ST01557AT
Installation of an AlliedSignal Mark II ACARS Communications Management Unit (CMU) . Held by Honeywell International INC, which holds 599 approved modifications in all. Last revised November 12, 2021. System: other and general.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Airbus; Airbus; Airbus
- Models
- A320 Series, A321 Series, A319 Series
- Type certificates
- A28NM, A28NM, A28NM
- On this site
- Airbus A319 329 registered
Airbus A320 797 registered
Airbus A321 931 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.