ENGINE FAILURE AFTER TAKE-OFF: SINGLE-ENGINED AIRCRAFT (PART 1)

 Acknowledged Source: Australian Transport Safety Bureau

Ed.Note: Extracted from the excellent booklet on the subject published by the ATSB

Historically, simulated total loss of power and subsequent practice forced landing has been the core of a pilot’s emergency training. The data, however, shows that during and after take-off, a partial power loss is three times more likely in today’s light single-engine aircraft. There have been nine fatal accidents from 2000 to 2010 because of a response to a partial power loss compared with no fatal accidents where the engine failed completely.

One reason could be the more challenging nature of partial power loss, due to the choices and decisions that must be made immediately. Another possible factor is training. Total engine failure after take-off is part of the VFR syllabus. Partial power loss after take-off is not a specific syllabus item and may not receive the same emphasis during training. Analysis of the occurrences supports the need for greater awareness of the hazards associated with partial power loss and to better train pilots for this eventuality.

Following a complete engine failure, a forced landing is inevitable, whereas in a partial power loss, pilots are faced with making a difficult decision as to whether to continue flight or to conduct an immediate forced landing.

Most fatal and serious injury accidents resulting from partial power loss after take-off are avoidable by using the strategies below:

1.   Pre-flight planning for emergencies and abnormal situations at the aerodrome:

·       the possibility of a partial engine power loss.

·       the runway direction and the best direction of any turn.

·       the local wind strength and direction on a particular day.

·       terrain and obstacles.

·       decision points where different landing options will be taken (based on current aircraft height and performance), such as landing on the remaining runway or aerodrome; landing outside the aerodrome; conducting a turn back towards the aerodrome.

2.     A thorough pre-flight check and engine ground run:

·       This includes engine and fuel system components. Some partial power loss occurrences had engine abnormalities which were identified by the pilot during high RPM engine run-ups prior to take-off. Checking for an RPM ‘drop and hold’ after carburettor heat application and checking and comparing individual magnetos for a specified RPM drop range are simple but important steps in preventing a partial engine power loss.

·       The appropriate selection of fuel tank before take-off.

·       Ensuring that fuel drains are not left open or leaking.

·       Fuel caps on and closed correctly could allow the detection or prevention of fuel-related partial power loss occurrences, which are associated with engine surging. This unpredictable form of partial power loss often leads to complete engine failure.

·       Be mindful of the fuel system fitted to the aircraft and the relevant engine manufacturer’s requirements. There have been partial power loss events where it was probable that a partially selected fuel tank or inappropriate selection led to a fuel starvation event. This is particularly applicable to aircraft with more than two fuel tanks.

3.   The take-off self-brief:

·       This is generally conducted once all engine run-ups are complete, just prior to taxiing to the holding point for take-off. It serves as a reminder of your original plan, and helps in responding to an abnormal or emergency situation. If you self-brief your plan of action just before flight, you have more chance of ‘staying ahead’ of the aircraft and being able to concentrate on flying.

·       Take into account the current wind speed and direction and the aerodrome surroundings when considering forced landing options, and include consideration of a complete engine failure. If considering turning back toward the aerodrome, forced landing options along the flight path should be considered, while keeping in mind that if any wind is present, the groundspeed will be increased when on downwind.

4.   The take-off run:

·       Incorrectly set power controls, such as the propeller not set to full fine, the mixture not set to full rich3, or carburettor heat not selected to off, because of missed or forgotten checks, can also lead to a partial loss of power.

·       An engine power abnormality may not be detected until engine run-ups or the application of full power on take-off. The aircraft acceleration should be monitored along the runway to ensure it is as expected. In some occurrences, partial engine power loss symptoms were present before rotation on the take-off run, ranging from misfiring to a static RPM reading less than the recommended minimum level, or sluggish acceleration. Pilots reported that they had noticed symptoms of an abnormally performing engine but had continued with the take-off as they did not consider that an engine failure or partial engine power loss would occur.

·       Use the entire runway length instead of making an intersection departure. This allows a greater possibility of landing on the remaining runway or field if an engine failure or power loss occurs.

5.     Managing a partial engine power loss after take-off:

·       Taking positive action under conditions of stress, uncertainty, high workload, and time pressure, and maintaining aircraft control until on the ground, either when turning back to the aerodrome or conducting a forced landing, while being aware of flare energy and aircraft stall speeds.

·       Maximise your height or minimise your distance. Climbing out at the manufacturer’s recommended ‘best rate’ or ‘best angle’ speeds, depending on your aircraft and location, will maximise your options if a partial power loss or engine failure occurs.

·       Lower the nose to maintain the glide speed of the aircraft.

·       Conduct the basic initial engine trouble checks as per an engine failure5 in accordance with manufacturer’s advice. However, this should be done only if there is sufficient time.

·       Maintain glide speed and assess whether the aircraft is maintaining, gaining or losing height to gauge current aircraft performance.

·       Fly the aircraft to make a landing. If turning, keep in mind an increased bank angle will increase the stall speed. Keeping the aircraft in balance will minimise rate of descent in any turn.

·       Have a minimum planned turning height; CASA suggests a minimum height of 200 feet AGL for rolling wings level.

·       Re-assess landing options throughout any manoeuvres. Be decisive but be prepared to modify the plan if required.

·       Maintain glide speed up to the point of flare to ensure that when flaring there is enough energy to arrest the vertical descent rate. 

Part 2 to follow......