ABRAHAM ACHIRGA A small Nigerian air force passenger plane crashed just outside Abuja airport after reporting engine failure on Sunday, killing all seven people on board, the air force said. The plane, a Beechcraft King Air 350i, was on its way to the city of Minna, 110 kilometres (68 miles) northwest of the capital, said air force spokesman Ibikunle Daramole in a statement. The aircraft "crashed while returning to the Abuja Airport after reporting engine failure," said Daramole. "First responders are at the scene. Sadly, all 7 personnel on board died in the crash." The chief of the air force…