A-034-4-13

Altitude display function of A-034-4-13

The A-034-4-13 uses an analog pointer scale with a measuring range up to 750 meters. The scale is arranged so that low altitudes can be read with better visual precision, while the upper part of the range is shown with larger intervals. This layout makes sense for radio-altimeter operation, because the most critical information is usually at lower heights. The pilot can monitor descent, terrain clearance and approach profile directly from the pointer position. For aircraft crews, this kind of display is simple, fast and easy to interpret under workload.

Danger altitude setting on the A-034-4-13

The indicator has a rotary control for setting a selected danger altitude. The crew sets the required threshold according to the flight task or operating procedure. When the aircraft descends to or below the selected value, the warning circuit activates a dedicated visual alert. This function helps the crew notice an unsafe low-height condition without constantly comparing the pointer position with the scale. The danger altitude feature is especially useful during night flight, poor visibility, low-level operation or any situation where attention is divided between several cockpit instruments and outside references.

Built-in test and fault indication of A-034-4-13

The A-034-4-13 includes a test function for checking system operability. When the TEST switch is activated and the radio altimeter system is serviceable, the pointer moves to the specified reference indication. If the pointer does not respond correctly, or if a fault is detected in the system, a drop-out blinker flag appears on the indicator scale. This gives the crew and maintenance personnel a clear visual sign that the indication should not be trusted until the radio altimeter system has been checked according to the applicable documentation.

A-034-4-13 with the A-037 Variant 11 radio altimeter

The A-034-4-13 works with the A-037 Variant 11 radio altimeter set. The system may include the A-037-1A transceiver, AR5-1 or A-037-2 antennas, wiring harnesses, mounting parts and the cockpit indicator. The radio altimeter measures height by radio signal reflection from the ground or water surface, while the A-034-4-13 provides the cockpit display and warning interface. Since the indicator is only one element of the set, any troubleshooting should include the transceiver, antennas, wiring, power supply and indicator circuit.

Installation and service notes for A-034-4-13

The A-034-4-13 is installed on the cockpit instrument panel, where the scale and warning elements are visible to the crew. During maintenance, the indicator should be checked for pointer movement, test response, warning lamp operation, blinker flag condition, connector integrity, mounting security and readability of the scale. If the instrument is supplied separately, it should be matched to the A-037 Variant 11 configuration and not treated as interchangeable with every A-034 indicator version by appearance alone. Documentation and system version are important for correct installation.

Identification and supply of A-034-4-13

For procurement or replacement, the full designation A-034-4-13 should be specified together with the target radio altimeter version. Alternate wording such as A034-4-13 height indicator, A-034-4-13 pointer indicator or indicator for A-037 Variant 11 can be used for clarification, but the final match should be made by the aircraft parts catalog and radio altimeter documentation. Before installation, the instrument should be checked for condition, testability, service history, storage status, and availability of passport or repair documentation.