Unable to accept Radar Vector.
Wonder if anyone can help in explaining the following.
A pasenger jet is radar vectored for an ILS approach. The radar controller gives a new heading to "turn right heading 340". The pilot answers "we are unable to accept a right turn at this time". Radar controller says, Roger, advise when you can accept a right turn. A few moments later the pilot says "we can accept a right turn now". The aircraft is given new vectors and and proceeds to intercept the localiser and lands.
Why would the pilot be unable to accept the right turn.
Thanks.