November 18th, 2015|
The NTSB has released its preliminary investigation report on the Raytheon Hawker aircraft that crashed in Akron, Ohio on November 10, 2015. Given that this tragic crash occurred just one week ago, the report contains limited information about the cause or causes of the crash. It will be at least one year before the NTSB will have completed its investigation; during this time several investigative groups within the NTSB will examine the cockpit voice recorder, the EGPWS (enhanced ground proximity warning system), the various control surfaces and systems (such as the flaps, ailerons, and rudder); the engines; and the wreckage remains. All possible causes will be investigated.
What we do know is this: a large percentage of aircraft accidents occur during the approach and landing phase, particularly in Instrument Meteorological Conditions, as was the case the day of the accident. We also know that Runway 25 at the Akron Fulton Airport does not have an ILS, i.e. an Instrument Landing System. The only guidance for pilots to this runway is a localizer beam which enables pilots to line up with the center of the runway. There is no vertical guidance or glideslope to enable pilots to ‘lock into’ an imaginary glide path to the runway. This means that pilots must either program their own descent angle on their flight computer, or carefully descend to the Minimum Descent Altitude until the runway is in sight.The minimum descent altitude for the approach to this runway is 500 ft and a requirement of one mile forward visibility.
The report from the Piper airplane which landed before the accident aircraft indicated that the weather was at “minimums” as the Piper’s crew descended along runway 25. Since weather is a fluid event, it is very possible that the ceiling (that is, the bottom layer of the cloud deck) changed and was below minimums during the approach of the Hawker Jet, in which case the Hawker should not have descended below 500 ft unless and until the runway was in sight.
While all possible causes are on the table, it is possible that the airplane may have descended too low, too soon. This could be the result of pilot error (lack of situational awareness), a malfunction of the instrument landing systems on board the airplane, a mechanical difficulty, or some other problem.
Until we have exhausted a review and analysis of all material evidence, all we can do now is hypothesize potential contributing causes based on the scant evidence which is available and reliable.
While the NTSB investigation is ongoing, we will be gathering information from known public sources such as the FAA, the Ohio State Highway Patrol (aviation division), and other entities which have relevant data.