Tire check...preflight. What are we looking for?

LongRoadBob

LongRoadBob

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image.jpeg Had an incident last time I flew. One thing, we took over the plane immediately after another student flight. It's a new plane to me, first time in a C172. We did a quick preflight.
On landing, not at touchdown but on rollout shortly after, pretty heavy shaking. I thought it felt like the motor, or as if the prop was suddenly out of balance. Held the centerline ok, but my CFI considered it and thought no...maybe a blowout.
We stopped, and he took over and taxied off the runway keeping pressure off the nose wheel.
Then we stopped after clearing the runway, got out and the tire was totally flat.

Here's the thing. So far I don't think I've seen a new tire on any wheel on a airplane. By design the ones I've seen seem "worn" flat with just a few lines. I am not sure other than if there was a hole developing, how to tell if a tire is too worn. Also tendency is to look at the tire from the front, and not move the plane to see the part on the underside, etc.

Glad that it wasn't one of the main wheels. Also, it was a great landing, not hard at all. It was on rollout.
 
It’s just flat on one side. The other side is fine...

Look for cords showing, any cuts, and proper inflation. Cords showing is no-go. On rentals roll the aircraft forward to check for flatspots. On the mains eyeball the brakes - no leaks and should be lots of friction material remaining.

Looks like good European weather. Do you remember that bright yellow ball that sometime shows in the sky?
 
Clark1961 said:
It’s just flat on one side. The other side is fine...

Look for cords showing, any cuts, and proper inflation. Cords showing is no-go. On rentals roll the aircraft forward to check for flatspots. On the mains eyeball the brakes - no leaks and should be lots of friction material remaining.

Looks like good European weather. Do you remember that bright yellow ball that sometime shows in the sky?
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Thanks, good advice! That yellow ball in the sky, it makes us afraid...we try to shoot it down, but so far no luck.

We ended up putting the nose wheel on a small dolly and pushing it back to the hangar. It almost looked to me like it wasn't a puncture, but the tire separated from the rim, but again, it was a smooth nice landing, not hard.

Say you do see a flat spot. Is that a no go? Depends on how flat, how big or ?

I'm also thinking, if it were a main wheel that might be a lot harder to control the plane, keep on the centerline. Are there any procedures or techniques that would help prevent going off the runway other than brake and slow down, hard rudder to the opposite side? Or are even these ideas maybe not the right thing to do?
 
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LongRoadBob said:
Thanks, good advice! That yellow ball in the sky, it makes us afraid...we try to shoot it down, but so far no luck.

We ended up putting the nose wheel on a small dolly and pushing it back to the hangar. It almost looked to me like it wasn't a puncture, but the tire separated from the rim, but again, it was a smooth nice landing, not hard.
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I think Kent @flyingcheesehead is POAs resident expert on mysterious flat tires. He had a string of them on his club’s aircraft.

So far I’ve been lucky with no flats. I check inflation fairly often (because it gets difficult to push with low tires) and put on new tires early - tread gone but no cords. That said, FOD happens. They aren’t the toughest tires on the planet.

On another note, that 172 belly is clean! Maybe cleanest trainer I’ve seen.
 
I had the exact same thing happen to me, except when getting ready to take off. Back taxied down the runway and did a 180 at the end. As I started accelerating for take off, I got the same wobble you described, and sure enough, flat nose wheel on a 172.

And of course it was 11pm on a Saturday night, at an uncontrolled airport and the temperature was -32C without the wind chill. That was a long, cold walk back to the ramp shack. Luckily someone knew someone at the airport and we got the nose wheel changed. The tire was undamaged, but somehow there was a puncture in the tube.
 
LongRoadBob said:
View attachment 62134 Had an incident last time I flew. One thing, we took over the plane immediately after another student flight. It's a new plane to me, first time in a C172. We did a quick preflight.
On landing, not at touchdown but on rollout shortly after, pretty heavy shaking. I thought it felt like the motor, or as if the prop was suddenly out of balance. Held the centerline ok, but my CFI considered it and thought no...maybe a blowout.
We stopped, and he took over and taxied off the runway keeping pressure off the nose wheel.
Then we stopped after clearing the runway, got out and the tire was totally flat.

Here's the thing. So far I don't think I've seen a new tire on any wheel on a airplane. By design the ones I've seen seem "worn" flat with just a few lines. I am not sure other than if there was a hole developing, how to tell if a tire is too worn. Also tendency is to look at the tire from the front, and not move the plane to see the part on the underside, etc.

Glad that it wasn't one of the main wheels. Also, it was a great landing, not hard at all. It was on rollout.
Click to expand...

There are a couple of issues that you want to check.

A tire on the main gear should be properly inflated and is considered airworthy as long as not white cord is exposed. You should also check for severe flat spots on the tire due to someone locking up a brake. If the tire has a really bad flat spot and you apply hard breaking the tire can stop on that flat spot and burn through leaving you with a flat on the runway and paying for a tire. You want to check the wheel for cracks or loose attachments.

On a nose tire, you want to inspect the tire and inspect the wheel closely for damage from a landing. That would include the outside circumference of the wheel both side for signs of damage and cracks.
 
I check my tahrs to make sure they still look like tahr. That's why they named them "tahr," so it's easy for Billy Bob to make shur there okay. If there the color of tahr, their okay. If they look like my bed sheets, with threads running to and fro and freyed. Than they ain't likely okay.

Easy.
 
LongRoadBob said:
View attachment 62134 Had an incident last time I flew. One thing, we took over the plane immediately after another student flight. It's a new plane to me, first time in a C172. We did a quick preflight.
On landing, not at touchdown but on rollout shortly after, pretty heavy shaking. I thought it felt like the motor, or as if the prop was suddenly out of balance. Held the centerline ok, but my CFI considered it and thought no...maybe a blowout.
We stopped, and he took over and taxied off the runway keeping pressure off the nose wheel.
Then we stopped after clearing the runway, got out and the tire was totally flat.

Here's the thing. So far I don't think I've seen a new tire on any wheel on a airplane. By design the ones I've seen seem "worn" flat with just a few lines. I am not sure other than if there was a hole developing, how to tell if a tire is too worn. Also tendency is to look at the tire from the front, and not move the plane to see the part on the underside, etc.

Glad that it wasn't one of the main wheels. Also, it was a great landing, not hard at all. It was on rollout.
Click to expand...
I’ve had that happen twice. Both times the nose wheel tire looked just fine on preflight.

First time happened in a Duchess landing at night. One if the smoothest landings I had made in that airplane and I even held the nose off and slowly lowered down. Then, just as you found.....lot of shaking.

Second time was in my Baron. But it was even more bizarre. I had a smooth landing (had a passenger on board as my witness) at Allentown and shut down briefly on the ramp to pick up a part we were taking to TEB. Nosewheel looked totally normal when I pulled the chocks. Started up, got my clearance and then about 500 feet before we got to the runway, the nose starts shaking just like it had with the Duchess. Flat nosewheel.

In both cases, it was a pinch/tear at the valve stem with no visible sign on preflight.
 
"Tire check...preflight. What are we looking for?"

Among other things, I have found broken wheel through bolts on a Bonanza main.
First thing I did was 'flatten' it.
 
Tire pressure is important and unfortunately hard to tell when low until it is way too low. I look for flat spots and too much sag (low pressure) in tires on preflight.
 
I like to check my tires every 30 days or so with a tire gauge. The plane rolls better with an extra 5 psi, that helps for pushing it back in the hangar, or for the max performance/weight takeoff. YMMV.
 
I've had two flats on landing. One was a rented 172 at Camarillo, CA and the other my RV at Fayetteville, AR.

Right main and left main respectively.

It's difficult to control steerable nose wheel plane in this condition. And MUCH more difficult with a full castering nose wheel.

Both times it was deemed to be the tube, not the tire.
 
LongRoadBob said:
So far I don't think I've seen a new tire on any wheel on a airplane. By design the ones I've seen seem "worn" flat with just a few lines.
Click to expand...
Typically, they don't have much of a tread pattern - just the grooves.
flightcustom3.jpg

But, remember, a proper preflight consists of two steps - Kicking the tire and lighting the fire. :)
 
Often what happens is a tire with low pressure spins on the rim with just the right touchdown technique. Oddly enough, if you slam it on, it's less likely to happen.

Unfortunately "a little low" and "significantly low" tire pressures look a lot like "properly inflated" on preflight.
 
Haven’t had a flat yet but a couple of times I’ve found a loose/worn wheel bearing on a preflight. Always grab the wheel and give it some side to side shake. Trainers get pounded pretty hard.
 
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