The most common and most likely answer to this crossword clue is the 10 letter word STEPHENSON
I've seen this crossword clue in The Daily Telegraph
S
T
E
P
H
E
N
S
O
N
More clues leading to the result STEPHENSON
- Engineer rung by female, number getting cut off
- Rocket builder is potentially way up on outside layer
- Railway engineer sent phones for repair
- Engineer‘s relative keeps fowl
- Order shop sent to stock cover of Elton’s Rocket Man
- Inventor of phone’s sent abroad
- Old engineer puts his foot down to keep female working
- Rocket engineer
- Females in crush for Rocket Man
- Railway pioneer’s relative by marriage has managed to conceal a bird
Buddy explains!

The straight part
We know that "Rocket engineer" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case rocket engineer = stephenson.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.