Model Variants (Including Prototypes)
He 49a - Initial Prototype Model showcasing a shortened fuselage.
He 49b - Second Prototype Model; revised lengthened fuselage; evaluated as both seaplane and land-based plane.
He 49c - Third Prototype Model; revised engine mount.
He 51a - Fourth Prototype Model; new radiator system; revised vertical tail fin and main wings; redesigned undercarriage.
He 51A-0 - Nine Pre-production Examples; based on He 51a.
He 51A-1 - Initial Full-Rate Production Model; 150 examples produced.
He 51B-0 - Second Pre-production Batch; reinforced understructure; 12 examples produced.
He 51B-1 - Second Production Batch; based on He 51B-0 model; 12 examples produced.
He 51B-2 - Sea-Plane Derivative; dedicated reconnaissance platform; 46 examples produced.
He 51B-3 - High-Altitude Platform
He 51C-1 - Ground Attack Variant
He 51C-2 - Improved He 51C-1 model; new radio equipment;2 1 examples produced.