Triple TE probes, failures

[cernauta]

I have seen many (including mine!) Total Energy probes fail: hairpin
cracks in the carbonfibre tube, in the area that fits most deeply into
the plug (in the fin of the glider). The terminal pin, made of aluminum
and glued to the inside of the tube, then is not retained correctly...
and it may stay in the glider as you remove the probe. (removing it from
the fin can prove to be a tough job)

IMHO, when ordering a new glider it is advisable to ask for 2 separate
plugs for Ptot, and TE+ Static, at the least; or better just 2 plugs for
TE and Ptot.

If you already own a glider fitted with one only plug for the 3
functions, then I strongly recommend you don't buy the composite probe
in carbon fibre, but the equivalent made of aluminum from the same
manufacturer.
More so if you own a motorglider!

Opinions?

Happy flying

Aldo Cernezzi
(remove PUSSAVIA to reply)

[cernauta]

Gary Evans wrote:
>
> Do you know who makes a direct all metal replacement
> multi probe to replace the carbonfibre style supplied
> by DG on the 800?

The same manufacturer offers them in aluminum as well as in carbonfibre:
www.esa-systems.com
the price is more or less the same (190 euro), but shipping is
expensive.
it is not possible to fit a normal TE probe to the triple plug in the
fin: even if you would seal all the tubes in the cockpit, they would
still act as a very big capacity, making TE pressures completely
unreadable.
The only way would be to open the fin and replace the plug...

I have saved two functions out of three on my broken probe: P.tot is
through the inner plastic tube which has been ripped off when trying to
extract the small metal end from the recessed plug in the tail of the
glider; I have sealed both the Ptot hole in the front of the probe AND
the small plug at the other end of the probe, then glued the small plug
into the carbonfibre tube with the best quality of cyanacrilic glue.
I can thus use TE and static pressure.
I have connected the flight computer to the Ptot coming fron the nose of
the glider.
We'll see if the repair holds for a long time...

Aldo