A4 flight
03-30-2002 | 04:17 AM
#1
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From: Richmond,
VA
A4 flight
Have an A4 with the sport wing and Dynamax fan/JMP II pipe system. Ground Handling...the A4 tends to want to wheelbarrow down the runway...if trimmed a slight amount of UP it will infact fly itself off the runway...if not then it will wheelbarrow until you rotate. If you try to fly to slow or get the nose attitude very high just after lift off then you will stall the wing...and since it is a Delta wing it will stall from the rear outboard section inward and foward...the result is a very noticable pitch up to about 60 degrees or more and no elevator effectiveness...ie. CRASH if you are not very lucky. The A4 slows down nicely once the gear is down and you should have a nice nose high landing attitude carrying some power to control the descent rate. I have brakes on mine and they work nice ...but once again if applied to much to fast, the aircraft will wheelbarrow...I would put some nylon wing skids (carl goldberg) on each wing tip to protect the fiberglass from rubbing on the runway. The weak link in the gear is the nose strut...the piano wire that connects the Robostrut to the retract will bend on just the slightest pressure...be careful. Wow the crowd with a low pass and ROLL...the roll rate is uncontionable...
Have Fun!
Scott
Have Fun!
Scott
03-31-2002 | 02:17 AM
#2
Senior Member
A4 flight
Scott,
I just stumbled onto your A-4 post and thought I would comment.
The A-4 is commonly called a double delta, but has absolutely no flight characteristics common to a conventional delta wing. Remember that a delta wing airplane has no tail!
Does the airplane sit on the ground with the nose high or is it level like a pattern airplane? It should sit with the nose high in order to rotate rather than respond abruptly to too much elevator throw. What is your elevator throw? It should be no more than 1/4" on low rates; ailerons should be at or just less than 1/4" on low rates.
On takeoff, it sounds as though you are killing your forward airspeed due to an abrupt change in AOA; the airplane loses lift and stalls. You may also have positive incidence in the stab, causing the wheelbarrow effect. You would be better off to get rid of the spongy nose gear and make it rigid. You'll continue to fight steering control as well as incidence as long as the nose gear is springy.
Best regards,
Larry Wolfe
[email protected]
I just stumbled onto your A-4 post and thought I would comment.
The A-4 is commonly called a double delta, but has absolutely no flight characteristics common to a conventional delta wing. Remember that a delta wing airplane has no tail!
Does the airplane sit on the ground with the nose high or is it level like a pattern airplane? It should sit with the nose high in order to rotate rather than respond abruptly to too much elevator throw. What is your elevator throw? It should be no more than 1/4" on low rates; ailerons should be at or just less than 1/4" on low rates.
On takeoff, it sounds as though you are killing your forward airspeed due to an abrupt change in AOA; the airplane loses lift and stalls. You may also have positive incidence in the stab, causing the wheelbarrow effect. You would be better off to get rid of the spongy nose gear and make it rigid. You'll continue to fight steering control as well as incidence as long as the nose gear is springy.
Best regards,
Larry Wolfe
[email protected]
