Through poor instruction or sheer laziness, most pilots never turn off the fuel valve on the Cessna 150/152. By leaving it ON at all times, the valve eventually jams itself solid and you can't turn it off without breaking the shaft. Shame if you can't turn it off if the engine catches fire or you have a forced landing. Try writing up that defect in the maintenance release and hear the screams of protest from the owner.

Exactly.... the C150 is a classic.......
and the students are still taught fuel off on EFATO.
The last thing these guys will ever see will be their hand trying to force that lever.

fly the aeroplane..... save your life

pretty easy checklist

addition
 

A little off track, but the answers always amazed me when i asked pilots of all levels to explain the difference between the POH and the FM. Soooo many didn't have a clue. gets back to the training....and personal interest. Guys and gals we had on line would come to me and ask a question about a certain aircraft, which was the easiest way out. I would always say "Go and find it in the book!". If you can't find it come back to me and we will both go through the book together, until you find it. Studying the POH and FM is an absolute MUST for each type/model of aircraft.

good call PA 39. that is the way

I've just moved from flying an Archer to C172s recently and I'm very glad that I don't have the misfortune of having to change tanks anymore. One of the scariest moments I've had would have been watching the fuel pressure slowly trickle down after swapping tanks just after take off from Goulburn.

However, on the other hand, fuel management awareness can dimish seeing that you don't have to monitor which tank you've been on and for how long. Never really did like the idea of "set and forget".

If you 'set and forget' you are begging for a fuel exhaustion scenario.

There is no difference between your previous type and the C172, every thirty or so minutes you still update your fuel log reducing your endurance by the appropriate amount. The only difference is you don't swap tanks in the process.

Safe Flying :cool:

One of the scariest moments I've had would have been watching the fuel pressure slowly trickle down after swapping tanks just after take off from Goulburn.

I have read this thread with increasing frustration and agree with all who state that the POH and FM are the correct sources for this information.

BUT what astounds me about the above comment is why on earth would you want to even think about changing tanks "just after takeoff" - unless of course you were suffering a possible fuel related engine problem - but Polymer's post does not indicate this.

I'm not trying to be a smart ass here but this thread does suggest some pretty poor training or at least comprehension of basic airmanship and tech knowledge.

Indianzz

Slight Drift.....
 

G'Day Indian,

On some aircraft I have flown, the 'taught' procedure was to T/O on "Both", then, when at a safe altitude, change to either the left or right tank for 'fuel management' and 'trim' purposes.

In early Bonanzas, beware the fuel return system from the fuel distributor valve - it was returned to the LEFT tank only....so if you selected the right tank for engine use, the 'excess' was returned to the left, until it was FULL again, and then it 'conveniently' drained out over the side via the underwing vent - just where it would not be noticed.....
So, obviously the 'trick' there was to use the left tank for a 'good hour or so', then use the right tank for an hour, and 'lo and behold' the LEFT was almost full again!!

But of course, as we had all 'been endorsed on type' in dem dere days, we knew this - it was 'drummed' into us - and, it was in the book!;)

They've fixed that little anomoly now, so you don't have to worry about it anymore....:D

Cheers:):)

Some suggest that you should switch tanks every 30 so that if one was to become unusable for any reason, then you find out about it while you still have plenty in the other tank. The theory goes that if running on 'both' you wouldn't know until the good one ran out of fuel.

So, has anyone actually every heard of a C172 tank becoming blocked, etc.?

You'd soon know with a large split in the fuel gauges and a wing low tendency :ok:

Typical C172 fuel gauge:
LEFT ---- RIGHT
http://madsenworld.dk/anigif/music/vu_meter.gifhttp://madsenworld.dk/anigif/music/vu_meter.gif

C172s that fly straight?
:}

Ok my final 2 cents worth on this thread.

Too many years ago when learning to fly the very forgiving PA28-140 the fuel management was this - and a confession - I cannot tell you what the POH says because this it what the instructors drummed into me!

Always start the engine off the tank with the lesser quantity of fuel - if applicable.

After start change to the highest (or other tank) - the idea being that for take off you were using the tank with the most fuel and if there was a blockage or flow problem it would manifest itself prior to takeoff.

After that change tanks every 30 minutes - fuel pump on - change tanks - record change in flight log - fuel pump off.

Did this VFR or IFR - for IFR it was "mandatory" in so much as it was part of the regular cruise checks.

Never suffered a fuel related problem which of course was a combination of good luck (no mechanical pump failures etc) and good fuel management.

Safe flying.

Indianzz

When I learnt in the 140, it was fullest tank for take off and landing, change tank 30 min after take off and then every hour after that. When its only using 30lph (22kg) their really isnt much point changing evey 30min, never any balance issues, and like the others have said, its less times your changing tanks in-flight and risking a problem arising. I too never saw its POH (I now know thier value :ok:), anyone know what piper reccomend?

The reason the fuel is unusable will be because the cock has jammed, fractured, sheared off........it really is the weak point in the fuel system. Well the gascolator is of major concern also of course. - they literally are hanging in there by a thread...... and a very sloppy one these days. These items are all that a seperating you from a fuel starvation issue.

I do basically that. fly until the end of the good terrain on the right tank (20 or 30 mins), change at the last landing point..... and then fly the remainder on the left tank.

On a Tomahawk that is 2 1/2 hours flying.... changing only once, no imbalance issues and I know that the 2 plus hours in the right tank is still there.

Crossing any large body of water requires a little planning, I plan the fuel management about that. Basically doing the change to the full tank at least 5 minutes prior to leaving land...... and touching nothing until reaching land again.

Some aircraft have notoriously unreliable fuel systems...... I have seen guys setting off on ferry flights in the likes of an Islander and returning because the tip tank valves didn't operate. Sure the little electric switch clicked up.....

I was thinking about all the flying instructors I have met or flown with..... and then judged their knowledge of the fuel system. I suspect there was one that knew his aircraft.....
Don't start me on some of the others. A schematic in a POH is exactly that...a schematic, simplified, - and still some would struggle with it.

I have yet to meet a 'bad' pilot.... could it also be that 'good' fuel management is actually not that CRASH hot also.

I do know I got a got deal on an aircraft purchase after a PPL showed his proficiency in fuel mismanagement and precautionary landing techniques.....
Brilliant.

33 responses on how to manage the C172 Fuel System!

Sheez! You people need a real fuel system to mull over!

C310/400 series with 6 tanks? Queenair with 4?
Beaver? MU-2?

That should keep the debate running! :ouch:

The real nasty is the Partenavia. The fuel valve has several selections and even with a new aircraft the valve operation is abnormally stiff to operate. Eventually it seizes and the problem is in the linkage at the engine end. Because few pilots turned the fuel valve off, the inevitable jamming in the linkage goes unnoticed. Then it becomes impossible to select fuel off or crossfeed.
During the servicing of one Partenavia in Melbourne the LAME attempted to turn off the fuel valve of each engine . It was impossible. The defect was reported to CASA who issued an AD which basically said pilots must write up the defect if the fuel valve was abnormally stiff to operate as it would steadily get worse. In addition the fuel valve must be checked for normal operation at each 100 hourly. Either the LAME's use both hands to turn the valve (and then say it is serviceable) or they just tick the box, I can't say. But the prevalence of seriously jammed fuel valves in the cockpit of Partenavias is proof that some pilots and engineers are ignoring the point of the AD.

In UK, a female pilot had an engine failure in a Partenavia while over the sea. She was unable to move the fuel valve because it was jammed so badly. She was forced to ditch and two passengers lost their lives.

No apologies for being a smartarse required. You're quite right about the fuel issue. I've not really worded my response properly and that can mean dire things on an aviation forum as I've now found out.

I was established at the cruising level after take-off and completed the fuel swap during my top of climb checks.

Scareostar with belly tank and twin comanche with tips.....oh the fun of it all !

You'd be the right person to ask PA39,

But in the Twin Catastrophe the tip selectors are electric are they not? and once selected, if and electrical failure occurs you are stuck out on the tips?