Enter body of aircraft for start of journey to Pennsylvania Avenue? (3,5)

I believe the answer is:
log cabin
'aircraft for start of journey to pennsylvania avenue?' is the definition.
I can't tell whether this definition defines the answer.
'enter body' is the wordplay.
'enter' becomes 'log' (log can mean to record or enter).
'body' becomes 'cabin' (I can't explain this - if you can you should believe this answer much more).
'log'+'cabin'='LOG-CABIN'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for log cabin that I've seen before include "small dwelling" , "Type of chalet" , "Hut, as in the Wild West" , "Wooden home" , "Simple dwelling" .)
