Is there any place where statistics are available for how often there are maintenance issues that must be handled at the gate? My personal experience over the last few months has been that there has been an uptick in UA "maintenance at gate" incidents. It was also my impression that this was a common occurrence back during the bankruptcy days. But of course my experience is a tiny sample of all UA operations. Are there any statistics available?

What company would report or give outside people access to such info?

Most maintenance issue are taken care of when the airplane is parked at a gate. If it's got a problem that can't be taken care of there, the airplane is taken out of service. Even then, most things are taken care of right there. At least half the flights I fly, we bring in an airplane with discrepancies, but usually they're addressed when passengers are either off the plane or are things that don't require the maintenance technicians to come onboard the plane.

FAB

Having worked at AA Operations DFW for 10+ years (though 20 years ago) I can tell you that it's rare for an aircraft to pass thru without having a mechanic visit it while on the gate.

If the inbound crew "wrote-up" any item in the log book, then the plane is technically grounded until a mechanic answers for the item(s). A repair might not be done, but at least is acknowledged and recorded so that the repair can be setup at a downline station (usually the next over night stop or passing thru a major maint station for the airline). So being that DFW is the major AA hub, if the inbound crew didn't have anything to report, the plane itself may have some "deferred" items that can be cleared at this stop.

And don't get into a tizzy over my comments about "deferred" maint.
An airline can't delay repair to a downline station just because they want to. Each airline has worked with the FAA to develop a "Minimum Equipment List" (MEL) for each aircraft type they fly. Calling it a "list" is silly as it's a huge book.
The MEL mentions practically every operating part on the plane and gives the requirements that need to be met to fly the plane with the part inoperative.
IE: You can fly with your "widget warning light" inop only if :

• before each flight, the pilots confirm the "widget warning horn" is working
• before the 1st flight each day, a mechanic verifies the "gizmo" is working ok.

AA used to say that for every hour a plane spends in the air, 11 hours are spent maintaining it. Of course those maintenance hours are "man hours". Most of those man hours are for scheduled maint when a whole crew are working on the plane. But many of the hours are for the mechanics lurking in the background while the plane is in between flights in its schedule.

There's no statistic for the hours of "maint at the gate". The number would be quite high, though most times said maint is finished before scheduled departure time so would be irrelevant.

At many (most?) UA airports there are few good alternative locations for performing maintenance other than the gate.

PHL is a good example. UA operates a decent number of flights per day in and out of PHL but has no hangar facilities there. There are some remote corners of the airport where aircraft can be parked and worked on for extended periods, but that is an extreme circumstance. It also means towing the aircraft from the gate, bringing air stairs out to the aircraft, moving parts, tools, personnel, etc.

So it's hardly surprising that there's a lot of maintenance "at the gate". The bigger issue is how often maintenance issues impact on time departures, regardless of where the maintenance occurs.

Thank-you for your informative replies. I guess I should refine my question to ask if there are any statistics on departure delays due to maintenance at the gate.