Arrow Fuel Pumps
 

Anyone fly an Arrow III? Had any problem with the electric fuel pump? Ours has had NINE pump failures in three years (and about five new pumps, the rest being "repaired").

Latest explanation was "fuel contamination" that took out the mechanical part of the pump. Other failures have been with the electric motor as well as the pump half.

We've had all the wiring (from bus bar/circuit breaker, via switch, filter, right to the pump changed. That didn't fix it.

Should there be a "return line" for high-pressure fuel back to the tank? We don't have one...

Keef

Clearly, this is a fairly exceptional case.

Same maintenance company involved each time?

Ever had an independent opinion on the nature of the failure(s)?

What kind of fuel contamination b*ggers up the electronic pump without leaving any other damage... I assume that the pump failure was the only evidence of this contamination?

-2Donkeys

To comment i need a little more info ...is this a turbo or non turbo arrow ? and who supplyed the pump and was it a new or OHC pump ?

[This message has been edited by A and C (edited 23 April 2001).]

Two different maintenance companies. One for the first two fixes, one for all the rest.

The pumps have come from two different suppliers - the same results both times!

It's a non-turbo Arrow. The pump is the rotary type (not the "ticker" type that carburetted Cherokees have).

The contamination claim was after last week's failure. We've never got any water out of the fuel drains; I suspect it was just an excuse to avoid the supplier having to replace it under warranty.

We were TOLD that four of the new pumps were brand new - no proof, of course.

Keef

Two points may be of interest
1) The pump manufactures have suggested that the fuel is not turned off when the aircraft is standing idle as a tiny unnoticed fuel leak will possibly leave the pump dry and a couple of seconds running will write the pump off.
2) The type of pump will not stand prolonged running, is every one in the group turning the pump off at 1000 feet ???
A pump running warning light could easily be fitted.
regards

Having not changed one of these pumps in living memory i think that.....
1 some one is leaving the pump running all flight or.
2 the pumps fitted may be OHC and not new.
3 i think that the chances of a pump "drying out" are unlikly unless the the aircraft is not flown for weeks on end.

I would first sujest that first you check the seals on the tank filler caps and the lugs on the bottom of the caps for slots worn in them ,this will eliminate most of the chances of water getting into the tanks.

If you have to replace another pump i can recomend buying it from airpart supply at booker (01494 450366) if they supply a new pump you can be sure that it is new and not OHC.

I overhaul my fuel pump (not an Arrow) these days because of a worn bearing. The last time the pump was overhauled was in 1988. The vanes of my pump are made of Nylatron (spelling?). I was told that if during an operation a foreign object hits them they can brake. My pump is manufactured by Dukes and is fitted in many Cessna and Piper a/c, hence I believe that you have the same pump. The repair kit cost about £350. Look inside your fuel tanks and lines, they might be contaminated with solids. 9 failures within 3 years… something else is at fault other than the pump.

AC-DC makes a good point , has some one used mogas in the aircraft ? this can attack the fuel tank sealant and tha small bits break lose and MAY damage the pump.