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Davtron Three-In-One 24 Hour Chronometer And Dropping Resistor

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Part# 10-24550-28
MFR Model# 811B-24


Davtron M811B-24 & Dropping Resistor.

  • 2-1/4" internal mount
  • Six-digit display on all 3 functions
  • Local time
  • Flight time
  • Elapsed time counter
  • Sunlight readable display
  • Nvis green a option
  • Memory battery included
  • FAA/PMA Approved
California Prop 65 Warning Symbol

WARNING: Cancer and Reproductive Harm -

FAA Approval

  • Davtron Inc has determined that installation of all Davtron products are considered minor according to (FAR) 21.93(a). All of our units are similar in design, with their electrical, mounting size, and weight being similar. Even though we consider installation of Davtron products to be minor, it is up to the installing mechanic to determine if the installation is minor or major. For a minor, a maintenance log book entry is all that is required. The FAA has determined that the installation of replacement clocks in non-transport category airplanes is considered to be minor, therefore only a maintenance log book entry is required referencing letter 100S-GA-10-53 from the FAA.
  • Download Letter
  • For a major installation on a non PMA approved airframe, a FAA 337 form should be filed with your local FSDO and a possible field approval done.
  • FAA/PMA Approvals
  • BAE Jetstream Models 3101 and 3201
  • Beech Models 35, A35, B35, C35, D35, E35, F35, G35, H35, J35, K35, M35, N35, 35-33, and 35-A33
  • British Aerospace Model BAE/Avro 146
  • British Aerospace Model 125-700
  • DeHavilland Models Dash-8 Series 100 (101,102,103)
  • DeHavilland Models Dash-8 Series 300 (301, 311)
  • Falcon Models 10, 900EX, and 2000
  • Gates Learjet Models 24E, 24F, 25D, 25F, 35A, and 36A
  • IAI Models 1125WW Astra and Astra SPX
  • Mystere Falcon Models 50, 200, and 900
  • Waco Model Classic WACO F5 and F5c
  • The 811-BATT-1 replacement batteries do not have PMA by themselves, they are part of the higher PMA assembly 811B clock.
  • Download FAA 337 Form


  • Six-digit display on all three functions
  • Local Time: 12 hour or 24 hour option (user selectable)
  • Flight Time: 24 hour
  • Elapsed Time Count Up: 24 hour
  • Battery supplied with a typical two year operating life. 6 Volts - 1 Amp hour
  • Polaroid filter
  • Incandescent Displays: Readable in sunlight
  • Input Voltage: 14 Volts
  • Input Current: 0.4 Amps
  • Maximum depth from mounting surface: 2.8"
  • Black Faceplate: Engraved Nomenclature
  • Grey Faceplate: Silkscreened Nomenclature
  • Weight: 7.5 ounces
  • Warranty: 1 year
  • Accessories
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