ehbowen
Engineer
In U. S. railroading, the term "pilot" referring to a member of the engine crew (the very front of a locomotive can also be called a 'pilot') is used in much the same way as a nautical pilot who guides a crew unfamiliar with a waterway in and out of harbor. Say you have an Amtrak train such as the California Zephyr and/or Southwest Chief, which normally operate in and out of Chicago on the ex-Burlington line to Galesburg through Naperville and Princeton. The Amtrak crew, which is qualified to operate the P42 locomotive, is also qualified to operate over that line which the train normally uses every day. Now, suppose that there is an accident or major track work which renders that line unusable and the decision is made to operate over the ex-Santa Fe line through Joliet. Amtrak has engineers who are all qualified to operate the P42s, but they are not familiar with that line. BNSF has many engineers who are familiar with that line; location of crossings, speed restrictions, and so forth; but most likely none of them are qualified to operate an Amtrak P42. So, what would happen is that Amtrak would request BNSF to supply a "pilot engineer" who would ride in the cab with the Amtrak engineer; the Amtrak engineer would operate the controls of the locomotive while the BNSF engineer would advise the Amtrak engineer about the locations of signal, grades, curves, grade crossings, and so forth until the Amtrak train was ready to re-enter its normal operating territory at (or near) Galesburg.Whereas in Britain a pilot is a locomotive that is typically used only within a given station, especially for the purposes of preparing and switching passenger cars. In steam days it would typically have been an older locomotive retired from front line duties, and could in case of a dire locomotive shortage be sent out onto the main line agiain .Unless you are in India, where the folks who operate EMUs are generally called Motormen.Dont ever call a locomotive engineer a motorman. That is for subways!
Other than that, the people who operate engines are called Loco Pilots and Loco Pilot Assistants (LP and LPA for short) in India. In general there are two LP/LPA in the cab for all long distance trains in India. Also in general, only one Motorman in the cab on suburban EMUs.