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ABOOD13
4th Jun 2009, 18:00
Hello everybody
A Jordanian Firefly crashed after a non recoverable right hand spin, student managed to abandon but the instructor couldnt leave the A/C and died, any body konws any thing about figures concerning the necessary abandon time and what is the situation up there looks like while its spinning and u want to jumb out ; G force , airflow, suction .....etc.


Thanx all

Spanish Waltzer
4th Jun 2009, 18:20
Sorry to hear the news ABO.

I seem to recall a RAF Firefly having the same fate back in the mid 90s, although I'm pretty sure in that instance both student and instructor (a civilian I think) sucessfully baled. I'm sure there'll be a ppruner out there who knows more.

SW

Duncan D'Sorderlee
4th Jun 2009, 19:23
Condolences from Duncs.

RIP.

US Herk
4th Jun 2009, 19:52
There was a spate of crashes at the USAF Academy in the '90s as well. Lost a mate in one of them. Various causes, I think, but I do recall at least one being spin-related I thought....

noprobs
4th Jun 2009, 20:40
It wasn't a spate in the USA - there were 2, I believe. One was a departure, the other possibly related to engine failure, both out of Colorado Springs. Hondo experienced no such problems. Subsequent testing (admittedly after a fuel supply modification) failed to find any fault in spin recovery or engine response following prolonged throttle-closed gliding. Both accident aircraft were the 6-cylinder version with the low canopy.

The RAF spin accident was the 4-cylinder 160 with low canopy. All in current UK military use are 6-cylinder with the high canopy and long-chord rudder.

As with most aircraft accidents, there is no single obvious cause.

There has been generic research into escape from spinning aircraft, including that in the vertical wind tunnel at Farnborough, and there is much evidence of experience of survivors.

50+Ray
4th Jun 2009, 22:01
Sorry to hear the news - will try to get some info when back at work on Sunday. This will be the third loss from their original fleet of 12, and the sad fact is that all the previous problems were crew related rather than technical. If you hit a single decker bus......
I can only reiterate that in my 4500+ Firefly hours I have not had a problem in my countless spins. Proper planning, simple drills, no problem, but always follow the student through because one day they will get it wrong. When they do, the high rotational speed can disorientate anybody, but observing the laid down rules has always worked for me!
RIP, and best wishes to all like me who will fly the T67 for as long as contract and Class 1 permit!
Ray

Sir George Cayley
4th Jun 2009, 22:44
I rarely venture here but having owned an early version T67B (and refrained from spinning it) can I add something?

My understanding is that there could be a problem with the rudder pedals being interfered with by other parts of the a/c. I'm sure I've read a report some where.

It must be worth a Google or a check on the UK AAIB website.

So many incidents in aviation are not new but also not widely known.

Sir George Cayley

betty swallox
5th Jun 2009, 06:21
My condolences too. Sad news.
BS

Karl Bamforth
5th Jun 2009, 07:24
I remember an instructor and student getting into trouble trying to recover from a spin in a T67 in the UK.

Its a few years ago but when the Instructor told me what happened I could see how a student could get themselves into serious trouble. Thankfully both student and instructor survived the incident.

To the best of my fragile memory.
The instructor demonstrated a spin and recovery with no problems.
Handed control to student, the spin and recovery was normal until the "pull out from ensuing dive" part, they started to pull out of the dive but suddenly and violently departed and flicked hard into another spin.

The instructor took control and initiated recovery, once again the recovery was normal but in the later stages the aircraft once again flicked into another spin.

The instructor thought the problem was they were pulling too hard during the recovery causing the pitch angle to increase rapidly causing a further stall spin. On the last attempt he was much gentler in the recovery from the dive. The aircraft recovered normally.

Now if this had been a low houred pilot watching the ground getting ever closer and with a certain amount of panic setting in I think it would have ended in disaster.

Its the only first hand account I have come accross and it seems to fit the other failure to recover stories I have heard.
It certainly cured me of wanting to spin a T67.

BEagle
5th Jun 2009, 08:02
Sir George C, see http://www.aaib.gov.uk/cms_resources/Slingsby%20T67M260,%20G-EFSM%2011-07.pdf and AAIB Safety Recommendation 2007‑077.

mac_scott
5th Jun 2009, 10:34
Short hours PPL but I learnt to fly on a T67B out of Woodford.

Back in 1998 while I was doing my PPL a T67 crash claimed two lives (student and chief instructor at test pilot school at Woodford). Planned exercise was spin performance but accident report (http://www.aaib.gov.uk/cms_resources/dft_avsafety_pdf_501247.pdf) suggests spin part of sortie was completed successfully and crash was during an unplanned low level return to Woodford.

Report mentions the T67's ability to flick rapidly to the left as a result of high pitch input. Likely cause of this accident, as a result of terrain avoidance at low level?

I flew both the T67 and the Diamond Katanna during my PPL training and I can remember my instructor being VERY, VERY nervous during approach to the stall/recovery training in the T67 (never even demonstrating a full stall) while being quite happy to allow us, with me at the controls, to go fully into the high AoA, wallowing, loss of altitude that passed for a stall in the much more benign Katanna.

BTW I loved flying the T67 and found it a pleasure to fly, much more lively than the Katanna, but was always very wary to keep well away from stalling.

Thoughts with family and friends of the instructor lost in this incident. I can remember the atmosphere at Woodford in the weeks after the 98 crash, I didn't know the lost crew there but knew people who were close friends of the CFI who went down, sad times :-(.

ABOOD13
5th Jun 2009, 12:41
Thanx Sir George For the rudder hint and for everybody, actually the survived student said that they did a right spin first it was ok then the Instructor did another one also to the right then the A/C didnt recover the Instructor ordered him to abandon and opened the canopy and pushed him away,he tumpeled in the air then pulls the D- handle, so its sure that once the Instructor left the controls to open the canopy it went into hi rotational spin and it crashed to the ground before he managed to abandon him self, it worth now everybody operating Firefly to cx. the rudder movement in accordance to the report attached from BEagle I read it , it was very interesting .

sycamore
5th Jun 2009, 14:32
ABOOD,it would be useful to know what height the spin was started at for planned spinning,as we used a `rule of thumb` for starting ie ground height+ Trans Level +turns X 800 +1500(recovery)=`y`ft. ie say;1000+3000+(4 x )800+1500=8700/FL90 to start.

50+Ray
5th Jun 2009, 16:12
Thanks for that information A BOOD.
In response to Beagle I believe that the RJAF carried out the necessary inspection and work under the tuition of the engineer from the Slingsby factory. When ours were inspected there was absolutely no problem with the pedal clearances, but obviously it can be a factor, with over enthusiastic towing possibly a factor. Others may speculate on why there was no problem on the first recovery, but the second proved fatal.
To max scott - I am appalled by the reported behaviour of your instructor, who seems unfit for purpose.
1.The stall performance of the T67M260 should frighten nobody. Wing drop in a clean stall is highly unlikely if entered in balance and not held in the full stall for a protracted period.
2.Wing drop is more likely if flaps are extended and power is applied. This should be demonstrated to the student as early as Stall 2(exercise 7 at Barkston Heath IIRC).
3.Comments on flicking do not gel with my experience, mainly on T67M260, but earlier on T67M160. Students are taught incipient spin recognition and recovery prior to their being taught significant aerobatics, and must prove their ability to do so on Test before being cleared to carry out solo aeros.
Entering from a steep turn to the right with low power and ignoring the audio warning increasing back pressure will generally cause a flick out of the turn into a near S&L attitude. From a right turn the same method generally rolls you inverted. If deliberately mishandling, with power, at low speed & high AoA, rolling to the left with and coarse application of more back pressure will cause a reversal to the right. All these characteristics are easily demonstrated, easily recovered from by unloading, and are used as a lead in to the recovery from Incipient Spins.
4.Flying into the ground in an apparently servicable aircraft when carrying out unauthorised low flying cannot be blamed on the aircraft manufacturer!

Getting out of a spinning aircrafty can undoubtedly be difficult. Colleagues proved that years ago in the Bulldog. We all know how(?) but few are unfortunate enough to find out how awkward it can be. The T67M which was abandoned in a spin back in the 90s was a result of a mishandled recovery which the instructor was late in taking control and attempting to sort out. They were still spinning when they reached the pre-briefed abandon height, and correctly jumped. It may well have been possible to recover that one, and it produced a change in procedures which Military users have used ever since:-
Min Abandon Height - Transition level + Height of Ground
Minimum Height to Commence Recovery - MAH + 2000ft
Minimum Entry Height - MHCR + 300ft per planned turn.
Sorry if this is long winded, but I have earned my living instructing on the T67 for the past 15 years and uninformed comments wind me up.
Ray

US Herk
5th Jun 2009, 17:05
It wasn't a spate in the USA - there were 2, I believe.
3 crashes in 2.5 years.

First delivery in Feb '94, grounded by Jul '97 - 3 crashes. Two blamed on pilot error and one stall/engine failure. So while I'm not certain if 'spate' has a defined minimum, but 3 in 2.5 years qualifies in my book. :p

I read the reports at the time (a decade+ ago), but don't recall specifics of any of the accidents - remember thinking it looked like standard CYA "pilot error" cause at the time...in other words, indeterminate or questionable causes with theoretical sequences of events...but hey, the SIB & AIB don't have to 'prove' anything, just put forward their best guess. :hmm:

I heard rumours back then there were elevator issues during spin recovery as well, but that's all it was then...and now...rumours.

BEagle
5th Jun 2009, 17:42
The only T67 I've flown was a T67A with a small engine, fixed pitch prop and forward fuel tank. We had to weigh both pilots, then add fuel very carefully to make sure that the CofG was within limits for spinning and aeros.

It was an excellent device for teaching correct stall recovery technique, very good for teaching incipient spin recovery and also for demonstrating fully developed spins. But b****y awful for teaching aerobatics as you had to spend most of the time preventing the engine from over-revving.

Quite fun if one's student got slow at the top of a loop though - it would either slowly flick erect or if very slow the engine would stop. Literally - the prop always looked huge when it stopped in front of you. A quick push on the starter button invariably got it going again though. But I always stayed within gliding range of somewhere friendly when aerobatting, just in case.....

Stalling in the turn was good - just invite the student to fly a 45 deg banked turn, then move the control column back a couple of inches...... 'Undemanded roll' sure as eggs!

It was a playful little thing, but what an utterly dismal roll rate compared to the Bulldog or Chipmunk! Unless you cheated and flicked it, that is.

What Limits
5th Jun 2009, 20:27
Hello Ray,

I think I worked for you at Barkston from 1997 to 99 and I see that you are back in the sandpit.

If anyone knows his stuff on the firefly its you.

I recall a rumour that the USAF losses were in part due to not allowing enough vertical to do the exercise and not wearing parachutes.

Loved the firefly, shame about the politics at Barkston!

AllTrimDoubt
5th Jun 2009, 23:24
Hi Ray

Glad to hear you're still in the saddle! Nowt wrong with the T67M260!

(You Know Who!)

kharmael
6th Jun 2009, 10:23
For all of the horror stories that people are mentioning and their ensuing reluctance at spinning or stalling the FF, hundreds if not thousands of DEFTS studes (myself included) will have pushed the ac to it's limits doing the above plus countless aeros and flick manoeuvres.

Seems like everyone likes feeling dangerous ;)

mac_scott
6th Jun 2009, 17:35
50+ray - the comments on any possible flick aspects of the T67 come from the report I referenced, not personal experience. Report suggest left aspect of flick is torque related - quote below.

"Aircraft handling
Discussions with the manufacturer's chief test pilot revealed that the T67 aircraft can be encouraged to 'flick' (ie pitch up and roll rapidly) by aggressive positive pitch demand. If this control input is applied the aircraft will tend to flick rapidly to the left as a result of engine torque reaction. "

Model here was T67C with a piston Lycoming, obviously a bit different from a T67M so don't know if this aspect applies to that model.

Sorry if my first post read as an attempt to blame the T67 for the 98 crash, if it came across that way it wasn't intentional. I loved flying the T67 and never felt unsafe in it at any time - would go back in one tomorrow without a concern.

Primary cause of the 98 accident was low level flying but report does imply that the flick aspect might have been a secondary factor when large positive pitch demands were made for last minute terrain avoidance.

As for my instructor at the time as a low time PPL I obviously can't comment on his abilities as an instructor.... But as I remember it he was always more nervous near the stall in the T67 than the Katanna.

ABOOD13
7th Jun 2009, 11:58
Hello Ray
It seems that u have a good experience on the FF, any way so do u think this a possible cause to what happened .....! by the way so may be they started a right hand spin then he applyed the recovery actions which is full left rudder, but may be it stucked there and didnt come out, so ,what do u think?

ABOOD13
7th Jun 2009, 12:30
Sorry for the repated massage twice

50+Ray
8th Jun 2009, 11:48
ABOOD
I can only suggest you inspect the clearances on the rest of your fleet and talk to the manufacturer. Possible damage/ reduced clearance due to over turning the nosewheel steering while towing/ground handling is a concern to me whenever I see an aircraft moved with the engine covers off.
Rgds
Ray

moggiee
8th Jun 2009, 12:16
Early in EFTS service there was an incident where the rudder pedal/linkage jammed at full deflection in a spin. It required both pilots to stamp on the pedal repeatedly to free it off.

Subsequent inspection showed that part of the linkage had been incorrectly assembled at the factory and could jam at full travel. Something simple like a washer being fitted in the wrong place, if memory serves me right.

50+Ray
8th Jun 2009, 13:44
Yes that incident was in the early days of JEFTS at Topcliffe in a 160hp T67M (1993?). The more recent example highlighted by Beagle (AAIB Safety Recommendation 2007-077) resulted in the SI issued by Slingsby to all owners.
I have had no response from Slingsby yet over this one - possibly because the facts are still under investigation.