I lived through the B747 experience at Eastern Air Lines. I ran the Tech Service group at JFK. We leased from Pan American two aircraft for year around service and a third one for the winter when they were slack and we were peaking out. To cover the costs, EAL expected them to fly 14 hours a day. The aircraft were onl to fly JFK, MIA and SJU.
The early B747 were not easy to maintain. The Pratt JT9D-3 was a miserable engine early on and not great later on either. I remember UPS and Orion Air for whom I then worked celebrating as we replaced the last -3 with -model 7 engines on their then fleet.
Those early engines had no stall margin at all for a start. The aircraft was designed for long haul. A takeoff. eight hours of cruise and a landing. Our longest leg was three hours. The delay and cancellation rate was so bad that at one point my small Techie group s were assigned to ride jumpseat on every flight for three days and report on what was doing wrong. Not acceptable was that it was the aircraft and engines that were still raw and for the time, were cutting edge and not matured. Nothing of course came of that except exhaustiuon on our part.
Then the VP of Line Maintenance, under the gun himself, announced that he would come up to JFK and ride with me around the ramp and HE would see what we were doing wrong.
JFK overnighted one aircraft but on this day it was coming out of a Pan Am maintenance check. The APU on the aircraft had been inop for a week and had been declared a failure by one of my Techies due to compressor rub. VP and I sat in my Econoline to the side of the aircraft and the VP was acrid pointing out the shiimer from the APU tailpipe and reminding me that PA AM had fixed it by just changing the battery.
The stairs came offn. Tug began the pushback, the APU tone changed as they started winding up Nbr 3 engine when the was a loud bang, flames and a few hard parts out the APU tailpipe. I couldn't gloat, not to a VP but I did mention that the battery change had not fixed it.
Aircraft pulled back in, APU inspected, put on MEL and two huffers and grouynd power needed to start nbr 3. Tug pushed back , then stopped once again and pulled back in. Up went the stairs, up went me with electrician. Front cabin stunk of electronic smoke. A passenge entertainment MUX controller had cooked off. Pax entertainment went on MEL too and I happily carried unit, still stinking back to my Econoline for VP perusal. A/C finally departed.
In came Miami flight. On gate a mechanic motioned me over to nbr 2 engine. A bleed air outlet opened on the side of the cowling with a coarse screen coverong it. A 2" x 2" flat piece of metal was caught up in it. I knew it was a piece of the inner case and pulled the a/c out of service for an engine change. Informed VP that I had seen this before.
Third a/c arrived from SJU. On taxi in I could see nbr 3 cold stream reverser was stiull partially deployed and there seemed to be material sticking out of the gap. Yes indeed, the engine had a hard stall on reversal and some acoutic liner had come loose. Second engine change required today. Also Nbr 4 engine had the hot stream reverser partially deployed too. It had jammed causing the reverser actuator on the gearbox to come apart. Ball bearing and bits insode the cowling.
The VP got on the next Miami flight. His only statement was on asking how I had arranged all this to happen. I told him it was not an uncommon day.
Apologize for being wordy.