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Part# 10-02778
MFR Model# 1U128-006


The Sigma-Tek 1U128-006 is a pump which carries a warranty for 2-years or 1000 hours. It uses an aluminum rotor and rotor housing, making the pump very resistant to damage from ingestion of foreign objects, excessive loads or engine oil. It provides clean, dry air for operation of air driven instruments in aircraft operating at medium altitudes. Pump rotates clockwise or counterclockwise in vacuum or pressure mode. May be mounted in either a vertical or horizontal position. FAA approved as a direct replacement for all instrument pumps but is not intended for supplying air to deicing boots. Mounting gasket furnished. Install suction regulator in line to instruments. Delivers 6 In. Hg vacuum (2.9-8.5 minimum CEM) or 6 In. Hg pressure (3.7-8.5 minimum CEM) from 1500 to 4000 RPM. No core charge.


  • Height: 3.825" .03"
  • Width: 3.55" .03"
  • Depth: 3.91" .06"
  • Weight: 2.2 lbs. (max)

  • Engine Pad: AND 20000
  • Rotation: Bi-directional
  • Overhang Moment: 5.2 in-lbs
  • Static Coupling
  • Shear Torque: 175 in-lbs (max)

  • Port Threads: 3/8" x 18 N.P.T.
  • Hose Fittings: 1/2" I.D. (min)
  • Hose / Tubing: 5/8" I.D. (min)
  • Inlet Filter: 0.3 microns

  • Ambient Temperature: -40 C to 93 C (typ.)
  • Exhaust Temp. (Intermittent): 375 F for 5 mins. (max)
  • Exhaust Temp. (Continuous): 300 F
  • Vibration:CPS: 5 to 150
    Maximum Double Amplitude: 0.100 in.
    Maximum Acceleration: 10 G's
  • Humidity (Dewpoint): -70 C
  • Altitude: -1,000 to 30,000 ft.


What it shoud a price however. Orde was processed et internationally shipped very quickly.

Andreas H
August 31, 2020

The pump I purchased was delivered promptly and in good condition. It replaced a pump that failed prematurely. Sigma Tek stood behind the product and made things right without a bunch of fuss.

September 1, 2017

The Good: Last 2 Sigma-Tec pumps lasted well over 1000 hours. Since they can turn either direction, I can keep one spare pump for multiple airplanes. The Bad: Different shape pump can make R&R tricky if currently using a different brand pump. Price is high, and zero core value makes price harder to swallow. No wear gauge. Reality: Pump costs twice as much but lasts twice as long, fewer scary moments IFR, less down time/expense replacing blown pumps.

Flying A
March 9, 2014

Pump made it 18 months and 60.4 hrs before bearing started howling. order# 365183

January 12, 2019


Q: On the 2 top inlet ports on the Sigma-Tek Dry Air Pump, if only 1 is used, does the other one need to be capped or plugged?

You will need to keep the other side open as one port is used for vacuum and the other is for exhaust. The vacuum and exhaust side will be determined based on the way your engine turns.

Q: We have SIGMA-TEK 5000B-36 SERIES STANDARD ATTITUDE GYRO. (P/n 5000B) Will this air pump will be Ok for it?

Yes, this will work as a air pump for the attitude gyro listed/

Q: Does this pump PN 10-02778 replace the 1U128-001? IO-520K

Yes this is a direct replacement for 1U128-001.

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