Section 7
Description of the Airplane and Systems
Columbia 400 (LC41-550FG)
RC050002
Initial Issue of Manual: November 10, 2004
7-16
Latest Revision Level/Date: -/11-10-2004
Door Locks –
There are door locks for each door that restrict use of the latching mechanism and
are intended as antitheft devices. The door lock on the pilot’s side is a tube-type lock and is
operated with a key. On the passenger’s side, there is an interior latch control for locking the
door. The keyed lock and the latch are moved counterclockwise to lock the door.
To lock the airplane, first engage the door latching mechanism on the passenger side, and then
activate the door lock by moving the interior latch. Next, close and latch the pilot’s door, and use
the key to activate the door lock. Ensure that the baggage door is locked.
CAUTION
The passenger’s door must not be locked during flight operations. Locking the
door would inhibit rescue operations in case of an emergency.
Door Seal System
– The airplane is equipped with a pneumatic door seal system that limits air
leakage and improves soundproofing. An inflatable gasket around each main door expands when
the door seal system is turned on. An electric motor near the pilot’s rudder pedals operates the
system, which maintains a differential pressure of 12 to 15 psi. The system is activated by a
switch in the rocker switch panel labeled “Door Seal” and is protected by a five-amp circuit
breaker. The cabin and baggage doors must be closed for the door seal system to operate. The
latching mechanism of each door moves a microswitch, which turns off the Door Open
annunciator. The Door Open annunciator must be extinguished for the door seal system to
operate.
The cabin door latching mechanism also controls the dump door seal valve. When either cabin
door latching mechanism is moved more than a half inch towards the open position, the dump
valve is engaged, and the pressure in the seals is dumped. This prevents inadvertent operation of
the doors when they are sealed; however, setting the door seal switch to the off position after
landing is recommended.
Normally, the door seal switch remains in the On position for the entire flight. If the system
pressure drops below 12 psi, the air pump will cycle on until pressure is restored. If the pump
runs continuously, it is an indication that a seal is damaged and incapable of holding pressure. In
this situation, the door seal system should not be operated until repairs are made.
Baggage Door –
The baggage access door is located on the left side of the airplane,
approximately two and one half feet from the left cabin entrance door. The door has Ace type
locks on each side of the door, and both locks are used to secure and unsecure the door. There is
a piano hinge at the top, and the door is held open by a gas strut during loading and unloading
operations.
To open the baggage door, insert the key into each lock and rotate 90º clockwise. The key cannot
be removed from the forward baggage door lock; hence, when opening it, release the aft lock
first. Once the aft lock is unlatched, remove the key and open the forward lock. This design
reduces the possibility of taking off with the baggage door open, provided the ignition and
baggage door keys are on the same key ring. When the second lock is unlatched, the gas strut
will raise the door. The baggage door is part of the door annunciator system. If the baggage door
is not properly closed and the forward latch secured, the red “Door Open” light in the
annunciator panel will illuminate and the aural warning will sound.
