The most common and most likely answer to this crossword clue is the 4 letter word HONK
H
O
N
K
More clues leading to the result HONK
Buddy explains!

The straight part
We know that "Call from flier" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case call from flier = honk.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.
What does HONK mean?
HONK noun- The sound produced by a typical car horn.
- The cry of a goose.
- A bad smell.
- To use a car horn.
- To make a loud, harsh sound like a car horn.
- To make the vocal sound of a goose.
- To vomit: regurgitate the contents of one's stomach.
- To have a bad smell.
- To squeeze playfully, usually a breast or nose.
- Imitation of car horn, used, for example, to clear a path for oneself.
- (racial slur) A Caucasian person.
- A factory hand or general unskilled worker.