M428

MKXIIA & Mode S IFF
Compact Transponder

The M428 compact transponder is the ultimate evolution of the existing and well-proven family of MkXIIA (MkXII+ Mode 5) transponders developed under the NGIFF program. Military identification is achieved through Mode 4 and Mode 5, supported by a removable encryption unit (SIT 2010 crypto appliqué) designed entirely in-house and certified by NATO Authorities (SECAN).

Removable encryption device and additional functions (e.g. ADS-B IN and Reverse Mode 5) are other topics that are coming up from the most demanding customers.

Compatibility with the latest ATC standards is provided by a Mode S (up to Enhanced Surveillance) that includes an ADS-B Out capability and ADS-B IN growth capability. Variants of the equipment can be provided for non-NATO applications with an M4-only or National Secure Mode capability. The equipment has been designed for all applications including avionic (fixed or rotary wings), UAS, and ships plus future air-to-surface identification as Reverse Mode 5 growth capability.

The new transponder is packed into a reduced ½ ATR form-factor for hard mounting, specially designed for small size applications such such as UAS. Integration with the platform can be via MIL-STD-1553 Bus, ARINC 429, or RS485; compatibility with conventional Control Panel (M910) is granted for legacy applications.

Operation

The equipment is fully solid-state and of modular construction to facilitate maintenance. Replies are transmitted on two RF connectors to provide full diversity operation, supported by a receive section that
provides two matched channels.

Multiple options are available in order to interface the host platform; all interfaces are available in the same unit and are automatically selected at power-up.

These options are:

MIL-STD-1553 to interface an avionic bus
RS 485 to interface an FMS or dedicated control panel
ARINC 429 to interface an FMS
Ethernet (growth capability)

For integration on legacy platforms that do not include a data bus or FMS, M428 is compatible with the M910 control panel for Mode S operation. The equipment is capable of providing Enhanced Surveillance operation with its own interfaces, without the need for an additional ADLP. The equipment is also capable of operating in conjunction with a TCAS II (V7.1) processor. Extensive BITE is provided, including Power-Up, Continuous, and Initiated BIT; test results and diagnostic information are available on the control interface.

Reverse Mode 5

Reverse Mode 5 is for Air-to-Surface Identification (ASID) and the relevant standard (STANAG 4722) has been approved and is under ratification.

Transponder and ADS-B (IN) Receiver Integration

The next market demand is the integration of the ADS-BIN functions inside the military transponder. Through the Mode S ADS-B IN function, aircraft will be able to receive surveillance information (about civil tracks) without the need to switch on the radar and the interrogator (if available on the platform). The M428 transponder also provides this capability.

Configuration

A transponder system includes, in addition to the IFF equipment:

Mounting tray
Two omni antennas (top, bottom) for diversity operation

In order to support the system, Leonardo can provide a full range of solutions covering:

Diagnostic SW (on OTS platform) for troubleshooting, calibration, and operational SW loading
Special Test Equipment
Automatic Test Equipment