Synopsis
The crew of an Airbus A300-605R, registration TC-MNV, were cleared to depart from RAF Brize Norton on a Malby Standard Instrument Departure (SID), requiring a climb to FL080. However, a Climb-out Restriction (COR) of 2,200 ft on the airfield QNH was imposed by Air Traffic Control (ATC) to provide vertical separation from a military Boeing Vertol CH-47D Chinook HC2, registration ZA720, which was in a holding pattern above the airfield. The COR instruction, which was not standard radiotelephony (RT) phraseology, was misinterpreted by the A300 crew. The A300 did not level off at 2,200 ft after departure but climbed through the level of the Chinook. The returns from the two aircraft were seen to merge on the ATC radar display. The A300 crew received a Traffic Collision Avoidance System (TCAS) Resolution Advisory (RA), which they followed.
History of the Flight
The A300 arrived from Istanbul that morning and was carrying out a return, freight-only flight to Istanbul Sabiha Gokcen International airport in Turkey. The crew comprised two pilots and a loadmaster. The aircraft commander was the pilot handling and the co-pilot was the pilot monitoring; his duties included radio communications. It was the commander’s first rotation through Brize Norton, but the co-pilot had been there a number of times before. Both were Turkish nationals with a good working knowledge of English.
The crew of the military Chinook helicopter were carrying out instrument flying training and were tracking 307°(T), inbound to the Brize Norton (BZ) NDB, to take up the holding pattern. The holding pattern is a standard, right hand hold with an inbound heading of 100°. This required the crew to perform a parallel join, followed by a left turn to return to the BZ. The helicopter, which was equipped with a Mode S transponder but squawking Mode C, was flying at 3,000 ft on the Cotswold QNH of 1010 hPa. The crew were instructed by ATC to set the Brize Norton QFE of 1005 hPa, adjust their height to 3,000 ft on that setting and contact the Brize Norton Director on 133.750 MHz. In order to provide vertical separation from the departing A300, the Chinook crew were then instructed to climb to 3,500 ft on the QFE.
Radiotelephony Communications
Prior to takeoff, the A300 crew contacted the tower controller and the following RT exchange took place. The tower controller transmitted: "BLACK SEA FIVE ZERO EIGHT, CLIMB OUT RESTRICTION TWO THOUSAND TWO HUNDRED FEET ON BRIZE QNH ONE ZERO ONE FIVE ACKNOWLEDGE." The co-pilot responded: "ONE ZERO ONE FIVE COPIED, WE ARE ALSO ABLE TO TAKE THE ECHO FOR, FOR DEPARTURE." The controller then asked for confirmation of the restriction, and the co-pilot replied "YES GOOD COPIED, THANK YOU." After further prompting, the co-pilot eventually stated "YEAH, TWO THOUSAND TWO HUNDRED FEET COPIED." The crew, who were expecting taxiway and runway related information, interpreted the 2,200 ft to be the runway length reduction when entering the runway from holding point Echo. Although both pilots were familiar with the term ‘Climb-out Restriction’, they did not register the information as an altitude and therefore did not read back the phrase.
After takeoff, the crew contacted the approach controller. The approach controller did not request the SID or cleared altitude initially. When the controller asked for passing altitude, the aircraft had already passed through 2,200 ft. The controller then issued an avoiding action: "BLACK SEA FIVE ZERO EIGHT YOUR CLIMB OUT RESTRICTION WAS TWO THOUSAND TWO HUNDRED FEET, AVOIDING ACTION STOP CLIMB IMMEDIATELY TURN RIGHT HEADING ZERO TWO ZERO DEGREES." The A300 crew responded that they were climbing due to a TCAS call. The aircraft were visually sighted soon after, and normal climb was resumed.
Radar and TCAS
According to TCAS data from the A300, the minimum lateral separation between the A300 and the Chinook was 0.11 nm and the minimum vertical separation was 496 ft. The returns of the two aircraft merged on the approach controller’s radar display.
Aftermath
The Chinook crew filed an Airprox report following the incident. Two Safety Recommendations were made with the intention of preventing similar incidents in the future.