AChS-1MK

AChS-1MK aircraft clock for cockpit use

The AChS-1MK is a mechanical aircraft clock intended for continuous operation in aircraft and helicopter cockpits. It displays current time in hours, minutes and seconds, and also includes separate timing functions for flight time and short interval measurement. The clock is installed on the instrument panel and is used by the crew as a direct time reference during flight operations. Its design is mechanical, but the unit also includes an electric heater powered from the aircraft DC network for operation in cold conditions.

Current time, flight time and chronograph functions

Unlike a simple cockpit clock, the AChS-1MK combines three practical functions in one instrument: current time indication, aircraft flight time counting and chronograph timing. This makes it useful for navigation checks, flight phase timing, mission time control, engine or system monitoring intervals and other cockpit procedures. The chronograph function allows measurement of shorter time intervals, while the flight time counter supports longer operational tracking. For crews working with older aircraft instrumentation, this type of clock remains a simple and reliable time-control instrument.

Mechanical movement of the AChS-1MK

The AChS-1MK uses a mechanical movement with separate mechanisms for current time, flight time and chronograph operation. After a full winding, the clock has a multi-day power reserve, with regular winding recommended during operation. The movement uses jeweled bearings to reduce friction and support stable operation over time. Daily accuracy is specified under normal conditions, but correct performance also depends on service condition, winding state, mounting, temperature and previous overhaul quality. Before installation, the clock should be checked for rate, reserve and proper operation of all timing functions.

Cold-weather operation and integrated heater

The AChS-1MK is designed for severe aircraft operating conditions, including low-temperature environments. The integrated electric heater with thermostat helps maintain stable operation when the cockpit or instrument area is exposed to cold. The heater operates from the onboard DC supply and has defined resistance, insulation and dielectric strength requirements. This is important because a mechanical clock can be affected by oil viscosity and temperature changes. The heater circuit should therefore be checked together with the mechanical movement, not treated as a secondary feature.

Dial and lighting compatibility

The dial and hands of the AChS-1MK are made for use with red cockpit illumination. The coating supports readability under red light, which is commonly used in aircraft cockpits to reduce glare and support night operation. The clock must remain easy to read without producing unnecessary reflection or visual distraction. During inspection, the condition of the dial, hands, glass and lighting compatibility should be checked. Damage, discoloration or poor readability can reduce the usefulness of the instrument even if the mechanical movement is still functional.

Installation on aircraft and helicopters

The AChS-1MK is used on aircraft and helicopters of Soviet and Russian origin, including transport, utility and special-purpose platforms depending on cockpit layout and documentation. It is installed as rigidly mounted onboard equipment on the cockpit instrument panel. The unit is compact and has a standardized aircraft-instrument format suitable for panel installation. Before replacement, the exact clock version, mounting dimensions, heater connection, lighting requirements and aircraft documentation should be confirmed. Similar AChS-series clocks may look close, but their functions and details can differ.

Supply, condition and documentation

The AChS-1MK may be supplied as new, overhauled or serviceable depending on availability and customer requirements. For aviation use, condition and documentation are important: a test report, Form 1, certificate, passport or other acceptance document may be supplied on request. The clock can be delivered with standard warranty, with extended warranty available by agreement. For export supply, individual packing, inspection before dispatch, export documentation and professional packaging may be arranged according to delivery terms.

Category: Aircraft instruments
Product Type: Mechanical aircraft clock with flight time counter and chronograph
Product Name: AChS-1MK Aircraft Clock
Alternative References: AChS1 MK; AChS 1 MK; AChS1MK; AChS-1-MK; AChS-1MK; A4S-1 MK; A4S1 MK; A4S 1 MK
Function: Display of current time and measurement of aircraft flight time
Application / Where Used: Aircraft and helicopters of Soviet and Russian origin
Associated Systems: Onboard instrumentation system; cockpit heating and lighting system
Installation Location: Cockpit instrument panel
Construction: Mechanical mechanisms for current time, flight time and chronograph operation
Mounting: Rigid panel-mounted onboard installation
Power Reserve: Not less than 3 days after full winding
Recommended Winding Interval: Once every two days
Daily Rate Accuracy: ±20 seconds per day
Number of Jewels: 26
Chronograph Range: 30 minutes
Operating Temperature Range: Down to −60 °C
Shock and Vibration Resistance: Acceleration up to 20 m/s², frequency range 18–144 Hz
Execution Version: Standard and tropical versions
Overall Dimensions: 85 × 91.4 × 91.4 mm
Weight: 655 g
Operating Conditions: Rigidly mounted onboard equipment
Heater Type: Integrated electric heater with thermostat
Heater Supply Voltage: 27 V ±2.7 V DC
Heater Electrical Resistance: 50 ±2 Ω
Heater Insulation Resistance: Not less than 20 MΩ
Heater Insulation Dielectric Strength: 500 V for 1 minute
Heater Vibration Resistance: Acceleration up to 20 m/s², frequency range 10–144 Hz
Dial and Hands Coating: Red-light compatible coating / white paint for red cockpit illumination
Condition: New / overhauled / serviceable
Documentation: Test report / Form 1 / certificate on request
Warranty: 6 months standard; extended warranty available
Country of Origin: Depending on production batch
Packaging: Individual export packing
Logistics: Worldwide shipping, export documentation, inspection and professional packing available

All shipments are carried out from our international warehouse in Dubai (UAE), as well as from our partners’ remote warehouses.

In Stock — items available in stock at the Dubai warehouse are dispatched within 5–10 business days after receiving 100% prepayment.

Remote Stock — items available at our partners’ remote warehouses are supplied within an average of 30–45 business days after receiving 100% prepayment.

Pre-Order — made-to-order products are manufactured and delivered within an average of 45–60 business days. Payment terms: 50% advance payment to start production, with the remaining 50% paid before dispatch from the Dubai warehouse after full readiness for shipment.

Returns & Changes (Restocking Fee)
For selected items, a RESTOCKING FEE of 10% may apply in case of return, order cancellation, or changes to the order specifications. This condition applies only to certain products and is confirmed at the order approval stage.

Warranty
All products are covered by a standard 6-month warranty.
Extended warranty is available upon request and is agreed individually; it may affect the final product price.