Date: 202106
Local time of day: 1201-1800
Location: ZZZ.TRACON, US
Flight conditions: VMC
Light: Daylight
Aircraft: SA-227 AC Metro III
Mission: Ferry / Re-Positioning
Flight phase: Takeoff / Launch
Airspace: Class D ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Horizontal Stabilizer Trim
Component problem: Malfunctioning
Reporter function: Captain
Reporter qualification: Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human factors: Troubleshooting
Anomaly: Aircraft Equipment Problem Critical; Airspace Violation All Types; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Landed As Precaution; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: I accepted a ferry flight for Aircraft X from ZZZ to ZZZ1.  This flight was accomplished as a single pilot operation. It was a perfectly clear day; with light winds from the south.  Aircraft X required a special ferry permit due to an inoperative stabilizer trim position indicator; coupled with an inoperative out-of-trim warning system.  Essentially; the pilot was unable to determine the position of the elevator trim from inside the flight deck; and there was nothing to alert the pilot that the trim was set outside of the takeoff range during takeoff.  I was thoroughly familiar with this discrepancy because I had recognized it and alerted Maintenance of the need for repair the night before this event.  The stabilizer trim itself had functioned normally.I felt comfortable accepting this flight; as I had been flying Aircraft X for many days prior to the aforementioned maintenance issues; and was familiar with this specific aircraft.  Before starting the engines; I re-trimmed the horizontal stabilizer by making adjustments on the flight deck and confirming the position of the trim visually from outside the aircraft.  Confident that the airplane was ready for flight; and assured that the trim was working; I started the engines and taxied to Runway XXL for takeoff.After experiencing no abnormalities prior to V1; and reaching the predetermined rotation speed; I took the plane airborne.  After attaining a climb and retracting the landing gear; I attempted to make my first adjustment of the stabilizer trim since starting the engines.  There was no response to my input.  My first reaction was to ensure that I had not switched the stabilizer trim off inadvertently; as the switch rests immediately adjacent to my right knee.  The switch was still positioned to the Captain's side.  At this point I quickly recognized the gravity of the situation; which was that I was now flying a nearly 11;000 pound airplane; and I had no mechanical assistance to maintain a level flight attitude. During the climb out; my yoke weighed approximately 70-80 pounds.In my initial radio communication with Departure; I informed the controller of my altitude and that I had no elevator trim.  I did not explicitly declare an emergency.  When asked if I needed assistance; I requested the most direct radar vector possible to join a visual approach at ZZZ1.  I knew from my preflight planning that they were landing to the south at that airport and Runways XXL and XXR were in use.  This meant that from the point at which I began my first turn to the point at which I joined final approach was a straight line just under 15nm long.  This reduced the physical burden on me significantly versus returning to ZZZ; as flying the airplane became noticeably easier in straight and level flight.I also requested a lower altitude than the 9;000 feet MSL that I was cleared to.  Departure requested that I maintain 8;000 feet MSL as there were military aircraft operating in ZZZ2 airspace at 7;200 feet MSL.  The vector I was given took me directly over the top of the military airfield.  I visually observed several military fighter aircraft engage in sharp right turns to remain clear of me laterally.  During level flight; I allowed the airplane to accelerate to approximately 215 KIAS.  Every bit of airspeed I gained translated into a lightening of my controls; and made it possible to continue flying without exhausting the strength of my arms.  It is possible that while at this speed; I descended under the Class B airspace into the Class E airspace that lies north of ZZZ1 and west of ZZZ2.  Meaning; under my authority as PIC of an aircraft under 14 CFR 91.3; I may have inadvertently violated 14 CFR 91.117 as it pertains to the maximum speed of an aircraft in Class E and Class D airspace. The conclusion of this flight was a safe landing at ZZZ1; followed by an uneventful taxi to the company maintenance hangar.  I believe that I conducted this 8 minute flight as well as could be expected of any pilot with a similar level of knowledge and experience.  My familiarity with the aircraft and the surrounding area; my current level of physical fitness; as well as the timely response and assistance from air traffic control led to the safe outcome of the flight.




Synopsis: Pilot reported the stabilizer trim malfunctioned after takeoff; requiring great physical strength to control aircraft pitch. Pilot performed a successful diversion to a landing.