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

SH101WE

Replacement of existing 50 ampere generator with 100 ampere RWS-985-1340 generator. Held by Aviation Power Supply INC, which holds 12 approved modifications in all. Last revised September 5, 1968. System: electrical power.

What it applies to

Kind of product
Aircraft
Design holder
Bell Helicopter Textron; Bell Helicopter Textron
Models
47 Series, 47 Series
Type certificates
2H3, H-1
On this site
Bell 47 477 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.