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

SH64WE

Turbosupercharged Lycoming TVO-435-B1A engine. Held by Progressive Avn Limited, which holds 6 approved modifications in all. Last revised January 1, 1960. System: engine.

What it applies to

Kind of product
Aircraft
Design holder
Bell Helicopter Textron
Models
47 Series
Type certificate
2H1
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 7, 2026.