AIM 8/15/19  FIG 6 − 2 − 16 Message received and understood (Aircraft) FIG 6 − 2 − 15 Negative (Aircraft) FIG 6 − 2 − 17 Message received and NOT understood (Aircraft) NEGATIVE (NO) Fishtail plane Negative reply from aircraft: Message received and understood by aircraft: Day or moonlight - Rocking wings Night - Green flashed from signal lamp Message received and NOT understood by aircraft: Day or moonlight - Making a complete right-hand circle Night-Red flashes from signal lamp. Emergency Services Available to Pilots 6 − 2 − 11