he worse case scenario happened, which was that the engine failed.
Answers
Conventional light twins have many significant advantages over their single-engine counterparts. One of the most obvious of these is that should you be unlucky enough to experience a major engine malfunction, the other engine should carry you safely to the nearest suitable airfield.
This can be particularly significant when flying over inhospitable terrain or over water - particularly at night or in IMC conditions. However, it is also a well documented fact that should you be unlucky enough to lose an engine in a light twin during the take-off, the margins for error, especially when at higher weights, are very small. Identification of the failed engine needs to be both rapid and accurate and the propeller must be feathered whilst simultaneously keeping the airspeed at the best single engine climb speed, often referred to as “blue line” speed because of such a line often seen on analogue ASIs.
Unless the landing gear is fixed, promptly raising can be vital. Then there are 'housekeeping' matters such as retracting the flaps at the appropriate time and making adjustments to the engine controls of the operating engine. If these tasks have been performed correctly and in a timely manner, the reward will be at least no loss of altitude and, in favourable circumstances, perhaps even a positive rate of climb. However, there is little room for error and, all too often, a score of less than 100% leads to an accident.
Effects
If a multi-engine aircraft suffers engine failure when airborne, there are two immediate aerodynamic effects. The initial effect is the yawing that occurs due to the asymmetry of the thrust line. The size of this initial yawing moment depends upon the engine thrust and the distance between the thrust line and the aircraft centre of gravity.
The yawing moment is also affected initially by the rate of thrust decay of the ‘dead’ engine and ultimately by its drag. In addition, the yaw is aggravated by the drag effect of the windmilling propeller. The total moment can be very large, particularly when the airplane is at high power and low speed.
The second effect is roll. This occurs when the aircraft continues to yaw towards the failed engine resulting in a decrease in lift from the ‘retreating’ wing and a yaw-induced roll towards the failed engine. This roll is reinforced by the offset of the wings and the loss of the lift from the slipstream in aircraft with the propeller in front of the engine.
As well as the aerodynamic consequences of the failure, the performance penalty is very significant. While the failure of an engine represents a 50% loss of available power, it can result in as much as an 80% loss of performance.