhaps you Brits are better drivers, but in the USA a jet fighter pulling out of a vertical maneuver a few hundred feet over a 4 lane highway would likely cause a pileup.

[A310bcal]

Having read the AAIB special bulletin, one thing that has grabbed my attention is the map of Shoreham airfield along with the restricted airspace around it.

It is no wonder that the Red Arrows do not display at the show as with the lack of free airspace around the actual airfield, there would be no place for the big formations to fly without infringing the "no fly " airspace.

Even flying a Fast jet as a singleton pilot must raise quite a few issues as to where and how to turn and how best to achieve the maximum time in front of the audience and yet stay within the constraints imposed by the organisers and the unshown constraint of controlled airspace above.

I suspect that these issues will have an effect on recommendations for the future of Shoreham Airports displays , altho' I hope that despite the tragic recent events the Airshow should continue , with suitable caveats .

[Dr Jekyll]

I would add that perhaps you Brits are better drivers, but in the USA a jet fighter pulling out of a vertical maneuver a few hundred feet over a 4 lane highway would likely cause a pileup.

I'd like to think we are better drivers. But realistically most British drivers are too busy phoning texting drinking coffee and programming the sat nav to notice if the Helicopter assault from Apocalypse Now was happening in front of them.

[118.9]

I assume the AAIB issued this preliminary report early to correct some of the misreported aircraft trajectories in the press. In any event, Shoreham is very tight for fast jets, yet it looked like a well planned sequence, including the necessary vertical quarter (it was more) roll to reposition.
The worry for me is the energy-robbing tight positioning pattern required, especially for a jet weighing about 17 800 lbs (assuming a little fuel in the jugs) and 7400 lbs of thrust, which would have left very little speed margin. The fact that the AAIB reported from a cockpit camera that the apex speed was as low as 100 kts means that the speed margin was well spent. But, if the pilot had achieved more height than planned, it should have been enough to trade for speed, albeit that any attempt to load the swept wing too early would have caused a lot more drag than lift which is the last thing you need in a marginal situation. And it came to pass; the aircraft stalled into the ground.
It leaves me wondering if there was a brief incapacitation of the pilot at the apex?
Irrespective, I am sticking to my guns about low-level pull through manoeuvres in high inertia aircraft like the T7: ban them from airshows.

[notapilotbut]

Shoreham displays

I'm not all that sure ppl living locally such as myself would agree with you. I would be happy with the majority of aerobatic manouvres carried out over the sea, or flypasts at reasonable height. I complained a few years ago whilst living in South Lancing (within the no fly under 1000' zone) about low flying by the Eurofighter Typhoon which completed a roll over the town, but did not feel that the complaint was taken any way seriously. If the Hunter pilot was found to have begun the roll/quarter clover leaf either too low or too slow, and given that the last fatal crash at Shoreham was due to an unplanned manouevre (a roll into the ground), how could ppl living locally ever trust the pilots?

[notapilotbut]

Full tanks

118.9: the AAIB report states that the aircraft's tanks were filled before leaving the home airfield. I wonder how full those tanks would then be when he arrived at Shoreham, given a slightly easterly breeze and a south westerly flight? I have wondered about the drag effect of control inputs, and the energy needed to 'move' the aircraft from one orientation to the other, all taking away energy from momentum. Note my name - yet, I do know from sailing on small boats in very tight racing that any control input, albeit in water rather than in air, takes away momentum and uses energy.

[Capt Scribble]

Do not know if the flaps were still down in the descent but they were down at the top and would have tightened the looping manoeuvre. As they could be used as airbrakes at high speed they would have contributed to a loss of energy far more than control movements.

[Derfred]

Flaps:

I'm no supersonic pilot, but here is my laymans understanding of flaps on supersonic wings.

A subsonic wing has a rounded leading edge, to minimise airflow separation over the top of the wing at high angles of attack.

A supersonic wing has a much sharper leading edge to minimise shockwaves at the leading edge in supersonic flight.

Therefore, the supersonic wing is much more susceptible to airflow separation at high angles of attack when flying subsonic.

Hence, training edge flaps are often used in subsonic flight to reduce angle of attack - at speeds up to M.9 or so.

The use of flap throughout this manouevre is probably normal.

Those with more knowledge may enlighten us for this particular aircraft.

[A310bcal]

Flaps

From previous posts , it seems it is a normal procedure on a Hunter to have the flaps partly set during an aerobatic routine.

Check out G-CPTN's second video clip/film ( post no 462 ) and the Hunter has flaps set during its display.

[Ranger One]

Derfred, Hunter isn't supersonic, tops out at ~0.95M IIRC.

Others have described the use of the flaps much better than I ever could.

R1