'Dan,
AD note 46-40-01 is the applicable AD note. SB 44-7-C is the Fairchild
Service note. You must install placard near both fuel tank valves which
states "Operate on one tank only at a time only" An accident, drove this AD
note.
All the AD notes are on the Fairchild CD ROM.
If you run a tank dry, you will/should be able to switch to tank containing
fuel and you will run normally. I happened to me this past summer. I ran the
Ranger hard for one hour on a 1/2+ tank at full throttle trying to out run a
thunderstorm. That sucker can burn some fuel at full throttle. When that
Ranger runs short on fuel, it stops right now, makes your heart beat a
little faster. F-24 is not a good glider at 14,000 feet denisty alt.
I have also found the following. I normally taxi on the low tank. Just prior
to takeoff I switch to the fullest tank. I modified my procedure. "After
this happend twice with the tail up, just prior to lift-off". I make sure I
run the tank on the fullest for at least two minutes prior to takeoff. There
must be trapped air in the line between the full tank and gascolator. That
air gets to the carb just as you have the tail up and the engine quits cold.
Makes for an interesting high speed taxi. Never does it in the air, just on
the ground.
As far as modifing, it can be done. But you will still be required to comply
with the AD note, which means placard and operation on one tank only. The
only way to get around that is contact the Eng office of the FAA and provide
engineering data that will satisfy the FAA that you have found a better way
of satisfing the AD Note. So, Paul is illegal unless he does the previous.
I wish somebody good luck, I have been working with the FAA in FTW in regard
to the Gear AD 47-50-09 note. The SB 41-8 states if you perform a NDI by
magnaflux you are no longer required to perform the recurring AD note. Those
words never got into the AD note due to the factory went out of buisness for
supporting F-24s. Also the SB does not call out the fueslage fittings nor
the 24R46 or 24W46. The later models had the heavy gear installed. So, the
FAA AD note does not match the Fairchild SB. But nobody in the FAA will
stick there neck out since it is a libility issue.
Jamie S. Treat A&P/IA
Aircraft Restoration & Repair
24201 David C. Johnson Loop
Kelly Airpark
Elbert, CO 80106
HM/Shop 303-648-0130
----- Original Message -----
From: "danMichael"
To:
Sent: Saturday, November 27, 2004 12:26 PM
Subject: Re: [fairchildclub] Fuel flow troubles
>
> All:
>
> Can someone explain the precise problem that restricts the 24 to
> running on one tank at a time? I had thought it was caused by the air
> pressure at the cap vents during flight being lower than ambient
> pressure at the carburetor. If both tanks are selected and a tank were
> to go dry, the head pressure of the full tank would cause it to
> crossfeed to the empty one rather than supply the carburetor. Is this
> right?
>
> I talked to Paul Conn at Oshkosh. He modified the fuel system in his
> (amazingly beautiful!) 24W to provide a pressure vent to each tank
> (similar to most single engine Cessnas). He says this allows him to
> safely operate with both tanks selected.
>
>> Remove left cowl, open line entering carb and turn on one valve at a
>> time.
>> It start with the left tank. Check both tanks for flow at carb.
>> Retorque
>> line and it should start.
>
> Isnt it a certification requirement that the fuel system prime if a
> tank runs dry and another source selected?
>
>> You are getting the same effect as running one tank empty or both
>> valves on
>> while flying, hence the AD Note.
>
> Is this an AD? I couldnt find it on the FAA AD site.
>
> Curiously yours,
>
> :Dan
> :NC81323
>
>
>
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>
> Yahoo! Groups Links
>
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