Cessna 172 SP nose wheel question

[LongRoadBob]

quick question, I have searched through the POH, but am not finding the answer as it doesn't totally describe he nosewheel operation/construction.

It was mentioned in ASA student pilots flight manual, regarding crosswind slip landings, that "some airplanes have nosewheels that "fall free" from the steering mechanism so that when there is no weight on the wheel (I.e. When it is airborne) the wheel will be free to track along the ground path when it touches. In other words, in the wing-down crosswind approach the deflection of th rudder does not have the nosewheel "cocked" at touchdown."

Which seems pretty smart. But I can't find out if the C172 SP is designed to have the nosewheel independent when not on the ground, or if the rudder actually still will deflect it when in the air.

I'm sure someone, or many here, know. So which is it? I'm guessing since it doesn't mention any such cool design, that it isn't there.

 

[Pilawt]

All high-wing Cessna singles have a centering cam on the nose oleo to keep the wheel centered when the oleo is fully extended. The bungee steering mechanism, through the rudder pedals, is not disconnected, but it’s loose enough to allow normal rudder deflection in flight even though the nosegear is held in the centered position.

Because of the centering cam it can be difficult, or in extreme cases impossible, to steer on the ground if the nose oleo is overinflated, or if aft loading casuses the airplane to be very nose-high while taxiing.

Piper fixed-gear singles have a direct connection between the rudder pedals and the nosewheel (a bungee was added to the system starting in 1974, to make ground steering easier), so the nosewheel "steers" in flight along with the rudder.

 

[Dan Thomas]

quick question, I have searched through the POH, but am not finding the answer as it doesn't totally describe he nosewheel operation/construction.

It was mentioned in ASA student pilots flight manual, regarding crosswind slip landings, that "some airplanes have nosewheels that "fall free" from the steering mechanism so that when there is no weight on the wheel (I.e. When it is airborne) the wheel will be free to track along the ground path when it touches. In other words, in the wing-down crosswind approach the deflection of th rudder does not have the nosewheel "cocked" at touchdown."

Which seems pretty smart. But I can't find out if the C172 SP is designed to have the nosewheel independent when not on the ground, or if the rudder actually still will deflect it when in the air.

I'm sure someone, or many here, know. So which is it? I'm guessing since it doesn't mention any such cool design, that it isn't there.

Pilawt has it right. I have never seen a nosewheel that "falls free" from the steering mechanism. Not saying that it's never been made; just not aware of any. Cessna's steering bungees are spring-loaded affairs that sort of have steering authority on the ground but rudder operation is still possible when the nosewheel locks straight-ahead in flight. In fact, that nosewheel steering is the centering device for the whole rudder system, and if it's misrigged it makes tha airplane fly cockeyed, with the ball off-center. Rigging starts with those bungees.

 

[LongRoadBob]

Pilawt has it right. I have never seen a nosewheel that "falls free" from the steering mechanism. Not saying that it's never been made; just not aware of any. Cessna's steering bungees are spring-loaded affairs that sort of have steering authority on the ground but rudder operation is still possible when the nosewheel locks straight-ahead in flight. In fact, that nosewheel steering is the centering device for the whole rudder system, and if it's misrigged it makes tha airplane fly cockeyed, with the ball off-center. Rigging starts with those bungees.

I think maybe the float free thing is a red herring. I mainly was interested in slip landings in X wind, to know if I have the rudder quite a bit to one side if the nosewheel is also cocked quite a bit or not. I think you guys answered it well, if I understood (had to look up oleo, also wondering, int the Piper warrior I was told it was nitrogen in the hydraulic part of the nw, I'm seeing oil/air for the Cessna?) it might be slightly but not a critically uncentered.

 

[H2daB]

I know that my Piper Warrior II has nitrogen in the cylinders for mains and nose wheel, along with fluid of course. However, I have flown a few of the Grumman AA1s and they do have a castering nose wheel. Steering on the ground is accomplished through differential breaking, which takes a bit a getting accustomed to on takeoff. Fun little airplanes though.

 

[Dan Thomas]

I think maybe the float free thing is a red herring. I mainly was interested in slip landings in X wind, to know if I have the rudder quite a bit to one side if the nosewheel is also cocked quite a bit or not. I think you guys answered it well, if I understood (had to look up oleo, also wondering, int the Piper warrior I was told it was nitrogen in the hydraulic part of the nw, I'm seeing oil/air for the Cessna?) it might be slightly but not a critically uncentered.

Nitrogen is commonly used rather than air because it has no oxygen or water in it. Oxygen causes oxidation (rusting), and water contributes oxygen and acts as an electrolyte.

Air or nitrogen just act as the spring in the oleo. The fluid damps the movement, like a shock absorber.

 

[frfly172]

HVe never seen a nose wheel that floats free.

 

[Mani kavuru]

quick question, I have searched through the POH, but am not finding the answer as it doesn't totally describe he nosewheel operation/construction.

It was mentioned in ASA student pilots flight manual, regarding crosswind slip landings, that "some airplanes have nosewheels that "fall free" from the steering mechanism so that when there is no weight on the wheel (I.e. When it is airborne) the wheel will be free to track along the ground path when it touches. In other words, in the wing-down crosswind approach the deflection of th rudder does not have the nosewheel "cocked" at touchdown."

Which seems pretty smart. But I can't find out if the C172 SP is designed to have the nosewheel independent when not on the ground, or if the rudder actually still will deflect it when in the air.

I'm sure someone, or many here, know. So which is it? I'm guessing since it doesn't mention any such cool design, that it isn't there.

 

[Mani kavuru]

My understanding is there are bungee cords from rudders to nose wheel for max 8 degrees on either side of center for ground ops; with use of differential breaking can increase to 30 degrees on either side. Airborne,the 172 has an automatic centering mechanism for nosewheel (so the wheel does not adversely affect aerodynamics); and for safety for landings? So nose wheel is in neutral position at touchdown. I assume same is true for rudder.....

 

[James331]

Or just get a tailwheel plane.

 

[Dan Thomas]

So nose wheel is in neutral position at touchdown. I assume same is true for rudder.....

No. The rudder is wherever the pilot has it using the rudder pedals. Only the nosewheel is locked at center.

 

[James331]

No. The rudder is wherever the pilot has it using the rudder pedals. Only the nosewheel is locked at center.

Well seeing most trike pilots don’t use the rudder lol

 

[Mani kavuru]

Thanks for setting me straight on the rudder! That’s what’s great about this forum, people with varying experience level!