Sender: <marv@lancaironline.net> (Marvin Kaye)
To: lml@lancaironline.net
Date: Sat, 15 May 2004 12:39:40 -0400
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From: J H Webb <airmale@bright.net>
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Subject: Re: FW: video
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Dave
    you should be improving the airplane that you are testing not just 
writing scary stories.  Aerobatics are fun but good handling qualities 
are built in or added in flight test.  I have evaluated many vortex 
generator kits and discovered that if you have a problem that cannot be 
improved by another means consider vortex generators but keep in mind 
that if you put rivets, probes, or any thing that protrudes on an 
airplane, if goes slower. Most of the heavily advertised 'lower stall 
speed kits' take at least 5 knots off the cruise speed.
     Changing the angle of incident or flow strips will improve low 
speed handling and stalls with little or no impact on the cruise speed.
    In answer to your question, a rolloff is an uncontrollable roll 
against full  opposite aileron and rudder. If a rolloff starts it is 
time to recover to avoid departures or spin entries.
    With reference to pitchups these have occurred at CG's other that 
full aft, but they are far more common at the aft limit of the CG 
range.  these are not necessarily only uncommanded in the sense of an 
abrupt rapid pitch up but gradual loss of ability to pitch the nose down 
to the point that the nose is slowly pitching up and full down elevator 
will not arrest it. We did deep stall tests and achieved angle of 
attacks up to 65 degrees. These were power on stalls and interestingly 
this caused rates of sink up to 3500 feet per minute with full power at 
gross weight and aft CG..

Jack Webb

>
>Jack Webb
>L 360, L IV
>ATP, CFI Airplanes & Instruments, Multi Sea
>Many Type Ratings
>Experienced Experimental Test Pilot both multi and
>single engine
>Former Chief Engineering Test Pilot for a Major
>Manufacturer
>AeroSpace Engineer BSAE
>Ohio
>
>
>  
>