DAB Controller experienced a loss of separation event between two IFR training aircraft listing language problems as a causal factor.
Synopsis
DAB Controller experienced a loss of separation event between two IFR training aircraft listing language problems as a causal factor.
Narrative
Both aircraft on training flights; Aircraft Y established on the transition from GUANO inbound for the DAB RNAV RWY 7R Approach. Aircraft X was assigned heading 250 which was a RADAR assigned vector that would take the aircraft to GUANO Intersection to begin approach. The pilot of Aircraft X was advised to expect to start the approach from GUANO at XA:28Z; which the pilot acknowledged whom I believe was the instructor. At XA:30Z Aircraft X was instructed to cross GUANO at 2;000 cleared RNAV Runway 7R approach straight in. I used straight in due to the on going communications issue with foreign pilots and the high volume of unpredictability in the training environment. The student pilot; I believe; responded with the botched phraseology 'CLEARED FOR APPROACH ON RWY 7 STRAIGHT IN'. At the time; I believed that I had heard and understood enough of the transmission that the pilot would fly the track I expected. At XA:21Z I observed that the RADAR track was not what I expected; appeared to be turning south; and asked the pilot if he was direct GUANO. The pilot replied that they were direct TACUR. The aircraft were observed on a converging course and separation was lost. Aircraft X was issued an immediate right turn to heading 290 to re-establish separation. I immediately called the FLM to my sector and advised him of the loss of separation. The FLM and I listened to the voice recording and discussed ways to mitigate this type of scenario from re-occurring. However; the pilot's poor communications skills were definitely a contributory element to the event. Unfortunately; due to the high volume of training with various degrees of experience within the instructor and student ranks; controllers at DAB are very adept at working with the students and their poor communications and aviation English. Often times a controller can only make out partial/incomplete transmissions; and through experience and observation of the flight tracks; the controller is able to determine if the pilot is complying with the instructions issued. It is not helpful when the student and the instructor have language issues and these types of incidents will continue to occur. Miscommunication is the root cause of this incident. Both the instructor and the student were answering calls and the language barrier was evident.
Second reporter narrative
The situation occurred during a normal instrument training flight. Due to scattered clouds at 3;000 FT instructor requested a 'local IFR' according to LOA and familiar procedures. This was approved by ATC; and we were cleared to Daytona Beach via RADAR vectors; the clearance also included an EFC time. This clearance was later amended by ATC to allow for a VOR 17 training approach to Ormond Beach Municipal Airport with a new clearance limit. After completion of the VOR 17; the next approach in the requested sequence was RNAV 16 to Daytona Beach. This approach was completed via IAF CEPDA after expected vectors to final. I can not at this time remember if the given clearance contained DAB as a clearance limit; or for the sub-sequent approach RNAV 7R. After the completion of RNAV 16 to Daytona Beach; we received RADAR vectors for RNAV 7R Daytona Beach. The vector I remember assigned was 250. This would position us on a 'downwind' opposite of the final approach course in Class C airspace. We were instructed to maintain 2;000 FT. Then we received an 'expect' information that instructor acknowledged with 'roger'. Instructor interpreted the information as the expected approach that was also requested. Then we received an approach clearance containing an IAF that by both pilots was interpreted as TACUR. We set course DCT TACUR still maintaining 2;000 FT. The Controller asked us to verify if we were DCT 'GUANO' (a IAF in the same approach) The instructor took the radios to clarify that we were inbound TACUR not GUANO. We were then instructed to fly DCT GUANO. This instruction was then acknowledged and followed. I then recognized that we might have been instructed to fly DCT GUANO at an earlier stage; since the Controller stated 'I say again'. Yet this; as a clearance/instruction; was not recognized nor acknowledged by the flight crew at any point. I notified ATC that we were unaware of the expectation and instruction. We got a re-issued instruction (I believe it was 'I say again' then IAF GOUDA. The approach then was completed accordingly; as cleared and acknowledged after the clarification. I suspect that we failed to follow a given clearance or instruction; and if so; we did not acknowledge or know that specific clearance/instruction at the point we were expected to. The reason I acknowledged the expected information previously given with the phrase 'Roger' was that this was an informative message; and did not require nor authorize compliance at that point. 'Roger' means according to pilot controller glossary; that the full transmission is received. In this case it might have been used incorrectly; it was meant as a reply to information. We were operating under IFR on a LOA without FPL; Airspace E and C. While this happened we were in VMC and received two or more traffic information advisories based on apparent visual separation. This also happened during the instrument approach itself. Yet I believe we were subject to IFR separation at the same time as a result of the requested; followed and intended flight rules. As ATC gave traffic advisories that was replied to by us; requiring visual separation; ATC was aware that we were not IMC at the time of the situation; thus able to maintain visual separation to any surrounding traffic. We were not informed about any possible pilot deviation by ATC; or any sub-sequent traffic conflict as a result of the situation that occurred. Usually ATC is very thorough when it comes to read back/hear back of clearances in this particular environment. As we did not read back; nor copy the correct intersection (IAF) that we were cleared direct to; we were clearly unaware the full given clearance/instruction. We made immediate correction as soon as we realized there was a conflict in intentions between ATC and pilots. I found the controller professional; clear and precise in all his instructions. As an on board pilot and flight instructor I am; and was; aware of the pilots responsibility to correctly; andin a timely manner; read back and comply with given clearances. In this case I believe I; as the flight instructor; unknowingly failed to do so because of mis-interpretation and lack of correct read back and hear back. I believe 'DCT TACUR' was read back at some point; as we did precede DCT TACUR; but I do not know if the transmission was received by ATC.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.