At the time of writing, 47 out of 56 Boeing 737MAX operators have grounded their MAX aircraft, following 2 crashes of brand new Boeing 737MAXs in less than 5 months interval.
In total, 260 out of 387 MAX family (-8 and -9) aircraft in operation are grounded.
The following operators are still flying Boeing 737 MAX 8s;
American Airlines
The US carrier has 24 737 MAX 8 aircraft in its fleet
Southwest Airlines
The US carrier has 34 of the aircraft in its fleet
Norwegian Airlines
Norwegian has 18 737 MAX 8 aircraft in its fleet
TUI
TUI Aviation has 15 of the aircraft in its fleet.
Fiji Airways
Fiji Airways currently flies two 737 MAX 8 aircraft.
Icelandair
Icelandair has three 737 MAX aircraft
Flydubai
Flydubai operates 11 Boeing 737 MAX 8s,
WestJet
Canadian carrier WestJet has 13 MAX 8 aircraft in its fleet
GOL Linhas Aéreas
The Brazilian airline has seven 737 MAX 8s in its fleet.
