Complex sentence: Some of the royalist air drops were organized by the British usring the Israeli Air Force (IAF) aircraft, which were contracted privately to the British mercenary operation and were either using Israeli air bases or Israeli transport planes themselves making the drops.
Split into simpler sentences: Some of the royalist air drops were aided by the Israeli Air Force (IAF). The aircraft were contracted privately to the British mercenary operation and were either using Israeli air bases or Israeli transport planes themselves making the drops.