In the UK there is a minimum published rate of climb/descent in the AIP. Maybe we need something similar for descent speeds above FL100 for jet aircraft as well ?
If there was a published minimum IAS (say 280Kts), then pilots who want to go slower for whatever reason would have to let us know and then they'd be accomodated, but in a planned manner and not as a fire fighting exercise for ATC. Faster traffic could also be given a more optimum profile (an overtaking manouvre
) rather than everyone else having to slow down to fit in with the slower guy at the head of the traffic sequence.
Even at cruise speeds we are now finding that some aircraft are flying at slower speeds than filed, due to the economic dictats. There's no problem with flying at the slower speeds in the cruise, but if you don't change the flight plan and let us know, then we can base some tight in trail radar separation on the basis of your declared speed. Or even worse, we can base procedural separation on your speeds where there is no radar !! On radar at least, the big clue is when someone (in an orange Airbus usually) has filed 460Kts true and is being caught by someone who is flying at his filed 420Kts true. Mmmm, how does that happen ?
The final comment I have is that we are now seeing some pilots (small in number but growing at a worrying rate) who state that they cannot speed up from 250Kts in the descent due to company SOPs for fuel economy (this is above FL100). In busy airspace we don't have time to argue the toss and if we need you to speed up for overall flight efficiency and safety (i.e. separation), then it's an instruction and not a request.
If there's a flight safety reason why you can't comply (turbulence penetration or airframe restrictions for example), then let us know and it's a valid circumstance for us to have to change our plan. We are here to help in such circumstances. And the valid reasons for your refusal will be on the tape.
If it's simply for the beancounters, then our fallback position is that ATC instructions are mandatory (within Controlled Airspace anyhow) and are being given to ensure flight safety and traffic management efficiency. That's not a glib excuse to get you to comply, but you're probably at the head of the pack and a lot of work and vectoring/slowing down is going to be needed to sort everyone else out. And as others have said, the fuel penalties on everyone else are not fair on them, as well as being inefficient to the whole system of moving traffic smoothly.
If there's no safety reason that you can't comply and you still refuse, then our brief is that the CAA regulator is the one who'll take it up with the company, either through a Mandatory Occurrence Report, or as a Breach of the Air Navigation Order.
Between us all, we can make the system work, but you need to give ATC a fighting chance by declaring slow speeds, and you need to think about the effects on the other aircraft in the sky, whatever your position in the sequence.