SA257CH
Increases the cruise interstage turbine temperature (ITT) limit to 695 degrees centrigrade. (C90 WITH PRATT & WHITNEY PT6A-21 ENGINES). Held by Elliott Aviation Technical Products, which holds 57 approved modifications in all. Last revised September 27, 1994. System: engine.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Raytheon Aircraft Company
- Models
- C90
- Type certificate
- 3A20
- On this site
- Beechcraft C90 King Air C90 607 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.