Investigation number
199303462
Occurrence date
State
Western Australia
Report release date
Report status
Final
Investigation type
Occurrence Investigation
Investigation status
Completed
Occurrence category
Incident

The Air Traffic Service (ATS) Officer issued a clearance for the aircraft to climb from FL330 to FL370. The crew did not receive the clearance. The ATS Officer did not realise he had not received an acknowledgement to the clearance and assumed the aircraft had climbed to the assigned level. He later misunderstood a further request from the crew for information about the climb clearance to be a statement that the aircraft was cruising at the new level. Consequently the aircraft transitted between two reporting points at the incorrect flight level. The error was discovered when the aircraft reported its level at the next reporting point. No traffic confliction resulted.

Aircraft Details
Manufacturer
The Boeing Company
Model
747-400
Registration
N117KG
Sector
Jet
Departure point
Changi Singapore
Destination
Melbourne VIC
Damage
Nil