Avoiding loss of control

Over the past 5 years more than 60% of RAAus fatal accidents are believed to have occurred due to loss of control events, but what do we mean when we talk about loss of control, and what are the most common scenarios resulting in a loss of control event?

At RAAus, we refer to two forms of loss of control events: • Loss of control in flight (LOC-I), and; • Runway loss of control (R-LOC)

Loss of control in flight events refer to occurrences where the aircraft operates outside of the normal flight envelope, or when normal control of the aircraft is lost during flight. These often result from failure to prevent or recover from a stall and/ or upset. This may refer to occurrences immediately after take-off, during the final approach to land, or during any other phase of flight, most commonly occurring within a turn. Loss of control events are the number one cause of fatal accident, not only within RAAus operations, but within light aircraft operations globally.

The most common cause of loss of control in flight is stall/spin events. Another form of loss of control event is entry into a spiral dive often from VFR flight into IMC which accounts for approximately 1 in 10 fatal accidents in Australia.

Runway loss of control refers to occurrences where directional control of the aircraft is lost, often resulting in a ground loop or runway excursion. Runway loss of control is one of the most common causes of aircraft damage and can often be avoided by maintaining a stable approach when landing and making an early decision to commence a go-around if necessary.

Who is at risk?

Loss of control in flight can occur to anyone. In fact, fatal loss of control accidents within RAAus operations range from low time pilots through to pilots with many thousands of hours experience. One area where the risk of a loss of control in flight is increased is during farming, mustering and low level flights or any other flight where a pilot may be focused on an object on the ground. During these operations, the pilot often commences a turn at below normal cruise speed. With an increased stall speed introduced by the angle of bank and with the pilot distracted by a point on the ground, it can take only seconds for airspeed to decrease reducing safety margins. If left unnoticed, this scenario may quickly lead to a stall. With these operations often conducted between 500-1000 feet, this often does not leave sufficient altitude to recover from a stall/spin event. Runway loss of control events occur more commonly for pilots with less than 250 hours total flying experience, or with low experience on aircraft type. In many cases these occurrences are linked to unstable environmental conditions such as turbulence or gusty wind conditions, or occur during the mismanagement of a hard or unstable landing. Pilots are reminded of the importance of electing to conduct a go-around if they are not stable on final approach or if they encounter a bounce upon landing. Early decision making could have undoubtedly saved many an aircraft from a runway loss of control event, and unfortunately, could have also saved lives.

Loss of control in flight

Loss of control is a broad category of occurrence which may occur due to a number of different factors. The most common scenario is inadvertent entry into stall and in many cases, is followed by entry into a spin.

So let’s take a look at some of the most common scenarios:

1. Loss of control after take-off Loss of control after take-off may occur due to a number of different reasons. The first of these is due to the failure to conduct appropriate performance calculations based on weight, density altitude or surface conditions. This may result in decreased take-off performance leaving the pilot unable to clear obstacles on departure, or insufficient runway available for the take-off. During this situation pilots may instinctively pull back on the controls in an attempt to clear obstacles, resulting in an unrecoverable stall.

Another cause of loss of control after take-off is when the aircraft encounters an upset due to environmental conditions or when the pilot is distracted, allowing the aircraft to become too slow during the climb out or turn onto crosswind. Failure to identify and prevent a stall during this phase of flight often leaves insufficient altitude for safe recovery from a stall.

2. Loss of control in the turn Loss of control events commonly occur in the turn due to the increase in stall speed with an increased angle of bank. One scenario where this may be emphasised is during the base to final turn where a pilot overshoots the centreline. The tendency in this scenario is to increase the angle of bank and apply more rudder to regain centreline, however in doing so, the result may be an uncoordinated, high angle of bank turn at low speed which may lead to a spin.

It is highly important that pilots recognise the increase in stall speed in the turn and avoid conducting steep turns at low airspeed and/ or low altitude. Pilots should ensure they apply power when increasing angle of bank to minimise airspeed loss during the turn.

Assuming a 40kt stall speed, if the pilot enters a 60deg turn, the stall speed is now 56kts.

If your aircraft has a stall speed of 40kts and you are approaching to land at 50kts then entry into a 45 degree turn onto base or final already significantly decreases your margin of safety with stall speed increasing to 48kts. If the angle of bank is further increased to 60 degrees, such as in the case of overshooting the runway centreline, then the stall speed increases to 56kts and the aircraft may encounter a stall. This may all happen in a matter of seconds resulting in a loss of control.

It is for this reason that the risk of encountering a loss of control is increased during farm flying operations or any flight where the pilot is circling a point on the ground. With the pilot focusing on a point outside the aircraft it is easy to become distracted, slowly increasing the angle of bank and failing to identify a reduction in airspeed. This may be further exacerbated by an unbalanced turn increasing the likelihood of encountering a spin.

Pilots conducting farm flying or spotting operations are highly encouraged to talk to your instructor about further training available to develop essential skills for conducting these operations.

3. Loss of control following engine failure Another common cause of a loss of control is following an engine failure. This is particularly important during an engine failure after take-off, where the aircraft is established in the climb. When an engine fails during this phase of flight, the pilot has little time available to immediately lower the nose in order to establish and maintain best glide speed. Failure to act immediately following an engine failure after take-off may result in a stall with insufficient altitude to

recover. Pilots should ensure they carry out a pretakeoff safety brief to rehearse the actions in the event of an engine failure after take-off and avoid the temptation to turn back towards the runway which increases the likelihood of a loss of control.

4. Loss of control during the go-around The go around is another scenario in which loss of control events commonly occur. These occurrences often occur due to a late decision to conduct a go-around when the pilot is attempting to quickly regain a climb. The tendency here is to apply full power and immediately pitch upward into a climbing attitude. This may be further complicated by trim settings and managing yaw from the increase in power.

It is important that pilots regularly practise goarounds remembering that the first phase is to achieve level flight to increase airspeed, then to commence a climb. Wherever possible, pilots should make an early decision to commence a go-around rather than leaving this to the last possible opportunity. When was the last time you practiced a go-around?

Tips to avoid loss of control events:

1. Stall recognition and recovery Do you know the signs of a stall? What are the characteristics specific to your aircraft? When was the last time you practised stalling? Stall recognition and recovery is the best method of avoiding loss of control events. If you feel like you may be a little rusty, why not contact your local instructor to practise stalls or conduct more advanced training. In addition to this, aircraft owners should consider fitment of a stall warning device as a last line of defence against encountering a stall.

2. Emergency drills Pilots should brief themselves on the actions in the event of an emergency prior to each and every flight. This includes the actions in the event of an engine failure after take-off, during which the first action must be to lower the nose. Pilots should regularly review emergency procedures and practise forced landings to familiarise themselves with the actions to be taken in the event of an emergency.

3. Performance Pilots must consider performance calculations relevant to their aircraft prior to every take-off and landing. It is important that pilots understand and consider the effects of weight, temperature, density altitude, and runway surface prior to each take-off and landing and always use full available runway length, even when you know sufficient length is available.

4. Distractions Pilots must continue to manage distractions during all phases of flight, however, this is particularly relevant at low altitudes. Pilots should ensure distractions are minimised wherever possible below 1000ft AGL, such as managing devices and communicating with passengers. Particular attention should be made to avoid becoming fixated on a point outside of the cockpit. Operations such as farm spotting or flying around a particular landmark are a common cause of loss of control events where the pilot is distracted and fails to identify increasing angle of bank and/or decreasing airspeed, leading to a loss of control.

5. Environmental Conditions Pilots should conduct thorough pre-flight briefings including review of weather forecasts, even if only conducting a local flight. Pilots should ensure conditions are within their personal limitations based on their total experience or hours on aircraft type. In the event that the pilot encounters turbulence or windshear during final approach, a go-around should be conducted to avoid a potential hard landing or loss of control.

6. Airspeed Pilots should be familiar with important airspeeds and limitations contained within the pilot operating handbook for your aircraft and ensure that these speeds are flown accurately at all times. If operating in gusty or thermal conditions, add a buffer to climb-out and approach speeds to offer an additional margin of safety. In the event that a stable approach is not maintained on final, pilots should elect to commence a go-around. Every year a number of loss of control events are reported which may have been avoided by an early decision to commence a go-around.