SA00863SE
Installation of two Pratt and Whitney PT6A-135, or -135A engines and two Hartzell HC-B3TN-3B/T10178B-8R propellers or as an option, two Hartzell HC-E4N-3N/D8990SK propellers. Held by Blackhawk Modifications INC., which holds 26 approved modifications in all. Last revised June 7, 2007. System: propeller.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Piper Aircraft Inc.; Piper Aircraft Inc.; Piper Aircraft Inc.
- Models
- PA-31T, PA-31T1, PA-31T2
- Type certificates
- A8EA, A8EA, A8EA
- On this site
- Piper PA-31 Navajo and Chieftain 935 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 21, 2026.