lml@lancaironline.net Mailing List Archive

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