Turning Radius
 

I was surprised to find that my 1970 T337E doesn't turn as tight as I expected. It will just barely make a 180 turn on a 50' runway. Is this normal?

Car makers publish turning radius data for their vehicles - I guess airplane makers don't? It would be a nice piece of info to have.

My guess is the turning radius would be the same as any other big single engine, since no differential thrust to make the radius smaller.

We still have differential braking - are you using that?

Next time I taxi, I'll try to remember to do a max-tight 180 and see how much space I use. I'll report back.

On page 1-2 of my POH it shows that the min turning radius, pivot point to outboard wing tip is 27 feet.

Frank

I did a tight 180 today and the 27' figure seemed about right. I did step on the right brake while making a right u-turn.

I can't get that using differential braking. It feels like the nosewheel isn't turning far enough to enable the turn. If I lock the inner wheel and floor the rudder pedal, I still need huge amounts of power to go through the turn. Is there a nosewheel rigging section in the service manual? I didn't see it.

Troubleshoot
 

Jim,
There are a few things that could be giving you a problem, you really need to check everything in the steering system first. You could have a worn out steering bungee, corrosion in the steering collar, bent bolt in the steering cam, rudder pedal bearing corrosion, or shimmy dampener problem. Best thing to do is jack the nose gear and physically check if you can turn the nose wheel from stop to stop (using your hands on the tire). Then check if you can do the same thing with the rudder pedals, paying close attention to the resistance in the pedals and the steering bungee in the cabin. that should start to give you an idea where the problem may lie.

The Maintenance Manual covers all of this, and has rigging checks. The thing to remember, is the connection you have to the steering is through that spring loaded bungee. It is "right in the middle", if you can picture it. factors influencing it can either be on the rudder pedal side, or on the gear side. It (spring loaded bungee) can also be weak or other things in the system could be providing resistance - this all effects your ability to transfer your intentions at the pedal, to the nose wheel steering.

When I had my nose gear out last summer, I found the following defects, and what the previous owner reported was "stiff to steer, oleo needs servicing".
- Shimmy dampener had been leaking and not resealed - body was scored and had to be replaced.$$
- large close tolerance bolt attaching steering cam to aircraft bent! I can only imagine what type of force it took to bend that bolt... That caused the steering cam to not rotate in the correct plain.$$
- Rudder pedal bar bearing on pilot side heavily corroded and seizing up rudder.
- due to seized bearing, pilot had been pushing harder on pedals, and cracked supporting bracket on structure that bearing mounts too (had to replace that structure (nose gear and rudder pedal system removal required).$
- Push pull rod from steering cam to the bell-crank inside cabin was bent. had to replace with new - not able to repair. $$$
- While gear was out, I rebuilt the nose gear - new bearings, bits, seals and repainted and greased everything. lots of old grease in steering collar - cleaned that up and made sure everything was "like new".
- ensured all rigging (steering push pull rod) was correct length and that steering bungee were set up correctly was the final item.

If you need - I can share some pics with you. Just don't have time right not to resize and post here.

Have a look at Ch 5 in your maint manual to become familiar with the system. Steering in 5-142 (page 5-32) and rigging is Chapter 9, Section 9-16 (page 9-7). Once you understand it, it is not that complicated.
Jeff

Hey JAG, I'd be interested in those pics from your nose gear rebuild too. :)

Mark - PM me an email, I can share that way better.
Jeff