066-1107-11

DME ranging and navigation role

The DM 441B transmits coded pulse-pair interrogations through a compatible DME antenna and receives replies from the selected ground transponder. It measures the elapsed time to calculate slant-range distance. That result can be delivered to compatible cockpit display or flight-management equipment. Depending on the approved system, derived groundspeed and time-to-station may also be presented by associated equipment.

Slant range is the geometric distance between aircraft and station and can differ from horizontal map distance, particularly near or above the facility. Reliable operation depends on line of sight, channeling data, antenna and coaxial cable condition, aircraft power, receiver-transmitter performance, wiring and ground-station availability. The DM 441B is not itself a complete cockpit presentation system.

Series III system composition and interfaces

Chelton Series III documentation describes a DMS-44A arrangement built around a DM-441B transceiver and one or two compatible SD-442B control or display units. Other approved installations can interface the transceiver with navigation radios or a flight-management system for channeling and DME data. The precise ARINC, analog or discrete interface configuration must be established from the applicable installation manual and aircraft wiring diagram.

A representative chain is approved NAV or FMS tuning source → DM 441B channel input → DME antenna and selected ground station → transceiver ranging processor → compatible SD-442B, cockpit display or FMS. Associated products are system components, not interchangeable substitutes. A control-display unit cannot replace the transceiver, and a transceiver must not be installed against an unverified rack or pin assignment.

Identification, condition and testing scope

The exact plate shows DM-441B DME Transceiver, Part Number 066-1107-11, TSO C66b and DO-160A references, together with a Wulfsberg Electronics Division manufacturer marking. The photographed unit also carries an antenna connector and a software-identification label. A serial number is not transcribed because it is not sufficiently clear in the available image. Exact weight, dimensions, voltage, current and connector assignment should be confirmed from approved data.

This inventory position is offered in Repairable condition. It should be treated as a unit requiring inspection, repair or overhaul and approved return-to-service work before installation. The six-month commercial warranty applies to the supplied terms stated in the quotation and does not convert a Repairable unit into Serviceable condition. Evaluation should include visual inspection, power and interface checks, RF output and sensitivity, channeling, ranging output, fault monitoring and documentation review by an authorized facility.

Repairable supply and ordering information

The quotation will confirm the allocated serial number, as-received condition, repair scope if requested, documentation status and included accessories. Rack, connector, SD-442B display, antenna, coaxial cable, navigator, FMS interface and wiring are not included unless expressly listed. Any exchange or repair quotation should define core condition, exclusions, certification and final release standard.

For an inquiry, specify Part Number 066-1107-11, model DM 441B, aircraft type, installed DME control or display, tuning interface, rack and connector configuration, quantity, desired repair or overhaul scope and certification. Related avionics are listed in the Garmin / BendixKing / Honeywell / Collins category. Final applicability and configuration must be verified from approved aircraft and Series III installation documentation.

Photographs and release records for the allocated serial-numbered unit should be reviewed before purchase because Repairable inventory can vary in cosmetic and technical condition.