ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL
Rev.
5
MM-2-10
Nov
5/13
2-9. Power
Train
The power train includes the main rotor transmission, upper pulley/overrunning clutch
assembly, drive belt, belt drive system, tail rotor drive shaft, and the tail rotor transmission.
A. Main Rotor Transmission: The main rotor transmission provides a 7.154:1 reduction
ratio between the upper pulley and main rotor system. The transmission incorporates
an over-running clutch in the upper pulley which allows the main and tail rotors to
over-run when the engine is throttled back for autorotations. The transmission has a
sight gauge which is located on the aft right side and is visible through a panel in the
baggage compartment or through the upper access step. Total oil quantity in the
transmission is 6 pints (2.84 liters). A magnetic drain plug located on the bottom left
aft side of the transmission can be checked for metal particle contamination. All
280FX aircraft are equipped with chip detector annunciator in the instrument panel.
Starting with serial number 744, F-28F aircraft may be equipped with the chip detector
annunciator as optional equipment. The chip detector is standard equipment on all
later production F-28F aircraft.
B. Tail Rotor Transmission: The tail rotor transmission supports and drives the tail rotor
assembly. The transmission utilizes a splash lubricated, non-vented, closed oil
system. A filler port and a sight gauge are located in the aft end of the transmission. A
magnetic drain plug located on the bottom aft side of the transmission can be
checked for metal particle contamination. All 280FX aircraft are equipped with chip
detector annunciator in the instrument panel. Starting with serial number 744, F-28F
aircraft may be equipped with the chip detector annunciator as optional equipment.
The chip detector is standard equipment on all later production F-28F aircraft. The
total oil capacity of the transmission is 5 ounces/.15 liters. An inspection plug, used to
visually inspect the transmission gears, is located on the top right side of the
transmission. The tail rotor transmission reduction ratio is 1:1.
2-10. Main Rotor Assembly
The main rotor assembly is a three bladed, high inertia, fully articulated rotor system.
Three hydraulic dampers are incorporated to control the lead-lag motions of the blades.
2-11. Tail Rotor Assembly
The tail rotor assembly is a two bladed, teetering, delta hinged rotor assembly.
2-12. Operating Limitations and Restrictions
Refer to the applicable F-28F/280F/280FX Rotorcraft Flight Manual for the aircraft
operating limitations and restrictions.
2-13. Placards
Refer to the applicable F-28F/280F/280FX Rotorcraft Flight Manual for the required
placards.
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