Here is a list of all the postings Jo has made in our forums. Click on a thread name to jump to the thread.
|Thread: OS 26 going dead stick|
I just went to Halford's, and they couldn't find Armour All vinyl cleaner in their PC lists; there were other applications by the same maker, though. Would some other type of cleaner do? Am anxious to solve this problem, which endangers both the model and other people!
|Thread: Centre of gravity|
|Thankyou too! May I say that my experience is of about 20 years of getting 'funny' models in the air - and back again - based on the work of the late David Fraser, an American glider designer of note who died young in a Cessna crash. I think he got 'CG position' right because my only real maiden flight failure in some 20 odd different model launches since then was due to my incorrect data entry in my computer program application for a (pusher) tailless model. Happily, the error was corrected, and it flies today.|
That "C of G calculator" site mentioned above is another misleading one. Like nearly everything else published on this topic - books and current magazines - it contains two errors: 1) The NP (given by 'Vbar') is wrong. 2) Stability has nothing to do with the length of an MAC. Suggest looking at my method. Another site includes correct NP in an easy to follow diagram here, scroll to para "The simplest way of locating the aircraft's NP..."
However, the usual error in NP location depends on the ratio of tail to wing area and is quite small when that is small - as for the usual conventional model. But, for such as a tandem-wing design the error is enormous.
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