Tracking left when taxying

[Blue Albatross]

Hi All,

I'm the proud owner of a little Robin ATL. Lately I've noticed that the plane has a severe tendency to track left all the time, requiring application of a lot of right rudder/brake to keep her straight.

This tendency to veer off to the left is noticeable at all taxying speeds, and I am curious if this is a common trait of the ATL or not?

After my last flight, I checked the brakes on both sides. The right hand-side was hot (probably as a result of a lot of differential braking to keep the nose tracking straight) and the left side was cool. I had thought that the left side would also be hot, thinking that maybe the disc was sticking or rubbing against the pads.

Visual inspection does not show up anything....no fluid leaks, excessive wear, tyre creep etc, so am at a loss to understand why she's always veering to the left.

Thought I would ask the question and see what replies I got before I fly her over to the mechanics for them to take a look at her.

Any input would be gratefully received.

[camlobe]

Hi Blue Albatross,

Used to look after one of these a few years ago. It had all the problems the ATL's suffer from, including your problem. May I suggest that you check the tracking of your mainwheels. Easiest way is probably in a hangar. Lay a piece of string or similar along the floor of the hangar aligned underneath the fuselage precisely along the centreline of the aircraft. Note: from the centre of the tailcone forward to the middle of the bulkhead/firewall - don't try and align the string from the tailcone to the spinner as these engines have considerable offset. Then align a straight edge (long piece of wood etc) fore and aft along the outside of each mainwheel. Now measure from the distance from the wood to the string both at the wheel, and then from approximately 10 feet/3 meters forward of the wheels. These distances should be equal (i.e. the wood runs parallel to the string). I suspect that your port wheel is toeing out.

Hope this helps.

camlobe

[Blue Albatross]

Thanks Camlobe,

I'll give that a go this weekend. You mentioned "other problems" that ATL's had. Can you let me know what were the other major issues you came across so I can be sure to watch out for them myself?

One noticeable one I discovered already is a significant nose shimmy when rolling out after landing. It's already been fixed. But am curious if there are other issues/traits for this specific model?

Thanks so much again.

Rgds,
BA

[englishal]

Is it castoring nose wheel? We had the same issues on the Rallye for a time - it would always try and turn left. The reason in our case was the left brake was binding slightly and then when you have a left cross wind trying to weathercock the aeroplane to the left, engine effects at power adding to the problems, it was at times almost untaxiable. The Rally is slightly different as the nose wheel is offset to the right of the centreline which compounded the problems. I'd always line up on the runway at about 30 degrees to the right of RW heading so that when I applied full power to start the roll we'd be straight on RW heading by the time the rudder had enough authority.

[Big Pistons Forever]

Many aircraft have centering springs on the nose wheel steering rods. If one were broken you would get the symptoms you describe. The easiest way to check is to centre the rudder pedals and tilt the aircraft so the nose wheel is off the ground and see if the nose wheel stays straight.