Loss of Pitch Control on Take off - Investigation Timeline
The Timeline off the investigation:
Investigators turned 5 hours after the crash to pick up the remains and determine what has happened. They begin to work backwards from the time the plane crashed to when it took off, to when it was loaded and finally to when it went through scheduled maintenance the previous day.
After arriving at the scene, the NTSB call a meeting with the first responders (fire, police, ambulence etc), first to determine whether the site is safe for investigators, also
too see if they had noticed anything significant about the plane that may have caused it to crash or that could help the investigation. After determining no information
was to be found from the responders, the Lead investigator, Lorinda Ward, declared the crash site a Bio-hazard due to the amount of bodies littered on the tarmac.
Upon taking off, it has been known for debris to be on the runway and jump into an engine or damage a tyre or wing.
The investigators (NTSB), led by Lorinda Ward, walk shoulder to shoulder down the runway looking for any debris that could have caused an accident or fallen off the Beechcraft.
One of the investiagtors finds a fuel cap on the side of the runway, but nothing else is found. After extensive testing, it is determined the cap is not from the crash aircraft nor was
the cause of any accident.
Bill English, another one of the investigators, produces a theory that wake turbulence may have been the cause of the accident. With the ATC at hand he checks what plane took off before the Beechcraft, when and where it took off, too see whether the flight paths crossed. It was determined that the Beechcrafts flight path was very much in the manner of an aircraft under the influence
of Wake turbulence. Once the flight paths had been established, Bill found out that the flight paths of the two planes never crossed, causing the proposition of Wake turbulence to be discarded.
With no more leads to go on Lorinda and her team begin to search through the wreckage to see if there is anything that could've led to an accident. The cables for the rear elevator are found, and the turnbuckles are found to be adjusted very differently to one another.
With this information, an investigator, Stephen Carbone, went to the maintenance facility and found out that they were indeed adjusted, but to the flight manual standards and were stamped for quality assurance.
After talking to a couple of the ground crew, it was found out that the plane looked quite heavy when taxiing out to the runway, Lorinda got proper weights from all the doctors and relatives of the victims on the plane and then weighed all the baggage that was on the ground. It was found after all the weights had been corrected, the plane was actually 500lb overweight. But shouldn't have been the main reason for the large increase in pitch.
After looking at three it was decided that the overweighted aircraft could not have been the only cause of the loss of pitch control on T/O. Lorinda went back to the control cables, and noticed that in the lab, one of the turnbuckles had been adjusted all the way in, and the other had been adjusted all the way out. Stephen Carbone went back to the maintanence facility and the mechanics story changed.
It was actually a new mechanic that had adjusted it, and even under the supervision of the head LAME, he was encouraged to skip 9 steps out of 25, one of these steps included checking to make sure that there was full movement up and down. The FDR information stated that the elevator went down 52 degrees causing a complete loss of control of pitch.
But the aircraft still took off normally, but finally it was figured out. When pilot, Katie Leslie, ordered the landing gear retracted, the CoG Arm moved back out of limits, and without any pitch control the aircraft would do nothing but climb at a too high angle. The rest, as they say, is history.
So Proposition Three and Four were considered inadverdently combined, the cause of the accident.
Accident Report from the NTSB at www.aviationsafety.net
National Geographic's 'Air Crash Investigation TV Series'
Knowledge Management Space