Sender: <marv@lancaironline.net> (Marvin Kaye)
To: lml@lancaironline.net
Date: Sat, 15 May 2004 13:29:33 -0400
Message-ID: <redirect-3234443@logan.com>
From: "David Allen" <daveandjj@hotmail.com>
Subject: ES vid site
Mime-Version: 1.0
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--- J H Webb <airmale@bright.net> wrote:
>Dave
>     you should be improving the airplane that you
>are testing not just writing scary stories.

Jack, I'm just reporting the facts of my flight test. I am surprised that a 
experience test pilot like yourself would take such offense to flight test 
results/facts.

Jack sez:
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.

Dave replies:
I wasn't doing flight test for a major manufacturer. We didn't have an 
unlimited budget. We didn't have the opportunity to cutup the plane and glue 
anything in place. I'm not even talking about "lowering the stall speed", 
frankly, I just would like the airplanes to have a more effective spin 
recovery. Glasair had some similiar issues and came out with a larger rudder 
kit for it's earlier airplanes. It doubt they would "take at least 5 knots 
off the cruise speed". I normally cruise around 10,000 and 55% - 65%. The 5 
knot impact more probably would be seen in top speed (1000' and 99% power). 
When Van's converted the RV-6 taildragger to the RV-6A trigear, they saw a 
loss of cruise speed of less the 5mph. Even so, if a fix was found that 
could be proved to vastly improve the spin recovery characterisitcs of the 
Lancair ES's or IV's and only cost 4 knots cruise, who whouldn't take that 
trade?

Jack:
>     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.

Dave:
That's what I encountered. When I tried to recover, the plane continued to 
spin 3 revolutions.

Jack:
     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..

Dave:
That's interesting, again, I bet you set the aft cg limit somewhat forward 
of where you encountered these uncontrollable situations. The F-4's I flew 
had a similiar characteristic called "Mach Tuck", but none of this is really 
relative to the subject.

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