I've read with great interest the discussion concerning wing loading.  It is
not apparent to me what has prompted this recent discussion but my suspicion
is that it is linked to the introduction of the turbine, its very high fuel
burn, and therefore the necessity to carry more fuel that increases gross
weight.  Having built one of the very first Lancair IVs, I have watched the
gross weight of the plane inch up over a decade.  The first increase was in
response to pressurization that added weight to the airframe (3200 lbs).
Then the extended fuel tank option appeared and the gross weight increased
again (3400 lbs).  Then people began to realize this four seater aircraft
was really a two - three seater (3600 lbs).  Now the airplane is being
packed with more fuel in belly tanks, new wing bays etc and it has been
suggested that it can be flown at 4000 lbs.  I'm not suggesting that it can
or can't and I'm not an engineer but some of the more learned in the group
have raised the more obvious issues of wing loading, structural integrity,
flight characteristics, etc.  Having flown one of these things to the ground
without a working engine, I'd just like to wave a flag of caution.  Most
accidents don't occur when everything is working right, they occur as a
sequence of things that went wrong.  Take a 4000 lb airplane on a hot day at
high density altitude, throw in a loss of power, and your margin for safety
sinks quickly to zero.  These planes may be experimental, and you are free
to do what you want with them, but they're still airplanes subject to the
same issues as "certified" aircraft.  While the plane may structurally fly
at a high gross weight, is this a safe thing to do?

Please be careful.  We've buried too many of our group this past year.

Doug Pohl
Lancair IV-P