The crew of a Fairchild Metro 23 aircraft report experiencing difficulty in maintaining directional control as they applied power during the take-off roll. The aircraft seemed to be sluggish in accelerating and was pulling to the left. The difficulty in controlling the aircraft was exacerbated due to the inadvertent deactivation of the nose wheel steering button on the left power lever.
This system had been checked during taxi and was confirmed as serviceable. The crew indicate that this switch was "on" at completion of the pre-take-off checklist but had somehow been released during the early stages of the take-off roll.
The crew detected that the left propeller had not released the start locks, resulting in asymmetric power being produced. A non-standard call made by the pilot not flying is reported to have delayed the crew's recognition of the problem. The crew were in the process of abandoning the take-off when the aircraft veered off the left side of the runway, stopping prior to the runway 10 T-VASIS. The crew taxied the aircraft back onto the runway, switched the nose wheel steering system "on" and taxied normally back to the hangar for maintenance investigation.
The aircraft was not damaged during the incident and all aircraft systems checked out as serviceable. The crew briefed themselves on aspects of the previous incident before departing on the planned flight.