SA531NE
Installation of a Simmonds Precision total fuel/Vref dual indicator, P/N 393080-203 thru -223. Must be installed concurrently with STC SA520NE. Held by Simmonds Precision Products INC, which holds 25 approved modifications in all. Last revised January 8, 2004. System: instruments and avionics.
What it applies to
- Kind of product
- Aircraft
- Design holder
- The Boeing Company; The Boeing Company
- Models
- 737-100 Series, 737-200 Series
- Type certificates
- A16WE, A16WE
- On this site
- Boeing 737 2,887 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 12, 2026.