Aviation Accident Reports

Accident Reports

With Nick Heard

Accident Reports

Not so good vibrations

When a warning light falls out of the instrument panel due to vibrations, then you know it’s time to land. As Safety Editor, Nick Heard, explains, trying to fly with unreadable instruments is a big ‘no no’…

Get the vibes

During the flight the aircraft developed severe vibration, requiring the pilot to return to the airfield where fatigue cracks were found in the propeller and its two mounting blocks. The cracks originated from fretting between the propeller assembly and splines on the engine hub.

During the initial climb after take-off, the pilot noticed some subtle airframe vibration. However, due to a lack of recency on type, he could not recollect if the level of vibration was normal for the aircraft – and elected to continue the flight.

While manoeuvring, the airframe vibrations increased abruptly and to a level that the pilot had difficulty reading the instruments. 

The pilot returned to the airfield where during the taxi the vibration caused the low voltage warning light to fall out of the instrument panel.

Comment: The point to note in this incident relates to the difficulty of reading instruments when vibration is severe. 

I have experienced similar incidents and can attest to how alarming and distracting it feels when you cannot read instruments. 

In this incident the fact that the low voltage warning light fell out afterwards gives a good indication of how severe the vibration was!

Taxying checks

Two de Havilland DH82A Tiger Moths were taxying in preparation for departure. G-ALNA was behind G-ADPC.

The pilot of G-ALNA was carrying out pre-take-off checks and became distracted from maintaining a good lookout. G-ADPC stopped, and the pilot of G-ALNA was unable to stop in time to prevent a collision causing damage to the wings of both aircraft.

Comment: We have probably all been taught to carry out instrument checks during taxi-out, but I do notice pilots doing so without much interest in where they are going as they complete those checks.

The lesson is obvious.

Open cowling panel

Approximately 30 seconds after take-off, the right side of the engine cowling top panel became detached and the panel lifted up 45°, partially obscuring the pilot’s forward view. 

A PAN call was made and the pilot flew one circuit to land on the departure runway. Due to the drag of the panel the pilot made the approach with increased power and airspeed. The aircraft landed safely.

Comment: Once again the main issues in this incident are the startle factor and distraction, which the pilot expertly dealt with. Accidents have been caused by the mishandling of such minor incidents, and by subsequent loss of control of the aircraft. Keep flying the aircraft at all times!

Carbon monoxide indications

During flight the pilot noticed that the two carbon monoxide spot detectors in the cockpit had turned black indicating the presence of carbon monoxide, so he elected to make a precautionary landing on his property’s landing strip. 

After touching down, he believed he couldn’t stop before reaching the end of the grass strip and decided to go-around.

The aircraft subsequently struck a wire fence and a dry-stone wall. The pilot escaped with minor injuries, but has since elected to cease flying.

Comment: The pilot did well to notice that the carbon monoxide detectors had activated and that there was therefore a danger of poisoning from this gas. However, he unfortunately damaged the aircraft and himself in the ensuing landing, and the results could have been much worse given the nature of the landing incident.

There is a balance to be struck in how rapidly to deal with an emergency situation. In this case, perhaps, the return to the airfield to land might have been carried out a little too hastily.


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