A magnetic tape drive in a helical scan system can shorten retry operation time. A data signal reproduced from magnetic tape through reproducing heads is supplied to a regenerative signal processing circuit. If an uncorrectable error is contained in the signal, the regenerative signal processing circuit outputs error information to a system controller. Then, the system controller sends a retry instruction to a movable head controller. When receiving the retry instruction, the movable head controller supplies movable head control signals to displacement elements which then displace the reproducing heads along a rotating shaft of a rotary drum for re-scanning an error occurrence data track. This retry operation is repeated until no error is detected. The magnetic tape is run at lower speed or is stopped as required during the repetitive retry operation.