No joy

NO JOY
Aircrew does not have visual contact with the target/bandit/ landmark. Opposite of TALLY.
NOAA ...

Navaid - Navigational Aid
NDB - Non Directional Beacon
No Joy - No communications established
NORDO - No Radio
NOSIG - No significant weather
NOTAM - Notice to Airmen ...

See also: Notice to airmen, Report, Pilot report, Airborne, Air traffic