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PA28 not complex accident analysis (fuel system)

This .ppt has some useful conclusions, and the author seems to have invested some time to produce it.

The fact that you need to switch tanks in a PA28 leads to more fuel mis management accidents is a bit of an indictment on the level of training on this simple aircraft.

http://www.wanttaja.com/pa28.pdf
Oxford (EGTK)

RobertL18C wrote:

The fact that you need to switch tanks in a PA28 leads to more fuel mis management accidents is a bit of an indictment on the level of training on this simple aircraft.

That is indeed surprising. I would imagine that contrary to what’s the case on a C172, if the engine sputters on a PA28 you just need to change the tank, turn the aux fuel pump on, land and that’s the end of it. On a C172, if the engine sputters that means you are simply out of gas. Changing tanks won’t help a bit because both tanks will be dry.

Last Edited by Aviathor at 23 Dec 21:51
LFPT, LFPN

Mags, primer, mixture, carb heat? A bit more than just switching tanks.

Fly safely
Various UK. Operate throughout Europe and Middle East, United Kingdom

I’d forgotten all about Ron Wanttaja, met him at a fly-in once in Pinckneyville, Illionois…

I think the issue is with changing tanks, is the engine sputters, pilot freezes up, doesn’t think to change tank (or follow a checklist) and ends up doing a forced landing/crashing with plenty of usable fuel in the other tank.

Andreas IOM

The issue I have heard of a lot is this:

A tank runs empty (useless fuel gauges, and bad planning+management).

Engine starts to sputter.

The pilot switches to the other tank.

The engine sputters more or stops (because on a certified SEP the engine has something like 10-20 secs to restart after a tank change, but on an old plane…?)

The pilot decides the “new” tank is empty too, so switches back to the original one.

The fuel from the “new” tank starts to come through, and the engine starts and runs great…. for about 20 seconds, then stops completely

Administrator
Shoreham EGKA, United Kingdom

Very good analysis in that PPT – thanks for posting it Robert.

The author did a good job of spotting 3rd factors e.g. low wing are more likely to get accidents related to flying longer distances because they are more popular for touring.

Administrator
Shoreham EGKA, United Kingdom

Aviathor wrote:

On a C172, if the engine sputters that means you are simply out of gas. Changing tanks won’t help a bit because both tanks will be dry.

Only if you have the fuel selector on “BOTH”. And for precisely this reason you shouldn’t have except during take-off and landing.

But an advantage is that since there is a “BOTH” position…

Peter wrote:

he engine sputters more or stops (because on a certified SEP the engine has something like 10-20 secs to restart after a tank change, but on an old plane…?)

The pilot decides the “new” tank is empty too, so switches back to the original one.

…that shouldn’t happen.

Last Edited by Airborne_Again at 24 Dec 12:45
ESKC (Uppsala/Sundbro), Sweden

Airborne_Again wrote:

Only if you have the fuel selector on “BOTH”. And for precisely this reason you shouldn’t have except during take-off and landing.

I have never heard anyone recommend that before. I cannot remember what the C172 manual says about the subject but I do not think they recommend running on L/R. Most things I hear about that subject portrays the BOTH position as desirable because it avoids running one tank dry. And since the tank selector is supposed to be on BOTH for landing, you’d better have about the same amount of fuel in both.

The only time I have ever used the L/R positions on a C172 was the one time I was low on gas approaching my destination.

When you are approaching the point where you risk running one tank dry, you should be springloaded to change tanks immediately should the engine sputter. At least I am. Been there, done that and the engine restarted immediately on a PA28-181

LFPT, LFPN

There was a time when it was suggested you ran high wing Cessnas from L or R above a certain altitude – possibly on some vapor lock theory? Also placing the selector on R when parked (the fuel vent being behind the port strut) to avoid loss of fuel if on uneven ground?

You always have the selector on Both on T/Off or Landing according to the AFM.

Oxford (EGTK)

Aviathor wrote:

I have never heard anyone recommend that before. I cannot remember what the C172 manual says about the subject but I do not think they recommend running on L/R. Most things I hear about that subject portrays the BOTH position as desirable because it avoids running one tank dry.

With the fuel selector on BOTH, very slightly uncoordinated flight will cause uneven fuel flow between the tanks leading to fuel imbalance. Since the C172 doesn’t have a rudder trim, this is difficult to avoid, particularly when flying on autopilot. I prefer to maintain fuel balance myself by switching tanks.

And since the tank selector is supposed to be on BOTH for landing, you’d better have about the same amount of fuel in both.

Why?

Last Edited by Airborne_Again at 24 Dec 19:20
ESKC (Uppsala/Sundbro), Sweden
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