Jon,
It seems you haven’t had a chance to give the paper a thorough reading yet. If you only read one section of the paper, I recommend starting on page 23 with Fred Moreno’s outstanding discussion on human performance. As this relates to check lists, the bottom line is that well trained, rested, and focused people will still eventually miss items on the lists – even if they’ve had several million dollars in military flight training.
If missing an item results in an increased probability of creating a catastrophic hazardous condition, then best design practice is to provide other means of ensuring the hazardous condition is not allowed. As flying machine designers we basically want to put obstacles between a flight crew and each catastrophic hazard until those risks are properly controlled. Critical hazards are not acceptably controlled (meaning reduced in probability of occurrence) by checklist use alone given the error rates of humans. Human performance testing shows that a well-trained, rested, and focused human is going to average an error one out of every 100 actions. It gets much worse if they are not trained, rested, and distracted…
I’m pretty sure that the designers of the military aircraft you flew went through the same design safety assessment. If your military aircraft were taken airborne without the canopy latched and that was likely to result in loss of crew and vehicle, that hazard would not be “controlled” only by use of a check list. There would be caution and warnings to help prevent the hazardous condition and if a C&W system doesn’t reduce the probability of occurrence enough, other more significant vehicle design changes would likely be undertaken.
In the case of the Legacy’s canopy, a simple and inexpensive warning system and very minor modification to the latching mechanism can significantly lower the probability of even tired and distracted pilots from taking a Legacy to flight with the canopy unlatched.
I’d like to see the community of Lancair Legacy builders and pilots grow. My view is that any prospective builders/pilots conducting due diligence on the airplane and its safety history would be happy to see that the cause of a considerable portion of the accidents and fatalities can be essentially eliminated by incorporating simple, inexpensive measures.
Valin Thorn
The Legacy canopy design is not unsafe or inadequate and does the job exactly as Lancair intended. In all my training in the Legacy, attention to the canopy has always been stressed. It’s a check list item and as in my military jet, a verification item by pushing on the canopy prior to takeoff. After the tragic Lakeland accident Lancair incorporated an additional canopy safety warning into the design. If a builder wants to change the design, that’s a judgment call.
I don’t believe there is a case of a “secured” canopy opening in flight and it has been demonstrated here, the plane can be flown with the canopy open. These are high performance airplanes, deserve respect and require skill to operate. Yes, some pilots failed to secure their canopies before fight. Some recovered their airplanes and some had lesser results.
Human factors are the issue here and unfortunately, failures will occur. Failure to use checklists or missing items, rushing, complacency and non-standard procedures, continuing takeoffs with the canopy unsecured, operating on runways with insufficient Accelerate Stop Distances, etc.
I am concerned how a paper like this may be perceived. Will it scare off potential builders and buyers or be interpreted to indicate a design flaw? I don’t believe this paper presents anything new or unknown. As far as I know, there is no record of an in-flight breakup or failure of a Legacy, yet the airframe has developed a certain reputation by biting a few unwary pilots, but just how does this paper help?
FWIW
Jon