The International Cessna^® 170 Association

I have the original style pitot tube. Attached to it is a relative wind activated bug flap (for lack of a better description). The flap is closed when the is stopped and is opened by air force on a tab located above the flap. I noticed the other day that my pitot tube seemed lose. I checked inside the wing and found the pitot tube fastener in place. However it seems to me that the hard rubber grommet may be worn - most probably from the up force created on the pitot tube by the bug flap tab. Anyone have a similar device on their pitot tube? Any opinions regarding the value of the pitot bug flap?

Could it just be a 60 year old grommet.

Speaking of grommets - where do you fidn these things? Don't see it in the parts manual.

I have the bug flap on my 170A and have never given it much thought. There is supposedly a drawing or template you can use to make sure the pitot tube is in the right position (George will know about that). If you need a new grommet, I think you can "manufacture" one.

You guys scare me sometimes.


http://www.aircraftspruce.com/catalog/a ... metkit.php


The outline drawing for the pitot tube is found on page 16-9 (fig 16-3) of the 100 Series, 1962 and Prior Service Manual.

Thanks George - that is what I love about Aircraft Spruce, I have to buy 270 pieces to get the single grommet I want.

I may have several of them over at RHV if you can get over.
Let me know the Inside and Outside diameters.
Need an excuse to get out of the house.

PM me for a phone # or look up in 170 directory.

Brent, at AIRBOLT in Fresno will OFTEN sell you one of almost anything.

559-264-8900

He still shows up on Google search.

Also in Santa Clara is Motion Industries which will sell a lot less than 270
Ya will need to know the dimensions.

Chris C.
Palo Alto

Robert Eilers wrote:Thanks George - that is what I love about Aircraft Spruce, I have to buy 270 pieces to get the single grommet I want.

Robert, go over to any NAPA autoparts store and tell them you want a rubber grommet for a 5/16" hole to hold a 1/4" tube. Probably cost you as much as twelve cents or so.

Make sure you go to their 'Aviation Dept.'.

By the way, the "Pitot Tube Bug Flap" ... is more commonly known as a "Pitot Tube Protector"



The one most 170's uses is PN 10-02000, (the one on the right)

About $8 from : http://www.aircraftspruce.com/catalog/i ... tector.php

Those Pitot Tube Protectors/Bug Flaps work OK for bugs while sitting on the ramp (not tarmac), but it won't keep out those pesky little spiders that like to get in there and a part of their web will stick the flap to the tube. Sure brings home the reason to include checking the "protector"/flap" during preflight checks.

My C140 had one until I was working one windy day and it spent most of it's time in the "flying position". Didn't take a lot of wind to open it. I used a small rubber cap with streamer after that.

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During the first annual after getting my 170 the A&P removed my bug guard. When I asked him about it he said they cause more problems than they salve.

Unless I execute one of my patented landings designed to calibrate the local university seismometer my bug flapper stays open even after shut down. I have often forgotten to check the thing following flight only to find it still in the open position days later (in the hangar). A slight finger bump will return it to closed but so far no amount of adjusting and applications of LPS seem to allow it to return closed following air movement. It is now simply an element of my post flight walk around to manually close the thing.