BDK-89
Su-24 Discrete Command Unit
Description
BDK-89 discrete command unit
BDK-89 is an aircraft discrete-command unit used in the engine control and indication circuits of the Su-24. The aircraft technical description identifies two units, one for each engine. BDK-89 converts monitored engine conditions into electrical command and indication signals for starting, afterburner control, cooling, time accounting and warning circuits.
Full descriptionCollapse description
Installation on the Su-24
The two BDK-89 units are installed in the left and right main landing-gear bays between fuselage frames 18b and 19. Each unit serves its associated engine. This placement and function are documented for the Su-24 with AL-21F-3 engines; effectivity and wiring must still be checked against the aircraft modification and equipment schedule.
Engine signals controlled by BDK-89
The documented logic issues generator-connection commands at engine speed n ≥54%, afterburner and turbo-starter exhaust-flap commands at n ≥80%, and turbine-stage cooling and indication commands at n ≥94%. It also participates in afterburner indication, engine operating-time counter modes at n ≥19% and maximum-hours accounting at n ≥97%, plus warning of limiting pressure in the middle-bearing cavity.
Power and associated equipment
BDK-89 uses the aircraft 27 V DC emergency bus through an AZRG-5 protection device and a nominal 115 V, 400 Hz AC supply. The existing record gives the permitted AC range as 109–121 V. Associated monitoring equipment includes DAT-4 oil-pressure transducers, P-77 oil-temperature probes, a P-63 fuel-temperature probe, MV-27-1 vibration transducers and the UM-4 magnetic-amplifier chip-warning chain.
Testing and supply request
Match the full BDK-89 marking, connector keys, mounting and the left- or right-engine wiring. Bench testing must reproduce the documented speed and warning inputs; BDK-1 is a separate unit. A request should include aircraft modification, quantity, condition, passport and delivery set. More products are listed in Electronic Control Units.
Technical details
- Product Type
- Aircraft discrete-command unit
- Documented Aircraft
- Su-24 with AL-21F-3 engines
- Quantity per Aircraft
- 2, one per engine
- Installation
- Left and right main landing-gear bays, between frames 18b and 19
- DC Supply
- 27 V DC emergency bus through AZRG-5
All specificationsCollapse specifications
- AC Supply
- 115 V nominal, 109–121 V range, 400 Hz
- Generator Command
- At engine speed n ≥54%
- Afterburner and Turbo-Starter Flap Command
- At n ≥80%
- Turbine Cooling Command
- At n ≥94%
- Operating-Time Counter Modes
- At n ≥19%; maximum-hours accounting at n ≥97%
- Associated Sensors
- DAT-4, P-77, P-63, MV-27-1 and UM-4 chain
- Alternative Designations
- BDK-89; BDK89; БДК-89; БДК89
Payment & delivery
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Dubai stock: 100% before dispatch. Partner stock (Remote stock) and Pre-order: 50% advance payment to start the order and 50% before shipment from Dubai to you.
Availability, lead time, delivery cost and payment terms are confirmed for your order before payment.
Payment & delivery terms