ASC-5A 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!


ASC-5A Specifications


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, 1/10 Amp

Display Modes


Displays Barometric Pressure setting.


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


Displays Outside Air Temp in degrees Fahreneit (°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



.01 Inches of Mercury


1°F or 1°C (Programmable)


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


1 minute.

Maximum Displayed Range or Setting

BAR Setting

28.00 to 29.00 Inches of Mercury, or 900 to 1199 millibars


-1000 to 30,500 feet.

Assigned Altitude (Setting)

0 to 99,000 feet.

Approach Altitude (Setting)

0 to 99,000 feet.

OAT (Displayed)

-99°F to 1999°F (-87°C to 999°C).

TIMER (Displayed)

00:00 to 17 hours, 59 Minutes.

Recurring Alarm/Start Time (Setting)

-00:00 to 99 Minutes, 59 Seconds.

Kit Details

ASC-5A Kit Details

Kit Includes

Instrument, Wire Harness, P-128 OAT Probe & XCP-6′ Precision Cable, Installation and Operating Instructions.


Normally Stocked Item.

Kit Price