The U.S. aircraft register, updated daily
Approved modifications · supplemental type certificate · current · reissued

SR09177RC

Modification of the vertical fin spar. Held by Midwest Aerospace Tc LLC, which holds 11 approved modifications in all. Last revised February 8, 2023. System: airframe structure.

What it applies to

Kind of product
Aircraft
Design holder
Garlick Helicopters Inc.; Garlick Helicopters Inc.; WSH LLC; International Helicopters Inc.; Red Tail Flying Services LLC; Southwest Florida Aviation International; Richards Heavylift Helo Inc.; Rotorcraft Development Corporation; Rotorcraft Development Corporation; Rotorcraft Development Corporation; Rotorcraft Development Corporation; Overseas Aircraft Support Inc.; Overseas Aircraft Support Inc.; Overseas Aircraft Support Inc.; Smith Helicopters; Bell Textron Inc.; Bell Textron Inc.; Bell Textron Inc.
Models
UH-1B, UH-1B, UH-1B, UH-1B, UH-1B, UH-1B, UH-1B, HH-1K, TH-1L, UH-1E, UH-1L, UH-1E, UH-1L, TH-1L, UH-1E, TH-1L, UH-1E, UH-1L
Type certificates
H13WE, H3NM, H1RM, H5SO, R00012AT, H6SO, H3SO, H5NM, H5NM, H5NM, H5NM, H7SO, H7SO, H7SO, H8NM, H4NM, H4NM, H4NM
On this site
Bell HH-1 13 registered
Bell UH-1 Huey (Iroquois) 404 registered
Garlick Helicopters Inc UH-1 10 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.