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

SA1-411

Goodyear SK306-1204 revision E propeller blade iceguard on Rotol propeller R130/4-20-4/12E with blades RA25842. Held by United Air Lines INC, which holds 27 approved modifications in all. System: propeller.

What it applies to

Kind of product
Aircraft
Design holder
Vickers-Armstrongs (Aircraft Limited); Vickers-Armstrongs (Aircraft Limited); Vickers-Armstrongs (Aircraft Limited)
Models
Viscount 745D, Viscount 745, Viscount 744
Type certificates
A-814, A-814, A-814
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.