Fuel Pump On While Maneuvering in Piper Warrior?

P51P28

P51P28

Pre-takeoff checklist
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Hello all. My instructor and I noticed for the first time in the Piper Warrior flight manual that the fuel pump should be turned on while performing maneuvers. Why is this? Fuel distribution risks?
 
No doubt your instructor knew that about Warriors well in advance and was just testing you to make sure you read the POH.
 
P51P28 said:
Hello all. My instructor and I noticed for the first time in the Piper Warrior flight manual that the fuel pump should be turned on while performing maneuvers. Why is this? Fuel distribution risks?
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Lawyers.
 
Read the POH and read the section on the fuel system.
 
Wasn’t required in my Cherokee and I never had any trouble importing fuel or anything else. The Warrior is almost the same airplane.
 
To keep positive fuel pressure during maneuvers.
 
Pretty sure the Warrior is also placarded for no zero or negative G maneuvers, isn’t it?
 
P51P28 said:
Hello all. My instructor and I noticed for the first time in the Piper Warrior flight manual that the fuel pump should be turned on while performing maneuvers. Why is this? Fuel distribution risks?
Click to expand...

CAR Part 3, 3.443 discusses certification of fuel flow systems for pump operations. The Warrior cannot gravity feed fuel, thus why it has the backup electrical pump.
 
P51P28 said:
Hello all. My instructor and I noticed for the first time in the Piper Warrior flight manual that the fuel pump should be turned on while performing maneuvers. Why is this? Fuel distribution risks?
Click to expand...

If your engine driven pump is on its last leg it may fail to provide adequate fuel pressure during low rpm maneuvers. But this shouldn't really be a serious concern because you can always turn on the pump if there is a problem. Where you really need the pump on is at low altitudes during approach.
 
P51P28 said:
Hello all. My instructor and I noticed for the first time in the Piper Warrior flight manual that the fuel pump should be turned on while performing maneuvers. Why is this? Fuel distribution risks?
Click to expand...

It was explained to me as risk mitigation by turning the backup on. The logic is that you’re going to be distracted from monitoring airplane systems, so be safer.
 
Thanks for the info everyone. The manual I have doesn't specifically instruct you to turn the fuel pump on while performing maneuvers. There is however, a line that says on "certain maneuvers the fuel may move away from the fuel tank outlet. If the outlet is uncovered, the fuel flow may be interrupted and a temporary loss of power may result."

What makes most sense to me is the engine driven fuel pump not being able to provide enough pressure at low altitudes which is why we turn it on while on takeoff, landings, and when switching tanks.

Thanks again!
 
I *love* low wings, and learned on a PA28 and have many fond memories flying her.. I also have some more nerve wracking memories.. with the fuel pump ON.. watching the fuel pressure gauge just *barely* in the green climbing over Nantucket sound
 
sarangan said:
If your engine driven pump is on its last leg it may fail to provide adequate fuel pressure during low rpm maneuvers. But this shouldn't really be a serious concern because you can always turn on the pump if there is a problem. Where you really need the pump on is at low altitudes during approach.
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There is also high RPM stuff. Like takeoff. It’s about pump failure. If it happens shortly after lift off, the electric is already on. Yeah, you’re going to get a little surprise when you get up there and turn it off but it’s no big deal up there. Just turn it back on.
 
The electric pump is there should the engine driven one fail.

Do the placarded or other landing checklist before maneuvering and before landing. That way you get in the habit of using it. Everything on there is common to both, and that includes the fuel pump. Most of the PPL maneuvers replicate something happening close to the ground like approach stalls, slow flight, departure stalls...situations where you would also have the electric fuel pump on for redundancy.
 
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P51P28 said:
Thanks for the info everyone. The manual I have doesn't specifically instruct you to turn the fuel pump on while performing maneuvers. There is however, a line that says on "certain maneuvers the fuel may move away from the fuel tank outlet. If the outlet is uncovered, the fuel flow may be interrupted and a temporary loss of power may result."

What makes most sense to me is the engine driven fuel pump not being able to provide enough pressure at low altitudes which is why we turn it on while on takeoff, landings, and when switching tanks.

Thanks again!
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Which manual? In 1965, there was no POH, but the AFM, which should have some instructions regarding takeoffs.
 
Kuma said:
The electric pump is there should the engine driven one fail.

Do the placarded or other landing checklist before maneuvering and before landing. That way you get in the habit of using it. Everything on there is common to both, and that includes the fuel pump. Most of the PPL maneuvers replicate something happening close to the ground like approach stalls, slow flight, departure stalls...situations where you would also have the electric fuel pump on for redundancy.
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Fuel pump on takeoff, landing, and when switching fuel tanks is ingrained in my current procedures. I started this thread out of pure curiosity when I went up last weekend with a friend/Delta pilot who was a former flight instructor. I wanted him to critique my flying and he asked if I turn on the fuel pump while performing certain maneuvers. I said no and he responded, "Okay fine, I don't want to reinvent the wheel to what you've been taught." Naturally, I went to the operating handbook and found the instruction above.

murphey said:
Which manual? In 1965, there was no POH, but the AFM, which should have some instructions regarding takeoffs.
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I fly a 1974 Piper Warrior. I was referencing a Cherokee Warrior Information Manual which is pretty much identical to what's in the airplane.
 
P51P28 said:
There is however, a line that says on "certain maneuvers the fuel may move away from the fuel tank outlet. If the outlet is uncovered, the fuel flow may be interrupted and a temporary loss of power may result."
Click to expand...

Having the electric pump on wouldn't make any difference in this situation...
 
and a zero or negative g maneuver may do the same fuel unporting and may also mess up the float in a float type carburetor
 
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