Have you noticed the number of density altitude related events lately?
Several weeks ago this hotter than usual summer is what initially had me thinking about the significance of density and AOA. Since starting these thoughts I have heard of half a dozen first-hand experiences of guys barely milking up through ground effect and finally getting the plane up to flying speed and altitude. Barely. Several types of aircraft. We have a couple of advantages with the canard configuration.
The major point I was thinking of was too easily accepting that the airplane was over weight from the beginning, whether we bought or built. Bottom line concern was the situation of a pilot reading in the POH a minimum speed value of maybe 65 (mph/kts/whatever) or so, when in reality on a real day with more than one person aboard and more than a few gallons of fuel the minimum speed may be 100 or so. So adding the 22 to dissipate descent rate-of-descent would be a minimum approach speed of 122; not 65.
It's one thing if we are well experienced in this heavy condition and have that buffer mentally ingrained. But it is a different story if surprised at this diference because of gross wt and DA. Weight has many implications. Some are OK, some are unacceptable. Especially on an unplanned unprepared-surface landing.
One of my most challenging takeoffs was in Buena Vista, Colorado; Elevation 7946 ft and 8300 ft long. Getting in there was fine. But because of the expected challenge, several precautions were made to prepare for the departure. I made a practice solo flight which was instructive. The departure was planned for an early (cool) takeof, and minimum fuel. The abort distance was determined. All went well, with everything working as planned. I had been thinking about it for weeks.
But it is the unexpected that gets us; either from an act of God or from our own complacency. One of my favorite phrases these days has to do with the “buffer” or “margin of safety."
What is our limit? What do we demand of ourselves?
So, here’s the question.
You are at KXYZ airdrome and because of the usual-suspect reasons you are slightly overloaded and MUST depart NOW at the worst-condition density altitude.
Other than “I think I can,” what are the planning elements that one should use for canard aircraft?
Thanks-
Bill James
