Transient Suppression Device (TSD)

Fuel Tank Protection

TSDs provide electrical surge protection — limiting the energy that may enter into a fuel tank. Butler National Corporation manufactures an entirely passive TSD. The Butler TSD is designed to interface transparently to FQIS (Fuel Quantity Indicating System) equipment. The Butler National TSD is a passive fail-safe device – the TSD circuitry is designed to always protect the connected FQIS lines into the aircraft fuel tank.

  • TSDs are available with short lead-times.
  • Cost-effective solution and 14 CFR 25.981 Compliance Tool.
  • Passive TSD prevents unsafe levels of electrical energy from entering the fuel tanks through FQIS system wiring.
  • Installation is designed for typical scheduled overnight maintenance.
  • The TSD is seamless to many FQIS.

Butler National Corporation has received the following Supplemental Type Certificates for TSD installations on “Classic” aircraft.

Auxiliary Fuel Tank Protection – TSD

Butler National has developed and assisted with FAA certification of a number of FQIS / fuel-tank protection devices. These devices include separate custom packaging and interconnects to minimize installation efforts.

TSD – 737
STC # ST01160SE

The Federal Aviation Administration has approved Butler National’s cost-effective Transient Suppression Device (TSD) for installations on the Boeing 737 classic airplanes.

TSD – 747
STC # ST00846SE

800147-112 (Circular Connector)

800037-112 (Rectangular Connector)

The Federal Aviation Administration issued Butler National Corporation, a worldwide supplier of aerospace products, Supplemental Type Certificate (STC) number ST00846SE. The STC approves the installation of its Transient Suppression Device (TSD) on Boeing 747 Classic Airplanes. The STC is approved as an Alternative Method of Compliance (AMOC) for Airworthiness Directive (AD) 98-20-40, which requires protection for FQIS fuel tank wiring.

Contact Us

Butler National specializes in custom fuel tank FQIS protection design.

Butler National continues to deploy its fuel tank protection designs to support 25.981 findings of compliance for avionics and FQIS upgrades. Contact Butler National to explore potential solutions. Call (913)-780-9595 or email for more information.