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Scott,
Thanks for the info. Do I
understand that you imply the 300-series wing that was load tested is the same
as the 200's?
I'll try to access Lancair factory
newsletters also, for further enlightenment.
Elsewise, I think it may be
'practical' to test glass airplanes at @2x limit for ultimate instead of 1.5,
because they (I think) fail more like wood than stretchey metal. I could
check with (send this Info to) sons Sean and Tim about that, as they
have experience designing tooling and structures for composites for
Boeing.
I'm presently starting work on my
'spats' (2-position slots to delay horizontal stab stalling), and expect
to be offered delivery of the 3-blade Vari-Prop in a week or so. Also the
Prince capacitance fuel level sensor was dropped onto the back porch by UPS a
few minutes ago, so I'm now thinking of the recent polsts of how to keep
warm in the hangar.
The sky's been beautiful lately ...
beconing the frustrated builders.
Terry
----- Original Message -----
Sent: Thursday, November 29, 2007 01:30
PM
Subject: [LML] Re: linit Gs for 235 (kit
#11)
Getting close to asking for
airworthiness... and noticed my Pilots Operating Handbook gives Limit
Gs' allowed as 4.5, but does not specify for which of the three airframes
the POH covers: 235, 320 and 360.
It also gives allowable
gross as 1400# for the 235, and 1685# for the 320 and
360.
Sounds like the gross limit
for the 235 is because of lower HP, not airframe... do you have a
reference spec?
Terry,
Interesting question for a 235. Lancair did a static G-test on the
300 series plane by loading the inverted craft's wings with sandbags to
9Gs. If I remember correctly, there was no failure at that load. I
also believe that this test was done on wings constructed before the
"cap-strip" rib-to-skin technique was used.
Lancair later raised the "suggested" max gross weight to 1800 but, if I
remember correctly, kept the landing max weight at 1685. These things
were documented in Lancair Factory newsletters that may be available at the www.Lancaironline.net site
(Marv?).
It is interesting that Lancair's ultimate load limit is 2
times the max G when the usual STC's planes use 1.5 times. In any
event,
(1685/1800)x4.5G=4.2G, still a pretty good max G load limit.
Note that a critical factor is what weight the landing gear was designed
to withstand. For your airworthiness W&B you may state any GW that
you want (within reason). I am sure a flying 235'er can describe
the effects of being overweight or out of CG.
I have flown my 320 at an estimated 1960 lbs only to find that
the AP altitude hold slowly wandered up and down until the weight got
down to 1900 lbs (burned off ten gallons). Uh, I try to be gentle on all
landings regardless of the weight ultimately contacting the pavement.
Scott
Krueger AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL
(KARR)
Darwinian culling phrase: Watch
This!
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