Emergency and Precautionary Landings — Page 208, Lesson 301

I want to walk you through the start of the chapter on Emergency and Precautionary Landings. This is a critical topic because, as a professional pilot, you will be trained to handle situations where continuing the flight is no longer the safest option. Let's begin with the core idea. During the progress of an emergency situation, it may become evident that it is desirable to abandon further flight. Clearly, where this is done, it should be achieved with the minimum risk to the crew and passengers and, where possible, to preserve the integrity of the airframe — that is, to keep the aircraft structure as intact as we can. Now, the variety of situations we face is broad. They range from minor restrictions of performance — things that limit how well the aircraft flies but don't immediately threaten it — all the way to major, or catastrophic, structural failures or total propulsion system failures. A catastrophic structural failure means a major part of the airframe has failed; total propulsion system failure means you've lost all engine power. A key factor here is the speed with which a situation deteriorates. That speed will often dictate the action to be taken. But where possible, consideration should be given at an early stage to landing the aircraft whilst full control — or with only minor limitations to performance — remains with the pilots. In other words, don't wait until you've lost control; if you see trouble coming, land early while you still have good control authority. In the extreme, total engine failure or severe structural failure will necessitate immediate landing, providing the attitude of the aeroplane can still be controlled. "Attitude" here means the aircraft's orientation in pitch, roll, and yaw — if you can still keep it pointing the right way, you can attempt a landing. If there is no airfield immediately available, then the aeroplane will have to be landed either on unprepared land — that's any flat-ish ground that isn't a runway — or on the surface of the sea. In any such event, procedures will be laid down in the OM, type specific. OM stands for Operations Manual, and "type specific" means the manual for the exact model of aircraft you're flying. That manual will cater for the situation of an emergency landing or ditching. "Ditching" is the specific term for landing on the surface of the sea. Now, there is a critical general rule that applies to all aircraft, unless otherwise stated in that type-specific manual. For an emergency landing on land, undercarriage should be down — you want the landing gear extended to absorb the impact on solid ground. But for all landings on water, the gear must be up. Why? Because extended landing gear would dig into the water, cause the aircraft to flip or break apart violently. With the gear up, the fuselage bottom can act like a boat hull, giving a much better chance of survival. Let's look more closely at ditching itself. During design, the ditching characteristics of the aeroplane will be explored fully. The manufacturer will test and calculate final attitudes, speeds, and configurations that would give the best chance of the airframe surviving the ditching. "Attitudes" here means the pitch angle at which the aircraft should hit the water; "speeds" means the indicated airspeed; "configurations" means things like flap setting and whether the gear is up or down. Statistically, ditching is generally successful, although subsequent survival — that is, surviving after the aircraft has come to rest in the water — is a separate challenge that we'll cover as the chapter continues.