• Primary Replacement (Clock)
  • 2 1/4″ Flush Mount
  • Full Functional, Panel-Mounted Aircraft Clock.


Meets FAA Requirements

  • Installed as a minor alteration, meets FAA requirements for IFR flying.
  • Upgrade your aircraft panel with this Super Clock.

Easy To Install

  • Replace your old clock.
  • ASC-5A is panel mounted and fits into your existing 2 1/4″ hole.

Accurate, Dependable & Easy To Use

  • Electronics International consistently has been a leader in digital engine instrumentation since 1979.

Altitude Management System

  • Displays both ATC Altitude and Density Altitude. 
  • Alarm when the aircraft reaches a programmed altitude and a deviation alarm when the altitude deviates too far from the programmed Destination Altitude.


  • Up timer and down (DN) timer with programmable alarms.
  • Engine Time keeps track of total time the engine has run.

ASC-5A Altitude Alert Super Clock Overview


The ASC-5A is a fully functional, panel mounted aircraft clock. Choose between local time or Zulu Time, and between 12/24 formats. The Up Timers and Down Timers have programmable alarms that will alert you at custom intervals, which is perfect for checking waypoint status, remembering to switch tanks, or for any of the other tasks for which you need an intermittent reminder.

Non-Volatile Memory

With the ASC-5A installation, it is not necessary to keep the clock attached to battery power. Non-Volatile memory ensures the clock is always accurate, to the second, without having to keep the instrument constantly powered up.


The ASC-5A is not only a world-class aviation clock, it is an altitude management system as well. The instrument displays both ATC Altitude (picked up in between the Encoder and Transponder), and Density Altitude. The Density Altitude is corrected for by barometric pressure (input by pilot) and an Outside Air Temperature probe, which comes standard with the ASC-5A. Pilots can program alarms that will alert when they’ve reached a programmed altitude. Then, a Deviation alarm will alert when the altitude deviates too far from the programmed Destination Altitude. These tools are perfect for reaching and maintaining ATC assigned altitudes, Minimum Decision Altitudes, or whatever cruise altitude you decide during a VFR flight.

IFR Capable

Because the clock is accurate to the second, the FAA considers the ASC-5A to meet the requirements for IFR flying.


The ASC-5A can be installed as a minor alteration, with a logbook entry. No certifications or field approvals are required!

Retail Prices


  • Instrument
  • P-128 OAT Probe with an 8′ Cable
  • Installation and Operating Instructions
Description Package Retail Price
ASC-5A Altitude Alert Super Clock ASC-5A $550


2.5″ x 2.5″ x 3.65″ Depth

2.25″ Bezel

Weight – Unit
11 oz.

Weight -OAT Channel
1.6 Oz.

Meets DO-160C

Power Requirements
7.5 to 35 Volts at .3 Amps

Display Modes

Displays Barometric Pressure setting.

Displays Encoder Altitude or Assigned Altitude, determined by the Display Configuration setting.

Displays Outside Air Temp in degrees Fahrenheit (°F) or Degrees Celsius (°C).

Displays the time on the Up or Down Timer. The Up Timer will automatically start when your aircraft reaches an elevation of 300 feet above the ground.


+/- 50 feet plus the accuracy of your Altitude Encoder (typically +/- 125 feet).

+/- 2% in accordance with TSO-C43a.

+/- .005% plus +/- .5 second.

+/- 2 minutes/month


1°F or 1°C (Programmable)

1 second resolution (switches to 1 minute resolution for readings over 59 minutes and seconds).

1 minute.


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