Model Variants (Including Prototypes)
U-2 "Dragonlady" - Base Series Deisgnation
U-2A - First production model; Fitted with J57-P-37A powerplant.
U-2B - Various improvements; Fitted with J57-P-31 engine.
U-2C - Various improvements; Features J75-P-13 engine.
U-2CT - Two-seat trainer.
U-2D - Two-seat research variant
U-2EPX - Naval surveillance version (proposed).
U-2R "Dragon Lady" (TR-1) - Increased wingspan; elongated fuselage; features J75-P-13B engine.
U-2RT - Two Seat Model
U-2S - R-model fitted with General Electric F118-GE-101 engine.
U-2ST - Redesignated two-seat models
TU-2S - Trainer variant of U-2S
TR-1A - Tactical Reconnaissance Variant
TR-1B - Two-Seat Model; tactical reconnaissance variant
ER-2 - NASA-operated U-2 aircraft (2 examples)