A breakdown in understanding between the Flight Crew and a Controller results in a perceived course deviation while circumnavigating weather. Subsequent exchanges resolve the issue.

Date: 2009-08 · Aircraft: Commercial Fixed Wing · Phase: descent

Anomalies: atc-issue-all-types|deviation-track-heading-all-types|inflight-event-encounter-weather-turbulence

Synopsis

A breakdown in understanding between the Flight Crew and a Controller results in a perceived course deviation while circumnavigating weather. Subsequent exchanges resolve the issue.

Narrative

In descent while flying the QUAIL STAR; thunderstorms were too close to our course; so the captain requested the DANDD STAR; which the Controller said would be available soon. The Captain then asked to deviate right of our course and the controller asked if we could wait 2 minutes and then the DANDD STAR would be available. The Captain said that we could and in 2 minutes we were cleared direct to DANDD and the DANDD STAR. We changed to another DEN Controller who gave us a clearance to cross DANDD at fl 190 and 250 knots. We decided that we wanted more separation from the storm and the Captain requested a 5 mile right offset from the arrival. The Controller approved this and the Captain executed a R5 offset in the FMC and we turned to the offset. The Controller called just as we were getting established on the offset to say we were 15 miles right of the arrival and going further away. The Captain explained that we had been going direct to DANDD and had offset 5 miles right from that course for the weather. The Controller said that we had to be 5 miles right of DANDD at fl190 and 250 knots and we said that we would be at that point. I think the communication problem was that the Controller expected us to be offset 5 miles right from the DANDD STAR from the point inbound to DANDD; which we had never been established on and would have taken us toward the weather from the position that we started our deviation. We discussed that it would have been easier to just ask to deviate right of course for weather; but the Captain felt that by giving the Controller more specific information; he was attempting to help. We made the restriction at DANDD at a 5 mile right of course deviation and then went back to course and finished the flight uneventfully.

Second reporter narrative

I meant our current course; he/she must have thought I meant the original published course. I should have been more specific and clear but I thought that it was clear that the weather was to our left as we had been deviating to the right through a couple of sectors. There was no traffic conflict and we remained clear of the weather.

Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.