Chancellor 414A / C414
Air Traffic Control Fully Certified
Confusion; Situational Awareness
Deviation / Discrepancy - Procedural Clearance; Ground Incursion Taxiway
General None Reported / Taken
Airport; Chart Or Publication; Human Factors
A C414 had been taxed to Runway 1 for IFR departure. The active runway was Runway 1. While holding short; the C414 asked for a Runway 32 departure. I restated the winds; (which were favoring Runway 32 at that moment); and confirmed with the C414 that he was indeed requesting Runway 32. The pilot said affirmative. I transmitted taxi instructions; saying 'C414; Runway 32 taxi via taxi North on Runway 1; then B2; B3.' The pilot sounded confused; and asked if Runway 32 was just in front of him. I said yes; and then explained that the two runways were once connected; but were no longer; so that he couldn't taxi straight across to it. I made another transmission to another aircraft.  The next transmission I received from the C414 was clear and confusing; but I clearly heard the pilot say he was going; and that he was cleared for take off. I never used the word 'take off' to him. I looked at him quickly; and not only did he taxi straight across the approach end of Runway 1 to Runway 32; on a surface that is no longer a portion of the movement area; but he had throttled up suddenly and already had gained speed. I did not say 'cancel take off clearance;' because the closest traffic I had was not enough of a factor; and I thought cancelling his take off could be potentially unsafe. I just coordinated with Low RADAR Approach for a release; even though the aircraft was airborne at this point; and control instructions for the aircraft to remain clear of a VFR aircraft under approach control I then switched the C414 to Low RADAR. I have heard from controllers that this has happened before. I would like to have the area that is no longer a movement area marked more clearly; so as to be obvious to pilots that it is not to be used for aircraft movement. Other than that; all I can think of to do is just watch more vigilantly to observe a turn in aircraft that are to be operating on Runway 1; so I can catch it more quickly if they do not correctly follow instructions.
ACT Tower Controller described an incursion into a non-movement area when clearing an aircraft holding short of Runway 1 for takeoff on Runway 32 with specific instructions to taxi via B2 and B3.