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.
Assuming a 40kt stall speed, if the pilot enters a 60deg turn, the stall speed is now 56kts. Angle of Bank
Load Factor
% increase in stall speed
Example stall speed
0
1
0
40
45
1.4
20
48
1. Loss of control after take-off
60
2
40
56
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.
75
4
100
80
So let’s take a look at some of the most common scenarios:
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. The following table shows the increase in stall speed with an increase in load factor.
6
From the information above, 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
