Fuel flow

If is indeed listed in your AFM then you are subject to the vagaries of the faa. The EI might be your best choice if you want a FF gauge.
After getting the K factor right the JPI 450 in my Viking was accurate to .5 gallon in a 75 gallon fuel system. Every flight. Actually helped leaning too.
Chris
 
Bob Turner said:
Sometimes I wonder why I need a fuel pressure gauge at all, except when the electric pump fails before start. All other times it would be obvious before you look at the gauge, seems to me.
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Well, the short answer is "because the FAA says so" ... maybe.

FAR 25.1337 Powerplant Instruments:

(f) Fuel pressure indicator. There must be means to measure fuel pressure, in each system supplying reciprocating engines, at a point downstream of any fuel pump except fuel injection pumps.
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Dunno if "except fuel injection pumps" means us, or not. :unsure:
 
I suppose that is why I still have that stainless line. But what I meant was - why is it useful for me during flight?

I know of two instances where a stainless line has broken, and one of them resulted in a fire! In a Decathlon! And don't forget - there is an AD on four out of the five in the Decathlon. Why is the fifth so bulletproof?
 
Bob Turner said:
I suppose that is why I still have that stainless line. But what I meant was - why is it useful for me during flight?

I know of two instances where a stainless line has broken, and one of them resulted in a fire! In a Decathlon! And don't forget - there is an AD on four out of the five in the Decathlon. Why is the fifth so bulletproof?
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I totally agree on the stainless line in the cockpit. Last thing in the world I want is a broken tube spewing vaporized avgas onto my crotch in close proximity to electrical connections.

Seems baffling to me that there is not a more cost effective option for a remote sender and electrical gauge. Actually there are several options, but for some reason they all stop at 30 PSI. The UMA gauge goes to 60 PSI, but the gauge plus sender cost is over $500, and another $125 to have it custom marked, which you might as well do.

Whether you actually NEED that indication in flight, I dunno. I don't know enough about the mechanics of the fuel system to conversate intelligently about the issue. But fuel pressure gauges are not a new thing, and the FAA seems to think it is useful enough to require it, so I'll go with that. As a general principle, more information is better than less. Maybe the gauge helps you troubleshoot faults involving partial leaks or pump degradation such that you are getting enough flow to run, but not enough to generate full power.
 
Hiperbiper said:
Ed, is your airplane governed by Part 25 ops?
Your airplane as it sits has no "block and bypass" capability on the fuel line components.

Chris
Click to expand...

Yeah, you have exceeded my knowledge level, so you'll have to 'splain please.
 
I think the Decathlon is a part 23 airplane. I can go look - Bart has the TC at our fingertips!
 
Hiperbiper said:
Ed, is your airplane governed by Part 25 ops?
Click to expand...

Ah OK, I get it now. Wording in FAR 23.1305 is different:

"4) For each pump-fed engine, a means:
(i) That continuously indicates, to the pilot, the fuel pressure or fuel flow; or
(ii) That continuously monitors the fuel system and warns the pilot of any fuel flow trend that could lead to engine failure."
 
Well, that takes care of that.

So I get warned of a fuel flow trend - by the gauge, not by the engine. I suppose I could panic a bit, but then what?
During critical operations I am not studying fuel pressure. If it quits, on comes the electric pump as I lower my nose and head for my chosen landing spot. Has nothing to do with the gauge, unless the gauge line has broken.
 
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