Pitot Question - Install/Removal

[Reflex]

I'm a bit perplexed about the pitot install. I've looked though countless builder sites and threads and believe I must be overthinking this. At issue: after the mast is installed, how is everybody getting the pitot assembly through the mast?

More specifically, if the tubing left close to it's original length (Garmin doesn't recommend cutting) and the bends in the tubing have been made, how is the pitot installed/removed?

It's easy to understand how the entire unit (mast and pitot) can be installed and then the bottom skin put into place, but I'm having a hard time visualizing installing the mast and then putting the pitot assembly though the mast with the bends made? If the assembly is installed after the bends are made, how can it be removed, replaced, or serviced? I understand that this is a simple device and that servicing or removal of the pitot is rare, but there is a chance that the element could quit, a leak could occur between the pitot tubing and the fitting, etc.

The builder sites I've checked have some very nice plumbing, but the skin has not been installed.

On the other hand, I haven't found any comments about any difficulty in installing the pitot though the mast after the bends have been made.

Is everybody installing the pitot before the bottom skin goes on and hoping that there are no issues?

[salto]

The tubing is soft aluminium you just shape it as you poke it through.

[Nova RV]

It's very easy to bend the tubing as you feed the pitot assembly into the mast. Reach through the access panel next to the mast. It's not difficult but there are several complex curves to make to be sure the tubes clear the aileron pushrod throughout it's range of motion.

[bkervaski]

I struggled a little with this as well.

There is a minimum length you can cut down to, I think it's 6" but please double check.

I cut mine down to two inches above whatever the minimum was and then put 30 degree bends.

Also, if you are using the nylon tubing (you should be) then there is no need for a fancy stacked connector/adapter to hold the nylon tubing on the pitot aluminum tubes, they will slide on air-tight and will not come off.

[kiljoy]

I cut 2" past the minimum tube length and did a straight fitting on each. I then used 90 degree elbows to connect to the vinyl tubing. That way removal of the mast is a breeze.

[Reflex]

Many thanks for the responses. It appears that there are several factors in play with the responses.

• Garmin does not have a minimum length, they recommend not cutting the tubing. Dynon has a minimum length of 6" I'm using the Garmin model.
  
• I have a concern about the tubing becoming work hardened. Perhaps this doesn't happen easily with this grade of aluminum.
  
• The length of the mast comes into play. I'm using the SafeAir pitot mast which is an inch longer than the Gretz, 1.4 oz lighter gets into cleaner air, won't rust, and fits much better onto the spar. Unfortunately, the longer length exacerbates the problem.

In the end, I'll likely test fire the pitot on the bench, take the temperature at multiple points along the tubing and decide how short and if they can be cut while maintaining temps below that which can be handled by the fitting and the nylon tubing.

I just don't like the idea of bending that tubing twice.

Again, many thanks for the responses.

Fred

[Bavafa]

If I am not mistaking, Garmin recommended not cutting or minimum length is for the heated pitot tube only and it is 8" for the heated pitot.

It is very easy to bend it as it is a soft aluminum and you can shape it away and clear from the push/pull tube.