ST389CH
Installation of a Bendix/King CAS 81 TCAS II and Mode S transponder. Held by Avionics Group INC., which holds 20 approved modifications in all. Last revised July 13, 2000. System: instruments and avionics.
What it applies to
- Kind of product
- Aircraft
- Design holder
- McDonnell Douglas Corporation; McDonnell Douglas Corporation; McDonnell Douglas Corporation; McDonnell Douglas Corporation; McDonnell Douglas Corporation; McDonnell Douglas Corporation; McDonnell Douglas Corporation
- Models
- DC-9-14, DC-9-11, DC-9-13, DC-9-15, DC-9-15F, DC-9-12, DC-9-21
- Type certificates
- A6WE, A6WE, A6WE, A6WE, A6WE, A6WE, A6WE
- On this site
- Douglas DC-9 7 registered
Mcdonnell Douglas DC-9 93 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.