Fuel System Limits

STUDENT GUIDE FOR T-1A AIRCRAFT SYSTEMS

CHAPTER FOUR

Pressure Sensing Controls and Indicators

Wing Tank Overpressure Switch - When pressure in the wing tank reaches 3.5 + 0.5 psi,

an amber legend L WNG TNK OV PRESS or R WNG TNK OV PRESS illuminates on the main

annunciator panel.

Engine Feed Line Low Pressure Switch and Annunciator - This fuel low-pressure

switch responds at 5.0 + 0.5 psi. In the event of a low pressure in either the right or left fuel

lines, the respective pressure switch illuminates the L FUEL PRESS LO or R FUEL PRESS LO

annunciator.

3. Low Transfer Pressure Switch and Annunciator - When fuel pressure in the transfer line

falls below 5.0 + 0.5 psi, a caution light on the main annunciator panel illuminates the amber

legends L F XFR PRESS LO or R F XFR PRESS LO.

4. Fuel Filter Bypass Switch and Annunciator - If the feed line fuel filter becomes clogged

causing the line pressure to exceed 2.3 + 0.2 psi, the bypass valve opens, routing fuel around the

filter directly back into the engine feed line. When either fuel filter bypass is being used, an

amber annunciator illuminates the legend L F FLTR BYPASS or R F FLTR BYPASS.

Fuel System Valves Controls and Indicators

Engine Fuel Shutoff Valve Switchlights - A switchlight in the fire protection group on the

shroud panel is used to close the main fuel line shutoff valve in the event of engine fire. The

switchlight serves as an annunciator as well as a switch. When the valve is closed, an amber lens

illuminates the legend LF/V CLOSE or RF/V CLOSE on the inboard side of the switchlight.

407. FUEL SYSTEM LIMITS

Refer to Fuel Limitations, Section V, T.O. 1T-1A-1, for specific limitations of the aircraft fuel

system.

FUEL SUPPLY SYSTEM

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