Re: X-Air Ultralight Aircraft Re: Indicated airspeed problem
|
?
John you mention 95knots its 95mph (83kn)
?
----- Original Message -----
Sent: Friday, July 27, 2018 9:25 AM
Subject: X-Air Ultralight Aircraft Re:
Indicated airspeed problem
?
This is all well and good, however if the aircraft has been changed since
it was built it could be that the MAAN figures used by the BMMA are incorrect
and they could potentially be asking members to fly their aircraft
significantly over VNE.
?
I solved the problems with my own aircraft and got my permit. I took
advice from various experts and then flew the VNE test again.
?
Before re-flying the the VNE test, I made a rough calibration myself to
check that I was not doing anything dangerous. I simply flew level at full
throttle into wind and then full throttle down wind and observed the GPS speed
and IAS.
?
The GPS speed was approximately in line with my expectations and so I did
the test. I actually did the VNE test twice, again into and down wind. ( there
was little wind on that day ) During the test I kept an eye on the GPS speed
and ensured that it never at any time exceeded 95 knots.
?
Which is 10 knots faster than VNE and also the maximum speed achieved by
the test pilot during certification of the the aircraft. By coincidence, my
particular aircraft was the prototype used in the original testing and so I
know it has flown at 95 knots previously.
?
I am very concerned that other owners may be persuaded to fly their
aircraft at dangerous speeds and I have heard stories of X airs being pushed
to a near vertical dive to achieve the required indicated airspeed.
?
To me that suggests they may well have been flying too fast. Mine
achieved VNE with a steep dive on full throttle, it was not vertical or
anything near it. I simply opened the throttle fully and when maximum level
speed was achieved, I pushed the nose down and allowed the aircraft to
accelerate to VNE.
?
Aside from the these particular concerns, more generally I don’t see the
point of any test where the only two possible outcomes are either a pass or a
fatal accident.
?
Regards,
?
Jon
|
