I started with a Flight Deck of 5; two pilots, a nav, flt eng, and signaller, that was then whittled down to four (no sig), and finally there was just the two of us. Meaning no disrespect to any of the others, I missed most not having a flt eng. They were, without exception, highly knowledgeable about all the various a/c systems and could diagnose faults, offer solutions, and in the final resort supervise repairs/replacements to get us going again. Gentlemen all, I salute you!