Why would anyone accept a clearance for immediate takeoff, taxi onto the
runway, and then tell the tower a moment on the runway was needed?
Perhaps they discovered something (potentially fatal) in the interim?
You don't believe the reason given by the submitter?

What reason? And why does it matter? You asked a general question. In
any case:

Narrative
ACFT WAS CLRED FOR IMMEDIATE TKOF (TFC INSIDE THE MARKER) ON RWY 22. WE
TAXIED ONTO RWY AND TOLD TWR WE NEEDED A MOMENT TO CHK OUR DEP ROUTING
WITH OUR WX RADAR (STORMS IN THE AREA, RAINING AT THE ARPT).

Nothing here precludes discovering something (potentially fatal) which
would warrant the request. Maybe that something =should= have been
discovered prior, but that's besides the point.

"Wait a moment - those storms are to the right of us, not the left. Our
clearance is 'turn right heading 280...' - let me check and make sure
we're still ok."

Jose
--
The monkey turns the crank and thinks he's making the music.
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