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Based on the report from the Australian ATSB, it appears that the aircraft was still controlable up to the point of hitting the curb
on the intended landing surface. Only then did things turn really bad.
Wolfgang
----- Original Message ----- From: "Kevin Stallard" <kevin@arilabs.net>
Sent: Monday, May 05, 2014 5:08 PM
Subject: RE: [LML] Re: P-38's and Legacy Canopys
Hi John,
There are two kinds of data we're talking about here. Accident statistical data and aerodynamic aircraft performance data. I'm
after the later.
I'm looking for flight data, controllability, stability, etc when the canopy is open. Just because the canopy opened prior to a
crash doesn't make it the fault of the canopy.
Sure it may have scared the pants off the pilot, but the question is: Is the airplane flyable with the canopy opened? We need
real, measurable controllability data. If the canopy doesn't inhibit the airplanes ability to fly when it is opened, then we
shouldn't be blaming the airplane.
Sure warning lights and such are helpful, but if the airplane can be shown to fly reasonably well with the canopy open don't you
think that the solution to this statistical anomaly would be to include a canopy open event during training? Show the pilot how to
turn a canopy open event into a non-event?
That's what I want to be able to do....I think that is a more sure way to keep me safe.
Thanks
Kevin
________________________________________
From: Lancair Mailing List [lml@lancaironline.net] On Behalf Of John Smith [john@jjts.net.au]
Sent: Monday, May 05, 2014 5:11 AM
To: Lancair Mailing List
Subject: [LML] Re: P-38's and Legacy Canopys
A reaction to prior post…. "………spending a bunch and time and money fix ing a problem that may not exist, we really need to gather
data, real hard data."
Problem that may not exist…..? Really need hard data?
Why don’t we start at the top of the tree? 3 known fatal events due flight with an open canopy (at the time that I looked at all
this a few months ago); this equates to around 1 in 100,000 take-offs. That’s appalling. Anyone think otherwise?
These events also happen to account for around 10% of Legacy related fatals. If increasing awareness of this possibility and of
simple practical procedures and systems to reduce the risk are available, why not do it? I’m all ears!
I’ll be honest – the only way I found about what could happen with the canopy was when I did my transition training in 2008 with Bob
Jeffries in N199L – if he hadn’t told me about this, I most likely would have never known and consequently wouldn’t have installed
the dual position / latch warning system in XTZ before I first flew the aircraft.
And then, it was the public discussion mainly on this forum that followed Gerry Gould’s accident that finally yielded reports (and
in effect a procedure for) of successful flight and landing with the canopy open. I am very grateful that I and others now have the
knowledge of what has worked. We never had that information as a community before – or at least it wasn’t out there for all to
benefit from. This accident triggered an immediate upgrade of my canopy alarm from a simple warning light to include large red
flashing warnings on both EFIS screens, audible alarm, and writing up canopy open procedures (pre-airborne, and post-airborne) into
my POH.
A few simple steps get us closer and potentially beyond what I understand to be a minimum GA target for fatal events of 1 in
1,000,000. They are all, along with the relative (indicative) benefits, documented in Valin’s report. Why strive to prevent that
very useful information getting out there??
I just wish others who have not survived a canopy open event had been able to receive Valin’s paper before those accidents occurred,
and especially Gerry Gould who was the pilot of the Legacy that crashed at Geraldton – Gerry was an experienced pilot who used his
Legacy routinely to get from “a” to “b” for his business in Australia’s northwest, yet what followed on 18 September last year
started with a simple error. The final report of this accident will be quite comprehensive and I think is about to be released, but
in meantime refer: http://www.atsb.gov.au/publications/investigation_reports/2013/aair/ao-2013-158.aspx
BTW – the figure of “around 1 in 100,000” comes from some assumptions below. I accept not "hard research quality data", but given
the goal of getting a feel for the stats on this, I felt the assumptions are probably OK for the current purpose. My approach was to
assume a pro-rata time introduction of Legacies over a period of 10 years. In other words, based on numbers below 35 in Yr 1,
another 35 in Yr 2, and other 35 in Yr 3 and so on. Of course that’s not what actually happened, but to get a feel for the risk of
this event, I think that’s good enough. Irrespective of what a calculated risk value might be, 3 fatal events - some or all that
could well have been avoided with some more broadly available knowledge - is 3 too many.
Event = "Flight occurs with canopy unlocked and leads to a fatality"
No. recorded events 3
No. Legacy's flown 350
Years in operation 10
Flight years 1925
Avg. take-off/yr 50
Total take-off to date 96250
Frequency of canopy open fatalties 3.12E-05 REF
This is a "Reference event frequency"(REF) assuming all past events occurred with aircraft / pilots:-
- no alarm system
- critical check lists not used
- abort procedure not acknowldged
- no predefined / rehearsed canopy open flight procedure
- no proven flight procedure "available"
Regards,
John
John N G Smith
Tel / fax: +61-8-9385-8891
Mobile: +61-409-372-975
Email: john@jjts.net.au
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