Undercarriage Failure
Undercarriage failure is a commonly reported occurrence for RAAus aircraft and may result in significant damage to your aircraft.
Thorough maintenance inspections, completion of hard landing inspections, and proactive preventative maintenance tasks may assist in avoiding undercarriage failure and serious aircraft damage before it occurs!
PREVENTING DAMAGE INCURRED FROM HEAVY LANDINGS
Maintenance Considerations
Due to the lightweight nature of RAAus aircraft, airframes and undercarriages are more susceptible to damage in the event of a hard landing. A common outcome of accidents reported as hard landings resulting in significant aircraft damage is undercarriage failure. Because of this, aircraft maintainers should pay particular attention to ensuring that thorough inspection is completed of aircraft undercarriage components during routine and scheduled maintenance. All pilots who encounter a hard landing should also ensure that a hard landing inspection is carried out by a qualified maintainer, even if no visible damage is apparent.
Maintenance requirements for the replacement of undercarriage parts should also be reviewed depending on the type of operations you conduct – If your aircraft is used in the flight training school environment, regularly operated out of a rough airfield, or conducts a high number of landings, then consideration should be made to replacing undercarriage parts more regularly than the minimum requirements specified by the manufacturer.
Human Factors Considerations
When it comes to heavy landings, the reality is that most of us have all been there, and no doubt, most of us will do again. It has been said that there are three simple steps to a perfect landing, but unfortunately, nobody knows what they are. Despite this, there are a number of ways that pilots can reduce the likelihood of encountering a hard landing accident.
- Currency and Type Familiarisation
RAAus data shows that pilot currency and/or type familiarisation is a common contributing factor in a range of accident types, including hard landing and runway loss of control events. Before operating a new aircraft type, or if you haven’t flown for a while, pilots should contact a qualified instructor who can ensure safety of flight. - Environmental Conditions
“A gust of wind came out of nowhere” is quite possibly the most common reported explanation for a hard landing. Whilst unexpected wind conditions can, and do occasionally occur, more often than not there are signs to indicate the presence of turbulence, windshear or other environmental factors on final. Weather forecasts play an important role in understanding the expected conditions, and observations such as checking the windsock and looking out for sources of mechanical turbulence including trees and hangars will also assist in building situational awareness. Pilots should maintain their personal minimums by not operating in conditions beyond their ability and should consider flying with an instructor to safely build experience in more difficult conditions or in strong crosswinds. - Go-Arounds
When all else fails, the go-around is often a pilots’ final chance to prevent an accident from occurring. A go-around can be commenced anywhere when the approach just doesn’t look right, through to immediately following a bounce during landing. It is extremely common that reports of hard landings resulting in undercarriage collapse or propellor strike report that the accident occurred due to a hard touchdown following a bounce. Pilots should always be prepared to commence a go-around during the final approach and flare, and should ensure that go-arounds are practiced regularly.
PROACTIVE MAINTENANCE – CASE STUDY
During a routine audit conducted by RAAus at one of our flight training schools it was identified that the maintainer had implemented a process to replace undercarriage bolts every 300 hours, over and above the manufacturers requirement of replacement every 500 hours.
This system was implemented following a previous occurrence during which an undercarriage attachment bolt failed, resulting in significant damage to the aircraft. As the aircraft was used within a flight training environment resulting in harsher conditions and an increased rate of landings, the maintainer implemented the system in an attempt to prevent undercarriage failure events in the future.
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