TM 1-1510-262-10
k. Wheel Brake System. The main wheels are equipped with multiple-disc hydraulic brakes, actuated by master
cylinders attached to the toe brake sections of the rudder pedals. A reservoir in the nose compartment supplies brake
luid to the system. Braking is permitted from either set of rudder pedals. No emergency brake system is provided.
Repeated application of brakes, with insuficient cooling time between applications, will cause a loss of braking
eficiency, and may cause brake or wheel failure, tire blowout, or destruction of wheel assembly by ire.
2-9. ENTRANCE AND EXIT PROVISIONS.
NOTE
Two keys are provided in the loose tools and equipment bag. Both keys will it the locks on the cabin
door, emergency hatch, tail cone access door and the right and left nose avionics compartment
doors.
a. Cabin Door.
Structural damage may occur if more than one person is present on the airstair cabin door at one
time. The door is weight limited to 300 pounds.
An airstair cabin door (Fig. 2-15), hinged at the bottom, provides a stairway for normal and emergency entrance
and exit. In the closed position, the door becomes an integral part of the cargo door. The cabin door is provided
with steps, two of which fold lat against the door in the closed position. A step folds down over the doorsill when the
door opens to provide a platform (step) for door seal protection. Two (2) plastic-encased cables, on either side of the
stairs, provides a handhold and support for the door in the open position and a convenience for closing the door from
inside. A hydraulic damper permits the door to lower gradually during opening. A rubber seal around the door seals
the pressure vessel while the aircraft is in light. Either of the two mechanically interconnected handles, one inside,
and the other outside the door operates the door locking mechanism. When either handle is rotated, three rotating
cam-type latches on either side of the door capture posts mounted on the cargo door. A button adjacent to the door
handle must be depressed before the handle can be rotated to open the door. A bellows behind the button is inlated
when the aircraft is pressurized to prevent accidental unlatching and/or opening of the door. A placard adjacent to
the window instructs the operator that the safety lock arm is in position around the bellows shaft which indicates a
properly locked door. Pushing the red button adjacent to the window will illuminate the inside door mechanism. A
CABIN DOOR annunciator on the caution/l advisory panel will illuminate if the door is not closed and all latches fully
locked. The cabin door opening is 21.5 inches wide by 50.0 inches high.
b. Cargo Door. A swing-up door (Fig. 2-15), hinged at the top, provides access for loading cargo or bulky items.
The cargo door opening is 52.0 inches wide by 52.0 inches high. After initial opening force is applied, gas springs
will completely open the cargo door automatically. The door is counterbalanced and will remain in the open position.
A door support rod is used to hold the door in the open position, and to aid in overcoming the pressure of the gas
spring assemblies when closing the door. Once closed, the gas springs apply a closing force to assist in latching
the door. A rubber seal around the door seals the pressure vessel while in light. The door locking mechanism is
operated only from inside the aircraft, and is operated by two handles, one in the bottom forward portion of the door
and the other in the upper aft portion of the door. When the upper aft handle is operated per placard instructions, two
rotating cam-type latches on the forward side of the door and two on the aft side, rotate, capturing posts mounted on
the fuselage side of the door opening. The bottom handle, when operated per placard instructions, actuates four pin
lug latches across the bottom of the door. A button on the upper aft handle must be pressed before the handle can be
released to open or latch the door. A latching lever on the bottom handle must be lifted to release the handle before
the lower latches can be opened. These act as additional aids in preventing accidental opening or unlatching of the
door. The cabin and cargo doors are equipped with dual sensing circuits to provide the crew with remote indication
of cabin/cargo door security. Annunciator placarded CABIN DOOR will illuminate if the cabin or cargo door is open
and the battery switch is on. If the battery switch is off, the annunciator will illuminate only if the cabin door is not
securely closed and latched. The cabin/cargo door sensing circuit receives power from the hot battery bus.
2-20
