B747-400
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft; Procedure
Contract maintenance noted a leaky hydraulic line on the right body gear and were replacing the line when I was conducting my preflight. I asked them about the repair and they said that they were finishing up. They signed the repair off and we pushed taxied and took off without incident until the first officer attempted to raise the landing gear. He could not get the lever past the off position and a 'GEAR TILT' caution message displayed on the EICAS.  We informed ZZZ departure that we needed to work a landing gear issue; and requested to level off at 5;000 feet.  I believe ZZZ TRACON [advised] an issue on our behalf; since thereafter they referred to us as an emergency aircraft. We completed the QRH for 'GEAR TILT' after advising departure of our issue; then consulted with our dispatcher and maintenance control via satphone; and determined that the best course of action would be to jettison fuel to below max landing weight and return to ZZZ. We calculated our maximum amount of fuel to be on board when landing by subtracting the zero fuel weight from the max landing weight. Since we were so close to the field we elected to jettison down to our max landing weight before returning to the field. We calculated 85.3 tons of fuel to be the maximum amount of fuel we could have on board considering a zero fuel weight of 210.4 tons and a max landing weight of 295.7 tons. We decided to be cautious and jettison down to 83.0 to ensure we were well below max landing weight. We ran the fuel jettison checklist in the QRH; and jettisoned fuel as per procedure. We were receiving radar vectors during this time. After our jettison was complete; we returned to ZZZ and conducted an ILS to Runway XXL landing without further incident. Bill contract maintenance when they make a mistake and cost the company money.
B747-400 First Officer reported an EICAS GEAR TILT message on takeoff; resulting in fuel jettison and an air turn back to a precautionary emergency landing.