The default language of international aviation worldwide is English, although local languages are used concurrently for RTF communications, even in busy and complex operational environments. Sometimes this practice is ‘justified’ on a local level by the reasoning that it avoids possible misunderstandings when addressing local specifics and facilitates the speed of the communication process with the native flight crews. However, controllers using both English for communication with international flights and the country’s native language for communication with the local crews potentially prevent both crews from achieving the desired level of situational awareness with respect of the other traffic.
In the context of the operational environment, the use of the English standard phraseology reduces the risk that a message will be misunderstood.
Use of Standard Aviation English phraseology is a major contribution to the reduction of ambiguity in aircraft/ATC communications and supports a common understanding among speakers of both:
- Different native languages and
- The same native language, but who use, pronounce or understand words differently.
English standard phraseology should be used in all communications (transmissions and receptions). When used properly, the information and instructions transmitted are of vital importance in assisting in the safe and expeditious operation of aircraft. However native language is still used locally, exceptionally for particular information or to describe unusual situations, or in case of an emergency. Incidents and accidents have occurred in which a contributing factor has been the poor situational awareness caused by the use of different languages on a single ATC frequency.
This subject was raised at the 40th Session of the Safety Regulation Commission (SRC) by the UK SRC representative, introducing a Working Paper SRC40.09 on the “Use of more than one language at airports in EUROCONTROL Member States” with the aim of drawing attention to this significant aviation safety issue and to seek support for the launch of an SRC-led initiative to standardise language use at major international airports within EUROCONTROL Member States. At SRC41 an update on the results of the consultation on the subject was provided. SRC tasked a coordination group to continue discussions on the issue of the use of more than one language at airports in EUROCONTROL Member States.
As result, the following Recommendation was presented to the members of the provisional council (4-5 December 2012): States to progress their considerations regarding extending the use of English at airports and relevant surrounding airspace sectors with international traffic of more than 50.000 commercial IFR movements a year, with a view to improving safety in this field.
Accidents and Incidents involving use of different languages
The following events include "Multiple Language use on Frequency" as a contributory factor:
On 12 April 2019, a Boeing 717-200 commenced a go around at Strasbourg because the runway ahead was occupied by a departing Bombardier CRJ700 which subsequently, despite co-ordinated TCAS RAs, then came to within 50 feet vertically when only 740 metres apart laterally as the CRJ, whose crew did not see the 717, passed right to left in front of it. The Investigation attributed the conflict primarily to a series of flawed judgements by the TWR controller involved whilst also noting one absent and one inappropriate ATC procedure which respectively may have provided a context for the resultant risk.
On 26 June 2017, an Airbus A319 which had just taken off from Stuttgart came into conflict in Class ‘D’ airspace with a VFR light aircraft crossing its track and when, at 1,200 feet agl, the TCAS RA to descend which resulted was followed, an EGPWS Mode 3 Alert was generated. Clear of Conflict was annunciated after 10 seconds and climb resumed. The Investigation concluded that the light aircraft pilot had failed to follow the clearance which had been accepted and had caused the flight path conflict which was resolved by the response of the A319 to the TCAS RA.
On 19 August 2017, an Airbus A340-300 encountered significant unforecast windshear on rotation for a maximum weight rated-thrust night takeoff from Bogotá and was unable to begin its climb for a further 800 metres during which angle of attack flight envelope protection was briefly activated. The Investigation noted the absence of a windshear detection system and any data on the prevalence of windshear at the airport as well as the failure of ATC to relay in English reports of conditions from departing aircraft received in Spanish. The aircraft operator subsequently elected to restrict maximum permitted takeoff weights from the airport.
On 17 March 2017, a Bombardier CRJ 700 which had just landed on runway 35R at Lyon Saint-Exupéry was about to cross runway 35L as cleared when its crew saw the departing Airbus A319 on runway 35L accelerating towards their intended crossing position and braked to a stop before entering the runway. The Investigation found that both aircraft had complied with all instructions issued by the TWR controller and concluded that safety management processes at the airport were not commensurate with the incursion risk involved and had been unchanged since an almost identical incident a year previously.
On 25 November 2014, the crew of an Airbus A320 taking off from Paris CDG and in the vicinity of V1 saw an A319 crossing the runway ahead of them and determined that the safest conflict resolution was to continue the takeoff. The A320 subsequently overflew the A319 as it passed an estimated 100 feet agl. The Investigation concluded that use of inappropriate phraseology by the TWR controller when issuing an instruction to the A319 crew had led to a breach of the intended clearance limit. It was also noted that an automated conflict alert had activated too late to intervene.
On 7 June 2018, a Boeing 737-800 operated by a non-Spanish speaking crew was given takeoff clearance at Alicante after the same supervised student controller had previously cleared two vehicles to begin a full-length opposite-direction runway inspection in Spanish. The controller error was only recognised when the vehicles were able to transmit that they were still on the runway, the aircraft crew being unaware of the conflict until then told to reject the takeoff. The maximum speed reached by the aircraft was 88 knots and minimum separation between the aircraft and the closest vehicle was never less than 1000 metres.
On 11 January 2018, a privately-operated Cessna 525A Citation with a two-pilot English-speaking crew made a night takeoff from Reykjavik without clearance passing within less than a metre of a vehicle sanding the out-of-service and slippery intersecting runway as it rotated. The Investigation noted that the takeoff without clearance had been intentional and due to the aircraft slipping during the turn after backtracking. It also noted that the vehicle was operating as cleared by the TWR controller on a different frequency and that information about it given to an inbound aircraft on the TWR frequency had been in Icelandic.
On 30 October 2014, a descending Airbus A320 came close to a Boeing 737-800 at around FL 220 after the A320 crew significantly exceeded a previously-instructed 2,000 fpm maximum rate of descent assuming it no longer applied when not reiterated during re-clearance to a lower altitude. Their response to a TCAS RA requiring descent at not above 1,000 fpm was to further increase it from 3,200 fpm. Lack of notification delayed the start of an independent Investigation but it eventually found that although the A320 TCAS equipment had been serviceable, its crew denied failing to correctly follow their initial RA.
On 21 September 2012, two aircraft came into conflict in Class 'A' airspace whilst under radar control at night and loss of separation was resolved by TCAS RA responses by both aircraft. Investigation found that one of the aircraft had passed a procedurally-documented clearance limit without ATC clearance or intervention and that situational awareness of its crew had been diminished by communications with the conflicting aircraft being conducted in Spanish rather than English. A Safety Recommendation on resolving the persistent problem of such language issues was made, noting that a similar recommendation had been made 11 years earlier.
On the 25th of May, 2000 a UK-operated Shorts SD330 waiting for take-off at Paris CDG in normal visibility at night on a taxiway angled in the take-off direction due to its primary function as an exit for opposite direction landings was given a conditional line up clearance by a controller who had erroneously assumed without checking that it was at the runway threshold. After an aircraft which had just landed had passed, the SD330 began to line up unaware that an MD83 had just been cleared in French to take off from the full length and a collision occurred.
- ^ (SRC) undertakes EUROCONTROL's work in the field of ATM safety regulation across the whole ECAC area and is composed of senior executives from within organisations responsible for ATM safety regulation at national level. SRC is responsible for the development and uniform implementation of harmonised safety regulatory objectives and requirements for the European Air Traffic Management (ATM) and ensuring their effectiveness through measurement of safety performance.