Mode S Transponders

Ready today to meet tomorrow’s NextGen mandates

L3’s NXT-600/-700/-800™ Mode S Transponders are ready to provide civil, commercial and military aircraft and helicopter manufacturers and owners with all the capabilities they need to operate safely and efficiently in NextGen Automatic Dependent Surveillance – Broadcast (ADS-B) airspace. Optimized for NextGen operations, the NXT family of transponders enables pilots to take advantage of more efficient routing, while increasing airspace capacity, situational awareness and overall operational safety.

  • NextGen ADS-B-compliant
  • Elementary and Enhanced Mode S surveillance-compliant
  • Function validity verification through simple built-in test and self-test capabilities
  • Compatible with all ARINC 735B/735A/735 TCAS II systems, including ACSS TCAS 3000SP™, TCAS 2000™, T2CAS™ and T3CAS™
  • Meets all civil, commercial and military aircraft and rotorcraft requirements with two form factor options for slide-in replacement of current XS-950 (4 MCU), RCZ-852 and 1/4 ATR Short

NXT-700 (BK MST 70B) for Business Jet and Military Aircraft

ACSS’ exclusive distributor of the NXT-700 (MST 70B) transponder for business jet and military aircraft is BendixKing. For information on purchasing product from BendixKing please use the button below.

For NXT-700 purchases for regional aircraft, please use the Request for Quote button above.

Highly accurate position reporting

High-level of ADS-B Out (DO-260B) reporting requires the transmission of precise, real-time flight data information, including current aircraft position, speed and intent. The NXT-600 automatically transmits all position data via ADS-B Out to other nearby aircraft (equipped) and Air Traffic Control (ATC).

NextGen ADS-B compliant around the world

L3 NXT transponders are DO-260B-compliant to meet NextGen & Standardized European Rules of the Air (SESAR) mandates requiring transmission of more precise position, speed and intent data. They also meet ICAO Level III standards for the latest functionality for the ICAO Airborne Collision Avoidance System (ACAS) II mandate and are also compliant with European Elementary and Enhanced Mode S Surveillance Downlink of Aircraft Parameters (DAPs) and ADS-B 1090ES extended squitter.

Software upgradability yields reduced maintenance costs

The capability to perform timely onboard software loads provides operators with simplified upgrades, increased aircraft utilization and lower maintenance costs. In addition, the high reliability of the NXT-series greatly enhances the overall validity of the TCAS system reducing Mode S transponder-induced No-Fault-Found (NFF) TCAS failures.


Environmental DO-160G
TSO/JTSO C112d, C166b/C112c
Software DO-178B Level B
Transponder Data Link Capability ICAO Level 3 (COMM-A/B/C)
ADS-B Capability 1090ES Extended Squitter per RTCA DO-260B MOPS for 1090 ADS-B Equipment
Operating Altitude Sea level to 55,000 feet
Operating Temperature -55 to +70 degrees C
Storage Temperature -55 to +85 degrees C
Power 115VAC, 400Hz or 28 VDC
Power Consumption 40 Watts (standby), 85 Watts (maximum)
No. of Antenna Ports 2 (diversity)


Size (inches) 3.4 (H) x 4.1 (W) x 14.01 (L)
Weight 5.0 lb.
Mounting ARINC 600 4 MCU Mount / MT-600 Mount
Cooling ARINC 600 External/Internal


Controller Low speed ARINC 429
TCAS II High speed ARINC 429
GPS High or low speed ARINC 429
Altimeter ARINC 429/575 (digital air data)
Flight Identifier Various
Maintenance Computer (Airbus & Boeing) Low speed ARINC 429

Product Support

Repair and Overhaul Administration:
Phone: +1 (623) 445-7030
Fax: +1 (623) 445-7002

Product Support/Customer Service:
Phone: +1 (623) 445-7070
Fax: +1 (623) 445-7001

AOG Services:
Regional, Business Jet & Military
Administered by logistics partner AVGroup
Provides exchange and rental services of ACSS LRUs to existing ACSS customers.
Phone: +1 (866) AOG-TCAS or (866) 264 8227 US callers
Phone: +1 (678) 597-2792 International callers
Fax: +1 (770) 457-8563

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