SH165NW
Installation of Model 1620 and 1621 aerial seeders systems. Held by Simplex Manufacturing CO, which holds 31 approved modifications in all. Last revised March 17, 1975. System: other and general.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Hiller Aviation; Hiller Aviation; Rogerson Hiller Corporation; Rogerson Hiller Corporation
- Models
- UH-12L4, UH-12L, UH-12E-L, UH-12E
- Type certificates
- H1WE, H1WE, 4H11, 4H11
- On this site
- Hiller UH-12 217 registered
- The FAA's record
- On the FAA's site
What an approved modification is
A supplemental type certificate is the FAA's approval of a change to a certified design: a new engine or propeller, avionics, an autopilot, floats, a parachute, a larger fuel tank, an ice-protection kit. The company holding it may sell the kit and the paperwork to owners of the listed models; the modification then becomes part of that aircraft's record. The FAA's list says what was approved and for which models, not how many aircraft carry it.
Source: FAA supplemental type certificates (Dynamic Regulatory System). Register counts from the FAA register of October 7, 2026.