Apparently the change fee on reusing the value in a canceled ticket can be avoided if there was a schedule change on the flight since it was booked. 1) Is this true? 2)How do I find out if there was a schedule change on a flight I bought last October (say) and just canceled? Will the "system" waive the fee for me automatically if there was?
Thanks,

m.

Before you accept the schedule change you may have some leeway with an agent, but I'm unaware of any CoC rule.

In fare rule, there is text:
Waived for schedule change

My interpretation of the OP's scenario is this: "I bought a ticket last October, I want to cancel today, and I'm hoping to avoid a cancellation fee if by any chance there was a schedule change between last October and today."

In this scenario, if you're planning to cancel your ticket online, then before you get to see your booking details you will be presented with a screen in which the schedule change is explained. You will need to accept the change before you can do anything else with the booking. If you don't accept the change, you can then call and cancel the booking. If you do accept the change, you're toast.

I don't know what happens when you cancel by phone without going online first. I don't know if the phone agent will proactively tell you there was a schedule change before you say you want to cancel.

The CoC has a specific definition of "schedule change". I don't have a copy right now, but as an example, a five-minute change doesn't qualify.

You can easily see if there's been a change.

1. Look at your confirmation email.
2. Look at the current reservation.
3. Do they match?

At some point, the system will auto-accept even unreasonable changes. This doesn't take away your rights for large changes.

It's easy:

1. Look at your original e-ticket confirmation. That will show your entire routing and times.
2. Look at what those flights are today. If they are the same, there hasn't been a change (or there was one, but it was switched back).
3. If there was a change and it is large enough, you can make your change and/or cancel fee free.

All that said, chances are that you would have received a notice if there had been a change, so it's not a high probability effort.

I haven't received email or any other notice of a UA schedule change in 3 years, despite having several dozen. Ymmv.

no but there are grounds for penalty free refunds. Change of carrier, adding of a stop, .... see the referenced CoC section.
If the schedule change is large enough, the agent at their discretion may waive the fees -- 2 hours change is usually enough but some will do it for less if you have a good reason.
There is no automatic waiver of the fees for any reason.

1) It depends on how great the schedule change was. If it's extensive enough, you have a right to a refund if the proposed alternatives are not acceptable to you. In practice, airlines often allow changes beyond the legal requirements as long as the alternatives you propose are reasonable.

2) If you've already cancelled, it's probably too late to do anything. The "system" is not likely to waive fees automatically.

But what if there was a schedule change some months ago that I accepted in innocence? Unfortunately I cannot find the original confirmation email (lesson learned). So I was hoping that there was a way to find old timetables, for example.

The reason for cancelation is a trashed knee. But I was thinking that flight schedule change would be easier to push through the system.

Have you tried searching the Wayback Machine?

If your time has any value, that's the angle to use. All you lose in that case is the $50 admin fee.

If you accepted the change, even unwittingly, the airline is much less likely to be accommodating than if you had no accepted the change.