Leaderboard

No - but try to open the sliding window after putting the FLT/GRD switch to FLT(with packs operating). Edit: To FLT, obviously.

The reason and explanation is in the post above yours . The reason for the "pressure bump" Hotdawg mentioned is that the outflow valve would be in the "far open" position, leaving a big hole in the aft lower section of the fuselage. As the plane rotates, air pushes against and into that hole, creating (uncomfortable) overpressure in the cabin. If you place the switch to FLT while still on the ground, this hole is almost closed, as the outflow valve is almost closed. Another benefit is that the cockpit sliding windows do not "rattle" in the guiding rails, they are pressed firmly into their sockets by the overpressure. Cheers, Jan

You place the FLT/GND switch to FLT during the after start flow and return it to GND during the after landing flow. In the FLT position the cabin is pressurized to about .2 psi or 200 feet below field elevation. If you forget an leave the switch in GND the cabin will still pressurize normally but you will get a pressure bump when the weight on wheels switch allows the outflow valve to close after takeoff.