201: Airframe System

201.1 SYSTEM COMPONENT AND COMPONENT PARTS Referring to a standard print of this system or the actual equipment, identify the following system components and component parts and discuss the designated items for each:

A. What is its function?
B. Where is it located?
C. What are the emergency modes of operation?

201.1.1 Main entrance hatch

A. The main opens outward and downward, it has four integral steps. It can be opened or closed from inside or outside the aircraft. An inflatable seal around the door keeps pressurization leakage to a minimum. A valve in the door operation mechanism shuts off the engine bleed air to the seal when the door is opened. The door is secured in the locked position by six retractable lockpins located on the sides and top of the door. Two hinges secure the bottom of the door. The main entrance door may be used as an emergency exit on the ground B. The main entrance door is on the forward left side of the fuselage.

201.1.2 Fuselage midsection

Main cabin A. Transport high priority cargo and/or passengers. The aircraft is capable of carrying 10,000 pounds of cargo payload or 26 passengers and two aft compartment crewmembers. A combination of passengers and cargo may be carried, providing that the combined payload does not exceed 10,000 pounds. B. Located from fuselage station 143.7 to 500.5 C. Main entrance hatch forward left side F/S 157.1, Two overhead ditching hatches located on the left and right section of the fuselage overhead, aft of the wing. (Hatches are removed by turning the T-handle clockwise to the UNLOCK position and pulling the hatch inward. A handhold on the edge opposite the T-handle facilitates its removal) B. Bailout hatch - forward end of the cabin floor, immediately aft of the cockpit. The hatch consists of a floor panel, T-handle, and a drop-away hatch faired with the under-side of the fuselage. To open the bailout hatch, the T-handle must be lifted to unlock the floor panel. The floor panel may then be pivoted upward by means of a track and roller arrangement and moved forward with a forward lifting motion. The forward edge of the panel strikes two hatch releases that unlock the dropaway hatch and permit it to fall free of the aircraft because of slipstream. When the floor panel is in the full vertical position at the forward side of the hatch opening, it protrudes below the underside of the fuselage to provide a windblock to facilitate bailout.

201.1.3 Fuselage aft section

Cargo ramp A. Provides cargo compartment access at the rear of the aircraft. The ramp opens to a level position and stops, but may be further lowered to contact the ground or deck for loading. B - Aft section of cabin from fuselage station 500.5 to 608.8

201.1.4 Flight control system

a. Aileron
A – Lateral control of the aircraft is provided by means of two semifowler-type ailerons
B – One on the trailing edge of each wing outer panel

b. Flaps
A – Flap and ailerons droop system provides additional lift during takeoff, loiter, and landing.
B – There are two flaps on each wing, one on each side of the wing fold joint.
C – (1) if hydraulic system pressure to operate the flap drive hydraulic motor is lost, normal flap operation is not possible. The system must then be operated electrically. (2) During an in-flight emergency or ground maintenance, it may be necessary to operate the flap and aileron droop system without using aircraft or external electrical power. The system is then operated by depressing the FLAPS UP or FLAPS DOWN manual override button on the flap selector valve. This procedure is to be considered emergency operation only. Using this mode there is no automatic intermediate stops. The flaps will continue, up or down, until the up or down stops are contacted. Contacting either stop will cause the load limiters to lock. Excessive system operation in this mode will cause the load limiters to become less reliable. When using the override button as soon as the flaps start to move.

c. Rudders
A - Directional control of the aircraft is provided by rudders (YAW)
B – Attached to the outboard fins and the right inboard fin. Each outboard rudder consists of an upper and lower assembly interconnected by a common torque tube. (aft end of A/C vertical)
d. Elevators
A – Longitudinal control of the aircraft (Pitch)
B - On trailing edge of the fixed horizontal stabilizer.

201.1.5 Landing gear system a. Nose gear
B - Forward section of aircraft (under cockpit)
C – If a combined or flight hydraulic system failure occurs, the landing gear and tailskid must be extended with an emergency pneumatic system. The system consists of a 3,000 psi nitrogen bottle, a nitrogen release valve, two pressure operated dump valves, and shuttle on the gear and tailskid actuators. Nitrogen is released from the bottle by actuating the emergency landing gear handle that is linked mechanically to the release valve. The released nitrogen positions the dump valves to open the uplines of the landing gear and door cylinders and the tailskid lift actuator to return fluid to the reservoir. At the same time, nitrogen enters the down side of the cylinders through shuttle valves and extends the cylinders. The system lowers the landing gear only once because the nitrogen cannot be recharged in flight.
b. Main gear
B - Mid section of aircraft outboard of fuselage. (one under each engine)
C - If a combined or flight hydraulic system failure occurs, the landing gear and tailskid must be extended with an emergency pneumatic system. The system consists of a 3,000 psi nitrogen bottle, a nitrogen release valve, two pressure operated dump valves, and shuttle on the gear and tailskid actuators. Nitrogen is released from the bottle by actuating the emergency landing gear handle that is linked mechanically to the release valve. The released nitrogen positions the dump valves to open the uplines of the landing gear and door cylinders and the tailskid lift actuator to return fluid to the reservoir. At the same time, nitrogen enters the down side of the cylinders through shuttle valves and extends the cylinders. The system lowers the landing gear only once because the nitrogen cannot be recharged in flight.

c. Wheel/brake
B – Each main landing gear wheel has a trimetallic, self adjusting, disk-type hydraulic brake ( wheel and brake are located on the strut mounted to the axle)
C – The emergency brake handle is a black and yellow striped T-handle immediately below the power lever friction lock on the control pedestal. Pulling the handle out positions a rotary selector valve that directs emergency brake accumulator pressure directly to the brakes; this applies the force necessary for emergency stopping or for parking. Squeezing the handle releases a lock and permits the handle to be pushed in; this releases the brakes. The emergency brake is either on or off dependent on handle position. If the handle is locked in any position other than full out or full in, actual brake position can not be determined.

Caution – The emergency brake is not a function of system pressure. Once the pressure has been depleted on the brake accumulator, it can be restored by use of the auxiliary handpump.

d. Nose wheel steering
A – Unstowing the handle when weight is on the wheels activates the nose wheel steering system. Moving the unstowed handle to the left or right turns the nosewheel to the left or right. B - Nose wheel steering handle is a pistol grip on the forward end of the pilot side console.
e. Main Gear Strut Extender system
A – The main gear strut extender system is incorporated into the landing gear system to provide sufficient clearance between the aircraft tailskid and deck hardware during catapult launch by means of extending the main gear shock struts from their normal position.
B – Two electric solenoid in overhead forward of landing gear selector valve and aft of AHRS #2 ECU.

201.1.6 Hydraulics a. Flight
A – Supplies power to the primary flight controls ONLY! (Ailerons, Elevators, Rudders)

b. Combine
A - Supplies power to the primary flight controls and to the rest of the hydraulically operated subsystems. Operates when engines are operating.
11 sub systems: Arresting hook, cargo doors and ramp, emergency generator, landing gear, main gear strut extender, nosewheel steering, tailskid, wheelbrakes, windshield wipers, wing flaps, wing fold and jury strut.

201.1.7 Wings a. Spread
A – For aircraft to fly. When wings are up and locked you are able to control the flaps and ailerons for flight
b. Fold
A – The outer wing panels can be folded to obtain the required clearance to permit stowage aboard carrier hangar decks.
C - If a primary electrical failure occurs, the wings can be moved by actuating the wing fold selector valve manual override buttons (extend or retract) after ensuring that the flaps are sent to 20 degrees. The selector valve is located on the right side of the fuselage on the hydraulic servicing panel. (Use of this override button will fold the wings even if the wings are not set to 20 degrees)

c. Jury strut
A – The jury strut latch engages the probe on the outboard fin. This support link then locks the wing in the folded position.
B – The actuating cylinder retracts to retract the jury strut, and stows it in the wing outer panel.

201.1.8 Arresting gear

A – To land on the Carrier and for emergency field landings
B – Bottom aft end of aircraft under ramp.
C – The emergency arresting hook release system is completely independent of the normal system and is used when the hook cannot be lowered by normal means. System operation is initiated by the EMER ARG HOOK handle on the copilot’s right console. The handle is marked with yellow and black stripes. When the handle is pulled fully aft, it is engaged and held in that position by a tab. Simultaneously, the arresting hook uplock is released and the arresting hook emergency dump valve is positioned to port return fluid from the arresting hook lift actuator. Dashpot air pressure is then able to force the hook down.

Note: The emergency system cannot be used to retract the hook after it is extended if no combined system pressure is available. However, the EMER ARG HOOK handle should be returned to its full forward position by pushing the PUSH TAB TO RESET tab to unlatch the handle and pushing it forward.

201.1.9 Nose-Tow Catapult system

A&B – All mechanical components necessary for a catapult launch are on the nose gear, they are retracted into the nose wheelwell when the landing gear is raised. A tow link mounted forward of the nose gear is used to guide the aircraft to the shuttle from the lead-in track and to attach the aircraft to the shuttle. A trail bar bellcrank aft of the nose gear strut attaches the aircraft to the catapult through a release element designed to fail at 53,000 pounds of tension. A lifter spring is compressed by the bellcrank to engage the tow link and shuttle as a thrust moment is exerted by the aircraft. After the release element is broken, the spring applies a force to a lifter pushrod through the trail bar bellcrank, thereby repositioning the tow link when the aircraft clears the shuttle. To store the launch mechanism within the nose wheelwell doors after landing gear retraction, a second retraction is used to raise the tow link to the fully up position. This is all done by mechanical linkage from the nose gear drag brace to the tow link. When the gear is extended, the linkage is moved out of the way and the toe link drops to its intermediate position. If the tow link does not reach its intermediate position after launch, retraction of the landing gear moves the tow link through the second retracting stage to a position where it engages the tow link uplatch.

201.3 Pararameters/operating Limits

201.3.1 State the proper tire pressure for the following:

a. Nose wheel
1. land - 140 psi 2. carrier based - 260 psi

b. Main wheel
1. land - 235 psi
2. carrier based - 290 psi

201.3.2 State the normal operating pressure of the hydraulic systems
a. 3,000 psi

201.5 Safety Precautions

201.5.1 What safety precautions must be observed when jacking a C-2A on a carrier underway?
a. Do not jack aircraft on wing and fuselage jack points aboard ship if wind exceeds 15 knots and/or pitch, roll, or heel of ship is expected to exceed 3 Degrees.
b. Ensure that equipment and personnel are clear of aircraft before jacking.
c. Ensure that electrical power is off except when performing landing gear operational check.
d. Do not jack aircraft when gross weight exceeds 50,060 pounds (22,707 kg), except for wheel jacking.
e. Do not bypass the AIR/GROUND SAFETY relay unless the ENGINE AIR CYCLE switch is in the OFF position.