23 Jun Cessna 172 Fatal Collision with Terrain Investigation
This video is a recreation of an actual Cessna 172 Fatal Collision with Terrain Investigation. It involved a Student Pilot flying their first solo navigation flight. This Air Crash Investigation video is based on the Australian Transport Safety Board (ATSB) Case Number AO2015-105.
At 14:10 local time, the Student Pilot departed on their first Solo Navigation flight from Point Cook (YMPC) to the township of Swan Marsh. From Swan Marsh to overfly Ballarat (YBLT) airport, then on to Melton Reservoir (MELS). From MELS, continue back to Point Cook (YMPC) airport.
The weather conditions included overcast Stratocumulus cloud at about 3,000 feet Above Mean Sea Level (AMSL). Visibility was 10 km (P6SM) clear of cloud. Wind was not an issue in this case.
Upon reaching Ballarat airport (YBLT), the Pilot tracked towards Melton Reservoir (MELS). East of YBLT, the terrain elevation gradually increases. The planned route between YBLT and MELS overflies Black Mount, an extinct volcano located in the town of Millbrook. The elevation of Mount Black is 2,200 feet AMSL. With the pilot cruising at about 3,000 feet AMSL, there was an approximate clearance of about 800 feet.
It is believed the pilot noticed the rising terrain and spotted Mount Black. As a result, started to gently pull back on the control column to increase the terrain clearance, while still remaining clear of the overcast cloud base.
When the autopilot is engaged in pitch mode and the control column pitch is manipulated, the autopilot counters any pitch input through electric trim. As a result, the electric trim moved forward, leaving the aircraft in a fully forward trim position. Upon letting go of the flight control column, the aircraft entered a rapid nose down descent due to the out of trim situation. With the engine set at a cruise setting, the aircraft accelerated in the nose down position, reducing the reaction time before contacting terrain.
The pilot reacted to the situation and came very close to recovering the aircraft. The aircraft nose was level in a slight right turn when the right wing contacted the ground.
The pilot did not survive the accident.
The ATSB discovered that Cessna C172S with the Bendix/King KAP140 Autopilot system installed had warnings in the manual not to manipulate flight controls when the autopilot was engaged. Cessna C172S aircraft with the Garmin GFC700 Autopilot system did NOT have any warnings in the flight manual regarding manipulating the flight controls when the autopilot was engaged.
The ATSB Safety recommendations to aircraft and autopilot manufacturers about providing limitations, cautions and warnings for autopilot systems and audible pitch trim movement.
The Flight Training organization also updated their operations manual to include warnings about the operation and function of the autopilot system absent in the manufacturers documentation.
The hazard of manual manipulation of the flight controls with the autopilot engaged was also emphasised to students.
Thank you to Arg for helping me specifically calculate and locate the actual crash scene without any Australian aviation charts. Appreciate your help mate.
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