On 4 April 2016, a Boeing 737-800 on a normal visibility night take-off from Jakarta Halim collided at high speed with an ATR 42-600 under tow which had entered the runway after unchallenged ambiguity in its clearance. Despite avoiding action taken by both parties, both aircraft were substantially damaged although all those involved escaped uninjured. The Investigation is continuing but has noted the failure to use a single runway occupancy frequency, towing of an unlit aircraft, the potential effect on visibility of embedded approach lighting ahead of the displaced landing threshold and issues related to controller traffic monitoring effectiveness.