Weather to go

This report was compiled in the interests of promoting aviation safety and reduction of the risk of aviation accidents or incidents and not to establish legal liability.

SYNOPSIS 

On 23 July 2006, the aircraft took off from Worcester Aerodrome on a private flight to Grabouw Private Aerodrome. When the aircraft did not land as planned, a search mission was launched. The wreckage of the aircraft was found in the mountains the next day. The pilot was fatally injured in the accident. 

The reported weather conditions in the area and witness testimony at the time of the accident suggest that the aircraft was flying in adverse weather conditions i.e. instrument meteorological conditions (IMC) prior to the accident. According to available records, the pilot was not instrument rated nor was he night rated. A possible scenario could be that, in an attempt to maintain visual meteorological conditions (VMC) flight in IMC, the pilot might have descended to a lower altitude and flown into a mountain (controlled flight into terrain: CFIT). 

PROBABLE CAUSE 

The aircraft flew into a mountain during adverse weather conditions (CFIT). 

The definition of CFIT as used by different organizations, varies slightly. However, CFIT can be seen as a scenario where an airworthy aircraft under the control of the flight crew is flown unintentionally into terrain, an obstacle or water, usually with no prior awareness by the crew. 

For an accident to be classified as a CFIT, it must satisfy the following criteria: 

1. the aircraft is under the control of the pilot; 
2. there is no defect or unserviceability that would prevent normal operation of the aircraft; 
3. there was an in-flight collision with terrain, water, or an obstacle; and 
4. the pilot had little or no awareness of the impending collision. 

In most cases, loss of situational awareness was one of the key contributing factors and which is specifically, the pilot’s loss of vertical or horizontal situational awareness in relation to the terrain. The greatest concern is a loss of ‘place information’. Once the pilot’s mental picture of where he is at the present time, and where he will be in the future, diminishes; his safety becomes compromised. This is particularly crucial during those phases of flight when terrain clearance is unavoidably reduced. 

All the above information describes exactly what transpired in this flight. The pilot encountered adverse weather; fog and very low clouds, he possibly became disorientated experiencing loss of situational awareness, and had little or no awareness of the impending collision. No defect could be identified in the investigation that could render the aircraft unserviceable. 

On 23 July 2006 the pilot and his son drove from Grabouw to Worcester Aerodrome (FAWC). The purpose of the trip was for the pilot to collect his aircraft, which he had left at FAWC because he could not enter Grabouw on the previous day due to adverse weather conditions. On arrival at FAWC, the son drove back to wait for the pilot at Grabouw Private Aerodrome and the pilot commenced the flight back with the aircraft. 

According to the pilot’s son, while waiting for the aircraft to land he could hear the aircraft approaching but could not see it because it was cloudy and misty. After waiting for more than 30 minutes and the aircraft not landing, he attempted to phone the pilot on his cellular phone, but without success. He then decided to contact the neighbours who live along the aircraft flight path to enquire if they had heard or seen the aircraft flying past, around or overhead. At approximately 15h30Z, when there was no news or contact with the pilot, the decision to inform the police and initiate the search for the aircraft was made. The search was not successful, and late that evening they decided to stop the search for the night. 

One of the neighbours, who is also a pilot and who assisted with the search using his aircraft the next day, stated that at approximately 14h30Z the aircraft was observed flying from a northerly to a southerly direction, heading towards the mountains. A moment later the aircraft turned back to the direction of FAWC. At approximately 14h40Z the aircraft was observed orbiting Caledon Aerodrome (FACG) which is 30 nm east of Grabouw. Between 14h50Z and 14h55Z, the aircraft was observed flying low level along the river pass, and again at approximately 15h00Z. Local weather conditions were raining, with a cloud base of 500 ft and reduced visibility. 

The next morning, when the weather had cleared, wreckage of the aircraft was found crashed into the mountain. The pilot was fatally injured in the accident. The GPS co-ordinates of the accident site were determined to be S 34º 07.877’ E 019º 05.882’, at an elevation of 2519 ft. 

IMPACT INFORMATION 

The aircraft impacted the mountainside in a straight and level attitude. The nose section impacted first, then both wings collided with rocks, followed by eruption of a post-impact fire. The aircraft was consumed by the fire. 

During the on-site investigation, the airframe could not be inspected because it was consumed by fire. The assessment of the wreckage indicated that the aircraft was still intact when it crashed onto the mountain, and there seem to have been no controllability problems. 

An assessment of the propeller indicated that the aircraft engine had full power when it collided with the mountain. The reported weather conditions in the area and the witness testimony at the time of the accident suggest that the aircraft was flying in adverse weather conditions i.e. instrument meteorological conditions (IMC) prior to the accident. According to available records, the pilot was neither instrument rated nor night rated. A possibility could be that in an attempt to maintain visual meteorological condition (VMC) flight in IMC, the pilot might have descended and flown the aircraft into the mountain (control flight into terrain: CFIT). 

JIM’S COMMENTS 

I have deliberately strayed from my normal format this month to include more detail from the full report. We have all read reports that tell us that Mr X hit a mountain in bad weather. But the purpose of these accident discussions is to bring home to readers the full impact of the accident in order to deter them from making the same mistakes. 

In this case, the human story, and the thought of the son waiting in his bakkie while he scans the grey overcast and listens for the distinctive sound of his dad’s Comanche left me with an emotional story. Hopefully it will leave readers with a powerful image that may cause some to think of their loved ones before heading into marginal weather. 

WHAT CAN WE LEARN? 

1. Takeoff is always optional. Give this a thought when things are stacked against you. 
2. If you do find yourself scud running, bring the airspeed back to 80 mph and chuck out a bit of flap. According to the times that this guy was overhead Grabouw, and then overhead Caledon – he was doing 180 mph. If you halve your speed you have a much better chance of seeing and avoiding obstacles – better still, you reduce the relative force of any impact by FOUR TIMES.