Well Executed Emergency Crash Landing a Cessna
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Attempting to decide between grass and tarmac isn't so simplistic. Flat grass with hard ground beneath is possibly a better option, but not much, and as has been mentioned, as soon as dirt and grass enter the structure (which will generally tear open anyway), it can do more damage than a prepared surface. If the ground beneath the grass is soft and wet, then a substantially lower expectation of a successful landing can be had, to include flipping the airplane or groundlooping. A high speed groundloop can cause significant injuries to occupants, especially neck injuries, and can cause additional airframe damage. One can expect the airframe in many cases to be twisted, which may mean difficulty or impossibility in opening the airframe doors (one more reason to have them open before impact).
Stopping the propeller sounds heroic, but you'd feel rather silly if you didn't make the runway, had to go around, or needed power for some reason. I don't know how many of you have ever actually made a forced landing (not a training landing while practicing in the traffic pattern) without power...but it's not really the same as having your flight instructor casually pull the power to idle while on the downwind. Not at all. You get one shot at it. Add to it the stress that can come with the actual emergency in progress, and your chances of making a successful forced landing go down; you complicate a situation that's already got your attention. How many of you have made engine-failed landings? How many have done forced landings during an emergency? Or precautionary emergency landings? Probably not too many. Do you want to complicate it further by attempting to concern yourself with stopping the propeller? No, you don't.
As for foaming the runway...water flows until the foam injection takes place. The foam is NOT doing more harm than good, and is NOT harming the aircraft, nor the occupants. It is NOT causing corrosion. It is there in the event of a fuel leak or spill, and has the added benifit of cooling action. The primary use of the foam is to act as a vapor barrier to prevent ignition or a flash fire. In a gear up landing, seeing sparks and seeing things get hot is very common, due to friction with the surface.
Don't get wrapped around the axle trying to save the airplane or save the propeller or engine. Your priority is to save yourself and to get the airplane on the ground. Get it stopped comfortably. If the engine is damaged or the airplane is damaged in the process, this is not your problem. You didn't create the emergncy, but even if you did, your sole mission as pilot in command is safety of flight. Don't get carried away with trying to be fancy. No stopping the propeller. No having mechanics drive beneath the airplane and pulling the gear down by hand. None of that. You know how to make a landing; do that. A stable, normal landing, just like you do every time. Make the situation as routine as possible to create the greatest opportunity for things to unfold normally, and give yourself the greatest possiblity of success.
Don't worship the checklist. Pilots tend to think that because something is written in the checklist, God Almighty has decreed it. This is not so. It's a bit of paper that includes a litany of things to accomplish...something to review to ensure you've managed to do all you need to do. It is not written by the finger of Jehovah in stone. If the POH or checklist tells you that landing on grass is the best choice, remember that the writer of that checklist isn't in the airplane with you, nor could that person possibly have known the condition of the surfaces on which you intend to land right now, this very second. Only you can make that choice...right now, this very second.
Grass, when wet, is much like ice. Very slick, and landing on wet grass can mean a much longer rollout, no control, little braking action, and a loss of directional control once you're down. A smooth, hard surface that's free of obstacles will not catch on the airframe nor tear it apart, and gives you a clear area in which you have a much higher level of safety. Emergency vehicles can access you on the hard surface. You can receive support. Fuel doesn't soak into the ground beneath you where it can burn and resist being put out. Foam is more effective on a hard surface, far less effective on a dirt or grass surface, and has a longer life on the runway than off. Putting water and foam onto the ground in the dirt or grass means the surface around the airplane deteriorates. Attempts to approach or exit the aircraft are made more difficult, and should a fuel spill be a problem, grass, weeds, and other things in the dirt penetrate the foam layer and create a greater liklihood of a fire by exposing the fuel beneath to the atmosphere.
See the big picture when you plan for these events, and remember that the time to plan for them isn't when it's happening. It's right now, while you read this thread.
Stopping the propeller sounds heroic, but you'd feel rather silly if you didn't make the runway, had to go around, or needed power for some reason. I don't know how many of you have ever actually made a forced landing (not a training landing while practicing in the traffic pattern) without power...but it's not really the same as having your flight instructor casually pull the power to idle while on the downwind. Not at all. You get one shot at it. Add to it the stress that can come with the actual emergency in progress, and your chances of making a successful forced landing go down; you complicate a situation that's already got your attention. How many of you have made engine-failed landings? How many have done forced landings during an emergency? Or precautionary emergency landings? Probably not too many. Do you want to complicate it further by attempting to concern yourself with stopping the propeller? No, you don't.
As for foaming the runway...water flows until the foam injection takes place. The foam is NOT doing more harm than good, and is NOT harming the aircraft, nor the occupants. It is NOT causing corrosion. It is there in the event of a fuel leak or spill, and has the added benifit of cooling action. The primary use of the foam is to act as a vapor barrier to prevent ignition or a flash fire. In a gear up landing, seeing sparks and seeing things get hot is very common, due to friction with the surface.
Don't get wrapped around the axle trying to save the airplane or save the propeller or engine. Your priority is to save yourself and to get the airplane on the ground. Get it stopped comfortably. If the engine is damaged or the airplane is damaged in the process, this is not your problem. You didn't create the emergncy, but even if you did, your sole mission as pilot in command is safety of flight. Don't get carried away with trying to be fancy. No stopping the propeller. No having mechanics drive beneath the airplane and pulling the gear down by hand. None of that. You know how to make a landing; do that. A stable, normal landing, just like you do every time. Make the situation as routine as possible to create the greatest opportunity for things to unfold normally, and give yourself the greatest possiblity of success.
Don't worship the checklist. Pilots tend to think that because something is written in the checklist, God Almighty has decreed it. This is not so. It's a bit of paper that includes a litany of things to accomplish...something to review to ensure you've managed to do all you need to do. It is not written by the finger of Jehovah in stone. If the POH or checklist tells you that landing on grass is the best choice, remember that the writer of that checklist isn't in the airplane with you, nor could that person possibly have known the condition of the surfaces on which you intend to land right now, this very second. Only you can make that choice...right now, this very second.
Grass, when wet, is much like ice. Very slick, and landing on wet grass can mean a much longer rollout, no control, little braking action, and a loss of directional control once you're down. A smooth, hard surface that's free of obstacles will not catch on the airframe nor tear it apart, and gives you a clear area in which you have a much higher level of safety. Emergency vehicles can access you on the hard surface. You can receive support. Fuel doesn't soak into the ground beneath you where it can burn and resist being put out. Foam is more effective on a hard surface, far less effective on a dirt or grass surface, and has a longer life on the runway than off. Putting water and foam onto the ground in the dirt or grass means the surface around the airplane deteriorates. Attempts to approach or exit the aircraft are made more difficult, and should a fuel spill be a problem, grass, weeds, and other things in the dirt penetrate the foam layer and create a greater liklihood of a fire by exposing the fuel beneath to the atmosphere.
See the big picture when you plan for these events, and remember that the time to plan for them isn't when it's happening. It's right now, while you read this thread.
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Sternone's picture shows the 172RG with the standard prop' in its normal stationary position. The prop' is indexed on the shaft to stop in the horizontal 9 o'clock, 3 o'clock position at shut down.
At slow speeds, and with normal compression, the prop' will stop as shown in the picture and not be subject to damage. Did Cessna know something when they designed the machine??
When you shut down a windmilling, or idling engine, the airplane will accelerate so you will land longer than you intended. A go round is a different matter??
Speedbird 48.
At slow speeds, and with normal compression, the prop' will stop as shown in the picture and not be subject to damage. Did Cessna know something when they designed the machine??
When you shut down a windmilling, or idling engine, the airplane will accelerate so you will land longer than you intended. A go round is a different matter??
Speedbird 48.
A buddy of mine had a gear failure in his Mooney. Brake line had come unsecured, prevented one main from coming down. He was on the ground, nosewheel and one main, and something seemed wrong as he started to settle where there was no wheel. Another airplane behind the hold short line keyed the radio and said "Mooney, your gear is up, go around." He did. Tried to get the gear down by manuvering to no avail. Ultimaltely landed on the hardtop, gear up, flaps up, and he only pulled the mixture when he had it made. Minimal damage to the belly, he was able to ferry it to have the skins replaced. No damage to the engine. Prop was destroyed. He had to pay a $200 deductible to get a new prop. Worked out good, as his prop was close to overhaul anyway.
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If the grass at an airfield isn't a declared landing area it can be pretty rough. Over the years trenches can be dug for cabling, rabbits can infest the area and holes are rarely filled in. Although trenches are back filled there isn't usually any great care taken in this - you can often see a lip of a few inches above or below the surrounding grass.
When a request came in to land on the grass at our airfield it was decided to take a look at it. On first inspection it didn't seem too bad and so a second run was made in the van at 60mph - and it was B
y rough! Despite this the pilot thought it worth trying and his eventual landing was fine.
Having said that, if an aircraft had made a wheels up landing on this grass it would have been a different kettle of fish. If the aircraft had impacted one of the ridges just after touchdown (belly down?) it would have been propelled back in the air pretty smartly. It was enough to make me think the hard surface is far more appealing should I ever find myself in the same unfortunate circumstances..
When a request came in to land on the grass at our airfield it was decided to take a look at it. On first inspection it didn't seem too bad and so a second run was made in the van at 60mph - and it was B
y rough! Despite this the pilot thought it worth trying and his eventual landing was fine.Having said that, if an aircraft had made a wheels up landing on this grass it would have been a different kettle of fish. If the aircraft had impacted one of the ridges just after touchdown (belly down?) it would have been propelled back in the air pretty smartly. It was enough to make me think the hard surface is far more appealing should I ever find myself in the same unfortunate circumstances..
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Sternone's picture shows the 172RG with the standard prop' in its normal stationary position. The prop' is indexed on the shaft to stop in the horizontal 9 o'clock, 3 o'clock position at shut down.
At slow speeds, and with normal compression, the prop' will stop as shown in the picture and not be subject to damage. Did Cessna know something when they designed the machine??
At slow speeds, and with normal compression, the prop' will stop as shown in the picture and not be subject to damage. Did Cessna know something when they designed the machine??
Your ability to adjust your glide path with power will have been sacrificed, of course, and you can't execute a go-around or balked landing. For those who'd prefer to stop the propeller...how many one-shot landings have you done from an engine-stopped approach with the propeller stationary? Do you want this landing emergency landing to be your first?
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No-one's yet congratulated the cameraman - unbelievably good steady tracking, zoomed carefully to keep the plane in shot, &c. Very impressive!
And nice to hear a sensible commentary for once, even if he did get a little tied up in the left/right thing!
Tim
And nice to hear a sensible commentary for once, even if he did get a little tied up in the left/right thing!
Tim
Moderator
Some propellers are "indexed". I'm certain that it is not for the purpose of assuring that they would stop in a given position in the case of an intended gear up landing, but because the propeller itself is forming a part of the balance of the crankshaft. This is the case with some Lycoming engines. The result might be though, that it could be very challenging to "starter" the prop to the desired position, compression strokes considered.
Smaller Continentals that I know of, do not have this design aspect, and it allows us to index the prop at the position of our choice, which in my case is just the ideal blade position for hand propping if needed again one day! Much more likely I'll be hand propping my 150 on day, than trying to get the prop around to the ideal position for a gear up landing.....
Pilot DAR
Smaller Continentals that I know of, do not have this design aspect, and it allows us to index the prop at the position of our choice, which in my case is just the ideal blade position for hand propping if needed again one day! Much more likely I'll be hand propping my 150 on day, than trying to get the prop around to the ideal position for a gear up landing.....
Pilot DAR
