Fuel Feed failure for a single engine Cessna

[Big Pistons Forever]

A Question


Has anybody ever experienced a spontaneous failure for fuel to flow from a wing tank in a Cessna when "both" was selected.

By spontaneous I mean the fuel system was working normally and then for what ever reason one tank failed to flow fuel to the engine.

Note I am not interested in situations where on the first flight after major maintenance ( ie wing removal/re-install, or fuel tank/fuel line removal replacement) there was a problem. In those cases there have been numerous reports of taped/cap lines which were not cleared prior to install.

[timel]

Don't know if it helps.

I know a case of a pilot that took off and found himself with a semi working engine in downwind.
Ended up well, but the fuel selector was not well placed on both. Personally I would always turn it left right it a little to make sure it was well positioned.

[Shiny Side Up]

Yes, a fuel selector valve was faulty. The selector while pointing at both, wasn't in both.

[GyvAir]

Haven't encountered this specifically on a Cessna, but perhaps a friendly neighborhood mason wasp visited?

[Big Pistons Forever]

Haven't encountered this specifically on a Cessna, but perhaps a friendly neighborhood mason wasp visited?

I could see a blocked vent tube causing uneven fuel flow from the two tanks but I do not see how this would cause a total lack of fuel from one tank.

[iflyforpie]

Piece of debris caught in either the screen of the pickup or the fuel selector itself. Could also be a venting issue; perhaps the offending tank doesn't have a functioning vented cap.

[ahramin]

I don't see how it could be a venting issue. One cap is vented, and the other tank is vented. The two tanks are connected by a crossfeed tube. If one vent plugs, the whole system is still vented. Isn't that why they added the vented cap in the first place?

[timel]

Cessna's I've flown had no caps with fuel vents. If fuel selector is on both, means boths fuel tank can be vented from on tank? Interesting. Hope you give us the answer when you find out.

[iflyforpie]

It's tough to find any Cessnas without vented fuel caps on both tanks. Just because it doesn't have the 'periscope' out the top doesn't mean it isn't vented. Most have very tiny holes and a rubber diaphragm in the center underneath.

It's unlikely, but I figure if there was one long term blockage (either the main vent or one of the caps) followed by a recent blockage of one of the same, then that would stop fuel flow from one tank.

[timel]

Interresting!
Last one I saw kind of looked like this one.

[iflyforpie]

That little orange thing in the center is the vent diaphragm I was referring to....

[timel]

Never though there could be a vent in that thing!

[Colonel Sanders]

It's tough to find any Cessnas without vented fuel caps on both tanks

Would that be, because that's legally required
by AD 79-10-14 R1 ?

http://wwwapps3.tc.gc.ca/Saf-Sec-Sur/2/ ... 0-14R1.htm

Do people here normally operate their aircraft
without bothering to comply with AD's?

[Docbrad]

I've heard that any negative G for more than a few seconds may cause an engine to sputter

[iflyforpie]

Oh, CS. Everyone knows that the only two ADs you need to worry about are CF90-03R2 and CF87-15R4 (er............... AD2011-10-09).

[iflyforpie]

I've heard that any negative G for more than a few seconds may cause an engine to sputter

Yes, this is true.... .....but unrelated to the discussion at hand.

Remind me one day to tell you the story of Miss Shilling's Orifice.

[Colonel Sanders]

Oh, CS

People here keep telling me that I don't
have very much aviation knowledge and
experience compared to them, but I actually
recall when that AD was issued, 35 years ago.

[JBI]

People here keep telling me that I don't
have very much aviation knowledge and
experience compared to them

Who on here says that you don't have very much aviation knowledge?

[ogc]

The two tanks are connected by a crossfeed tube.

Are they? Been awhile since ive flown a cessna but are the tanks not independant of each other?

[Colonel Sanders]

Older 172 POH (not online) shows same
interconnect tube between the tanks.

The original design did NOT have vented
caps on both tanks, see the 1979 AD.