Hi Wally,As far as how big a problem MEL items are for crews, it totally depends on what the item is. Our first exposure to an MEL item is usually when we review the paperwork(flight plan etc.) before a flight. We see that something on the aircraft has been defered and there is an MEL "card" that tells us what the restrictions are that we have to comply with. Some MEL items are almost meaningless to us, for example, a burned out reading lite back in the cabin. Others can have a significant impact on the flight, for example, if the anti-skid brake system was inop, it would require a very large adjustment of our take-off and landing wieghts(tens of thousands of pounds). Most MEL's fall somewhere between those extremes and are more of an annoyance.
I guess the types of MEL's that add the most workload for us are ones where whole systems aren't working that require us to do something manually. Some examples would be an auto pressurization controller not working or the FMC(Flight Management System) box being dead. Those types of failures add a lot ot work load in the terminal environment when we are already very busy.
Often we will discover something in flight that isn't working. In those cases we usually pull out the MRM( Maintinance Reporting Manual) and send a coded report of the problem to Maintinance over ACARs. Faults found in flight aren't required to be defered until before the next flight. Of course if the item is something significant, we have Irregular and Emergency checklists to deal with the ramifications of it.
United is also one of the few airlines with the capability for all our crews to be able to speak to SAM(System Aircraft Maintinance) via Satcom 24 hrs a day worldwide. We often use this to discuss the ramifications of a system failure if we feel that it will affect the rest of the flight.
It's interesting to know that every airliner you've ever flown on more than likely had at least several defered(MEL'd) pieces of equipment. Airliners are very complex pieces of equipment and they never have everything working at any one time!
Anyway, another long-winded answer! I hope I don't get a bad reputation for it! It's hard to answer these types of questions well but shortly.
By the way who do you work for? What do you do with MEL's?
Mark