[jump4way]

Can anyone educate a non builder on what might be involved to install a heated pitot tube on an already finished and flying RV4?

Obviously, wires need to be pulled. I believe a mount has to be installed for the pitot tube but I'm really not sure what's involved and how much fabrication is required. I am curious how much access there is to install the mount in an already closed wing.

I understand there are a couple of options out there in heated Pitot tubes, the Dynon and Gretz. I've searched a bit but am still unsure which is regarded as the better unit of the two. I suppose the reviews seem to be about equal. I would greatly appreciate any wisdom from someone that has done this type of an install before. Thanks in advance.

 

[Dean Pichon]

It's not a big deal....

In my -4, the pitot tube is located near the aileron bellcrank access panel so I can get to it quite easily. To install a heated pitot, you would need a skin doubler (may already be installed) along with the pitot mast and pitot. Some fairly heavy wire (14AWG?) and a dedicated circuit breaker and switch would also be required.

I installed a heated pitot during building of the wings, but by the time I got to wiring, I realized I did not want to be flying when pitot heat may be needed so I never connected the system.

Regards,

 

[terrykohler]

Do-Able

I retrofitted one on my 9A without too much difficulty. Like most projects, it just took more time than I originally thought. While I did not use the Gretz tube, I purchased their mounting hardware, which turned out to be a good choice. The Gretz mounting stack comes with a backing plate for inside the wing. The plate has a joggle in it to allow attachment to the spar flange for added strength. I also added an angle to the plate so that one side is fastened to a rib web. Most of the time was spent in aligning the plate properly - first drilling 2 pilot holes in the plate and 4 in the angle, then "fitting" the plate in the wing, using a small angle drill inside the wing to penetrate the bottom skin and 2 holes in the rib web. Plate was then removed and clecoed to the outside of the skin to complete drilling of the skin. Plate then re-fitted inside, again clecoed, and the two remaining web holes drilled out. Remove, vacuum inside of wing, cleco, and fasten with Cherry Max rivets. It's probably strong enough to be used as a tie-down. Wiring was straight forward. Good luck.
Terry, CFI
RV-9A N323TP