When do you use boost pumps?

"Robert M. Gary" wrote in
:

On May 9, 4:21*pm, Bertie the Bunyip wrote:
"Robert M. Gary" wrote in
news:8212d5a7-22b3-4ead-96aa-

:

Different than on a light plane anyway.

Bertie

Ah, so he probably can fly a 747?


If by that you mean he can put it on his back and flap his arms to get
it airborne, he'd have as good a chance as anyone.


Bertie

Mxsmanic wrote:
When do you use boost pumps on small GA aircraft?

The purpose of a fuel boost pump is to assure adequate fuel flow in all
flight conditions, especially in a nose high attitude when the tanks are
nearly empty; where the height difference between the fuel level and the
engine pump is considerable. Another vulnerability is on hot days when
vapor lock in hot spots nearer the engine is possible. It probably is
discovered by the test pilot in the ceritifcation process that fuel
starvation occurred in some situations. Thereafter, the manufacturer of
that aircraft is obliged to install one in the aircraft, likely in a low
and cold spot such as under the cabin, then certify that it solves these
problems, then tell in the flight manual how and when to apply it.

The pilot is obliged to comply. The most applicable condition is that
it should be used on every takeoff until flight climb is stabilized....

Angelo campanella

On May 12, 7:28 am, Angelo Campanella wrote:
Mxsmanic wrote:
When do you use boost pumps on small GA aircraft?

The purpose of a fuel boost pump is to assure adequate fuel flow in all
flight conditions, especially in a nose high attitude when the tanks are
nearly empty; where the height difference between the fuel level and the
engine pump is considerable. Another vulnerability is on hot days when
vapor lock in hot spots nearer the engine is possible. It probably is
discovered by the test pilot in the ceritifcation process that fuel
starvation occurred in some situations. Thereafter, the manufacturer of
that aircraft is obliged to install one in the aircraft, likely in a low
and cold spot such as under the cabin, then certify that it solves these
problems, then tell in the flight manual how and when to apply it.

The pilot is obliged to comply. The most applicable condition is that
it should be used on every takeoff until flight climb is stabilized....

Angelo campanella

Boost pumps are often used even on high-wing airplanes if the
engine also has a mechanical fuel pump. Some systems don't have enough
flow capacity via gravity alone and need the pump, and any pump needs
a backup. Low-wing airplanes having fuel in the wings need a pump, of
course, to lift the fuel, and that's where vapor-lock becomes a
hazard, when the fuel is being pulled from the engine end of the
system. A good boost pump system there has the boost in the tank
itself, so the fuel is pushed all the way. Pressure on the fuel raises
its boiling point and vapor lock disappears.

Dan

Angelo Campanella writes:

The purpose of a fuel boost pump is to assure adequate fuel flow in all
flight conditions, especially in a nose high attitude when the tanks are
nearly empty; where the height difference between the fuel level and the
engine pump is considerable. Another vulnerability is on hot days when
vapor lock in hot spots nearer the engine is possible. It probably is
discovered by the test pilot in the ceritifcation process that fuel
starvation occurred in some situations. Thereafter, the manufacturer of
that aircraft is obliged to install one in the aircraft, likely in a low
and cold spot such as under the cabin, then certify that it solves these
problems, then tell in the flight manual how and when to apply it.

The pilot is obliged to comply. The most applicable condition is that
it should be used on every takeoff until flight climb is stabilized....

OK, thanks. Given the advantages that you cite, why wouldn't one leave the
boost pump on all the time?

On May 12, 9:12 am, Mxsmanic wrote:

OK, thanks. Given the advantages that you cite, why wouldn't one leave the
boost pump on all the time?

Because it will wear out for no good reason and maybe not work
when you need it. If you have altitude and the engine-driven pump
fails, you cant turn on the boost without losing much altitude. Most
boost pumps are electric, either motor driven or some sort of solenoid-
piston arrangement. The motor has brushes and bearings that wear out
much faster than a mechanical engine-driven pump, and the solenoid
affair has a switch that burns out. There are some electronically-
driven pulsation pumps, but they, too, suffer from heat and wear.
The boost need only be on if the main pump fails, or if you are
taking off or landing where a loss of power, even for a few seconds,
would be disastrous.

Dan

writes:

Because it will wear out for no good reason and maybe not work
when you need it. If you have altitude and the engine-driven pump
fails, you cant turn on the boost without losing much altitude. Most
boost pumps are electric, either motor driven or some sort of solenoid-
piston arrangement. The motor has brushes and bearings that wear out
much faster than a mechanical engine-driven pump, and the solenoid
affair has a switch that burns out. There are some electronically-
driven pulsation pumps, but they, too, suffer from heat and wear.
The boost need only be on if the main pump fails, or if you are
taking off or landing where a loss of power, even for a few seconds,
would be disastrous.

OK, so as a general rule, I could say, use it if the engine pump fails or
whenever an even momentary loss of fuel flow would be dangerous (takeoff,
landing, any type of flight in which a loss of power would be an immediate
problem).

don't use the boost pump.. except for when the POH states..
some aircraft, the electric boost pump is not really to "boost" pressure,
but to provide service if the mechanical pump fails
some designs are such that the combination of electric pump and mechanical
pump is too much and the engine runs in an over rich condition and can
stumble when you need power the most
B

"Mxsmanic" wrote in message
...
writes:

Because it will wear out for no good reason and maybe not work
when you need it. If you have altitude and the engine-driven pump
fails, you cant turn on the boost without losing much altitude. Most
boost pumps are electric, either motor driven or some sort of solenoid-
piston arrangement. The motor has brushes and bearings that wear out
much faster than a mechanical engine-driven pump, and the solenoid
affair has a switch that burns out. There are some electronically-
driven pulsation pumps, but they, too, suffer from heat and wear.
The boost need only be on if the main pump fails, or if you are
taking off or landing where a loss of power, even for a few seconds,
would be disastrous.

OK, so as a general rule, I could say, use it if the engine pump fails or
whenever an even momentary loss of fuel flow would be dangerous (takeoff,
landing, any type of flight in which a loss of power would be an immediate
problem).

wrote in message
...
On May 12, 9:12 am, Mxsmanic wrote:

OK, thanks. Given the advantages that you cite, why wouldn't one leave
the
boost pump on all the time?

Because it will wear out for no good reason and maybe not work
when you need it. If you have altitude and the engine-driven pump
fails, you cant turn on the boost without losing much altitude. Most
boost pumps are electric, either motor driven or some sort of solenoid-
piston arrangement. The motor has brushes and bearings that wear out
much faster than a mechanical engine-driven pump, and the solenoid
affair has a switch that burns out. There are some electronically-
driven pulsation pumps, but they, too, suffer from heat and wear.
The boost need only be on if the main pump fails, or if you are
taking off or landing where a loss of power, even for a few seconds,
would be disastrous.

Dan

You're feeding a troll.

"Maxwell" luv2^fly99@cox.^net wrote in
:


wrote in message
news:213d884c-ad6d-4e57-bc15-46e4c76b8ae8
@w5g2000prd.googlegroups.com..
.
On May 12, 9:12 am, Mxsmanic wrote:

OK, thanks. Given the advantages that you cite, why wouldn't one
leave the
boost pump on all the time?

Because it will wear out for no good reason and maybe not work
when you need it. If you have altitude and the engine-driven pump
fails, you cant turn on the boost without losing much altitude. Most
boost pumps are electric, either motor driven or some sort of
solenoid- piston arrangement. The motor has brushes and bearings that
wear out much faster than a mechanical engine-driven pump, and the
solenoid affair has a switch that burns out. There are some
electronically- driven pulsation pumps, but they, too, suffer from
heat and wear. The boost need only be on if the main pump fails, or
if you are taking off or landing where a loss of power, even for a
few seconds, would be disastrous.

Dan

You're feeding a troll.





No, actually, you are, fjukktard.


But since you're a k00k, you'll neve see it!

God I love k00ks.