Model Variants (Including Prototypes)
B-66 "Destroyer" Base Series Designation
RB-66A - Pre-production photographic reconnaissance variant; five examples produced.
RB-66B - Definitive photographic reconnaissance mark; fitted with Allison J71-A-13 engine; 149 examples.
EB-66E - Highly specialized ECM model based on the RB-66B.
B-66B - Tactical Light Bomber Variant based on the RB-66B; 72 examples.
RB-66C - Electronic CounterMeasures (ECM) aircraft based on the RB-66B; bomb bay converted to mission room for four additional operators; 36 examples.
EB-66C - Four RB-66C models with updated ECM equipment.
NB-66B - One-off B-66B and RB-66B models used in radar testing for F-111 program.
WB-66D - Weather reconnaissance platform with five crew; 36 examples.
X-21A - Pair of WB-66D airframes used in laminar flow wing testing by NASA; work by Northrop.