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This is relatively recent, 6 July 2013, so you may remember a few particulars.
The Boeing 777 was Boeing’s first new airplane in ten years and was the first digitally designed on computers. It represented a new era in cockpit automation. It also heralded a new age in passenger safety. From its first commercial flight on 7 June 1995 until this accident, 18 years, there had not been a fatality on the aircraft.
The particulars are that it was a trans-Pacific flight from Korea, that it was a training flight for some of the aircrew, although all were experienced pilots, and that it was inbound to SFO and cleared for a visual approach on a nice weather day. The crew, apparently assuming software controls that were not programmed for the autoflight mode selected, lost track of their sink rate and wound up landing short and hard, although the aircraft did wind up on the opposite side of, but clear of the runway. There were three fatalities as a result of the accident and 192 survivors.
Although a two pilot aircraft, there was a third, relief pilot on board due to the length of the trip, as is customary on transoceanic flights. Two of the pilots were captains, one with more than 12000 hours and the other with more than 9500 hours. The third pilot was FO rated with about 4500 hours. These were experienced airmen.
My impression from reading the report a couple of years ago was that the crew wasn’t as knowledgable about the aircraft, nor as disciplined as they should have been while conducting the final segment of the flight. Visual approaches are piloting 101, and although the skills may derogate after years of being vectored to final and letting the autopilot fly the approach, it’s still a fundamental aviation skill which needs attention. It’s not like all the time in the simulator is spent on emergencies—there are skill evaluations, too, and visual approaches are among them.
The 777 has a lot of automation built in to it, especially the autoflight system, what lay people might blanketly label the “autopilot”. In fact, the autoflight system has many modes, each governing the system by its particular parameters known as laws. There are modes such as altitude hold, heading hold, autothrottle, nav (both VOR course as well as localizer/glide slope or ILS), etc. It turns out that regardless of law, some piloting functions might not apply as one might expect. In this case, there was a dependence on FLCH (Flight Level Change Speed—a function of the auto throttle) to ensure throttle adjustment while in a high energy descent. Except it doesn’t quite function that way, as was discovered.
The result was a high sink rate developed at quite a low altitude and close in to the runway. They found themselves in “coffin corner”, where they no longer had time nor altitude to spool up the engines for a go around. The data show that the engines did spool up to nearly 100% within 7 seconds of command, which is pretty quick for a turbine, but it was far too late to save the airplane.
Any pilot with an interest in aviation history knows that when jet engines were first introduced in the ’40s, the lack of instantaneous throttle response with which they were accustomed in large piston engines, took some getting used to. Modern engines spool up much faster than the early versions, but nothing like what legendary Flying Magazine contributor, Len Morgan, described when he suggested that would be P-51 pilots should learn of the danger of too rapid power application by taking their craft up to 10,000' feet or so, dirty it up (drop gear and flaps) and slow to approach speed (100 knots or so), and then “cram on 61 inches” (61 inches is max manifold pressure in a supercharged Merlin engine). It will flip the airplane over. That’s largely torque from the big prop, but the point is the engine could produce it very rapidly. It’s hard to imagine any turbine powered propeller craft could yield the same result.
I also noted considerable discussion (not all from the report, but ancillary conversation in the media and online) about the role of superior and subordinate males in an Asian culture. In commercial aviation this is applicable to CRM (Crew Resource Management) and if the case, runs somewhat in contravention of the concept.
My attempt to summarize this seemingly simple, yet complex accident, illustrates how difficult it must be for airline pilots to keep up with the systems in the aircraft they are operating, and especially when they change equipment. I consider myself pretty tech savvy, a good pilot, and someone accustomed to complex, high tech tasks (30 years ATC in the busiest facilities). But I found the discussions in this report to be right at my threshold of understanding. If you’re able to grasp it more easily, chapeau. I recommend settling for my basic overview and accept that high energy descents, manually flown (or even with autoflight assist), in big iron, is something to be practiced, and kept well inside the operating envelope one imagines the aircraft to possess.
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