Subject: 1st flight mishap
From: Rotary Engine
Date: 9/11/2009, 12:00 PM
To: AAA Put this in the To box


 The  whole incident, from start to finish  consumed about 3500 - 4000 feet
 of
 the  6000 foot runway.   She was off the ground before the 2000 foot
 marker.
 And today  was not a standard day -- DA this afternoon was about  8300
 feet.
 So yeah -- plenty of get up & go.

 Agree on  the slower  warm-ups vs blasting down the runway at full
power...

 Live & learn  I suppose...

 Mark


 Mark,
 You might not need to make any more  high speed taxi tests, but a good
 suggestion was made by a friend of  mine. Run it without the wings on
until
 you're ready to fly. You can  go as fast as you want without unexpected
 aviation.
 Bill  jEPSON


 On a canard airplane, if you take the wings off, be _sure_  to take the
 canard off too.  If not and you accelerate to near  rotation speed, the
 aircraft will likely flip over uncontrollably due the  center of lift
 being so far forward..  An early Varieze or Long EZ was  significantly
 damaged because of  this.


 Regards,

 Matt-

 Matt, et al,

 Other than to test the engine, what is the purpose of the high speed taxis
 sans wings? Do you have any concern about torque roll on the ground? You
 should  be able to get a good idea of tracking with slow taxi tests. Your
 brakes will  not be as effective at the weight which will be much liter
 since
 there will not  be much weight on the wheels (skidding).

 If your plane is ready to fly, do graduated speed runs aiming for a
 particular target airspeed, chopping the throttle and bringing the stick
 back. 5
 mph (K) increments would be good. At a given point, the nose will raise
off
 of  the ground and allow you to gently put it back. (don't yank the stick
 back, but  give it just a little tug.) Because the thrust is now 0, the
nose
 should settle  back.

 However, be prepared to fly the aircraft in case of a malfunction.

 This will give you some numbers as well as confidence handling the
aircraft
  at takeoff speeds.

 If you use too much of the runway in this exercise, your runway is too
 short.

 Rich


I'm not a fan of high speed taxi without the complete control system
installed and functioning.  I think it's generally a dumb idea..  I
was just making a comment about one of the (possibly not so obvious)
hazards of doing so..

I think ground running is a tough question..  You'd like to run the
engine enough to gain confidence that it will function well, but you
end up exploring areas of operation which are often irrelevant to how
an airplane will be used - high power with zero airspeed isn't
required of a normal airplane.  On a reciprocating engine you may
cause a condition which makes it difficult to properly seat the rings
on the freshly honed bore.  I don't know if that concern exists with a
rotary - do the apex and side seals "seat?"

Rather than extensive ground runs, I'd prefer that new engine installs
be tested at an airport where landing after an engine failure or burp
or hiccup is basically expected, and where damage because of such an
event is unlikely..  A big airport with runways crossed in a triangle
would be ideal..  Expecting a failure and being surprised by continued
operation will help you be in the right mental state for dealing with
whatever happens.

Rich, your suggestion for how to sneak up on a first flight seems like
a good one.  It's essentially what Rutan suggests, and is the method I
used for checking myself out in my Varieze.  Gaining recent experience
in the same type of airframe prior to first flight with a new engine
setup should be just about mandatory in my opinion.  Or at least
recent experience in airframes of several different types will be
good.  Go get some glider, some tailwheel, some retract, some Cessna,
and some RV time.  Spend some time transitioning back and forth
between slow flight and cruise flight, both turning and level.  If you
get glider time, practice rope-break exercises, and in a powered
airplane, practice engine failures.  It will sharpen your flying
fundamentals and get you used to dealing with the variety of control
feel and responses you can encounter.  It will make it less likely
that you will suffer PIO or porpoising..  Make sure the new airplane
has zero control slop and friction in the elevator (for the same
reason).


Regards,

Matt-


If one has great concern about handling the aircraft they just built on
initial flight testing, perhaps they should consider getting someone else,
who is very experienced, to perform these preliminary flights.  Or, at
least, get experience in a similar plane so that you don't end up testing
your flying skills at the same time you're testing your aircraft!

Georg Lasik



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