pushback times inaccurate?
 

Love the new baggage app. But I do find it curious that DL shows we pushed back on time at 8am, but that the bag was subsequently scanned plane-side at 8:12am.

Only a cynic would think the pushback time is "massaged" to improve and maintain ontime performance stats. Good thing I'm not a cynic...

You are allowed.

I find the official pushback time often has no relationship with the actual time. I have seen it vary by up to 10 minutes.

ACARS have different trigger points depending on the aircraft. Btw on time performance stats by the DOT are measured by the arrival time not departure time.

Exactly, "pushback" can be measured from brakes off. Doesn't mean you actually move.

I think it can also be measured as Gate pulled back. I have been on many flights where they rush to pull the gate back so they "left" on time but will sit and wait for an ATC delay at the gate or in the penalty box.

I have sat at the gate with the door open, gate attached, passangers boarding, luggage clunking in the hold and later the flight was listed as leaving 5 minutes earlier. What ACARS trigger point would that be?

Guess what the pilot often does once the jetway is pulled back... Turn off the brake.

Pilots and FAs are usually paid from brakes off to brakes on. So that's part of the reason for the rush to get ready even if a delay is inevitable. The other reason is that delays can change quickly and they want to be ready to go if things open up unexpectedly.

Hmmm...possibly the "manual non-ACARS" entry method?

...what I'm thinking.

My point was that we all know it happens. But the baggage scan times confirm it, with documented evidence.

One could also think that in many stations that scanners aren't RF enabled and the "loaded" time might also be the time one of the ramp guys docked his scanner in a cradle?

This is the generally correct answer. However sometimes bags are loaded after the parking brake has been released.