49 CFR §240.231

1. (a)Except as provided in paragraph (b) of this section, no locomotive engineer shall operate a locomotive over a territory unless he or she is qualified on the physical characteristics of the territory pursuant to the railroad's certification program.
2. (b)Except as provided in paragraph (c) of this section, if a locomotive engineer lacks qualification on the physical characteristics required by paragraph (a) of this section, he or she shall be assisted by a pilot qualified over the territory pursuant to the railroad's certification program.
   1. (1)For a locomotive engineer who has never been qualified on the physical characteristics of the territory over which he or she is to operate a locomotive or train, the pilot shall be a person qualified and certified as a locomotive engineer who is not an assigned crew member.
   2. (2)For a locomotive engineer who was previously qualified on the physical characteristics of the territory over which he or she is to operate a locomotive or train, but whose qualification has expired, the pilot may be any person, who is not an assigned crew member, qualified on the physical characteristics of the territory.
3. (c)Pilots are not required if the movement is on a section of track with an average grade of less than 1% over 3 continuous miles, and
   1. (1)The track is other than a main track; or
   2. (2)The maximum distance the locomotive or train will be operated does not exceed one mile; or
   3. (3)The maximum authorized speed for any operation on the track does not exceed 20 miles per hour; or
   4. (4)Operations are conducted under operating rules that require every locomotive and train to proceed at a speed that permits stopping within one half the range of vision of the locomotive engineer.