Good fliers who provide good service (4)

I believe the answer is:

aces

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'service' is the definition.
(I have seen 'excellent service' mean 'aces' so perhaps 'service' could also mean 'aces')

I don't understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for aces that I've seen before include "Expert fliers" , "passes with flying colours in US" , "Ones or elevens in cards" , "Unreturnable services" , "Top (or bottom) cards" .)

I've seen this clue in the Sydney Morning Herald.

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