Mpl 503 Air Pressure Switch - Normally Closed

Part# 11-13477
MFR Model# 0503DC-BP-0006


MPL 503 Series pressure sensor switch activates between 120-125 knots.

The accuracy and reliability offer an excellent general purpose low pressure to electric interface for monitoring and control applications.

The miniature size make the 503 Series ideal for OEM applications.

Setting: Normally closed between 120-125 knots
California Prop 65 Warning Symbol

WARNING: The product may contain and/or expose you to a chemical(s) or substance(s) which are known to the State of California to cause cancer and/or birth defects or other reproductive harm.


  • NEMA 0.020" x 0.187" male tabs are standard
  • Low-profile terminals for 18-22 gage wire
  • Optional bifurcated terminals accept 0.020" x 0.187" or 0.020" x 0.110" female quick disconnects
  • Terminals are available for printed circuit board mounting.
  • Custom applications requiring elongated terminals, tinning, and custom wiring can also be accommodated.


  • Diaphragm material can be selected for the operating medium, temperature range, and other parameters
  • Actuation point can be moderately adjusted by the designer
  • Designed for low current and logic applications ( LED indicators, solid state relays)
  • 10 to 20mA loads ensure reliable switching (Varistor or R-C snubber recommended for inductive loads)
  • Heavier loads require the use of interface devices such as solid state relays
  • Features an integral triac


  • The diaphragm functions as both sensor and seal
  • Dynamic applications, the diaphragm provides an adequate seal
  • Static applications, a secondary internal gasket will ensure a near bubble tight seal


This item does not work as advertised. The switch opens at 60 MPH and does not close again until 40MPH. The adjustment screw did not correct the problem.

James R
July 2, 2019


Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: Is the pressure switch, part # 11-13477, normally open or normally closed?

This pressure switch is normally closed.

Q: In reference to the Spec Sheet (PDF), what is the set point range for your PN 11-13477 MPL503DC Air Pressure Switch Normally Closed Setting ? Reference:

Per the vendor it is set to 1" in water.

View in Catalog

View Image View in Catalog