cessna 150 safety question
 

After an engine power loss in our C150, a possible cause of the problem put forward is fuel not reaching the engine due to rear shift of fuel in the tanks during a touch & go with high nose attitude / acceleration?
The aircraft was ending its circuit practice and had 18 Ltrs onboard.
Any opinions?? Apparently 1/4 in each tank is minimum for slipping and running take off's ??

The unusable fuel in a Cessna 150 is 15 litres, so I guess the theory put forward is probably correct, as you were on the edge of running out of fuel altogether!


MJ:ok:

The dip stick takes into account for unusable. ��

Then I think the theory put forward is unlikely, as 18 litres of useable fuel is almost 1/4 tanks. More likely to be carb icing, or a fouled spark plug. Did the engine cut completely, or just misfire?


MJ:ok:

Nah. Unless you were just about out of fuel, this was not the cause in a serviceable system. I have many hours in my 150 doing horrible nose up attitudes (it has a STOL cuff on the wing). I have never had a burp form doing that.

A fouled plug will cause roughness, but not a noticeable power loss at a higher power setting, unless both in that cylinder are fouled.

Depending upon the symptoms, and time in service for the cylinders, you might have had a sticky exhaust valve, I've had a few of those, and the engine seems terrible at about 2000 RPM, but it will keep running, unless you stick two, then you are going down (or are very glad you are down!).

Ask the maintainer for a good discussion about sticking valves, this is what to watch for (presuming you're carrying enough fuel).

How did you know it had 18 litres and did you dip the tanks when you landed ?

Very unlikely. C150/152/172 are not that unsafe on low tanks. When flying Africa the boys usually flew them down to 5-10 Liters remaining and their nose was most probably at angles you never see in Europe ... My best guess for such an occurence would be a sticky valve - not uncommon for O200.

Thanks for the replies. It was a complete cut after rotation. Engineers are investigating today.

The 150 & 152 have feed pipes at both the front and rear of the fuel tanks so under normal conditions aircraft attitude will not be a factor in fuel feed.

This is the case for the Aerobats.

I cannot speak to the 152's (though I don't think they have two outlets per tank).

The 150's have one outlet per tank. But, that said, unporting it during co-ordinated flight with any safe amount of fuel would be very difficult to do.

I would be very surprised to hear that a fuel issue caused an engine stoppage, when adequate fuel was being carried in a 150.

I'm not clear from the OP, was this a total stop of the engine? Or a momentary "burp" and restart without pilot action? Or could the engine have momentarily lost enough power that it seemed to stop, but was really running the whole time?

The Cessna 140 has ports in the rear of the tank. The tanks in a Cessna are high enough that I don't think you can run out of head pressure in any climb attitude. A light Pawnee with a cowl tank will quit due to fuel during a power on stall.

Only one tank outlet in a C150. There are two in a C152 one at each end of the inboard side of the tank. Extreme attitudes and less than X litres of fuel causes an issue. The POH is not the last word on the matter. I have a C150 tank out at the moment and going to conduct a home test to see what X litres is that would cause unporting in a zero bank climb or descent. I'm in no rush to do it but its a useful exercise. Once you hold the tank in your hand you can see how it can happen.

It appears the cause was low fuel. Now resolved ��

So, what the HECK were you doing with such a low fuel level?

Even after 1 hour of flying, you should have had plenty of fuel if you took off with enough.

Funny thing similar thing happened yesterday to me at Wellesbourne.
Left Kemble with full tanks, 2 POB, in a C150 aerobat.
Landed at Wellesbourne, had tea and cake and a couple of hours later checked over aircraft..... plenty of fuel for trip home.... started no probs, taxied off grass and tested the brakes...all good... asked P2 to test brakes...he pulled the power and as braked engine cut off. Weird.
Started again with no probs and no probs on way home... though did keep a look out for suitable fields

Our incident has been traced to an incorrect dip stick !

Jude 098, what were the temperature and dewpoint, and was the grass wet?

Lucky escape then.:)

Just what I was thinking. ;)


MJ:ok:

Enlighten me, please (wrt the wet grass temp/dewpoint thing), merci d'avance :)

OK just their name.......;:ooh:

SGC