The most common and most likely answer to this crossword clue is the 3 plus 7 plus 2 letter word ALL SYSTEMS GO
I've seen this crossword clue in The Guardian
A
L
L
S
Y
S
T
E
M
S
G
O
More clues leading to the result ALL SYSTEMS GO
- Gassy smell to change report of perfect readiness
- Every constitution’s to lapse; nothing to prevent it’s going ahead
- Everything’s ready – Sally nervously checks zip
- Ready description of total mechanical failure?
- Everything working fine in production of glossy metals
- Everything's ready - Sally nervously checks zip
Buddy explains!
The straight part
We know that "report of perfect readiness" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case report of perfect readiness = all systems go.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.