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stall spin

Posted: Wed Jul 09, 2008 3:18 pm
by hum
The report into the tragic accident where 2 of our colleagues lost their lives in EI CHM was published yesterday.

Probable Cause: The aircraft suffered a loss of flying speed at low altitude, stalled and spiralled to the ground

This must have been one of the more difficult of reports for the AAIU guys to write - not a lot of information to go on, yet such a tragic outcome. It is a very good report.

Brian Lecomber, one of the best writers in General Aviation, wrote a piece on stalling for the Spring 2004 edition of GASCO - a UK GA charitable organisation that strives for improvements in GA Flight Safety - mostly through education. His article is on page 16 of this link - it is highly recommended reading..

Posted: Wed Jul 09, 2008 5:59 pm
by Bluebeard
I note the inspector recommends that EASA should study the installation of flight data recorders in GA aircraft.

Posted: Thu Jul 10, 2008 1:56 pm
by Cosmic
The quality of the AAIU investigations and reporting is amongst the best that there is in my opinion. One would only have to look at the junk churned out by some of the foreign investigators to see this. The Helios report was one such example: incoherent, rambling and flawed.

I feel the AAIU (and AAIB for that matters) terrible sense of frustration that a simplified lightweight FDR/CVR/Camera can not be fitted to light aircraft. In an age of technological advancement that we live in, where I can record all the stats of my jog using a tiny light weight iPod and a transponder "fob" which sits in the sole of my shoe, it cannot be beyond us to rig up something similar in light aircraft that can record simple parameters like configuration. Even a simple "webcam" pointing at the front of the aircraft would provide vital clues to the investigators.

Posted: Fri Jul 11, 2008 10:59 am
by OnTheNumbers
it cannot be beyond us

It isn't; but your ipdod/transponder gizmo, is a couple of hundred Euros. Something similar, suitably tested, certified and installed for an "aviation application" would undoubtably run to a couple of thousand.

I can't see too many aviators, even the most safety conscious ones, being prepared to pay that sort of money for a device installed to record any event that every pilot actively avoids.

If it could be done for 2-300Euro, then I am sure some civic minded pilots would install them. Having said that, even a handheld GPS does record basic track/speed/height info.


btw - excellent piece by Mr Lecomber. I don't always like the sometimes blunt way he puts things but he does talk a lot of sense.

Posted: Mon Jul 14, 2008 10:06 pm
by buzz
I don't think we will ever see any form of flight recorder on light aircraft.

As for the accident, it was well known from early on that it was some form of stall/spin accident. I was in Weston that day. I was puzzled as to how it could happened from a practice spin with two experienced pilots on board.

However I didn't realise that it was off a PFL. It's a sobering thought. I have done a few of those in my time, in that particular aircraft too. I suppose in the end, it will be recorded as pilot error but can any of us here honestly say the result would have been any different if we had been on board?

If there is a lesson to be learned it's that even a PFL can turn real anytime and carb icing can happen at any engine power (that I found out myself the hard way once).

Posted: Tue Jul 15, 2008 4:30 pm
by Cosmic

[quote I suppose in the end, it will be recorded as pilot error but can any of us here honestly say the result would have been any different if we had been on board? [/quote]

I don't think anyone was implying that, nor would any real pilot. It seems just a numbers game when you read some of these reports. Lots of Pilots out there made their mistakes similar to this one during their training, scraped through it, and love to tell it as their favorite "war story" in the hotel bar after a hard days flying their big shiny jet they progressed on to.

I know I did. I inexplicably pulled the mixture to cutoff on a PA28 at a low enough altitude as to very much concentrate my attention, and make sure that my restart drill was quite impeccable. Pure blind luck seems to be the only difference.

Even a little recorder built into the headset could provide so much useful info to the investigators, it seems such a shame when you see how they can reconstruct what happened from something as basic as the flash drive from a GPS.

Posted: Tue Jul 15, 2008 8:11 pm
by Little Boy Lost
This unfortunate accident set my mind going, so after a bit of searching I retrieved some good advice from Annette Carson and Eric Mullers book "Flight Unlimited" which should be compulsory reading for all pilots and especially those of us who fly the light stuff and engage in training.
In Chapter 7, The Stall he warns if you are near the stall one should never make big power increases without moving the stick forward at the same time.
Chapter 15 The Spin is also well worth the read.

Reading these two chapters alone are well worth the price of the book.

Posted: Tue Jul 15, 2008 8:27 pm
by Nanolight
That's an excellent piece on the mechanics of stalling.

The fact that stalling relates NOT to speed of the air over the wing but solely to a 'critical' angle of attack was explained to me by my instructor, but prior to this I had never really thought about it and always just assumed that when the ASI rolled back out of the green, the aircraft stalled.

Re: Recording devise.... I am sure that something standard could be rigged simply and easily, but would people want it? Is it an infringement of civil liberties? Do you think tat if you were acting the maggot in your plane it could be used against you to prosecute you or whatever? I would imagine the idea mighn't be as popular as you'd think.

I know if you keep to the rules you have nothing to worry about, but having said that, I still wouldn't like to have a speed recorder on my car when I am approaching a garda checkpoint...

Posted: Wed Jul 16, 2008 11:28 am
by Cosmic
but would people want it? Is it an infringement of civil liberties?

It's not for you, it's for the people you leave behind so that they can know what happened and gain some closure and so that others may learn and perhaps prevent another fatal accident. The AAIUs recommendation to EASA was not that it would be an Optional extra but a legal requirement. In commercial aviation the CVR and FDR data is legally protected (in broad terms) from anyone having access to it except for accident investigators. If EASA enacted the AAIU (And many others) recommendations I would assume by default the legislation used to enact it would cover this.

People said glass cockpits weren't practical/affordable in light aircraft too, but then someone came up with an affordable AHRS. Necessity is the mother of invention.

Posted: Wed Jul 16, 2008 11:42 am
by ceatach
Cosmic wrote:The AAIUs recommendation to EASA was not that it would be an Optional extra but a legal requirement.

I think the recommendation was for aerial work aircraft. Average Joe probably doesn't practice too many stalls/PFL in his personal cessna.

Posted: Wed Jul 16, 2008 12:09 pm
by Cosmic
You're right, they did.

Posted: Wed Mar 18, 2009 11:25 pm
by JimC
What about those of us who fly antique aircraft that are certified non-electric? I wouldn't want a flight recorder on board anyway.

Posted: Fri Mar 27, 2009 12:20 pm
by Cosmic
I don't think anyone was suggesting retrofitting older aircraft JimC. You might not want a recorder fitted, but I bet your Father, Mother, Wife, Husband, daughter and Son (Delete as appropriate) would want to know what happened to achieve closure. I can tell you it's agony to always wonder what happened to a loved one after an accident and to never know. I think some form of simplified data recorder should be mandatory on all newly certified light aircraft. When you are talking about aircraft with Glass panel cockpits it is just a small effort to run everything through a solid state memory card which could be downloaded afterward.