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

SH1170SW

Installation of tail rotor gear box no. 47-640-065-31 and tail rotor hub and blade assembly no. 47-640-071-3. Eligible on Bell model 47G with Franklin 6V4200-C32, 6V335-A, or 6V350-A engines installed. STC SH479SW required. Held by Texas Helicopter CO. INC, which holds 4 approved modifications in all. Last revised December 15, 2010. System: rotorcraft systems.

What it applies to

Kind of product
Aircraft
Design holder
Scotts-Bell 47 Inc
Models
47G
Type certificate
H-1
On this site
Bell-Carson 47 5 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 8, 2026.