safetypee,
Good post, I was beginning to think along your lines, it is a two way street. One thing that struck me was
Nats post in which he said: (The bold is mine)
All of the qualified pilots on here - could just as easily fly a fully automated flight from A to B or indeed, fly it manually, as that is what they were trained to do and that is what they have been doing all of their flying lives, `till FMGS came along - and now they get to play with something on those long flights, its fun, for everything that the pilot has just worked out with a pencil, why, there it is in computor LEDs, it is also entertaining to see how accurate the box of tricks can be, and as mentioned before, if it does not behave, then switch it off and fly the aircraft - just as we are trained to do.
Well, interestingly, boredom can and often does lead to curiosity as to how the automatics work and do they work correctly? Here is an example of what can happen when fun and curiosity goes too far. BTW, this was a highly experienced crew.
Curious Crew Nearly Crashes DC-10
Have you ever flown a DC-10 at 39,000 feet with 115 passengers on board and been tempted to experiment with autothrottle system - just to see what would happen? In late 1973, a pair of curious National Airlines personnel, a captain and flight engineer did and their actions nearly cost everyone on board their lives.
On November 3, 1973, National Airlines Flight 27 was operating as a scheduled passenger flight between Miami and San Francisco. At about 4:40 p.m., while the aircraft was cruising at 39,000 feet 65 miles southwest of Albuquerque, the No. 3 engine fan assembly disintegrated and its fragments penetrated the fuselage, the Nos. 1 and 2 engine nacelles (which contain those engines), and the right wing area. The resultant damage caused decompression of the aircraft cabin and the loss of certain electrical and hydraulic services.
You want to try it and see? However, it is clear that the captain and flight engineer's irresponsible actions were to blame. They were experimenting with the autothrottle system, which supplied the instruments that measure the rotational speed of each engine's fan and low pressure compressor. The cockpit voice recording contains the following conversation just prior to the number 3 engine exploding:
Flight Engineer: "Wonder, wonder if you pull the N1 tach will that, -- autothrottle respond to N1?"
Captain: "Gee, I don't know."
Flight Engineer: "You want to try it and see?"
Captain William Brookes, who had been a National Airlines pilot since 1946 and who should have known better responds, "Yeah, let's see here."
Flight Engineer: "You're on speed right now though."
Captain: "Yeah."
Flight Engineer: "You know what I mean if your annunciated speed - if you got, ---"
Captain: "Still got 'em."
Flight Engineer: "Well - - haven't got it -"
Captain: "There it is."
Flight Engineer: "I guess it does."
Captain: "Yeah, I guess it does - right on the nose."
[At the instant he says the word "nose" there is the sound of the number 3 engine exploding followed by ratcheting sounds.]
Captain: "[expletive deleted] what was that?"
By playing with the autothrottle controls - in what amounted to an in-flight failure-analysis test of the autothrottle system - the crew managed to produce a condition where the engines were pushed to higher rotation speeds than they were designed for. According to audio analysis of the CVR tape, all three engines surged (#1 to 105%, #2 to 107% and number 3, which failed, to 110%).
There are many things to consider when considering the human attitudes to automation, "fun" and curiosity/entertaining are but two consideration to keep in mind.