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

SH2572NM

Increased takeoff and landing density altitude limit. Held by North American Heli Svc INC. Last revised January 15, 1986. System: other and general.

What it applies to

Kind of product
Aircraft
Design holder
Sikorsky Aircraft Corporation; Sikorsky Aircraft Corporation; Sikorsky Aircraft Corporation; Sikorsky Aircraft Corporation; Sikorsky Aircraft Corporation; Sikorsky Aircraft Corporation
Models
S-58BT, S-58DT, S-58ET, S-58FT, S-58JT, S-58HT
Type certificates
1H11, 1H11, 1H11, 1H11, 1H11, 1H11
On this site
Sikorsky S-58 25 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 20, 2026.