Visible and Invisible Aircraft by RADA

Which aircraft are visible on Flightradar24?

Common aircraft models that are visible on Flightradar24 (have an ADS-B transponder):

All Airbus models (A300, A310, A318, A319, A320, A321, A330, A340, A380)
BAe ATP
BAe Avro RJ70
BAe Avro RJ85
BAe Avro RJ100
Boeing 737
Boeing 747
Boeing 757
Boeing 767
Boeing 777
Boeing 787
Most new deliveries of Embraer E190
Fokker 70
Fokker 100
Gulfstream V
Gulfstream G500/G550
McDonnell Douglas MD-10
McDonnell Douglas MD-11
Sukhoi SuperJet 100
Some newer Ilyushin and Tupolev for example Il-96 and TU-204

Common aircraft models that are NOT visible on Flightradar24 (no ADS-B transponder):

Antonov An-225
ATR-42
ATR-72
Boeing 707
Boeing 717
Boeing 727
Boeing 737-200
Boeing 747-100
Boeing 747-200
Boeing 747SP
All CASA models
All Bombardier Dash models
All Bombardier CRJ models
Dornier 328
All Embraer models (except most new deliveries of Embraer E190)
Jetstream 32
Fokker 50
McDonnell Douglas DC-9
McDonnell Douglas MD-8x
McDonnell Douglas MD-9x
Saab 340
Saab 2000
"Air Force One"
Most older aircraft
Most military aircraft

Of course there are lots of exceptions.
For example one Lufthansa CRJ900, one LOT ATR-72, one Wideroe Dash, some MD8X from Onur Air, some Saab 340 in Australia and several private Cessnas are visible.
There are also some older A300, A310, A320, B737, B747, B757, B767 aircraft without the ADS-B transponder, and that makes thoose aircraft invisible on Flightradar24.