DUS-1209G/E/K

Function in the AP-34B autopilot

Electrical outputs proportional to helicopter angular rate are passed to compatible amplifiers and autopilot control equipment. The system uses these signals for oscillation damping and stabilisation in roll, pitch and heading. The three channel sensors must not be presented as interchangeable merely because their housings are similar.

In the closed autopilot loop, each sensor supplies feedback for its own axis. The signal passes through compatible conditioning equipment to the control channel, where it supports damping and stabilisation. A fault may be in the sensor, amplifier, wiring, supply or actuator path, so troubleshooting must cover the complete AP-34B channel.

Mi-8 and Mi-17 helicopter installation

Operating documentation identifies the 1209G, 1209E and 1209K set in the AP-34B system used by the Mi-8 helicopter family. Roll and heading sensors are installed on the right equipment rack in the crew compartment, while the pitch sensor is located in the radio compartment. Exact positions depend on helicopter modification.

The mounting positions and orientation of the three sensors are different. Replacement requires verification of the suffix, sensitive axis, connector, base and location against the diagram for the individual helicopter modification. Moving sensors between channels because the housings look similar is not permitted unless the approved maintenance documentation explicitly authorises it.

Supply and technical inspection

Retained product data specify a 36–40.5 V, 400 ±8 Hz supply and current consumption up to 0.5 A per sensor. Maintenance includes verification of the channel suffix, mounting, connector, housing condition and passport limits. Testing is performed with the compatible equipment or test bench specified for the AP-34B system.

Set inspection covers supply, mount and connector condition, response of each channel and agreement of output with the passport characteristic. On-aircraft testing is performed with the autopilot, while bench testing follows the approved procedure. Numerical data for one DUS execution must not be transferred automatically to another angular-rate-sensor family.

Identification and ordering

Search forms include DUS-1209G, DUS-1209E, DUS-1209K, DUS1209 and the original Cyrillic DUS-1209G/E/K. An inquiry should state whether a complete set or an individual channel is required. Individual cards for DUS-1209G, DUS-1209E and DUS-1209K are available in the Aviamisto Sensors category.

An inquiry should state whether the complete set or separate DUS-1209G, DUS-1209E and DUS-1209K units are required, together with helicopter type, AP-34B execution, condition and documentation needs. Links to the individual cards help identify each channel. Cross-sells provide navigation to related equipment and do not establish interchangeability.

This card identifies DUS-1209G/E/K as an individual aviation product and does not replace its passport, illustrated parts catalogue or maintenance manual. Before supply, the nameplate, condition, delivery scope, required documents and applicability to the individual aircraft or system should be agreed. When the marking, equipment record and inquiry contain different information, the approved documentation for the installed execution takes priority and any disputed parameter must be confirmed before ordering. Incoming-inspection results and traceability data should be retained with the supply documentation.

Related products are selected by common system or measured parameter. This grouping improves catalogue navigation but is not a list of approved replacements. Any substitution requires matching designation, electrical interface, mounting dimensions and range, together with explicit confirmation in the applicable maintenance documentation.