- Attention needed
- ...to referencing and citation • ...to coverage and accuracy • ...to structure • ...to grammar • ...to supporting materials
- Expansion needed
- American Dynamics AD-150 • Frank Piasecki • Erickson Air-Crane • Columbia Helicopters • Bell 412 • Sikorsky HH-60 Jayhawk
- Citations needed
- Cessna CH-1 • Bell XV-15 • Bell 212 • Sikorsky MH-53 • Kamov Ka-50 • Mil Mi-28 • Sikorsky S-70