I should know the answer to this question but can't for the life of me remember or find the answer. OK, happy with 4 engine aircraft performance, climb segments, V speeds required, loss of one engine and acceptable critical time for the loss of a second. I explained this in layman's terms over a beer to a friend. Then he asked about a three engine aircraft
. Can you lose two before the 4th segment or indeed at all before a safe level? Any assistance welcome please, he will owe you a beer.