flat spot on tire, or...?

[ocelot]

The other day on a flight out of DEN, towards the end of the takeoff roll significant vibrations developed, at a rate plausibly consistent with wheel speed. I figured we'd blown a tire and half expected to return, but apparently not. A flat spot is sufficient to produce such behavior, I know, but... wouldn't you then also get vibrations on landing? There were no symptoms at all on landing. (After getting off at the other end, all the tires were definitely intact. One of the nose gear tires had a suspicious-looking spot... but that couldn't have caused the behavior since the vibrations continued after rotation until liftoff.)

What else would produce this behavior?

(Plane was an A319 but that probably makes no difference)

[Gabriel]

What else would produce this behavior?

Shimmy?

[elaw]

Flat spot from sitting for a long time? One of my cars does that... I often don't drive it for several days at a time. When I do, there's some vibration for about the first 10 minutes that once gone, stays gone for the remainder of the trip.

[ocelot]

The plane came in from elsewhere an hour or so before, so it hadn't even been sitting overnight.

Shimmy? Maybe... no idea what that would feel like but I would think it would be more side-to-side than up-and-down.

anyway, not going to find out...