Why do some pilots consider speed control to be optional??
Hi there,
I am an area controller in the UK and I have a question for pilots. This has begun to annoy me now as it seems to be happening more and more. I give a pilot a speed to fly and the pilot ignores the instruction. Either he/she doesn't fly the speed at all, or they choose to comply at a point that suits them etc. Heading/level instructions are not optional. Nor is speed control, so why do some pilots continually refuse to fly the assigned speed??
I am aware that if aircraft are not given descent early enough then they may be unable to comply with level restrictions and speed control at the same time. I always make allowances for this by informing the pilot which constraint to comply with first (I know there are plenty of controllers out there that don't and then moan about it afterwards when the pilot is unable to do as requested).
The scenario I had today was a very short haul flight (B734) cruising at FL170 and had been cleared when ready to FL130. I asked the pilot his speed, he said 320kts. A few minutes later I asked him to slow to 300kts, which was readback correctly. 5 minutes later the aircraft is still showing the same groundspeed and is catching up the aircraft in front (hence giving the speed restriction in the first place), so I checked the mode S which still said 320kts! I queried this with the pilot, to which he said he was planning on 300kts for the descent. He then reduced his speed and separation between him and the aircraft in front was not lost.
Perhaps I am missing something here, but to me there seems little room for confusion. In this scenario all that resulted was it increased my workload, clogged up the RT even more, and the pilot was still stuck behind the aircraft in front of him so achieved nothing by ignoring the restriction.
I know the vast majority of pilots comply with the speeds that have been assigned, but the few that don't really do increase our workload considerably as we have to issue more instructions (headings, stop descents etc) to achieve exactly the same result.
Perhaps someone can shed some light on this from the point of view of pilots.