Agreeing with Ed: this long after manufacture, with unknown
variations & modifications, you need to test your own plane's
performance. FWIW, my 415-C, with a C-85 engine, carrying 310# (me &
a CFI) and about 1.5 hr. less than full fuel, found 12,200' MSL
absolute ceiling. (That was over the Inland Empire area of SoCal,
where it was desert-hot at the ground level, and so cold at altitude
that I wouldn't let him open the window to check the air temp. after
about 10,500'! I do still have the temps recorded somewhere if it's
important to anyone.) Since I fly under SP rules, 10,000 MSL is as
high as I go.
Linda
N3437H ("SkySprite")
415-C
L.A.
