Help Needed on Fuel Emergency

[Gunship]

Morning all Rotorheads,

Our Mi-24 had a recent engine conversion whereafter a fuel "clog" light and fuel "low - pressure" lights was installed.

Yes - we never had them before !

Can you guys please help me with an Emergency that I must write on "FUEL CLOGGING" and "FUEL PRESSURE" please.

The "standard" one's will be off great help please.

Mail them to [email protected] - will really appreciated or post on this forum.

Kindest and have a GREAT, fantastic, accident free day / weekend and year. :up:



G U N S H I P

[Thomas coupling]

GunZ;

FUEL PRESS 1 , or FUEL PRESS 2


Procedure:

1. FUEL PRIME PUMP sw - ON; "PRIME PUMP"
(affected engine) caution indication will come on

If "FUEL PRESS" caution indication goes off:

2. Land as soon as practicable

If "FUEL PRESS" caution indication remains on:

2. FUEL PRIME PUMP sw - OFF

3. Land as soon as practicable

CATION: BE PREPARED FOR ENGINE FAILURE.


For fuel 'clogging' by that I presume you mean: fuel filter clogging.



FUEL FILT 1 or, FUEL FILT 2


Procedure:

One caution indication:

Land as soon as practicable.

CAUTION: BE PREPARED FOR SINGLE ENGINE FAILURE

Both caution indications:

Land as soon as possible.

CAUTION: BE PREPARED FOR DOUBLE ENGINE FAILURE.


Have a safe flight!!!

[212man]

Where does the pressure warning come from? is it engine driven pump or booster pumps. If the former then you would need to check for engine fluctuations and possible flame out. If the later then there may be unusable fuel consderations if jet pumps and scavenging are involved. There may also be an altitude limitation.

[Old Man Rotor]

A typical Fuel Filter System has an inline filter with two external lines....one line going to a pressure differential switch which simply compares the fuild pressure on the delivery and departure side of the inline filter. If the pressure differential exceeds a set value the switch is closed and your warning light is illuminated.

The other line goes to a bypass pressure valve which bypasses the clogged filter if the pressure in the delivery line exceeds the preset value.

Is this the type installed in your Mi-24???

If it is.......adopt a normal BHT procedure from a RFM.

"Land as soon as practical"...would be a typical statement from a Bell RFM. [B412]...basically a base level emergency.



As far as the Fuel Pressure is concerned............would not like to guess as the engines may have all sorts of different systems to the normal "western" style.

[SASless]

Good info so far....but final procedure should be predicated on the actual configuration you have.

One side affected....generally expect a single engine failure.....both sides affected....might want to land as soon as possible while expecting a sudden onset of silence from both sides. Unusable fuel might be a concern if pump failures are the cause....but like 212Man correctly states.....if engine driven pump fails...much different than if a tank pump retires.

By "clogging"....do you mean a filter bypass caution light suggesting a filter is becoming clogged but still allowing fuel to pass? If filter "cloggs"....will fuel bypass the filter and contaminated fuel be able to enter the fuel control unit? Any filters on the fuel control unit itself (in addition to the in-line filter)?

Will the engine run without boost pumps but run with engine driven pump....what triggers the pressure light would be telling.

Real question......why the modification? How did the system work prior to the change....if no warnings provided...would the engines continue to run despite filter and pressure problems?

[Gunship]

Thank you very much so far for all your inputs !

The systemn works like this ... (quick one)

Fuel get's pumped by an electrical pump from the tanks. Then a Mechanical Booster pump sends it to the fuel filter. I would think the pressure pick up is situated between the two.

Thereafter the fuel flows to the fuel filter and an actuator and pressurising air valve on the high pressure side.

Many thanks for the inputs so far - I am trying to go through the manuals (badly translated Russian - English ) but no indications of any pressure switches or pressure pick ups.

Cheers and tx again so far ! :up:

GUNNS