Where / what is the fuel manifold?

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Code90

Pre-takeoff checklist
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Code90
Lost a friend to a crash a while back. NTSB concluded : "partial loss of engine power due to contamination in the fuel manifold".

http://aviation-safety.net/wikibase/wiki.php?id=175988

I fly the same plane now and am wondering if that is something that should be checked in my plane. I don't know enough about the issue. What is the fuel manifold, where is it, and should I consider having that evaluated in my plane (same year, make, model)?
 
Applies to fuel injected engines. It's the thing that sits in the center of the spider of fuel injection lines that go to all the cylinders.
 
Look at photo 9: http://dms.ntsb.gov/public/58500-58999/58940/593744.pdf
It would seem to me if contamination in that unit could bring a plane down, it would be reasonable to periodically inspect it. Not sure if one can be opened up or not, but certainly worthy of a discussion with your mechanic. The report wasn't clear what the contamination was, it sounded like it could be one of many things.
 
good reason to invest in engine monitor i believe all io engines should be so equipped.
 
iflyvfr said:
Look at photo 9: http://dms.ntsb.gov/public/58500-58999/58940/593744.pdf
It would seem to me if contamination in that unit could bring a plane down, it would be reasonable to periodically inspect it. Not sure if one can be opened up or not, but certainly worthy of a discussion with your mechanic. The report wasn't clear what the contamination was, it sounded like it could be one of many things.
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Given the after crash fire I'm surprised they could even find the fuel manifold, let alone discover contamination inside it. The materials described in the report sound like something you'd get with ethanol enhanced autogas stored for an extended period. There is a fine particle filter well upstream of the fuel manifold so I would assume that the "debris" was either caused by the fire or had formed inside the fuel system. In any case, the fuel manifold isn't supposed to be disassembled so it would be rather difficult to "inspect it" for debris.
 
weilke said:
Applies to fuel injected engines. It's the thing that sits in the center of the spider of fuel injection lines that go to all the cylinders.
Click to expand...
Correct. It's the mechanism which sends the fuel through the fuel lines into the cylinders. Any disturbances within the device poses problems of insufficient fuel being delivered or in some cases none at all. It's definitely worth checking during each annual, if not more regularly.
 
The manifold has a screen in it, a last-chance thing. It can get contaminated if the upstream filters aren't doing their job. The manifold also has a valve in it that shuts off the flow to the injectors when the mixture is pulled to ICO. The valve is lifted open by fuel pressure, and falls shut when the pressure falls off. It's there to sort of prevent the injector lines dribbling all their fuel out and trap the fuel in the metered pressure line that feeds the manifold. A hot engine tends to boil the fuel out of the injector lines anyhow.

I recently found some white, wet, sugary stuff in the bowl of a fuel strainer. I think it was from ethanol-contaminated Mogas. That sort of stuff could cause lots of headaches in an airplane.
 
Engine monitor is a great thing, and I have one. It don't know how much it would help though. It shows EGT and CHT for each cylinder. If fuel flow is cut off from debris acutely, neither of those numbers would go up. Maybe if one cylinder was running lean with debris, you might pick up that fluctuation? Might have had some warning on previous flights?
 
There is a finger screen in the fuel servo that should be checked at annual/100 hrs
 
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