Pros and Cons

By lex, on September 7th, 2010

The conventional landing gear equipped single engine aircraft is trickier to fly under normal operations, requiring exacting attention to wind corrections and drift in order to prevent the back end racing towards the front. Land in a crab, and sideloads kick the center of gravity out beyond the main wheels, while gyroscopic precession as the tail rises or plants subtly imparts yaw that, left un-countered, could result in a ground loop. Which – I am told – is nothing like as fun as an “air” loop.

But there are certain advantages as well:

The pilot of a single-engine Cessna who made an emergency landing on a Virginia Beach, Va., baseball field was uninjured, a fire department official says.

The nature of the emergency was not specified, but the plane overturned upon landing, Fire Department Battalion Chief Kenneth Pravetz told the Norfolk (Va.) Virginian-Pilot…

A witness said the plane made no sound as it descended on the baseball field at Cape Henry Collegiate School.

“It really didn’t have a sound,” said Anthony Checchio, who was playing tennis nearby. “It just came out of nowhere.”

The tailwheel aircraft, properly flown in glider mode, has a much lower propensity towards flipping over on its back in the event of an off-airport landing.

Update: Occasional reader Mike offers this correction clarification on my closer –

Whoops! Back to Tailwheel 101 for you lad! And just when we thought you were getting the hang of it.

An airplane will flip on an off-field landing when an obstruction impedes the progress of a landing gear while the rest of the airplane (according to Newton) attempts to continue downrange. This creates a rotational moment around the point of obstruction (usually the axle of the impeded wheel). Now, postulate it either way for the tri-gear: if the nosegear hits the obstruction first, the fulcrum is much farther forward of the CG than in a tailwheel aircraft, and thus requires more work to accomplish the 180 degree rotation (second or third class lever vrs a first class lever). If the main gear of the tri-gear is obstructed first, the effort to start the rotation is less, but then the rotation is obstructed by the nose gear, and you’re back to the original case.

As an experiment, go out to your local airport, pick two equivalent-size aircraft, one a tri-gear, the other a taildragger. Chock the wheel(s) you suppose to be obstructed, then lift the tail and see what effort is required to put the nose cowling on the ground. It’s illustrative to note that most well maintained tailwheel aircraft can be put on their backs by brake application alone during a landing, leaving the landing gear undamaged. The tri-gear aircraft usually only arrives on it’s back after destroying the nose gear structure.

It’s why they moved the tailwheel up front in the first place.

Now if you were to say that the nosewheel aircraft is more likely to be DAMAGED in an off-field landing, then I might agree with that. But the damage most likely starts with nose gear failure.

Intuitively, I took it for granted that a tri-gear aircraft would have the nose gear collapse under load in a soft-field, off airport landing, which tends to lead to the nose digging in straight ahead and the aircraft over on its back. Which is why you see those jollies flying their Super Cubs, Huskys etc. into gravel bars on Alaskan stream beds – a place the tri gear pilot would ordinarily fear to flare.

But Mike is right, and I was insufficiently precise.

(And I thought they put the tailwheel up on the nose only to provide humility doses to aging former fighter pilots.)

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Filed under Best of Neptunus Lex, by lex, Carroll "Lex" LeFon, Carroll LeFon, Flying, Lex, Neptunus Lex

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