No target attacked. Attacked by JU88 on bombing run. Mid upper gunner killed and rear gunner wounded. Bomb Aimer pressed bomb release and took jettison action at first indication of tracer but was unaware bombs had not released due to electrical failure. He manned the front turret and got several bursts away, the last causing sparks from port wing of JU88 which was not seen again. Bombs jettisoned mid-channel.