All of the comments on stalls
have been fairly stated. Bear with
me and try to understand my perspective.
I will be speaking generally about the 200/300 series Lancairs, but more
specifically my own 320. The
200/300 series are the most optioned/modified kit aircraft you will ever
encounter – every one of them is different from any other, including the CG
range in various flight configurations, parts locations, engines, props, tail
size, fuel distribution and human weight.
Because of that fact, these aircraft are ideal for the installation of an
angle of attack (AOA) system that uses upper and lower wing pressures along with
pitot/static pressures and therefore adjusts for atmospheric conditions, wing
loading and indicated speed. Some
also provide an indication of best glide speed (useful when the engine stops
providing thrust). One drawback is
that it is a measurement on only one wing and there are two.
Those folks that have had
aerobatic training or are ex-military fighter pilots and also fly a lot are
certainly capable of enjoying to the maximum the responsiveness and
maneuverability of these wee Lancairs.
Stalling their plane, often entering unusual attitudes and performing
aerobatics (even remaining inverted if so equipped) is fine in these strongly
built bundles of fun.
I have arranged my 320 for
maximum efficient forward speed (honking Hartzell prop, heavy harmonic damper,
pitot fed hi pressure air to the injectors, gap seals, internal trim control –
no draggy tabs, etc.) with a somewhat forward biased CG that still gives me
complete small elevator authority in all useful flight regimes.
The only stalls that interest
me are those that have occurred at slow speeds and “close” to the ground (i.e.
on approach, in the pattern, during turns, upon takeoff and climb out,
etc.). Why?, because they almost
always end in death. The FAA
classifies these as loss of control but they seem mystical to me as they
frequently happen to experienced Lancair pilots or those trained in spam cans
that maybe don’t respect a slick experimental hi-performance aircraft for what
it is. Reading the NTSB accident
files reveals such accidents during S-turns at OSH, departure stalls in a
climbing turn, attempted (stretched) off airport landings, flight in the
pattern, yada, yada, yada. All of
these were likely unrecoverable because the departures from the intended flight
occurred too close to the ground.
These mystic misadventures
occurred during a period of slow flight where there is little margin away from
the stall AOA. Slow flight without
at least some flaps also leads to a hi AOA, the wing loading is increased in
turns, there is a small margin for wind shear, a distraction may result in back
pressure on the stick, etc. ???? An
IAS of 1.3 times the stall speed is not enough in these planes. When it goes bad, it goes bad very
fast.
Perhaps those that have
experienced stalls in their 200/300 series might relate their experiences with
departure type stalls, clean/dirty stalls from decreasing airspeed in level
flight, stalls out of slowing speed turns with and without 1/3 or 2/3 flaps,
etc. Even though you were expecting
the stall, how many feet were lost before recovery? What was the recovery pull out speed and
how many more feet would be lost if the reaction time was 1 or 2 seconds longer
caused by a surprise stall? Was
there a difference when the plane was loaded up vs light (one or two people,
full or lo fuel)?
Fred detailed the
characteristics of the IVs and some of them are similar to the 200/300
series. High wing loading
(weight/70 sqft for the 300 series – around 22 #/sqft, the wings utilize
extensive Laminar flow, etc. But,
there are others factors that are unique to this series, especially the reflexed
flaps and that dirty wings result in increased drag but not a loss of
lift.
I don’t practice stalls
because there are so many types at slow speeds that will kill me (I only fly 2
speeds – cruise and near the airport).
Any time I am not at cruise speed I am extra alert – I do not even like
the mushiness of the controls when in level flight practicing emergency gear
drops at 87 KIAS, using 1/3 flaps to keep the nose down. I like a circular arc when flying from
downwind to final for adjustments throughout the turn. I reject requests from the tower for a
close in downwind or to make the turn tighter.
You folks fly’m the way you
want – I don’t mind being called a wuss or being urged by a pleasant female
voice - “Angle! Angle! Push!” I am more alarmed (no pun) when I hear a mellow
voice announcing “Traffic.”
Blue Skies,
Scott Krueger AKA
Grayhawk