Air Traffic Control Fully Certified
Confusion; Situational Awareness
ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Loss Of Aircraft Control
Air Traffic Control Issued New Clearance; General Declared Emergency
Aircraft; Human Factors
I was training a Student. We were busy with Runway 13R arrivals. A PA32 called. The Trainee instructed him to depart GREGS heading 120. There was no other traffic in the vicinity and at his speed; we had some time before we would need to get back to him. The next thing we knew; the adjacent position Controller; who wasn't busy; informed us that the PA32 had turned northbound back into the Center's airspace. We called the aircraft and tried to get him turned back around in the direction he was supposed to be going. He advised us that he had instrument problems and I assumed a directional gyro (DG) problem and told the student to issue 'no gyro vectors'. I took the position when the Student was unsure about issuing the no gyro vectors and asked the Supervisor to open another position to take the Runway 13R traffic off our frequency. I also asked the adjacent Controller to call the 2 Center sectors near the PA32 and advise them of the problem. It turned out that the pilot was unable to maintain directional control. I changed my mind from instrument trouble to a pilot with vertigo. At this point I simply advised the pilot that he was still turning and asked him to simply keep the airplane straight and level. This went on for a little while; during which the PA32 also climbed from 040 to 060. Once or twice he seemed to stabilize but then would lose control again. He finally got the aircraft enough under control that we were able to vector him for and ILS approach. He went below his assigned altitude when being cleared for the ILS and reported the airport in sight. At this time; we cleared him for a visual approach switched him to the Tower. He answered but failed to do so with his call sign. However; he was having enough problems and didn't need anything else to confuse him so we didn't berate him over the no call sign. Recurrent training for the pilot on partial panel procedures and following the instruments when disoriented.
Enroute Controller initiated 'no gyro vectors' to an aircraft that was experiencing difficulties complying with assigned headings; the reporter recommending more pilot training to prevent future occurrences.