“For Flight 143, things happened in horrifyingly rapid sequence. For the two pilots, the first sign of trouble came when a warning horn sounded indicating a lack of fuel pressure....Moments later, however, the left engine died, which didn’t make sense given the fuel pressure warning and action taken...”
“However, just then, another warning horn sounded, one that they had never heard before, even in simulators — it was a sort of a “bong” noise, as they would later describe it. There was a “what was that?” moment before the right engine abruptly quit. Suddenly, they were flying an airliner with both engines out — and at that, the instrument panel died, as did all electrical indicators and lighting. The EFIS (Electronic Flight Instrument System) and all other electrical devices on the plane draw power from one or both of the engines.”
“The two pilots quickly checked the Boeing 767 books for a two engine out checklist, only to find that there was no such thing — they would have to make it up as they went along... He immediately treated the B767 as if it were a giant glider and made an educated guess of his best glide speed — 220 KIAS (something that was also not published). Then, he realized that there were no instruments giving him his vertical speed (aka “sink rate”). How far would the jet glide?”
http://fly.historicwings.com/2012/07/the-gimli-glider/
The article at the link makes a good case