The Maule Airplane Flight Manual is one of the skimpiest pilot operating handbooks I've ever seen. Since I want to explore some of the backcountry strips in Idaho and Washington State, I'd like a little more hard data on my plane's climb performance at various weights and density altitudes. Some real life performance graphs would be great to have. In my search for how to compile this data, I came across the spreadsheet models created by Dr. John Lowry, an aviation physicist and all around smart guy. I plan to use his system to develop performance charts for my plane at various gross weights. Before I do, I was wondering if any other BCP pilots have gone through his process. If so, do you have any practical advice for me before I start my data collection efforts? Here is a link to his article in AvWeb that includes his spreadsheet for calculating performance numbers for a plane with a constant speed propeller. He has published a parallel article and spreadsheet for planes with fixed pitch props. I also posted this question on the Maule Pilots website, but given the broader participation here, I thought it would be well worth reposting. By the way, the recent issue of Kitplanes has a story about this process written by a Bearhawk builder. That is what got me started down this path to enlightenment.

http://www.avweb.com/news/airman/182418-1.html?redirected=1

I played around with that spreadsheet using data for my Savannah. It was a kit plane, and came with a POH that was less than useful, so I ran a number of experiments and used that data to enter into the spread sheet you are asking about. The results seemed to be pretty good. For example, the Savannah, with minimal load, was predicted to have a maximum ceiling of about 18000 feet. I gave it a try and was making about 100 ft/min climb at 17500. I called it good. Nice view from up there.

Here's is a pretty good book that covers flight testing of aircraft:
"Flight Testing of Homebuilt Aircraft" by Vaughan Askue.

All that said, my experience in flying has shown that you rarely have all the variables known well enough to just look stuff up and go with that number. Conditions are constantly changing, and you need some safety factor to accommodate the real world. How close you want to slice it is up to the individual pilot.

Have fun with your plane,
tom

I like it. It is easy to see just how much an engine upgrade or other improvement might affect performance.

I saw this article in Kitplanes magazine as well. Good stuff. I plan on using this approach for a Rans S-20 Raven I will be building this fall.

That's Jared Yates.