For an airliner the answer is at
http://www.jaa.nl/jar/ihs_data/frame...6435/46435.htm
For a smaller aircraft, it's at
http://www.jaa.nl/jar/ihs_data/frame...5865/45865.htm
And for a yet smaller aircraft it's at
http://www.jaa.nl/jar/ihs_data/frame...0511/50511.htm
I'm not honestly sure why transport aircraft such as are in parts 23 and 25 use 35 feet, and "very light aeroplanes" use 15m (49ft). Anybody else know ?
G