"I'm reluctant to question ATC but at times have felt they are giving me instructions that aren't correct or even safe. What can I do when ATC tells me something I don't agree with?" - Steve W
“One of the most important words we have in our pilot vocabulary when dealing with ATC is the word Unable.
Air traffic control sometimes can ask you to do something that you are completely incapable of doing. I remember this – I was going into the vineyard and I was in a Cirrus, an SR-20. The controller said, Can you give me your best speed to the marker?
I said, No problem, and I gave them my best speed. We were doing about 145 or so.
He said, Well can’t you give me 160?
And I said, Did you see this is an SR-20 not an SR-22. UNABLE.
He had a King Air behind me. I said, If you want to turn me out, that’s fine. Turn me out and bring whoever’s behind me past and bring me back in, but I’m going as fast as I can.
It might be that your aircraft is capable of it; but you as a pilot are incapable of staying ahead of the aircraft. Perhaps ATC is pushing you to give you that best speed, but it’s too fast for you to stay ahead. You’ve got to be able to say, Unable.
Or if they turn you 20° to the right and looking out the front window you see, My gosh! That looks like a cell going up to at least 60,000 feet, that sucker’s going to tear my airplane apart. UNABLE.
It’s a magic word that we have to be able to use all the time.”