"Copter" is a known word, short for helicopter.
https://dictionary.cambridge.org/dictionary/english/copter
On a related note, pronunciation variance in "Helicopter" -> "Helacopter" -> "Helocopter" leads to a confusing abbreviation - "Helee" vs "Heelo"
On a related note, pronunciation variance in "Helicopter" -> "Helacopter" -> "Helocopter" leads to a confusing abbreviation - "Helee" vs "Heelo"