Lost pitot?

OneTwoSierra · #1 03-05-2006, 04:36 PM

Has anyone ever had to tighten their Van's pitot fitting? It just occurred to me that this is a fitting (excuse the pun) comparison to the fuel tank pickup problem on which the recent SB was based. Its an angled tube that gets lots of vibration (probably more due to the lack of dampening that the fuel tube probably gets from fuel) and torque applied by the relative wind when yawing.

I've never had to tighten this tube in my 80 hours of flying. I'm wondering what others have experienced. If there are a lot of folks out there who have to routinely tighten this fitting, then maybe that's further evidence to support the SB. If not, then its supporting evidence that the fuel tube fitting issue was caused by poor QB assembly.

DeltaRomeo · #2 03-05-2006, 04:43 PM

Interesting comparison!

500+ hrs and I've never had to tighten my 'Van style' pitot fitting (but I admit I did take off once with the cover still on

).

B,
D

robertahegy · #3 03-05-2006, 05:59 PM

Interesting you should bring this up. I was just starting my annual and checked that. I never had to tighten it and it was tight when checked today. I also found all of my other AN fittings tight as well. I do remember tightening my fuel pickup tube prior to closing up the tanks, too.

I'm going to run the tanks down to below half and do a volumetric test by running all the fuel to one tank and then back to the other to make sure I can pump them dry.

It does look like my screws are all exposed (not buried in proseal) so if I do decide to do this SB, it should not be too difficult. I really hate to pull my covers off, since they are so well sealed. It looks like all the work can be done from the bottom, so fully removing the root seals should not even be necessary. We'll see.

Roberta

OneTwoSierra · #4 03-07-2006, 10:22 AM

Bumping. Still curious about loosening pitots or rock solid pitot fitting performance as evidence for the Fuel Pickup SB. I'm also curious to hear if others think this is a valid comparison.

Ironflight · #5 03-07-2006, 11:38 AM

Quote:

Originally Posted by OneTwoSierra

I'm also curious to hear if others think this is a valid comparison.

My personal opinion is that it might be a valid comparison IF you knew that the fittings were tight to begin with. The problem is that if you aren't 100% sure that you tightened the fuel tank pickup fitting, then you don't know it's initial condition. The other problem, of course, is that you have no way of knowing the vibration frequency/mass characteristics of the two, so one might get excited (and tend to loooses) more than the other.

I guess I just talked myself out of thinking that you could KNOW that it was valid...

Paul

PJSeipel · #6 03-07-2006, 12:06 PM

The difference is that if the pitot falls off, you're likely to notice that it fell off because it is visible. If your fuel pickup falls off, you're not likely to notice it until you start sucking fumes because it is not visible . Hence the SB.

rv8pilot · #7 03-07-2006, 02:41 PM

The pitot can come loose due to vibrations,and mine did crack internally after
130 hours off flight,made a new collar ad refitted it,at 200 hours I changed it for a new stainless one from VANS

j?rn M?ller
RV8 206 hours

jlfernan · #8 08-16-2006, 01:26 PM

On the subject of these fittings, what is the torque value for fuel fittings?

RV7Factory · #9 08-16-2006, 02:21 PM

Torque Tables for fittings can be found in the Standard Aircraft Handbook and I am sure other sources as well.