SA1529SW
Modification of hydraulic system and air conditioning pressurization system. Held by A D Howard JR, which holds 9 approved modifications in all. Last revised July 25, 1973. System: heating, ice protection and utility systems.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Twin Commander Aircraft LLC; Twin Commander Aircraft LLC
- Models
- 680-V, 680-W
- Type certificates
- 2A4, 2A4
- 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.