SR00266SE
Replacement of the Lycoming Model T53-L-13B engine with a Lycoming Model T53-L-703 engine flat rated to the same power settings specified in Type Certificate Data Sheet (TCDS) H15NM. Held by Overseas Aircraft Support INC.. Last revised June 26, 2025. System: engine.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Hagglund Helicopters LLC; Overseas Aircraft Support Inc.; JJASPP Engineering Services LLC
- Models
- UH-1H, UH-1H, UH-1H
- Type certificates
- H15NM, H7SO, R00004RC
- 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 20, 2026.