ST01444LA
: Installation of reinforced cockpit door in accordance with FAA Approved Duganair Technologies, Inc. MDL QS-00003, Revision J, dated April 1, 2003, or FAA approved revision (for 727-200 series airplanes) or MDL QS-00003, Revision L, dated July 21, 2003, or later FAA approved revision for both 727-100 and -200 series airplanes). Held by Quiet Wing Technologies, INC., which holds 9 approved modifications in all. Last revised November 18, 2011. System: airframe structure.
What it applies to
- Kind of product
- Aircraft
- Design holder
- The Boeing Company; The Boeing Company
- Models
- 727-100 Series, 727-200 Series
- Type certificates
- A3WE, A3WE
- On this site
- Boeing 727 37 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 22, 2026.