Hanger Flying/ I learned from this experience

On Thu, 09 Apr 2015 09:10:15 -0700, Jonathan St. Cloud wrote:

Anyone have a detailed checklist or procedure they use to inspect a new
(or new to you) glider? How do you check TE connection on the ground?

No detailed checklist, but I always check ASI and TE connection after
reinstalling my panel: I take it home when the glider is in winter
storage.

ASI check. My pitot is a fairly large metal tube sticking out of the fin-
about 12mm diam and 120mm long with a hemispherical end and 3-4mm hole in
its centre. I put my thumb over the hole and then close my hand around
the tube. If the ASI doesn't go up to about 20 kts and stay there until I
let go, I know there's a problem. The exact reading depends on the day
temperature because what makes the reading go up is the pressure rise due
to my hand warming the pitot probe.

TE check. With a vario on and volume fully up, I put a flat hand on
either side of the TE probe and blow hard between my hands. If the vario
yelps I know the TE connection is good.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Friday, April 10, 2015 at 7:35:10 AM UTC-4, Martin Gregorie wrote:
ASI check. My pitot is a fairly large metal tube sticking out of the fin-
about 12mm diam and 120mm long with a hemispherical end and 3-4mm hole in
its centre. I put my thumb over the hole and then close my hand around
the tube. If the ASI doesn't go up to about 20 kts and stay there until I
let go, I know there's a problem. The exact reading depends on the day
temperature because what makes the reading go up is the pressure rise due
to my hand warming the pitot probe.

TE check. With a vario on and volume fully up, I put a flat hand on
either side of the TE probe and blow hard between my hands. If the vario
yelps I know the TE connection is good.

The above checks will not catch water in static,
nor leak in TE connection, nor leak in statics,
nor pitot plugged by bugs, all common problems...

Hope that helps,
Best Regards, Dave

I've told this story before, but...

When I lived in Texas, I stored my ASW-19 in an open front shed along
with several gliders. One day at takeoff speed, I glanced at the ASI
and saw an odd reading (I don't recall what it was). After liftoff I
noted that my vario was acting strangely as well. I figured there was a
problem with my static system.

Remembering my Air Force training, I thought I'd break the glass in the
mechanical vario thus venting the statics to the cockpit. Then I
thought that I, instead of the tax payers, would have to pay for the
damages, so I reached under the panel and disconnected the static line
from the ASI. Everything then worked pretty well and I had a nice flight.

Not having any compressed air on the ground, I disconnected the static
line at the "T" behind the panel and extended it sufficiently to reach
overboard. Then using a very large syringe filled with water, I pumped
water into one of the static ports with the other one securely covered.
What came out of the line by the cockpit was a load of cut up grass and
a bunch of ants who had decided to make my static system into their home.

I moved the glider to an air source and thoroughly blew out the lines,
reassembled, tested, and called it good. It was. After that I taped
over my static lines when the glider was parked and had big red
streamers hanging from the tape so I wouldn't forget.

On 4/10/2015 5:38 AM, Dave Nadler wrote:
On Friday, April 10, 2015 at 7:35:10 AM UTC-4, Martin Gregorie wrote:
ASI check. My pitot is a fairly large metal tube sticking out of the fin-
about 12mm diam and 120mm long with a hemispherical end and 3-4mm hole in
its centre. I put my thumb over the hole and then close my hand around
the tube. If the ASI doesn't go up to about 20 kts and stay there until I
let go, I know there's a problem. The exact reading depends on the day
temperature because what makes the reading go up is the pressure rise due
to my hand warming the pitot probe.

TE check. With a vario on and volume fully up, I put a flat hand on
either side of the TE probe and blow hard between my hands. If the vario
yelps I know the TE connection is good.
The above checks will not catch water in static,
nor leak in TE connection, nor leak in statics,
nor pitot plugged by bugs, all common problems...

Hope that helps,
Best Regards, Dave

--
Dan Marotta

Dave Nadler wrote: "The above checks will not catch water in static,
nor leak in TE connection, nor leak in statics,
nor pitot plugged by bugs, all common problems... "

Not being very mechanical I was wondering if someone could explain what procedures will detect water in the systems, leaks in the systems, plugged pitot,... etc. Thanks fellow pilots for all the great discussions.

On Friday, April 10, 2015 at 10:16:19 AM UTC-6, Jonathan St. Cloud wrote:
Dave Nadler wrote: "The above checks will not catch water in static,
nor leak in TE connection, nor leak in statics,
nor pitot plugged by bugs, all common problems... "

Not being very mechanical I was wondering if someone could explain what procedures will detect water in the systems, leaks in the systems, plugged pitot,... etc. Thanks fellow pilots for all the great discussions.

There are such things as water traps for pitot/static systems which go in a low spot. I recall some of these are transparent so they can be inspected for water.

This is not exactly what I was thinking of but it gives the idea.
http://www.trutechtools.com/Bacharac...ly_p_1472.html

The filter would keep insects out of the system.

On Friday, April 10, 2015 at 9:16:19 AM UTC-7, Jonathan St. Cloud wrote:
Not being very mechanical I was wondering if someone could explain what procedures will detect water in the systems, leaks in the systems, plugged pitot,... etc. Thanks fellow pilots for all the great discussions.

To check for leaks, connect panel end of tube to airspeed pitot and put tape over other end. Connect a syringe to static on airspeed and gently pull a vacuum until airspeed reads around 80 knots. It should stay that way for many minutes.

Applying pressurized air to plumbing that runs through the fuselage may cause some hidden connection to break apart. Always use a vacuum.