# PF vs pi

> English confusable word pair

## The two words

### PF
*noun · frequency rank #16,301*
Initialism of pilot flying, a pilot currently in control of the flight trajectory of the aircraft, as opposed to pilot monitoring.

### pi
*noun · IPA /paɪ/ · frequency rank #8,073*
The sixteenth letter of the Classical and Modern Greek alphabets and the seventeenth in Old Greek.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-09-03.
Canonical page: https://plainspell.com/en/vs/pf-vs-pi