The AV-8 Harrier II's Cross Missile is of average power without power-ups; however, when fully powered, it is fairly strong. The Supporting Bomber special weapon calls three Avro Bombers which drop bombs on the enemy; oddly enough, this bomber is also the boss of the England level of the game.
AV-8 Harrier 2
VTOL [Vertical Take-Off and Landing]. Shots can be fired in 3 directions.
-Aerofighters 2 English game manual
The AV-8 is fairly powerful, and although its Napalm Bomb does not fill the full screen as some bombs do, it does cover enough area to be useful and can take out a wide field of enemies.
The AV-8 Harrier II Plus is of average strength on all levels of power, although at full power it does fire additional missiles which can help to take out enemies faster. Its bomb consists of two diagonal bursts of flame which strike enemies to the sides but may miss those directly in front of the plane.