Forced Landings

The unexpected should not go unplanned

December 1, 1992

There is no question that a forced landing, like a midair, can spoil your whole day. An unscheduled off-airport landing will, at best, turbocharge your adrenaline-pumping system and challenge your piloting skills, and you'll probably get your shoes muddy as well. There is also the experience of being responsible for an airplane that is neither in flight nor on an airport.

Forced landings happen in all types of airplanes, too. Just thinking about jet airliners for a moment, I came up with five in North America. In all types, there is a number-one cause available for viewing in any mirror. The only statistics available on forced landings come from the ones that result in enough aircraft damage to be classified as an accident. In these, well over half are caused by the pilot using all the fuel, trying to run on a tank that has no fuel, or failing to pull the knob labeled "carburetor heat" at the proper time. About a fourth of the forced landings are due to mechanical or maintenance-related causes. Using the available numbers, there appears to be a forced landing accident about every 200,000 flying hours. Events that don't result in much damage to the airplane are not included in that figure.

There are some logical outcomes to forced landing accidents. The size and the stalling speed of the airplane have a direct bearing on the severity of the event. In fixed-gear singles, fewer than 5 percent result in serious or worse injuries to occupants. The number doubles in single- engine retractables, and in twins, more than a fourth of the off-airport landings involve injuries. Of the jet airliners I recalled being involved in off-airport landings, a full 80 percent were truly serious accidents. The one that wasn't, an Air Canada 767 that ran out of fuel, appropriately had one crewmember on board who was an experienced sailplane pilot, and the airplane was dead-sticked into an abandoned airfield.

When examining a broad sample of forced landing accidents, some other things stand out. While there are more Cessna 172s in the fleet than 150/152s, the latter were involved in 26 percent of the forced landing accidents where the 172 was involved in fewer than 10 percent. It thus stands to reason that student pilots have more forced landings than other pilots. The fact that a lot of these are fuel exhaustion accidents should alert flight instructors to examine their emphasis on fuel management.

Almost half of serious forced landing accidents in singles and twins occurred during or right after takeoff as the pilot attempted to return to the airport and land. In twins, this can be expanded to include trying to make the airplane fly on one engine when the performance simply isn't there. In either case, the result was a loss of control.

Fourteen percent of all forced landing accidents that occurred in the daytime were serious; the number rose to 20 percent at night and to 25 percent in instrument meteorological conditions.

Almost everyone facing an off-airport landing tries for a field (so you can get your shoes muddy), and in the sample studied, those accidents proved not to be serious. Of those who ended up in the trees before reaching the field, more than 20 percent were serious. Road landings generally worked okay, but airplanes that wound up in wires or residential areas fared poorly.

If you think one brand of engine is more reliable, consider that Continental and Lycoming engines are about equal when it comes to the number involved in forced landings.

With that background, let's consider how to avoid forced landings and how to behave should one become unavoidable.

More than half the exposure to the risk goes away when you keep fuel in the tanks, manage the fuel properly, and remember the carburetor heat. Fuel contamination accounts for another 10 percent, so draining those sumps and checking the purity and correctness of the fuel is an important event. The only other cause that has a big number is related to mechanical items.

Reading the accident reports, it becomes evident that a lot of pilots apparently skimp on maintaining their airplanes, and a lot of pilots take airplanes flying when an engine or they are not running well. Poor maintenance is something we will likely see more of as the fleet of airplanes ages and the cost of maintenance increases dramatically in relation to the total value of the airplanes. If there is any question about the condition of the airplane or the engine, best not take it flying. If the airplane is yours, look for the best shop, not the cheapest.

An item of equipment that can help avoid some problems is an exhaust gas and cylinder head temperature measuring system that gives information from every cylinder. Any anomaly noted might send you to the nearest airport instead of waiting for a loud noise, followed by silence, and then a trip to the nearest cornfield. The devices can't warn of all failures, such as a broken crankshaft, but they would probably send a signal about the majority of problems that lead to engine failure.

Even if you take all the precautions, the possibility exists that you might wind up having to land an airplane away from an airport or perhaps on an airport within gliding distance. Is there a best way to prepare for and do this?

One of the best safeguards is to have and wear a shoulder harness. Without one, any stop other than a gentle one will result in your face looking a lot like the instrument panel. In a sudden stop with only a lap belt, the body bends in the middle as the torso goes forward and upward. Then, when the stretch in the belt and in your tightly muscled gut is reached, your head goes for your feet — except for the fact that the instrument panel gets in the way. Shoulder harness kits are available for most airplanes now, and to fly without this equipment is to not really care about the outcome of anything other than a routine landing.

If an engine fails or loses power, don't give up on it right away unless the condition is obvious such as the propeller stopping with a clunk or there is no longer fuel on board. Change everything that can be changed. Switch tanks, switch magnetos (if one mag fails, it might send sparks in all the wrong directions — taking that mag out of the loop might restore power), experiment with the mixture and the fuel pumps — do whatever the check list says. "Engine failure in flight" is one portion of the check list that needs to be in memory for instant recall.

If you are unlucky enough to have an engine fail, perhaps you are lucky enough to have an airport within reach. The proliferation of loran sets with the "nearest airport" feature means a lot of pilots can know in a flash what is available and how far they have to limp or glide to reach that airport.

The goal in an off-airport-landing attempt is to arrive at whatever surface is available with the airplane going as slowly as possible but still well under control. Out-of-control arrivals of the stall/spin variety in any airplane or the loss of control due to asymmetric thrust in twins most often result in serious damage to the airplane and its occupants. Some passengers survived in the Southern Airways DC-9 that lost both engines in a hailstorm because the pilots maintained control of the airplane and made a successful touchdown on a road, even though obstructions on each side of the road caused the airplane to break up. If control hadn't been maintained until touchdown, nobody would have survived.

What is the best place to land? A field is always preferable. Roads might be attractive because they are paved, but roads have wires along them and cars and trucks and other obstructions. If you land on a road and strike an automobile and hurt someone else, you might spend a lot of time in court later on, too. You could be held at fault for any damage done to persons or things on the ground. If there is any good road landing site, it might be the median of an interstate, but those are not always friendly; control of the airplane could be lost, and you could wind up in the ground-bound person's space.

As long as control is maintained and the field is not strewn with unavoidable boulders, the outlook is good. If you are in a retractable, should you leave the gear up or put it down for a random field landing? The pilot's operating handbook for my Cessna 210 says the gear should be down unless the terrain is rough or soft. Unfortunately, in a forced landing, we do not get to sample the terrain before we touch it, so this leaves the question open. Certainly in a 210, the landing gear would provide shock absorption. Were it to be removed from the airplane by something, like a large rock, the landing gear would just be pulled from the fuselage. With wing-mounted landing gear, you would have to consider that the destruction of an extended landing gear might rupture a fuel tank. The position of the landing gear in an off-airport landing would have to be an individual decision, based on the airplane and whatever knowledge you might gain about the surface available for landing.

What about speed? The objective is to touch at minimum controllable speed, but if the choice is between losing control because of a lack of airspeed and touching a few knots faster than minimum, the latter would be preferable. The normal approach speed of the airplane would be the best target in most cases because it gives a good margin above the stall. The final approach and touchdown should be normal, too, for as long as possible. It goes without saying that the airplane should be maneuvered in a manner that avoids hitting any obstructions with the fuselage, if possible.

With no power available, a plan is required to take maximum advantage of the potential energy available, which is in the form of altitude. The two main ingredients are the airplane's gliding ability and the wind. For example, with no wind, my airplane will glide 1.5 miles for each 1,000 feet of altitude lost. I can make it glide less than that by adding the drag of the landing gear or flaps or by slipping, but unless I can find a source of lift, there is no way I can make it glide farther than that. The plan would thus be to visualize distances and plan the approach so that it would be a bit high with the airplane clean, and then use the added drag to fine-tune the approach to the desired landing spot. The effect of wind on the glide is important, and landing into the wind lowers the touchdown speed and reduces the risk.

It could be argued that, unless distance is needed to reach the landing site, the best thing to do is get the gear and flaps down and adjust the flight path to reach the desired spot. That works, too, unless you find some settling air out there and need to increase the gliding distance. If in a retractable, the gear can be raised, and in some airplanes with constant-speed propellers, the prop control can be moved to the low rpm limit to reduce drag. Retracting flaps once they are extended is less desirable because retracting flaps raises the stalling speed, so you have to increase the approach speed. This costs altitude.

Some emergency check lists call for unlatching the door before touchdown. There are usually other items on the forced landing drill, too, and the list should be followed.

There is no question that if a forced landing is to occur, it best be on a clear day over the Great Plains. Of course, that's not always the case. Until the airplane has gained some altitude after takeoff, the options might be few. The proven killer is turning around and trying to return to the airport. You can practice this at altitude, but remember that it could take a lot more altitude to complete the turn at low level, and it takes a lot more than 180 degrees of turn to get the airplane back to the runway. Wind shear could be a big factor as well.

The best precaution is to gain as much altitude as possible as soon as possible after takeoff. Also, know the pitch attitude you must go to in the takeoff configuration to maintain a safe airspeed should the engine fail. Some of the rotation speeds given in POHs are quite low, very near the stall for the takeoff configuration, so if the power disappears early in the initial climb, you have to be quick on the attitude. The POH on my airplane says to rotate at 65 to 70 knots; 65 knots is the stalling speed at maximum weight and mid-CG in the takeoff configuration. A failure soon after liftoff would result in a plop back onto the runway or worse — if the POH speed is used.

A forced landing could ruin your whole night just as it could your whole day. What's the forced landing procedure to use when it is dark? Theories abound. One is to head for a dark spot. Then, when a few hundred feet high, turn on the landing lights. If you don't like what you see, turn them back off. That "theory in jest" has been around for years, but it probably has as few holes in it as any. I think I would leave the lights on, though, to try to make the most of what is seen, like it or not. When accident records are studied, most night forced landings appear to occur in random locations, none of which sound very good. Imagination would suggest that many times more night forced landings would be serious when compared with day events, but perhaps the relatively low stalling speeds of our airplanes, coupled with keeping them under control on a dead-stick approach and taking whatever comes along, works to some extent.

If the engine quits in IMC, the drill is to establish a glide and hope for some time and visibility beneath the ceiling. If there is no ceiling or it is limited, you'll have to glide into whatever is there. If over mountainous terrain, knowledge of ridge orientation would be essential, so you could plan an arrival on a heading parallel to the ridges.

In any of these cases, compare what is about to happen with an automobile wreck to cheer yourself up a little. Unless you are unlucky and fly into a brick wall or other unyielding surface, an in-control touchdown in an airplane should result in a gentler stop than in a car-to-car collision, even with both cars going at moderate speeds. In an airplane, as long as the approach speed or sink rate is not too high and the deceleration can be spread over a little distance, the main damage should be limited to bruises from the belts and other relatively minor things. Plenty of crushable stuff separates you and the obstructions to cushion the arrival. On a single, it helps that the engine, the heaviest item on the airplane, is leading the way.

Finally, there's the paperwork. If the airplane is substantially damaged or anyone gets hurt, you are supposed to immediately notify the National Transportation Safety Board. Presumably a call to the Federal Aviation Administration would accomplish this. Later, a written report might be required. Then there is the insurance company. Policies differ; mine says that I have to do everything I can to protect the airplane from further loss or damage and that the insurance company will reimburse me for all reasonable expenses I incur in doing this. Presumably that means I should find a Rent-A-Cop to watch over the airplane until it can be taken to a secure spot. Then, all that's left is to clean up those muddy shoes and catch a bus home.