Spinning stories

[Worf]

This thread is in response to Lomcevak's excellent posts and rather broad hint to start a "spinning stories" thread.

Tell us about "memorable" spins. Suggested topics are spin trials of new aircraft (like the one about Tornado spin trials in the Jaguar thread), Flight Cadet Bloggs putting you in a unexpected spin, spins from which recoveries seeemed uncertain, interesting spinning characteristics of aircraft (my father particularly "liked" the HAL HT-2 and Prentice spinning behavior) and so on...

In anticipation

Worf

[Fox3snapshot]

I think some of the RAAF Macchi 326 test pilots could pass on some entertaining and at the same time concerning moments whilst spinning the jet after a major....some were so bent by the end of their service life they would only spin one way!

:ooh:

[Razor61]

Just so anyone interested doesn't have to go searching other threads, here is the Tornado Spinning story, a very informative read to all accounts...

Tornado Spinning Trial (http://www.tornado-data.com/History/Jeremy%20Lee/close_to_the_edge.htm)

[SirToppamHat]

I suspect the improtant thing is knowing when to get out....

Once attended an ACMI brief ine Deci where the Stn Cdr (Pilot)was putting in a guest appearance, having flown out to visit the sqn from the UK. Got to the end of a pretty standard brief for the 4 v 4 into ACT, when the briefing offr decided to ask a couple of straightforward questions including the lowest height from which to get out if the ac was in a flat spin or otherwise unrecoverable situation.

"Erm 250 feet"

was the response.

The question was re-phrased, placing emphasis on the nature of the emergency:

"Ah Yes, 1000 feet"

At this point, the QWI gave up:

"Shall we try 10,000 feet Sir?"

I'm pretty sure it didn't impact on the QWI's career (or the Stn Cdr's). What really sticks in my mind is the look on the face of the chap (a Nav if memory serves) who was due to fly with him ... he seemed to become progressively paler as the situation unfolded.

Happy Spinning!

STH

[Lafyar Cokov]

I remember once, I didn't complete my pre-spinning checks properly - and all the guys from the course burst into my room and caught me.........


Tug

[Roland Pulfrew]

Never trust a student to get it right!:uhoh: :\ :yuk:

[Icecap]

Perhaps, if he's reading this, S/L "Buffet" Bxxxxx might like to recount how he spun the mighty Nimrod MR 2 some years ago.............

[Art Field]

"Never trust a student to get it right", how true. Syerston, Jet Provost, Saudi, spin to right, perfect entry, OK recover, student freezes holding full into spin controls, shouting waste of time, "I have control" waste of time, thump round earhole finally worked. Did not give up smoking that day. What's this about flying pay????

[LOMCEVAK]

Worf,

Thanks for starting this. I will start writing my stories down and post them one at a time. They should include: Tornado GR1 inadvertent spin, Jet Provost 5 inverted spin from an erect entry, Hawk inverted spins, Tucano spin clearance trials (including full power spinning) and as many Hunter spin stories as you wish. Back to the typing!

Rgds

L

[LOMCEVAK]

In early 1987 the Tornado GR1 was coming to the end of the stores clearance and envelope expansion trials. The final sorties by the military test teams were to be flown on a pre-series airframe, P14, at the Italian flight test centre at Pratica Di Mare near Rome. Yet another week in Rome - it was going to be hell but someone had to do it! I was the Tornado GR1 project pilot on 'A' Squadron at Boscombe Down so I hastily volunteered myself. I was accompanied by one of 'A' Squadron's navigators, an experienced F4 man who had a few hours on the Tornado F3 and was easily coerced into this plot with: "Fancy some GR1 flying - and by the way it's in Rome". The flight test engineer (FTE) for the trial was an experienced helicopter FTE, but this was his first real Tornado trial having "crossed over".

The first sortie was to be flown with two 1500 l underwing fuel tanks and five BL755 cluster bombs. The first test point was a wind-up turn to the g/AoA limit (irrelevant to this tale) and the second test point was a rapid rolling test point in 25 cruise wing (wings fully forward, flaps and slats up) at 340 KIAS and 20,000 ft. The test was to commence at 18 degrees AoA in a constant speed descending turn, the aircraft rolled through the erect using full lateral stick (whilst maintaining constant longitudinal stick position), and after a 180 degree bank angle change the roll was to be rapidly reversed with full lateral stick and held for a further 180 degree bank change. The test was to be flown with the SPILS (spin prevention and incidence limiting system) switched off, a normal practise for Tornado handling trials at the time as this was the worst case. Now, I was a little circumspect about this test point as the clean aircraft SPILS off AoA limit for rapid rolling was 18 degrees and we had a lot of stores (albeit with empty underwing fuel tanks for this rolling test). Knowing that the company had not flown this test but had cleared it on modelling data, I asked how far we were from the departure boundary to be told: "You're well clear". At this stage I was less than 18 months into my first flight test tour and had not yet developed a healthy enough level of scepticism and cynicism about "LCCs", an abbreviation which I shall not define for fear of libel. Therefore, I accepted the brief in good faith.

The initial wind-up turn was uneventful and we set up for the rolling test. A very steep nose down, overbanked attitude was required with COMBAT power (fully rated Mk 103 engines) to try to maintain speed, and there was only a very brief period of stabilisation at 18 AoA in a left turn before the very rapid (less than 0.5 seconds) application of full right stick. The aircraft rolled smoothly but VERY slowly to the right and I remember thinking: "Why do they call this rapid rolling?". After 180 degrees of roll, the stick input was reversed to full left, again in about 0.5 seconds, and the aircraft started to roll to the left but at an even lower rate than before. Before the aircraft had reached wings level I realised that the roll response was not normal and started to centralise the stick (the rudder pedals had been neutral throughout). Too late! The nose sliced and the aircraft pitched up as it departed more rapidly and violently than anything I have seen before or since. Subsequent data analysis showed that it went from 340 KIAS into a fully developed spin in less than 2 seconds with a yaw acceleration of at least 140 degrees/second/second. As it departed I immediately centralised the stick, which did nothing. Based on Hunter spinning experience, I continued to full forward stick but that also did nothing; the aircraft was in a fully developed spin. I should add that I had flown a Hunter spin practise sortie only five days before so I was very current in swept wing spinning. I started to carry out the Aircrew Manual full spin recovery procedure: airbrakes in (they were), throttles idle (they were still at the fully forward COMBAT position, although the reheats had extinguished, so had to be retarded), full back stick (to minimise fin blanking) and full in-spin lateral stick. This latter action was to saturate the CSAS (the analogue fly-by-wire flight control system) by demanding a roll rate greater than can be achieved in spin, thus maintaining full spoiler and differential taileron deflection and providing some anti-spin moments. Now, I thought that we were spinning left so applied full left stick; the aircraft stayed in a fairly smooth and very steady spin.

At this stage I transmitted that we were spinning to our FTE who was on a radio link but had no telemetry data as this was not supposed to be high risk nor a high AoA trial! He instantly called back; "Centralise". We were a little past that stage. Two thoughts then went through my mind. Firstly, as altitude reduces, air density increases, aerodynamic damping improves and spin recovery characteristics get better. Then, followed about a nanosecond later by :"S**t, we're going to have to eject"! We were over the sea and the spinning ejection height was 10,000 ft. I had decided to go at 9,000 ft just to give the aircraft every chance to recover, knowing that the seat was still well within parameters. At 12,000 ft, a little voice from the back seat was heard for the first time during this event: "Twelve thousand". He was obviously thinking about ejecting as well. I have no idea how many turns we did from our 21,000 ft entry altitude down to 10,000 ft but it was quite a few. And then, as if by magic, at 10,000 ft the strip AoA gauge (an indicator to the left of the HUD) went from full scale deflection high to reading on scale. Based on Hunter experience, this told me that the aircraft was recovering from the spin although I could not detect any change in the rotation. Therefore, I immediately centralised the stick. I was very disorientated by this stage and could not read the HUD accurately but became aware that the airspeed indications changed from two to three digits; the airspeed was increasing. Now, the book said to level the wings when the speed builds to 200 KCAS then pull out of the dive. In this configuration, there was so much drag that it had only reached 130 KCAS by 8,000 ft and acceleration was very slow. Therefore, at that point I selected the manoeuvre flaps and slats down, rolled wings level, and started a gentle pull out of the dive. It was soon obvious that we were going to have plenty of separation from the sea, at which point the second rear seat comment was made: "Yeeeee Haaaaaa"! We bottomed at 3,000 ft.

The engines had not surged, there were a few CSAS failures (most of which reset) and every piece of navigation equipment had failed. We flew straight and level for about 5 minutes to allow our gyros to re-erect then followed a road back to Pratica for a gentle downwind join to land. Straight away we went to see the boss of the test squadron to tell him what had happened to his aeroplane. His reply? With a glare and very positive eye contact, "So, we almost get rid of the P14". I think that he would have preferred us to leave what was quite a hangar queen in the Mediterranean!

So why did it spin? Well, although the AoA had appeared to be steady at 18 degrees, it continued to increase after the initial lateral stick input was made, without any further aft stick input from me, to 20 degrees. This, unbeknown to us, was the predicted departure boundary. The sideslip generated during the roll reversal triggered the departure, and we validated the model! It is worthy of note that all SPILS off rapid rolling clearances had been set at 5 to 6 degrees below the departure boundary. Therefore, we would never have attempted the test point had we known that we were only 2 degrees below. This configuration was cleared to a limit of 15 degrees for service use.

And why did it take so long to recover? I had "sensed" that we were spinning left and had thus applied left lateral stick. We discovered when we analysed the flight test instrumentation data that we were actually spinning right and thus I had applied outspin roll control which generated some pro-spin moments. Subsequently, I discovered that just about everyone who had departed a Tornado inadvertently had either mis-identified the direction of departure or had been uncertain of the direction. The Tornado does have a very small turn indicator at the bottom of the attitude indicator but in my 36 hours on type at the point I had never noticed it making it, in my opinion, not likely to be found and interpreted correctly in the disorientation of a spin!

Why had other departures in service generally not resulted in a fully developed spin? Most had been with the same wing sweep angle (25 degrees) but with the manoeuvre flaps and slats down. In this configuration, the Tornado does not have a fully developed spin mode such that centralising the controls after departure will result in a recovery. With the manoeuvre flaps and slats up, especially with no stores on the outboard wing pylons, it will invariably go into a fully developed spin post departure.

I could carry on a lot longer analysing this incident, but I will await any questions. As one final thought, my recent Hunter spin experience when this happened was probably what gave me the little capacity that I had to recover this situation, and even then I mis-identified the direction of spin. If you are involved with manoeuvrable aircraft, take every opportunity that you can to practise spinning.

[sycamore]

Lomcevak, you should have remembered the vital piece of TP`s instrumentation......a piece of knotted string taped to the w/screen...on the outside...!!

[Razor61]

Absolutely great reading! :ok:

[The Rocket]

Excellent post LOMCEVAC.

Very interesting, and very thought provoking:eek:

[John Farley]

Well done LOMCEVAK. With an entry as quick as that I guess you had a nystagmus hence the misident of direction?

J

[Samuel]

1962, near Cottesmore,crash crew turn out to a Syerston-based JP lying in a farm paddock more or less in one piece, the student having ejected after failing to recover from a spin.

Pilot is located in another paddock about half-a -mile away, and duly collected by the crash crew and taken to view his aircraft, by which time the much be-medalled CO Syerston was also present.

"You alright?"

"Yes Sir!'

"Where's your parachute?"

"Err....".

"Go and get it, there's a good chap"

[treadigraph]

Superb account Lomcevak - can I suggest you submit this to my excellent successors at "Flog". Please do keep 'em coming...

Cheers

Treadders

[Impiger]

ACMI training in F4s during 1 v 1 v 1 the chap in the gunsight pulls a little too hard to the left and departs in majestic fashion to the right.

One turn, two turns, pops brake chute and recovers but is still in the windshield so .......

Scimitar 2, Scimitar 1 are you OK?

Scimitar 1, Scimitar 2 - ah yes I think so!

Roger - Fox 2; oh and ditch the chute now it'll look awfully shabby on the break otherwise.

[MLS-12D]

Do a Hover - it avoids GWhy would anyone want to avoid G?! :D

[lscajp]

To ensure good airmanship throughout your flight???

[BEagle]

Thanks for some excellent tales, Lomcevak! You TPs certainly earn your crust when exploring the spinning behaviour of swept wing jet!

It's guys like you who ensured that ham-fisted types like me learned to apply spin prevention techniques such as the 100 knot recovery in the Gnat and the 19 units(?) recovery from low speed in the F4.

Many thanks!!


Interesting to learn that Harrier mates avoid the G-spot.... That's what the Wegberg girls always suspected when the bona mates were at Wildenrath;)

[mr ripley]

Brand new B2 QFI on UAS Summer Camp in Germany, teaching Spinning 2 for the first time.

Spinning 2 = Academic full spins and recoveries.

Student reproduces Incipient Spin Recovery satis.

Student enters Spin, teach maintain spin = maintain full pro-spin controls whilst monitering height.

Student enters Spin and maintains Spin, teach recovery.

Now the big one.

Student enters Spin, maintains Spin then recovers on my command.

Nope.

Student enters spin, maintains spin then when ordered to recover decides to mumble a bit and let go of the controls.

I am a bit confused as students are not meant to do this. End up in a high rotational spin.

Spend what seems a while but wasn't, trying to decide whether to put controls back to eye pleasing pro-spin position before recovery or to just carry out recovery.

Decide to carry out recovery which does work but end up with a recovery at abandonment height.

Tell student that he got it wrong.

Climb back up for a re-teach of recovery. Student throws up during spin. Recover to base for sit down and a cup of tea.

What did I learn from that.

Spinning is one of those areas in flying where you can not afford for students to make mistakes.

When teaching spinning I subsequently kept a firm grip on the controls and only let them travel in the direction that I wanted them to.

[BEagle]

The fuel gauges on the Bulldog were notoriously unreliable. I once had a delayed recovery from a spin to the right which surprised me as the gauges indicated perfect balance and the student had applied precisely the correct tehcnique.

A few months later I was reading another QFI write-up on one of my students (a different one), in which he'd criticised him for poor spin recovery. That surprised me as I though he ws pretty good.

It turned out to be the same aircraft, so I demanded that the fuel gauges were checked. They were found to be reading incorrectly! So all the dutiful fuel balancing to achieve a < 3 gallon imbalance had just made things a lot worse.

If you took off with both tanks full, kept the selector on 'both' and ensured that the ball was in the middle throughout, you would probably have a much greater likelihood of correctly balanced fuel than relying on those lousy gauges!

[LOMCEVAK]

John F,

I have suffered nystagmus once whilst spinning (and for those of you like me who need the dictionary, nystagmus is an involuntary slow drift of the eyes followed by a rapid flick back, often caused by rotation of the body). It was following recovery from a flat spin in an Alpha Jet (front cockpit, harness unlocked) during which I had been subjected to around 3g "eyeballs out" longitudinal acceleration. After the aircraft stopped rotating, I could focus on the instrument panel without any problems, but looking at the horizon resulted in the whole world visually "flicking" in azimuth. This lasted for about 30 seconds - very interesting. In the Tornado incident, I attributed my disorientation to a vestibular function caused the very high yaw acceleration, combined with high roll and pitch rates at departure, and then the sustained yaw rate during the spin. I discussed it with the Institute of Aviation Medicine but they had no data on the effects of these high accelerations as they could not be achieved in the centrifuge.

Treadders,

I enjoy reading KF's articles, but when he runs out of stories, my arm could be twisted to contribute to "FLog". Are you at DX in May?

mr ripley,

You raise a very interesting point. Some aircraft, following a mishandled spin recovery that has resulted in a high rotational spin, need full pro spin controls to be re-applied in order to stabilise in the normal spin mode before the normal spin recovery drill is effective (early T67s I believe). An aircraft with spin characteristics such as this would never be given a UK Military Release to Service clerance for intentional spinning. Therefore, you chose the correct course of action.

It is probably worth saying for those who do not know the Bulldog that if, once stabilised in a fully developed spin, you moved the stick only about 1 inch forward of the back stop or release the rudder from the stop by the same amount, the spin would go VERY high rotational and would have a prolonged recovery.

Back to writing the next tale.

Rgds

L

PS. Anyone from the other side of the Atlantic flown the F-18 or F-16 departure demo rides or carried out inertia coupled departures in the T-2? They are interesting rides (especially the Hornet with 10.4 flight control software - inverted falling leaf mode).

[John Farley]

LOMCEVAK

The reason I mentioned nystagmus was that the IAM docs convinced me many yonks ago that after some high rate rides you should not trust your eyes. So when I had one such ride at Edwards in the second AV-8B (following an aerodynamic departure that popped up in the middle of doing an engine point -as they do....) at the debrief I said I had no idea which way it was rotating. This did not go down well with the young punchy marine who was flying chase who could not understand how a competent tp could fail to know something like that. When asked what he thought had happened it became clear that he was looking the other way and had missed the whole event. Two days later I chased him, he departed and despite my calls on the R/T failed to close the HP cock so wrote off the turbine of our instrumented donk. When I asked why he had failed to shut down the engine he replied he needed to make sure which way the aircraft was rotating. He was asked which way and said left. Wrong I said it was right. The tape said right too. He had never heard of a nystagmus.

J

[Wholigan]

Not quite a spinning story, but a form of departure that was slightly exciting for a while.

Once upon a time, a certain prooner was sat in the back of a Jaguar T2 on a dual combat 1 v 1 sortie. The chap in the front was flying the aircraft and it had got into a (relatively) slow speed situation. Yes I know that’s not a particularly good idea in a Jag!

As you probably know, the Jag does not have ailerons, it has spoilers. (Who the Hell could ever design an aircraft that does not have a lot of lift and then cause it to destroy some of that lift in order to roll ---- but that’s another story.) The chap in the front was using ailerons to roll the aircraft, when – in fact – in certain conditions (ie slow speed) it is much better to use the rudder. The prooner in the back said words to the effect of “use the bl00dy rudders” and then stamped on the rudder pedal to illustrate what he meant. At the same time the front-seater added a lot of aileron in the same direction. Guess what? The aircraft decided that it had had enough of this combined ham-fistedness and elected to do its own thing for a while. It was apparently quite interesting for the next few seconds or so – with lots of unburned fuel streaming around the outside of the cockpit from the intakes. A beer was had that evening!

[BEagle]

1v1 'combat' in the mighty SEPTIC pussycat? :\

That must be like 2 one-legged men at an ar$e-kicking party! :D

[UNCTUOUS]

Scene: Macchi MB326/Impala type

Task: Impress other Flt instructor (in rear cockpit) during end of Fiscal Year hours burn-off staff continuation sortie.

Sequence: A mixture of high g aerobatics culminating in a Porteus Loop (flick roll through 360 degrees using full pro-spin at the top of a loop)

Difficulty experienced:

1. Failed to recover from flick entry to Porteus and entered high rotational inverted spin with accelerometer fluctuating between -3.9 and +4.4g (neg g conf by later fatigue meter readings)

2. Other Flt Instructor kept saying his goodbyes after checking me central (and chortling a bit) - as I'd signed for the airframe no doubt (robbo always did have a great sense of humus).

3. Having peaked out at 20,000ft we were now passing 8000ft and it was looking like a back-breaking neg g punch-out when it suddenly snap-recovered itself.

Post-Flight Engineering Revelations

Engs found that large tip-tank on port side hadn't had all its toe-in/toe-out shims replaced on the fore and the aft locating spigots plus the big jeezus torque nut in the middle hadn't been done up (during an in-the-shop NDI inspection some many flights prior). Tip-tank had displaced and rotated on the wing-tip during the pro-spin entry evolution. Evidence for that was witness-marks plus one grease-held shim stuffed back into the hole by its relocating spigot.

Complication:

The Fun police at the higher HQ banned Porteus loops meaning that I had to work up a whole new low-level aero

display. That airframe subsequently wouldn't do a symmetrical buzz/buffet/judder max-rate turn without flicking

violently so it couldn't be utilized for student flying. The experts tried for a year but couldn't cure it. Someone

decided that it would be good for checking out test-pilot's trouble-shooting skills so it got shipped off to

irritate a whole new genus of unsuspecting tyros.

Theory: Asymmetric negative g rolling overstress can cause permanent deformations within a wing's attachment

structure

Lessons Learnt

a. Thinking and conversing under cyclically fluctuating pos/neg g causes voice to rise to a high pitch

b. The oral contraceptive abortion-avoidance strategy of an invitational "Handing over" doesn't work in dodgy

situations unless the other party is dumb enough to say "taking over"

c. Difficult to come up with a witty riposte when other cockpit says: "I'm impressed. What did you call this again?"

d. Departing suddenly, unexpectedly and violently during a stock-standard manoeuvre can be disorienting. When the triply checked recovery controls position then fails to work... after about 2 minutes you are quite clueless.

e. Looking out at alternate wing-tips during such a ride is highly unrecommended.

f. NDI isn't always non-destructive

[Yellow Sun]

JP3

Student was ex-UAS and had iro 130 hrs Chipmunk before starting the BFT course at Cranwell.

It was the second spinning sortie, the first one the day before having gone alright. Started off with me doing another patter/follow-through 4 turn spin before handing over to stude' for his attempts. Entry was fine and recovery OK except, whilst he centralised the rudder at the correct point (when the spin stopped) the rate of rudder movement was a little slow and we exited in an uncomfortable sideways manner until he reached the neutral position.

"No problem" thought I,"he did it alright yesterday and he's pretty competent" so I decided to rebrief him on the recovery and give him another go.

(As an aside- and maybe an echo of another thread - it was being gently suggested that maybe we should be treating the JP BFT phase as more of a type conversion, after all, they had all this "good experience" on the Chipmunk. "They aren't Flight Cadets now")

So, in we went for the 2nd spin. Good entry, held full pro-spin control, and I said "Recover!".

He did, unfortunately he took me completely by surprise by crisply centralising the rudders well before the spin had stopped! It was at this point I did the short course in Jet Provost high rotational spinning! Apart from the acceleration in roll rate to a value I wouldn't have believed the docile little jet was capable of, what I best remember is the size of the aerial farm at Digby very rapidly increasing. I took control, re-applied full anti-spin rudder and
effected a normal recovery, but it did seem to take an age, recovering just above the minimum height of 7000ft.

It was quiet for a bit after that as we both slowly and carefully re-erected our internal gyros.

Stude' broke the silence by saying "I don't think I got that
right" I agreed that it could be polished up, and we climbed (well, "struggled" - it was a Mk3) back up to FL180. I pattered a further spin, laying particularly emphasis on the use of the rudder.
He then did 2 more; perfect.

What did I learn?:

1. Don't accept any error in handling on spin recovery.

2. High rotational spins, even in the JP, even when you know the orientation and direction, are very disorientating.

What did I re-learn?

1. Students will always surprise you!

2. Don't try and save a little time when teaching critical items. If they don't get it right, then re-demo it until they do.

A somewhat chastened

YS

[Circuit Basher]

A Pre-PPL Spinning Story
Half my training was done in Canada, where full spin training is still mandatory part of the syllabus. I quite enjoyed this in a C172, although some days it took quite an effort to get it to spin, rather than spiral dive - I remember a whole hour of spins on a hot sunny day; I'm not usually one prone to going green, but I did gently mention to my instructor that I was beyond learning anything more and could we go home, please?! By the end of around 3.5 hrs of spin / stall training, he was getting me to recover after a set number of turns and on a given heading - that was quite fun!!

That training has saved me from one possible incident in a C150 that dropped a wing in a stall straight into a spin when I was on a pre-PPL solo jolly trying to get my 10hrs solo up.

I had done all the tests, exams, etc and was still an hr short on solo time. Went up for final sortie and was doing 'general handling' sortie in a C152, stalling at varying power settings. Got caught out on one at full power when the wing suddenly dropped and I finished up in a fully developed spin - luckily I was at 5k ft and with the previous spin training was able to recover quickly, but I was a somewhat deflated student after that!! Also, was about 0.8 hrs into the trip when a shower came through and threatened to take Bournemouth (my home airfield) below VMC, so I landed and did a *VERY* slow taxi in to get up to the hour!

I am an advocate of full spin training (with exemption only if you get a signed chit from your mummy that you're prone to dashboard decorating ).

[engineer(retard)]

Unctuous

Theory: Asymmetric negative g rolling overstress can cause permanent deformations within a wing's attachment structure.

Saw the end result of this one but do not have any pictures but the wing was definitely deformed. The garden shed engineer might call it corrugated:

During a test flight from Boscombe Down, a drop tank became insecure after a bolt sheared off and fell out, causing the drop tank to oscillate violently, resulting in momentary loss of control. After regainin control, the pilot was able to return to Boscombe for a safe emergency landing, however, CAT 4 damage was sustained to the wing.

[OVERTALK]

AFAIK that Macchi bent by UNCTUOUS is still doing hack service at ARDU at RAAF Edinburgh.

It was last time I was there anyway. It's got an 0 something number (029 or 026 I think).

I flew it later on after it got permanently bent and its flick roll was quite frightening. The Hawker de Hav TP's tried all sorts of wing fence and inner leading-edge wedge positions to try and cure it but nothing could.

There was nothing structurally unsound about it and it passed all it's mensurations with flying colours. It just "gave" more on one side under positive G - to the extent that one wing stalled well before the other.

Luckily nobody thought it worthwhile shipping it back to Hawker de Havs at Guildford for it to have the terminatorial experience ofa Hawker de Hav wing spar rework - so it survived when all the others were shedding their wings.

[safetypee]

I had several flights in a USN T-2 Buckeye. A fun trainer, easy to fly, but with an interesting habit of very rapidly swapping ends if it stalled with any yaw asymmetry. Normal upright spins were as to be expected from a training aircraft. However spinning inverted, particularly from a dynamic wind-up were eye popping; vertical climb, high roll rate, a tad of rudder then push !!! Not withstanding the post flight requirement to X-Ray the fin-tailplane attachment.

I suppose the T-2 yaw divergence and tumbling entry was a good introduction to the A-7 ‘loss of control’, it too swapped ends and twisted very rapidly at high alpha. Its recovery was very simple:- pick your nose and wind your watch; 3000 ft later it came out of the tumble. Unfortunately many of those who inadvertently entered ‘a loss of control upset’ did so below 3000ft.
--------------------
Airspeed and Upwardness

[LOMCEVAK]

John F,

Interesting. The problems with ascertaining spin direction that you had in the AV-8B and I had in the Tornado probably have the same cause and occurred after a short but very rapid departure. However, what I saw after the Alpha Jet flat spin fitted the dictionary definition of nystagmus and I think was caused by a prolonged high yaw rate. The question is whether nystagmus is caused by prolonged rotation or sudden rapid rotation. Also, did you have any "flicking" sensation of the visual scene? I will try to dig a little deeper on this.

BEagle,

The fuel asymmetry effect that you saw in the Bulldog is one that could (and did!) occur in the Hunter also. We span the Hunter T7 with two 100 g drop tanks on the inboard underwing pylons. These were ungauged tanks, and the internal fuel was split into left and right groups, each with its own gauge. One day I was acting as safety pilot in telemetry and the sortie was planned to start with a normal, erect spin. This spin mode was normally moderately oscillatory about all axes but the first spin was the smoothest, steadiest spin that I had ever seen a Hunter perform! I was not too concerned as the recovery was reasonably normal and the precise nature of the spin in the Hunter was somewhat unpredictable. I, and the tutor in the cockpit, thought that it would be interesting to see what happened next. The second spin was a normal entry with full outspin aileron applied after one and a half turns (to demonstrate the pro spin, stabilising effect of outspin aileron upon the spin of a swept wing aircraft). This one was even more smooth and had an even higher rotation rate! After the normal 4 turns the recovery controls (full opposite rudder and stick progressively forward) were applied correctly. The stick soon reached the forward stop and the controls were held in the recovery position for a considerable time before the spin finally stopped. We decided to stop spinning at that point and try to work out the cause of this atypical behaviour. The internal fuel gauges were still indicating full (i.e. there was still some fuel in the underwing tanks) but I started to suspect a lateral fuel asymmetry. Soon, one internal tank gauge started to reduce, but it had decreased by 300 lbs before the other gauge started to drop. In other words, there had been a 300 lb asymmetry in the underwing tanks. The fuel was then balanced by selective booster pump switching and the sortie continued with all subsequent spins being normal.

So, what could we have done to mitigate the lack of fuel gauging? Firstly, there must have been a refuelling error (as there was no sign of a leak). The fuel put in plus fuel remaining should have equalled 4850 lbs (which was signed for in the F700); we never bottomed this one out! Secondly, in air-to-ground days with the Hunter there was an SOP that once at a safe height after take-off you deselected the aileron hydro-booster and trimmed the ailerons in manual (via a trim tab) such that if you had a reversion to manual at low level, it was laterally in trim. (Note that the powered ailerons had a separate spring feel bias for trimming with the hydro-booster on). This manual aileron check would probably have shown the asymmetry but the pilot on this sortie was not a A-G Hunter man and this SOP was not widespread at Boscombe by this time.

Out of interest, The Tucano spin is relatively insensitive to lateral fuel asymmetry at the 100 kg maximum (which is the maximum for flight overall).

OVERTALK,

Did this airframe have the same flick roll characteristics in both directions? When we span the Hunter inverted we always retorqued the underwing tanks after flight as they did become a little loose sometimes.

[BEagle]

I was once flying in a Hunter T7 with OC 3 Sqn at Valley who suspected that there was something wrong with the RH fuel gauge due to a seeming need to keep rebalancing by selective boost pump switching. After we landed and taxyed in, he deliberately kept the engine running off the suspect side until it flamed out. "Good", he said, "Let's see the engineers talk the way out of this Incident Report - engine flamed out with 400 lb remaining indicated on starboard fuel gauge!"

Funnily enough, they didn't - and it was soon fixed!

I've also had that horrid 'flicking horizon' thing after doing high-rot spins in the Bulldog - very unpleasant.

When we first had the Hawk at Chivenor, a number of guys used to feel very weird after ACM trips. "Doggers Wobbles" we called it - something to do with semi-circular canals, I guess. I can't remember the sequence, but after taxying in and braking, the a/c used to nod slightly, then you had to look down as you pulled the park brake on, turned various things off and hopped out. I guess all the mental gyros had gone tilt - it usually lasted as far as the crewroom. But the funny thing was that no-one mentioned it to anyone else for months as they thought it was only affecting them. Of course, the staff mate would go and sign the jet in and meet you for a coffee a bit later; by then all was well. We sorted it by waiting for a minute or so before getting out - and by not making rapid head movements.

[OVERTALK]

LOMCEVAK

It always went the same way when balanced (ball or yaw string in the middle). It could be delayed by adverse rudder and induced earlier (and nastier) by high onset g as well as a little "pro" rudder - but always to the right as I recall. As I had about 2000hrs on the Fanta Can I was familiar with its vices in the stall, spin, flick department. Asymmetric fuel in tiptanks didn't have any great effect on either departure or spin characteristics - as long as it was within reason.

We had seen a couple of inverted spin ejectees (and I seem to recall Clive Blennerhasset was one - but may be wrong). Anyway I do recall that I got the message that inverted ejection under cycling g was a definite six months in hospital if you were lucky. I'm starting to lose it a bit now, but I think it had seat-top canopy breakers (no MDC, LDC for canopy jettison failure). As I vaguely recall there was some concern that under a neg g spin, the canopy might not go cleanly. It was a lethal canopy anyway. It decapitated a few in its time.

Always wondered how the Tucano front-seat ejectees made out with LDC spatter. That was one thick canopy in the front.

[R Birkin QC]

Once had girlie nav student following me through on an inverted push up to stall turn.. inadvertantly departed the aircraft and entered inverted spin. When I tried to recover I thought the I had broken the aircraft as the control col was stuck full forward, checked G for overstress, checked height, checked needle checked student... found problem eyes closed pushing as had as she could. To three shouts to get her to let go.
Performed Grob emergency recovery drill (let go of everything) ac recovers go home beers all round.:O

[Runaway Gun]

I once had a girlie nav in a spin, with her eyes shut and pushing hard....

[John Farley]

LOMCEVAK

Can't help really. I had my head down doing the normal sort of IF trick trying to set up an ADD IAS Ht combination during the top end of a slam accel when it departed. I had no idea what the manoeuvre was, plenty of g coming and going in both directions plus rolling and sideways. My only concern (I was at over 35K) was to get the donk shut down which I did. Then I made myself double check the JPT was going all the way down and that I really had the HP off not at idle. With that done I started to think about the recovery. Plenty of tumbling still so I looked in again, and centred all the controls visually, looked up still tumbling, so I double checked I had everything central and looked up again. Just as I was thinking I don’t know what to do next it all stopped. I asked the test director what he thought had happened he was clearly shocked and said he could not tell as everything had gone essentially full scale. So I glid down, relit and then climbed back up for some more of the engine points on the card.

Throughout I cannot say I noticed any visual aberrations at all. I just remembered what the docs had said about the unreliability of ones eyes in high rate circumstances and decided not to try and guess what happened but wait for the onboard traces which had plenty of aero data unlike the TM which was mainly engine stuff. I certainly felt on my back foot when the mother departed as I was flying head down. Otherwise one might have had a bit more sense of did it start to the left or right for example.

See you Friday?

John F

[PTT]

Always wondered how the Tucano front-seat ejectees made out with LDC spatter. That was one thick canopy in the front.
Wasn't too bad. Looked like a light case of the measles and didn't really hurt at all - in fact, I didn't notice it until it was pointed out to me, but that was probably due to adrenaline initially and then several pints of Yorkshire's finest!

[OVERTALK]

PTT
It's always surprised me that no solo Tucano student has yet (AFAIK) had to eject due to prop oil-seal failure and no visibility (per the earlier experiences dual).

Early on, the CFS solution was to have a dual aircraft formate on the student and "talk him down". Yeah, right. As if any instructor wanted that fire-ball on his conscience or seared into his memory.