Possible Clues:

• Near miss, and what the ends of 17-, 27- and 44-Across may provide
• Terrible chaos with elves in narrow escape
• Danger narrowly averted, result being not so hairy
• Thorough trim, or a hint to the starts of 17-, 32-, 38- and 42-Across
• Chases vole (anag.)
• Lucky escape of plane by dead-end street
• Shuts short road after hospital's lucky escape
• Near disaster
• Ends with experience from near disaster
• Narrow escape from danger