Heavy Rains Have Delayed Removal Of Wreckage
The National
Transportation Safety Board has issued its Factual Report on the August 16, 2005 downing of a West
Caribbean Airways MD-82 that claimed the lives of all 160 people
onboard. The findings, according to the NTSB, concur
with those of French investigators, as well as the Comite de
Investigation de Accicente Aereos (CIAA) of Venezuela.
According to evidence found at the scene near Machiques,
Venezuela, the MD-82 (file photos of type,
below) impacted in a nose-up attitude, with a slight rolling
attitude to the right. Both engines exhibited indications of
high-speed compressor rotation at the time of ground impact --
although the flight crew had reported a dual flameout, according to
the cockpit voice recorder (CVR) -- and the engine inlets,
empennage and wing leading edges showed no sign of pre-impact
damage.
Movement of the wreckage has been delayed due to very heavy
rains in the area where the airplane went down. However, the NTSB
noted the wreckage should be moved to a secure area in Maracaibo in
the next few days.
Investigators were able to locate both the cockpit voice
recorder and flight data recorders (FDR), although both were
damaged in the accident. The FDR was in good overall condition,
however, and gave the following information to investigators --
- The accident flight lasted about one hour, from takeoff to the
end of the recording.
- The flight reached its initial cruise altitude of flight level
(FL) 310 at about 6:25 UTC (universal coordinated time).
- At about 6:41 UTC -- about 20 minutes before the end of the
recording -- the airplane began a normal climb to FL330. It leveled
off at about 6:43 and accelerated to Mach 0.76. The right engine
engine pressure ratio (EPR) was consistent with normal climb and
cruise values. (The left engine EPR readings were judged inaccurate
by the NTSB).
- About 90 seconds after reaching Mach 0.76 (6:49 UTC), the
airspeed began to steadily decrease. The horizontal stabilizer
moved from about 2 units nose up to about 4 units nose up during
this deceleration.
- About 3 minutes and 30 seconds (6:57 UTC) from the end of
recording, the Mach number reached about 0.60. The autopilot was
then disengaged and the airplane started to descend from
FL330.
- As the airplane descended past about FL315, the airspeed
continued to decrease and the right engine EPR decreased to about
flight idle. The airplane descent rate increased after passing
through FL310, and the airspeed reached a minimum of about 150
indicated air speed (IAS) knots at about FL250.
- Right engine EPR stayed at approximately flight idle through
the descent, and even increased several times -- including shortly
before the end of the recording.
According to NTSB investigators, the CVR protected module was
partly opened due to impact forces. Overall, though, the magnetic
tape was in good condition, although the tape was partially cut due
to impact forces.
The overall quality of the recording is poor, with many areas of
static and loud background noises. However, valuable data was
obtained. Almost all crew discussions to communicate with each
other and with air traffic control (ATC), in Colombia and
Venezuela, were in Spanish --
- At about 06:53 UTC,
approximately 8 minutes before the end of recording (while the
airplane is level at FL330) the flight crew discusses weather
concerns that included possible icing conditions. The flight crew
also discusses turning on engine and airfoil anti-ice.
- About 3 minutes and 30 seconds (6:57 UTC) before the end of the
recording, the crew requests and is cleared to descend to
FL310.
- About 3 minutes before the end of the recording, an audio
warning similar to altitude alert is heard, followed 22 seconds
later by a sound similar to stick shaker (6:58 UTC) and then an
aural stall warning alert. These warnings sound continuously until
the end of the recording.
- The flight crew requests subsequently lower altitudes of FL290,
FL240, and finally 14,000 feet. The flight crew does not declare an
emergency, and they do not refer to any checklist during the
descent.
- About 1 minute after the start of the sound similar to the
stick shaker, the flight crew states that they had a dual engine
flameout when asked by ATC if they had a problem. The last radio
transmission from the flight crew to ATC was at about 07:00:11
UTC.
- About 8 seconds before the end of recording, a ground proximity
warning system (GPWS) warning starts to be heard and continues to
the end of recording.
- The time from first sound similar to stick shaker, to the end
of the recording, is about 2 minutes and 46 seconds. The end of the
tape occurs at about 7:00:31 UTC.
The NTSB did not give a timeframe for when that agency, or the
CIAA, expects to issue a probable cause report on the mishap.