Towcester, Northants Incident, Inquest report. Update.

[rotorcraig]

Source: BBC News (http://news.bbc.co.uk/1/hi/england/northamptonshire/4580897.stm)
Two injured in light plane crash
Two people have been injured after a light aircraft crashed into a farm field, police have said.
The two-seater Slingsby T67 aeroplane came down in a field off the A5 at Potterspury, near Towcester, Northamptonshire, on Wednesday evening.
http://newsimg.bbc.co.uk/media/images/41185000/gif/_41185001_potterspury_map203.gif http://newsimg.bbc.co.uk/media/images/41185000/jpg/_41185057_towcrash2_203.jpg
Northamptonshire Police said the extent of the injuries of those in the aircraft was not yet known.
A spokeswoman for the Air Accidents Investigation Branch said the plane was based at Turweston Airfield, Bucks.
A Northamptonshire Police spokesman said: "Police are securing the scene and are awaiting the arrival of air collision investigators.
"I can confirm that there are casualties but at the moment cannot give any further details as police try to identify the plane and those on board."
The Northamptonshire Fire Service were called to the scene of the accident to ensure that there was no risk of the plane catching fire.RC
Updated with additional information from BBC News

[boomerangben]

Just heard on the radio that it was two fatal. Thoughts are with family and friends.

[rotorcraig]

The Northants Chronicle & Echo (http://www.northamptontoday.co.uk/ViewArticle2.aspx?SectionID=317&ArticleID=1037414) today carries the following report:

Two killed in plane crash

AN investigation was under way today after the pilot and passenger of a light aircraft were killed when their plane crashed into a field in Northamptonshire.

Officials from the Civil Aviation Authority Air Accident Investigation Board were immediately called after the two-seater plane came down near Potterspury, at about 5.10pm yesterday, with the two bodies trapped in the cockpit.

The plane was a single-engine Slingsby Firefly which had left Turweston Aerodrome earlier in the day.

Two aeroplanes were seen circling overhead shortly before the tragedy, with witnesses saying they were flying perilously close to each other.

A teenager, who asked not to be named, said: "It sounded like the engine of one cut out and it started plummeting down, swivelling in the air, kind of wobbling.

"It hit the ground, but there was no explosion just a loud thump and then lots of smoke."

Witnesses called the emergency services after seeing the white aircraft come down on the Wakefield Estate just west of the south Northamptonshire village.

Firefighters from Milton Keynes and Towcester, plus an emergency tender from Mereway attended along with officers from Northamptonshire Police and paramedics.

Insp Gary Ashton said: "We have begun our investigations and posted a senior investigating officer to the scene along with a chief inspector and command unit.

"I can confirm two people died in the crash and we are likely to be there for much of the next 24 hours."

The incident caused major hold-ups on the A5 and A508 as traffic was diverted from the scene.
BBC News (http://news.bbc.co.uk/1/hi/england/northamptonshire/4581851.stm) article also updated:

Two killed in light plane crash

A trainee pilot and an instructor were killed when a light aircraft crashed in Northamptonshire on Wednesday night.

Investigators are at the scene of the crash in a field off the A5 road at Potterspury near Towcester.

The Air Accidents Investigations Branch (AAIB) is trying to discover why the single engined Slingsby Firefly aircraft crashed.

The aircraft, which is believed to have belonged to a flying school, had flown out of Turweston Airfield in Bucks.

A spokesperson for Turweston Airfield said: "The people who died were friends. We are speaking to the AAIB now."

Northamptonshire Police are trying to trace the relatives of the people who died.Saddened to read that the casualties are now confirmed fatalities.

RC

[charlie-india-mike]

My condolances to the family and friends of those who lost their lives in this terrible incident.

I have this aircraft in my logbook and am truly saddaned with the event, does anyone know who the instructor or student was?

C-I-M

[rotorcraig]

Yes, names were released by police today.

From Milton Keynes Today (http://www.miltonkeynes.co.uk/ViewArticle2.aspx?SectionID=415&ArticleID=1039833)

Plane Crash: Victims Named

THE two men killed in the light aircraft crash in a field at Potterspury on Wednesday evening, have been named by police.

Rudi DeLavergne, aged 49 of Stock Lane, Whaddon, and Michael McKechnie, aged 43, of Passenham, both died of multiple injuries when the two-seater Slingsby Firefly they were in crashed at Wakefield Estate at about 5.15pm.

The pair had flown from Turweston near Buckingham when the plane dropped from the sky and landed in the field, killing the occupants instantly.

One eyewitness said: "It sounded like the engine cut out and it started plummeting down, swiveling in the air, kind of wobbling. "It hit the ground but there was no explosion - just a loud thump and then lots of smoke."

On Thursday afternoon the aircraft was taken to Farnborough, Hampshire, where the Air Accident Investigation Branch (AAIB) will carry out a more detailed examination.

Earlier that day the AAIB inspected the site and examined the plane with officers from Northamptonshire Police.
Condolancies to all involved

RC

[rotorcraig]

Inquest report from BBC News (http://news.bbc.co.uk/1/hi/england/northamptonshire/5094056.stm):

Manoeuvre blamed for plane deaths

A student pilot and his instructor died when their plane crashed as they attempted a manoeuvre now banned in training, an inquest heard on Monday.

Francois De Lavergne, 49, of Milton Keynes, and Michael McKechnie, 43, of Passenham, Bucks, died after flying out of Turweston Airfield, Bucks, last May.

Air accident investigators said it was thought a manoeuvre known as oscillatory stalling was to blame.

The jury returned verdicts of accidental death on both men.

Mr McKechnie was about a quarter of the way through training for a private pilot's licence when he and instructor Francois De Lavergne, crash landed in a wheat field in their two-seater Slingsby Firefly plane.

Stalling simulated

The inquest at Northampton General Hospital heard witnesses saw the aircraft spinning and spiralling towards the ground with little or no engine noise.

An oscillatory stall, the jury heard, is when a wing of the plane is made to drop to simulate a stall in the aeroplane. It produces a move similar to a spin, but which is more difficult to rescue.

AAIB inspectors agreed the oscillatory stall was "unnecessary and inappropriate" and should not be taught to novice pilots.

New guidance from the Civil Aviation Authority now states it is not to be taught to new pilots.

Inspectors found there were no engineering problems with the Firefly or with the engine.

'Tragic death'

Mr McKechnie's wife Karen said in a statement: "The verdict of the inquest has highlighted that the oscillatory stalling exercise is inappropriate and unnecessary for students training for their private pilots' licence.

"We welcome the new accepted recommendation that flying instructors do not include oscillatory stalling in flying exercises in the future.

"Mike was much loved by his family and friends and we were all devastated by his tragic death at the age of 43.

"However, we take comfort from the fact that tragic accidents such as this may be avoided in the future."RC

[Deano777]

One word

nightmare :(

[Alvin Steele]

Sorry to sound like a whinger, but when updates to past incidents are posted can they be suitably titled as such......my heart sank when I saw 'Light aircraft down.........' thinking it was today.
Thanks

[rotorcraig]

Tried to, but don't think I can edit the thread's main title.
Think that only a Moderator can do that?

RC

[chrisN]

Am I the only one never hitherto to have heard the expression "oscillatory stall"?

What is the difference between that and a stall with wing drop?

What is this mode of (unstable?) motion that is harder to recover from than a spin?

(Seeking knowledge of the phenomenon, not commenting on this or any other accident where full cause has not yet been established.)

Chris N.

[Nov71]

AAIB report here: aaib.dft.gov.uk/cms_resources/G-FORS%203-06.pdf

I too am unfamiliar with 'oscillatory stall' AAIB reports "One other student of the instructor described the oscillatory stall as being in a deep stall with the pilot controlling any wing drop with applications of rudder." Surely the student means 'incipient' stall?

I hated stall practice, one aircraft just wallowed at onset, another did a violent R wing drop. Hammerheads were a 'rush' and spinning was better than any video game.

Initial (RAF) training was in a Chipmunk T10 so the parachute was essential for a 'soft' ride. Was never offered a 'chute for those Cessna armchairs during PPL, could even wear my nylon underwear!

IMO stall ident & recovery should be taught straight after basic flying controls as part of lift, weight, thrust & drag, due to unexpected icing; which could have been a factor in this incident

[phnuff]

Am I the only one never hitherto to have heard the expression "oscillatory stall"?

I am glad you asked that because I have spent the last couple of hours trying to find out what it means (which appears to be a stall with a wing drop).

Last evening, either BBC or ITV Teletext were suggesting that the manoeuvre was carried out at 500ft which strikes me as a bit odd (to say the least). I am not at a TV and cannot verify if this is still showing.

[bingoboy]

Why have I never heard of this killer maneouvre before ? Can someone at the aaib plse explain.

[Cricket23]

I too have never heard of this type of stall either, but I've found this on the instructor forum.

The discussion is not conclusive, but there are some interesting points.

http://www.pprune.org/forums/showthread.php?t=216431&highlight=oscillatory+stall

[UV]

The whole thing is explained at the AAIB website:

aaib.dft.gov.uk/cms_resources/G-FORS%203-06.pdf

Worth a read...

UV

[chrisN]

Why is the oscillatory stall as described in the other thread, harder to recover from than a spin as mentioned in the AAIB report? I have certainly held a stall, in some gliders, balancing potential wing drop with rudder. Some types won't let it happen - the machine tries more and more extreme departures from level until this pilot could not react fast/accurately enough. Also, some types do the "nodding" pitch motion which I suspect is alternating full stall and partial recovery. With full flaps on some types the end result of both effects together is "interesting".

I suspect that the answer lies in what happens when a relatively benign "only just stalled" oscillatory stall flicks into a full spin with very rapid rotation, and very extreme attitude perhaps.

I think it would have been helpful if AAIB had explained what is to many of us an unknown expression. Lord only knows how they expected a lay coroner and jury to make any sense of it. Blinding with quasi-science is nearer the mark, IMHO.

I used to have a lot of respect for AAIB. I regret that I have over the years seen enough dubious analyses and conclusions leading me to think that they are less perfect that we are accustomed to crediting them with. [I grew up in aviation thinking they were the best in the world and virtually infallible. Just my naiveté, I suppose.]

Chris N.

[waldopepper42]

Isn't the "Oscillatory stall" as described the same thing as the "Falling Leaf" manoeuvre"?

It certainly sounds like it... this from Fighter Combat International's website (hope they don't mind me copying - I certainly spent enough money with them!). I did the Emergency Maneuver Training course with them and it's the same excercise as described at Turweston.

THE FALLING LEAF / RUDDER STALL EXERCISE

The Falling Leaf Exercise is not unique to FCI Emergency Maneuver Training. This exercise is a great opportunity for the client to observe and experience flight beyond the normal envelope at angles of attack greater than the critical angle of attack. In a addition to simply getting the students feet moving, the Falling Leaf Exercise is an excellent demonstration of the aerodynamic reality of negative roll damping, exponential drag affects and reverse aileron effect. The awareness of and first-hand experience with negative roll damping is important to the avoidance, understanding and recovery from the various stall conditions, specifically uncoordinated traffic pattern stalls covered later in the course.

[chrisN]

If the OS as described by AAIB is a falling leaf, does the latter fit their statement that it is harder to recover from than an ordinary spin?

Chris N.

[waldopepper42]

I am not an expert, so can only speak from personal experiance. In my case, one the couple of occasions where I was not quick enough with the rudder, the aeroplane did indeed enter a spin. However, at that altitude (starting at 6000') and in that aeroplane (Extra 300L) the recovery was no different from any of the others I've done. I have also done the same manoeuvre in the Pitts S2-C and DH Chipmunk, again with no difficulty getting out of the spin.

All I can think of (I also fly the T67M-160) is that in this aircraft, if you move the stick forward before applying opposite rudder, you can enter a "high rotational" spin (never done it myself). I understand that this can take longer and therefore much more altitude to recover from. Maybe the surprise of the spin contributed to this?

N.B. I was really not sure whether to add the last paragraph as it is pure conjecture, guesswork and filling in detail that I do not know....