"Bob F." wrote in message
. ..
"Dallas" wrote in message
...
On Fri, 15 Aug 2008 23:02:16 +0000 (UTC), Bertie the Bunyip wrote:

There is the question. I'm in a mood today. Have you flown your
favorite aircraft with zero or near zero indicated airspeed?

I haven't done it, but flying through some icing with the pitot heat off
should do the trick.

So... what's your answer?

--
Dallas


If the pitot and weep hole ice over, the airspeed will not change until
you change altitude.

--
Regards, BobF.


I had these airspeed experiences:
1. We were moving gliders from our winter storage location to our filed of
operation near Seattle. It was the first flight in the morning. This was
an extremely short field take off. We had a specially developed technique
to handle this including a very short tow rope. I was towing using a Pawnee
and noticed the AS to be very sluggish and it stopped at about 50 Kts. I
was committed for this size field and with a glider behind me to boot. I
wasn't sure of how fast I was going and just depended on experience,
aircraft feel and field length. I just cleared the fence. We climbed to
our agreed altitude, and kept a known throttle setting. When we got near
our final field, the glider released. My ASI was still indicating abt 60
kts but not changing except with altitude. I did a couple of stalls in
order to refresh myself of the nuances and feel of the Pawnee and then
returned to the field and made an uneventful landing. I later talked to the
glider pilot and to my delight he said he didn't notice anything out of the
ordinary during the whole event. A bug was found wedged in the pitot tube.

2. I had an instrument student on a 172 long cross country from SJC. We got
clearance, took off, and I noticed the ASI behaving very similarly. It was
indicating low but for some reason, the student said nothing. Just before
entering the cloud base, I pushed it over, asked the student to return for a
landing, negotiated this all with the tower and the student made an airspeed
indicator failure landing, a little hot, but just fine. Taxied back (still
indicating about 40 kts) to the flight school and pried out another bug.

A story I know of:
727, pitot heat breaker tripped, pilot didn't know. Pitot (actually called
an "air data sensor") froze over and as he was climbing the ASI was now
behaving like an altimeter. As the AS was increasing, he was increasing
pitch. It wasn't until he reached "stick shaker" did he put it all
together. There might be another variation and more details to this story,
since I now only remember the lesson and not the facts.

--
Regards, BobF.