My 415C was off half a bubble (less than my friends said I was off) and I had no problem with cross wind landings. Dan C
On Aug 20, 2010, at 9:40 PM, Ed Burkhead wrote: > > On 2010-08-20 4:18 PM, Linda Abrams wrote: > >> how level is "very nearly level?" How much of a bubble "off" is >> still "level enough" for cross-wind purposes? (assuming I'm using a >> large, good carpenter's level) > > > Linda, > > I can't say how much of the bubble I'd want out of center. > > We used to primarily talk about the "tail height" needing to be 75", the > original specification with the single fork nose gear and I forget which > tire. For single fork nose gear planes, we'd consider that 75" was ideal, > 74" inches would be OK, 73" is still sort-of OK (but was sub-optimal in > strong crosswinds), 72" should be fixed and anything lower was getting > dangerous. These numbers were not scientifically arrived at but were derived > from reports and experience. > > How that translates to bubble diversion, I just don't know. > > If the plane has a longer double fork nose gear (usually longer by 1.5") then > the tail would need to be 1.5" higher than the original standard to keep that > on-the-ground datum (the window sill) level and the angle of attack of the > wings at the specification. > > More recently, we've been emphasizing that the window sill needs to be level > as that is the specification and applies to all models and all landing gear > modifications. > > Unless we can get something more definitive, I'd suggest you measure your > tail height with a friend or two. Set the bubble level on the window sill. > Then have one friend lift the tail till the bubble is showing level and > determine how many inches difference there is between level and its normal > on-the-ground attitude. > > If I were only 1"-2" low, I would probably wait will next year to put in new > donuts or add a spacer. If there were a 3" differential, I would do landing > gear maintenance. > > If you do this, perhaps you can report back on how much the bubble was off > center on your bubble-level for each inch of droop from level. > > Sorry I can't be more specific. > > Ed > >
