SA2764WE
Altitude alerting and reporting capabilities are provided by installation of Harowe P/N 2031-01-1 altitude alert system, replacement of captain's barometric altimeter with a Harowe P/N 2050-01-1 servo actuated altimeter and two existing air data computers are replaced by Sperry P/N 2587400-176 air data computer. Held by Northwest Airlines, INC, which holds 14 approved modifications in all. Last revised November 14, 1986. System: flight controls.
What it applies to
- Kind of product
- Aircraft
- Design holder
- McDonnell Douglas Corporation
- Models
- DC-9-15
- Type certificate
- A6WE
- On this site
- Douglas DC-9 7 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.