Door Systems

Crew Entry Door location

forward left side of the fuselage

Where is the crew entry door hinged?

at the bottom to open outward

Can the crew entry door be opened from both outside and inside?

yes

Release Handles

-one internal and one external

-rotate down to open crew entry door

Never open crew door when?

Aircrew is onboard

Telescoping Arm

-limits distance door can be opened

-contains a cable attached to the counterbalance

What is the function of a counterbalance mechanism?

It assists in raising the door.

What is a key component of a counterbalance mechanism?

It consists of a negator spring wound opposite of its coil.

How is the negator spring in a counterbalance mechanism secured?

It is secured to an output drum.

What happens when the door is opened in relation to the counterbalance mechanism?

It creates a spring force to aid in returning the door to the closed position.

Latching mechanism

-latch hooks located at top of door opening

-pull door inward; which seats the door closed

What is the purpose of the jettison mechanism in an airplane?

It allows the door to free fall from the airplane in case of an emergency.

What is one use of the jettison mechanism besides emergency situations?

It is used for maintenance removal and installation.

What is the only door that can jettison?

Crew door

How do you begin jettison sequence?

Rotate handle down

Jettison Sequence:

-top of telescoping arm disconnects from door frame

-door latch hooks lower

-lower door hinge disengages from door frame

-door falls away from the airplane

Paratroop Doors location

-each side of the fuselage, forward of the ramp

How are paratroop doors operated

manually with release handles (one internal/ one external) and with an inward vertical movement

Paratroop doors are guided upward/ downward by what?

two roller/ arm assemblies in a channel track

What does the counterbalance mechanism do for the paratroop door?

balances the weight of the door to assist in opening and closing the door

pip pin

prevents accidental release of the spring loaded latch

What position must the pip pin be installed when paratroop door is open?

locked position

Latching Mechanism on paratroop door:

-operated from two centrally located handles (one internal/ one external)

-handles engage/disengage latch dog pins

How many pins does each paratroop door have?

4 pints total (two one each side)

Aft cargo door and ramp

-provides entry/ exit for rolling and palletized cargo

-ramp and door can also be used for aerial delivery of cargo

Cargo door is secured in the closed position by what?

two down locks and the weight of the door

What direction does the cargo door open?

upward

How many mechanical uplocks does the H model have?

One

How many actuating cylinders does the H model have?

One

How many actuating cylinders does the J model have?

Two

How many uplocks does the J model have?

Two

Where is the emergency cargo door release handle located on the J model?

Aft of the left paratroop door manually releases the door

Which direction does the cargo ramp open?

Downward to the Aerial Delivery System (ADS)

How many uplocks does the cargo ramp have on each side?

Five (10 Total)

How many actuating cylinders does the cargo ramp have?

-Two to raise and lower

-One inside the ramp to extend and retract the ten uplocks

Cargo ramp and door are controlled how?

electrically or manually

What does the ramp and door control consist of?

pump switch, door switch, ramp switches

When is manual operation of the door and ramp used?

Emergencies

How many escape hatches are located at the top of the fuselage

Three

(flight station, center of fuselage, cargo compartment)

What is the ladder called to reach the center escape hatch?

stanchion ladder