Two more data points from AMA record flights are instructive to observe.
First is Rob Romash's ministick at LH. Rob did not give the motor weight for his 16:39 flight but I estimated the motor weight from the plans to .313g. The flight launched with no back off. The KE is about 6.6.
Second is Brett Sanborns 43+ minute F1D 1.2g flight. The KE for that flight is about 12.
Both of these flights are extraordinary and represent the very best in the respective classes. Why is Rob's flight so low and why is Brett's less than Kang's F1D 1.4? Kang alluded to this earlier in noting that it is not always possible to use all of the available rubber energy (Brett needed a vp to keep the plane out of the LH girders, for example, and this made for less prop efficiency early in the flight).
The KE is actually the proportionality constant, for a given flight, between the theoretical (first order) maximum duration and the actual duration. However, different planes to different designs have differing proportionality constants. If we are looking for a contest that looks toward the highest proportionality constant, this is what we might do. We can discuss at a later time the pluses and minuses of such a route.
LeoP
Received on Sat Feb 20 2016 - 05:56:10 CET
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:48 CET