Line Oriented Flight Training (or LOFT) is training in a simulator

Flight simulator

A flight simulator is a device that artificially re-creates aircraft flight and various aspects of the flight environment. This includes the equations that govern how aircraft fly, how they react to applications of their controls and other aircraft systems, and how they react to the external...

 with a complete crew

Aircrew

Aircrew are the personnel who operate an aircraft while in flight. The composition of the crew depends on the type of aircraft as well as the purpose of the flight.-Civilian:*Aviator** Pilot-in-command** First officer** Second officer** Third officer...

 using
representative flight segments that contain normal, abnormal, and emergency procedure

Emergency procedure

An emergency is a serious, unexpected, often dangerous situation that requires immediate action. The emergency procedure is a plan of actions to be conducted in a certain order or manner, in response to an emergency event.-Need for Emergency Procedures:...

s that
may be expected in line operations.

An instructor will monitor the crew's performance and review the simulated flight or flights with the crew afterwards to point out errors or good decisions that were made.