Originally Posted by Typhoonpilot

I picked the B777 since it is a FedEx aircraft and both the Boeing FCOM and Boeing Flight Crew Training Manual state that sideslip only (zero crab) landings are not recommended with crosswind components in excess of 28 knots. The aircraft has a maximum demonstrated crosswind components of 38 knots. Some operators go up to the Boeing FCTM guidance of 45 knots on a dry runway.

Another large widebody is the 747, which FedEx does not operate, but is still a good example to use. It has a maximum crosswind landing component of 36 knots on a dry runway (30 is the demonstrated number in the FCOM). The FCTM states sideslip only (zero crab) landings are not recommended with a crosswind component in excess of 20 knots.

The reason for these limitations is to prevent engine pods, flaps, or wingtips from striking the runway. This was not normally an issue in the early DC-9s, 727s, and 737-200s so many American pilots tended to use the sideslip technique quite effectively. But once you get into larger aircraft with wing mounted engines the sideslip technique becomes less desirable. A transition to de-crab in the flare is preferred so as to prevent parts of the airplane (other than the wheels) touching the runway in strong crosswinds.