A Condor Airbus A320-200, registration D-AICD performing flight DE-1745 from Kavala (Greece) to Munich (Germany), was in the initial climb out of Kavala's runway 23L climbing through about 2650 feet MSL when the crew received TCAS Traffic Advisory followed by a resolution advisory to climb a second later. The crew complied with the instruction, while climbing through 2770 feet the TCAS reversed now issuing a resolution advisory to descend. The crew descended the aircraft, descending through about 2450 feet MSL the Terrain Avoidance and Warning System (TAWS) issued a terrain warning prompting the crew to initiate a terrain escape maneouver. The aircraft subsequently continued to Munich without further incident.
Greece's AAIASB reported the lowest critical altitude during all critical phases was 2529 feet. The occurrence was rated a serious incident and is being investigated.
On Jul 9th 2020 the AAIASB released their final report in Greek only (Editorial note: to serve the purpose of global prevention of the repeat of causes leading to an occurrence an additional timely release of all occurrence reports in the only world spanning aviation language English would be necessary, a Greek only release does not achieve this purpose as set by ICAO annex 13 and just forces many aviators to waste much more time and effort each in trying to understand the circumstances leading to the occurrence. Aviators operating internationally are required to read/speak English besides their local language, investigators need to be able to read/write/speak English to communicate with their counterparts all around the globe).
The AAIASB reported the minimum separation between the two aircraft was 208 feet vertical and 0.09nm (167 meters) horizontal and concluded the probable cause of the serious incident was:
The prolonged activation of TCAS was the result of unsatisfactory response to the TCAS instructions.
Contributing factors were:
- Lack of information by ATC to the Condor crew about VFR traffic operating in the Kavala control area as well as non-use of English standard phraseology
- inaccurate adherence to cleared altitude (2500 feet) by the helicopter
- the decision by the Condor captain to turn right towards SID waypoint XERIS immediately after takeoff rather than follow the SID left insufficient distance to climb above the VFR maneouvering area with sufficient safety margin.
The AAIASB reported the crew performed a visual departure from runway 23L towards waypoint XERIS, part of SID, part of the XERIS 1C standard departure route. The first officer (33, ?, 1033 hours total, 682 hours on type) was pilot flying, the captain (35, ATPL, 5,063 hours total, 4,886 hours on type and 675 hours in command) was pilot monitoring.
While climbing out of Kavala the first officer observed traffic ahead about 300 feet above according to his TCAS display. Climbing through 2510 feet MSL the crew received a TRAFFIC! TRAFFIC! Advisory, the captain selected the navigation display to 10nm range. The first officer stated "TCAS! I have control!" Climbing through 2635 feet MSL the crew received a TCAS Resolution Advisory "MAINTAIN VERTICAL SPEED!", at that point the aircraft was climbing at about 1600 fpm and within the green band of permitted vertical speeds within the TCAS resolution advisory. The first officer responded with a nose down input however, the vertical speed reduced to 1100 fpm outside of the green band of permitted vertical speeds. Although the first officer subsequently provided nose up inputs again, the nose dropped further due to inertia and the rate of climb reduced to 500 fpm and never reached the green band again. While the aircraft was climbing slowly through 2730 feet MSL TCAS reversed the command and now instructed "Descend! Descend Now!" (TCAS RA Reversal) requiring to establish a sink rate of 1500 fpm within 2.5 seconds. Both captain and first officer now provided nose down inputs resulting in a vertical acceleration of -0.05G, still not reaching the green band of permitted vertical speeds. At 2763 feet MSL TCAS issued "INCREASE DESCENT!" while the aircraft was at 600 fpm descent, the helicopter was at 2869 feet MSL at that point and maintained that altitude throughout the event, the vertical separation was 106 feet and the horizontal separation 0.4nm. The first officer gave nose up inputs in response, the captain significant nose down inputs (without initiating the takeover procedure), in sum the aircraft increased the descent. The closest point of approximation was reached at 208 feet vertical and 0.09nm 4 seconds later.
The A320 was still over waters but closing to the coast line. The first officer stated in his testimony he wondered about the strong nose down pitch movements and provided nose up inputs to counter, being unaware of the captain's inputs. Both crew stated they never saw the dual control indication or heard the aural warning, neither pressed the take over button.
Descending now through 2414 feet MSL the crew now received a "TERRAIN AHEAD!" indication by the EGPWS, the aircraft was descending at 1973 fpm at that point. The immediate obstacle ahead was at 2049 feet MSL and mountains a bit further ahead at 3000 feet MSL. The captain shouted "I have control", applied TOGA and rose the nose to 11 degrees nose up producing a vertical acceleration of +1.77G. The first officer still provided minor opposite control inputs but ceased inputs about 7 seconds later. About 12 seconds after the TERRAIN AHEAD! warning Kavala control stated they were now clear of the traffic. About 35 seconds after the TERRAIN warning the aircraft came clear of the terrain, resumed normal climb and continued the flight to destination.
The AAIASB analysed that ATC did not provide information about the helicopter to the Condor flight crew nor was the crew able to understand the communication with the helicopter because that communication was done in Greek.
The AAIASB also analysed that it appeared the captain provided control inputs without following the takeover procedure causing the first officer to perceive the aircraft responding in an unexpected way and provide correcting inputs.
Metars around 07:09Z (the time of the occurrence):
LGKV 160720Z 23005KT CAVOK 28/18 Q1011=
LGKV 160650Z 23004KT CAVOK 27/18 Q1011=