The A-1O is a single-seat close air support aircraft manufactured by Fairchild Republic Company, Farmingdale, New York. The aircraft is a low wing, low tail configuration with
two high bypass turbo fan engines installed in nacelles mounted on pylons extending from the aft fuselage. Twin vertical stabilizers are mounted on the outboard tips of the horizontal tail. The tricycle forward retracting landing gear is equipped with an anti-skid system and a steerable nosewheel. The nose gear is installed to the right of the aircraft centerline to permit near centerline gunfire. The nose gear retracts fully into the fuselage while the main gears partially retract into streamlined pods in the wings. A titanium armor installation surrounds the cockpit.
The primary flight controls are equipped with artificial feel devices to simulate aerodynamic feel.
The elevator and aileron controls split into redundant separate systems before leaving the armor protection. The controls are powered by two independent hydraulic systems, either of which has the capability of controlling the airplane. If both hydraulic systems fail, the airplane can be flown using a manual reversion system. The ailerons consist of an upper and lower panel that become speed brakes when opened. The windshield front panel is resistant to
small arms fire and birds. The windshield side panels are resistant to spall spray caused by penetrations. The fuselage fuel cell sumps are self-sealing on the lower portion and tear resistant on the upper portion. The cells are filled with a flexible foam to prevent fuel tank explosion. Single-point ground refueling and engine feed lines are self-sealing. The escape
system provides a zero/zero capability (zero velocity, and zero pitch and roll attitude) either with the canopy removed or through the canopy.
ENGINES
The aircraft is powered by two General Electric TF34-GE-100i -100A engines.Sea level, standard day, static thrust for an installed engine is approximately 8,900 pounds at maximum
thrust. The engine incorporates a single-stage bypass fan and a 14-stage axial flow compressor. Bypass air produces over 85070 of engine thrust. Therefore, engine fan speed is the best indication of thrust. Variable inlet guide vanes automatically modulate throughout the engine operating range. An accessory gearbox drives a hydraulic pump, fuel pump and fuel
control, oil pump, and an electric generator. An air bleed for aircraft systems is provided. Engine acceleration time from IDLE to MAX thrust will be approximately 10 seconds at sea level. Engine thrust droop results from differential expansion of the engine turbines and casings during transients from low to high thrust operation. The duration and extent of the thrust droop is dependent upon the rate/ range of throttle movement. Thrust droop is decreased if the engines have been idling for a period of time. Thrust droop is further decreased if the engines have
been run up before takeoff. An example of the worst condition would be a scramble takeoff where takeoff is accomplished shortly after engine start. Maximum droop occurs approximately 10 seconds after the throttle is advanced from IDLE to MAX. After approximately 4 minutes of operation at MAX thrust, power output returns to normal. Elimination of thrust droop can be observed on the engine fan speed indicator. Thrust will increase as fan speed increases.
TURBINE ENGINE MONITORING SYSTEM (TEMS)
The turbine engine monitoring system (TEMS) provides a means for supporting the on-condition maintenance concept for the TF34-IOOA engine installed on t he A-lOA aircraft.
Information is provided to the system electronic processor unit (EPU) automatically whenever the engine is operated . I f any engine operation limit is exceeded, or when the TEMS DATA switch is pressed, a frame of data is recorded. An overlimits event will be displayed on
the umbilical display unit (UDU), located in the nosewheel well. This data is provided in code form for the technician or pilot to determine engine condition.
ENGINE OIL SYSTEM
The engine oil system is self-contained and all the oil supplied is used for lubrication and cooling . Usable oil capacity is 5.6 quarts, and maximum oi l consumption is 0.5 pints / hr . An oil pressure indicator and an independent light on the caution light panel monitor oil pressure of each engine. Oil grade and specification to be used arc co\ered ill the servicing diagram.
Engine Oil Pressure Indicators
An oil pressure indicator is provided for each engine. They indicate oil pressure in psi, and are powered by the 26 V instrument transformer bus.
Engine Oil Pressure Caution Lights
An engine oil pressure caution light (independent of the oil pressure indicators) on the caution
light panel, is provided for each engine . The lights are placarded L-ENG OIL. PRESS and
R-ENG OIL. PRESS and will come Oil if the pressure is less than 27.5.
ENGINE FUEL SYSTEM
The engine fuel system (figure FO-4) provides fuel required for combustion, cOl1lrols engine variable geometry actuation, and provides engine oil cooling. Fuel is supplied to the engine fuel pumps, where it is pressurized and directed to Ihe fuel control. From the fuel control, metered fuel passes through the engine oil cooler to the distribution valve.
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