Maintenance Issues, Unapproved Latch, Appear To Have
Contributed To Downing
It was a tragic
accident... 6 people dead, and 4 injured... all because of the
hazards of an open baggage door. The NTSB has recently issued a
probable cause in the downing of a Kodiak AK Chieftain (file photo
below) that suggests that an open baggage door and some of the
maintenance issues associated with it appear to have contributed to
a no-win that precipitated "a rapid, nose- and right-wing-low
descent" into water just after takeoff.
The NTSB Probable Cause Synopsis follows:
NTSB Identification: ANC08MA038
Nonscheduled 14 CFR Part 135: Air Taxi & Commuter
Accident occurred Saturday, January 05, 2008 in Kodiak, AK
Probable Cause Approval Date: 4/15/2009
Aircraft: PIPER PA-31-350, registration: N509FN
Injuries: 6 Fatal, 3 Serious, 1 Minor.
The airline transport pilot and nine passengers were departing
in a twin-engine airplane on a 14 Code of Federal Regulations Part
135 air taxi flight from a runway adjacent to an ocean bay.
According to the air traffic control tower specialist on duty, the
airplane became airborne about midway down the runway. As it
approached the end of the runway, the pilot said he needed to
return to the airport, but gave no reason. The specialist cleared
the airplane to land on any runway. As the airplane began a right
turn, it rolled sharply to the right and began a rapid, nose- and
right-wing-low descent. The airplane crashed about 200 yards
offshore and the fragmented wreckage sank in the 10-foot-deep
water. Survivors were rescued by a private float plane. A passenger
reported that the airplane's nose baggage door partially opened
just after takeoff, and fully opened into a locked position when
the pilot initiated a right turn towards the airport.
The nose baggage door
is mounted on the left side of the nose, just forward of the
pilot's windscreen. When the door is opened, it swings upward, and
is held open by a latching device. To lock the baggage door, the
handle is placed in the closed position and the handle is then
locked by rotating a key lock, engaging a locking cam. With the
locking cam in the locked position, removal of the key prevents the
locking cam from moving. The original equipment key lock is
designed so the key can only be removed when the locking cam is
engaged. Investigation revealed that the original key lock on the
airplane's forward baggage door had been replaced with an
unapproved thumb-latch device. A Safety Board materials engineer's
examination revealed evidence that a plastic guard inside the
baggage compartment, which is designed to protect the door's
locking mechanism from baggage/cargo, appeared not to be installed
at the time of the accident. The airplane manufacturer's only
required inspection of the latching system was a visual inspection
every 100 hours of service. Additionally, the mechanical components
of the forward baggage door latch mechanism were considered "on
condition" items, with no predetermined life-limit. On May 29,
2008, the Federal Aviation Administration issued a safety alert for
operators (SAFO 08013), recommending a visual inspection of the
baggage door latches and locks, additional training of flight and
ground crews, and the removal of unapproved lock devices. In July
2008, Piper Aircraft issued a mandatory service bulletin (SB 1194,
later 1194A), requiring the installation of a key lock device,
mandatory recurring inspection intervals, life-limits on
safety-critical parts of forward baggage door components, and the
installation of a placard on the forward baggage door with
instructions for closing and locking the door to preclude an
in-flight opening. Postaccident inspection discovered no mechanical
discrepancies with the airplane other than the baggage door latch.
The airplane manufacturer's pilot operating handbook did not
contain emergency procedures for an in-flight opening of the nose
baggage door, nor did the operator's pilot training program include
instruction on the proper operation of the nose baggage door or
procedures to follow in case of an in-flight opening of the door.
Absent findings of any other mechanical issues, it is likely the
door locking mechanism was not fully engaged and/or the baggage
shifted during takeoff, and contacted the exposed internal latching
mechanism, allowing the cargo door to open. With the airplane
operating at a low airspeed and altitude, the open baggage door
would have incurred additional aerodynamic drag and further reduced
the airspeed. The pilot's immediate turn towards the airport, with
the now fully open baggage door, likely resulted in a sudden
increase in drag, with a substantive decrease in airspeed, and an
aerodynamic stall.
The National Transportation Safety Board determines the
probable cause(s) of this accident as follows:
The failure of company maintenance personnel to ensure that the
airplane's nose baggage door latching mechanism was properly
configured and maintained, resulting in an inadvertent opening of
the nose baggage door in flight. Contributing to the accident were
the lack of information and guidance available to the operator and
pilot regarding procedures to follow should a baggage door open in
flight and an inadvertent aerodynamic stall.