British Airways A319 G-EUPH operating BA1421 Belfast City – London Heathrow stopped the climb at 3,200 ft this evening due to a technical issue, climbed to 6,000 ft and circled over Lough Neagh to work checklists and then diverted to Belfast International for a safe landing. The aircraft remained on the taxiway for several minutes with fire crew in attendance and then taxiied to the terminal under its own power.