| How To Prevent a Forced Landing |
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| Written by Ray Leis |
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If you have ever experienced it, you’ll never forget it. A real one is a heart grabber. Forced landing! You’ll always remember clearly how it first started. The smooth, growling engine missed a beat, then missed again. Next, there were short periods of silence, followed by total silence. Or, it might have been slowly rising cylinder-head and engine-oil temperature, followed by a loud banging and clanging, then silence. There are pilots who will tell of their experiences with emergencies like these that happened 25 years ago. They begin to tremble slightly, and their voices sound strained as they talk about it. It’s a permanent memory. Long before the engine is started, many takeoff accidents could be avoided by the pilot making a careful pre-flight. If you are flying an aircraft that is parked in tie-downs –especially the leaseback, club and rental airplanes–you should give them a very careful pre-flight. One thing that happens quite often with club or rental aircraft is that squawks and discrepancies aren’t noted carefully (or at all). Either the pilots are in a hurry, or they are hesitant, because they feel they might be blamed. A careful use of the checklists can uncover many errors of omission and possibly help catch some new commission errors, too 
Every type of travel involves some form of risk-taking. The PIC of every flight is expected (by FARs) to be able to understand and evaluate flight risks. Risk management by the pilot means that he or she knows his or her personal limitations and capabilities and those of the airplane he or she is flying. The pilot should only accept risks that will allow the flight to reach its goal safely.
Start With Pre-flight How do you prepare to avoid the unexpected? An excellent place to start things off in the right direction is the pre-flight inspection. If you don’t own the airplane, it’s a good idea to look over the engine and airframe records closely. What squawks have been recorded? Can the A&P mechanic show you what repairs have been made to return the airplane to airworthy condition? Careful use of checklists can help catch new problems, and make certain that any critical items are not overlooked. There are pilots who forget to release all of the control locks during run-up, and attempt to take off with red-flagged jammed controls. Other pilots forget to remove the pitot tube covers, and start their flight without an airspeed indicator. Care needs to be taken not to develop a trust in what should or ought to be. A worn-out tire is a worn-out tire. It’s an unnecessary risk. Marginal fuel is an invitation for big trouble. Oil quantity that is too low for safe engine operation may result in engine stoppage. Weather forecasts are correct. They never improve as you fly toward your destination. Wishing and hoping won’t make it so, unfortunately. All certificated pilots have been tested on these points. Sometimes they forget. No matter how new and sophisticated, never trust the fuel-quantity gauges. Rely on the visual check or your known consumption. How many pilots drain the sumps before a flight and then smell the sample before throwing it away? A cup of fuel and a cup of water, under certain light conditions, look exactly the same. You won’t have trouble smelling the difference. If your airplane has been topped with jet fuel, it will smell like kerosene. Fuel-valve selectors can throw off the unwary pilot also. If you are in an unfamiliar airplane, you want to know exactly (visually and by feel) the proper detent positions of the selector. It’s usually a safe idea to cycle the fuel-valve selector through all of the possible positions and lock it in to the detent before engine start. Is the valve selector tight? Try it. They can come off in your hand at exactly the wrong time. One of the most comprehensive studies of aircraft accidents ever made was done by the NTSB over a five-year period. They evaluated the causes of 4,310 fixed-wing General Aviation aircraft accidents, which had developed from engine failure or malfunction. The PIC was blamed in 51.81 percent of the engine-failure accidents, and the powerplant got the credit for 44.62 percent of those accidents. The PIC was at fault for 2,281 accidents for these reasons: • Inadequate pre-flight - 934 • Fuel mismanagement - 615 • Improper operation of powerplant - 504 • Improper in-flight decisions/planning - 127 • Pilot became lost or disoriented - 101 These following engine problems were blamed for 634 accidents: • Valve assemblies - 130 • Carburetor - 102 • Master and connecting rods - 86 • Cylinder assembly - 72 • Piston/piston rings - 70 • Magnetos - 64 • Crankshaft - 57 • Spark plugs - 53
Starting and Run-Up Check It’s safest to start on one set of tanks, then taxi and run-up on the primary (main) tanks. Once you have checked all the tanks feeding, after the engine run-up, you can leave “well enough alone.” Another potential troublemaker is the auxiliary fuel pump. If your POH calls for it to be on, as a back-up to the engine-driven fuel pump, it may not actually be on even if the switch is in the correct position. To be sure, when you kick on the switch, check for a “spike” in the fuel pressure reading, or watch for a drop in the ammeter. In some cases, you can listen for the sound of the pump, before the engine start. If you are flying IFR, you should add the vacuum gauge to the power check. If the suction isn’t where it should be, that’s enough reason to abort an IFR flight.
60 Seconds for Survival Takeoff is where everything needs to work as expected. It’s the critical part of any flight. The pilot must be capable of peak performance through this very narrow time period. In those first 60 seconds of flight, all of the mechanical, electrical, hydraulic, and pneumatic systems need to function perfectly. The airplane is most at risk when it is slow and close to the ground. Once the runway is behind, any major system failure may leave the pilot with no place to go but straight ahead. There are fewer margins for error during takeoff than any other phase of flight. If a system fails in cruise or during an approach, the pilot may have some time to deal with the problem, before the emergency off-airfield landing is inevitable. If the same system fails during the takeoff phase, the pilot will have to make instant decisions to survive. Highly experienced pilots sometimes get in trouble on takeoff. Pilots who have been able to fly several thousand hours without any major takeoff emergencies may assume that, because it has never happened, it never will. One way to make sure that it won’t is to understand all the systems and the condition of the aircraft you are going to fly. |