Part #: 066-01143-2101

Model: MST-67A






Mode S Transponder

Part Number :




  • Remote mounted Mode S Transponder designed to fulfill role of airborne beacon equipment
  • Designed TO MEET TSO C112 FAA specification for ATCRBS/Mode Select Airborne Transponder System
  • Fully compatible with conventional Mode A and C transponder formats
  • TCAS versions permit rapid transmission of compressed bursts of communications, enabling on-board processors to coordinate between TCAS-equipped aircraft
  • Modem-like feature also permits exchange of other useful information such as weather forecasts, safety advisories and terminal data directly to pilot
  • Contains automatic self-test
  • Can be used with either panel-mount KFS-578A control unit with gas discharge display or DZUS-mount CTA-81A control unit with liquid crystal display (not applicable to -2001 and -2101 P/Ns)
  • Both control units also serve as aircraft's TCAS controller
  • Non TCAS or TCAS compatible versions available (see table below)
  • Version available with remote IDENT features allowing for IDENT transmission from source other than control unit (see table below)
  • Versions available with limited or full Built In Test Equipment fault annunciation [BITE] (see table below)
  • Versions available with Limited Level 2 data link capability that supports TCAS only as defined by DO-181A MOPS (see table below)
  • Versions available with Level 3 (Comm A/B and Comm C ELM) datalink and Flight ID reporting which also have seperate ADLP input/output ARINC 429 ports as defined by DO-181A MOPS and ARINC 718 (see table below)
  • Versions available with Flight ID ARINC 429 input port as defined by DO-181A MOPS and ARINC 718 (see table below)
  • Version available with burst tuning compatible with "burst mode" control word format where tuning data is transmitted only during tuning activity and not refreshed in between (see table below)
  • Enhanced versions available to comply with Elementary and Enhanced Surveillance Mode S mandates (-2001/2101 versions)
  • -0601, -1301, -1602 non-enhanced versions can be upgraded to -2101 version ($8000 est.)
  • -2001 non-diversity unit can be upgraded to -2101 unit by the factory, Olathe facility or Toulouse France facility



Size: 2.25"W x 7.63"H x 15.0"L Weight: 8.5 lbs.
Receiver Frequency: 1030 MHz +- 0.2 MHz Temperature Range: -55C to +70C
Transmitter Frequency: 1090 MHz +-1 MHz Power Requirements: 28VDC @ 2 amp max.
TSO Compliance: TSO C112, RTCA DO-160B, RTCA DO-178A Level 2 Software Form Factor: 4 MCU per ARINC 600
Connector Type: ARINC 404A Suppression: ARINC 718
Transmitter Power: 400 Watts (nominal) Transmit Reply Rate Capability: Rate limits of replies: ATCRBS 750 PRF, Mode S 50 PRF
Input VSWR: 1.5:1 Altitude Inputs: Dual ARINC 575 Air Data (ARINC 419), Dual ARINC 706 Air Data (ARINC 4219), Dual Gillham (Mode C Gray Code)
Control Inputs: Dual ARINC 718 (ARINC 429) Maintenance Inputs: Per ARINC 604 (ARINC 429)
Datalink I/O: Per ARINC 718 (ARINC 429) Flight ID Input: Per ARINC 718 (ARINC 429)
TCAS I/O: Per ARINC 735 (HI-SPEED 429) Squitter: Transmitted at 1 +- 0.2 sec. random, full self verification of every squitter's data and occurrence
Part Number: Description:
066-01143-0201 Limited BITE, Non TCAS Compatible, No Burst Tuning, No Remote IDENT, Level 2 Data Link, No Flight ID Reporting
066-01143-0301 Full BITE, TCAS Compatible, No Burst Tuning, No Remote IDENT, Level 2 Data Link, No Flight ID Reporting
066-01143-0601 Full BITE, TCAS Compatible, With Burst Tuning, With Remote IDENT, Level 2 Data Link, No Flight ID Reporting
066-01143-1101 Limited BITE, TCAS Compatible, No Burst Tuning, No Remote IDENT, Level 3 Data Link, With Flight ID Reporting
066-01143-1201 Limited BITE, Non TCAS Compatible, No Burst Tuning, No Remote IDENT, Level 3 Data Link, With Flight ID Reporting
066-01143-1301 Full BITE, TCAS Compatible, No Burst Tuning, No Remote IDENT, Level 3 Data Link, With Flight ID Reporting
066-01143-1602 Full BITE, TCAS Compatible, No Burst Tuning, No Remote IDENT, Level 3 Data Link, With Flight ID Reporting (same as -1301 but tested to DO-160C for RF signal and lightning suspectibility)
066-01143-2001 Flight ID, Surveillance Identifier (SI) codes, Non-diversity version, Enhanced Surveillance, Only compatible with PS-550 and PS-578 controls
066-01143-2101 Flight ID, Surveillance Identifier (SI) codes, Change 7 compliance / diversity, Enhanced Surveillance, Only compatible with PS-550 and PS-578 controls


Serial # MST67A-G3097
Condition OH
Mods 4,5
Tag Date 07/03/24
Shop Southeast Aerospace Inc.
Warranty 6 Months
- Mode S Transponder

NSN: 5895-01-450-7800

Price Condition Status
- Enhanced Mode S Transponder

NSN: 5826-01-551-2080

Price Condition Status
- Mode S Transponder

NSN: 5841-01-561-8169

Price Condition Status
- Mode S Transponder (Non-Diversity)

NSN: 5821-01-482-8862

Price Condition Status
- Mode S Transponder
Price Condition Status
- Mode S Transponder

NSN: 5895-01-552-8116

Price Condition Status

Click on a question below to see the answer. If you have a question about this model that is not answered below, please contact

In relation to NE (New) parts, many OEMs change their prices and availability without any notice to dealers or the industry. Therefore, through the REQUEST or RFQ indication, we ask that customers contact us for the most accurate price and availability.

In relation to SV & OH parts, the used parts aftermarket in the aviation industry is not an infinite supply. It is a dynamic, constantly changing market that is significantly affected by and susceptible to highs and lows in supply and demand. Therefore, although we attempt to, at times, we are unable to predict the exact moment when an item may be available. Once again, through the REQUEST or RFQ indication on our website, we ask that customers contact us for the most current and accurate price and availability.

Citation S550 equipped with: Transponders MST-67A 066-01143-2101. Chance to update to ES?

Garmin GPS400. Chance to update software to WAAS? Or maybe to replace with a GPS400W and link it with transponders? - FMS UNS-1L SCN 803.1. Citation Mustang C510 equipped with G1000 Integrated Flight Deck. It is a 2008 plane.

What can I do to get ADS-B at an affordable price?

A: Since the aircraft are operated in Spain, what region or ADS-B spec do you need to meet? (i.e. USA, DO-260B?)

Without knowing exactly what ADS-B requirement or mandate you might be trying to comply with, I can only provide information relative to what we know here in the USA in reference to ADS-B for Part 25 aircraft.

For the Citation 550, the MST-67A will be superseded by the MST-100B if/when Honeywell can produce and certify the MST-100B. I have attached the only details that we currently have on the MST-100B. Honeywell has not even released pricing on this unit yet, however, ideally it would be an ideal solution ultimately since it is said to be plug and play with the MST-67A. With a WAAS GPS interfaced it would meet all ADS-B mandates. Also, keep in mind, that your CAS-67 can be upgraded fairly easily to Change 7.1 via Honeywell sales bulletin upgrading the TPU-67A processor to the TPU-67B. There is a company that offers some STCs for Part 25 aircraft if your region requires an STC for the 7.1 upgrade -

If the MST-100B does not pan out for some reason and/or Honeywell keeps delaying its release, then there is a company named Jettech that has released Garmin GTX 3000ES ADS-B capable transponder to its existing STC covering Garmin GTN install on Citation and Citation Jet aircraft equipped with TCAS II. In addition, the company amended its Garmin GTN autopilot coupled LPV FAA STC for the Citation 500 series to include all Primus 1000 equipped Bravo, Ultra, Encore and Excel aircraft. They do not have much information on their website about the ADS-B STC but I recently learned about it at the AEA convention last week -

Regardless of what direction you might go in, you should most likely get your GPS-400 upgraded to the GPS-400W while Garmin is still offering the upgrade. It is relatively inexpensive at around $3000 USD. Most FANS type systems will require WAAS GPS input or accuracy ultimately. Plus, Garmin's WAAS interface tis very compatible with most ADS-B solutions. Regarding the Citation Mustang C510 equipped with G1000, Garmin is still working on this solution. We assume it will include the GTX-3000 transponder(s) as this aircraft will require a 1090 MHz, (not 978 MHz UAT) system. I would continue to monitor Garmin's website for announcements relating to the G1000.



Bendix/King, L3 and ACSS released the NXT-700/MST-70B as form fit replacement for the MST-67A. It is DO-260B compliant to meet the ADS-B Out mandate.

There are other options besides the MST-70B to gain ADS-B compliance. There are various STCs that allow the removal of the Bendix/King transponder system and installation of Rockwell Collins or Garmin transponders. Upgrade prices vary depending on actual installed equipment. 

Regarding ADS-B for the Garmin GTX-330 transponders, the best solution is to simply have the units converted by Garmin to include the ES (Extended Squitter) upgrade. This upgrade is about $2000 approximately. Additionally, a WAAS/GPS source will need to be interfaced. We can process the upgrade for you or any other Garmin dealer can as well.

Negotiating the exchange price of a unit only limits the allowable repair cap for the core unit. Southeast Aerospace's exchange transactions are based on the return of economically repairable core unit. Once the core is received and evaluated, the core repair cost incurred by SEA cannot exceed 75% of the original exchange price. That is, it cannot cost SEA more than 75% of the original OH/SV exchange price collected from the customer. Therefore, when and if an SEA exchange price is discounted, there is a risk that additional charges may be assessed once the core is returned and evaluated.

In relation to the transponder technology, a squawk refers to a response that a transmitter responder (i.e. transponder) is making to an interrogation from Air Traffic Control (ATC). In a classic Mode A/C transponder, a squawk response included very basic aircraft ID, general status, and pressure altitude information.

A squitter or squit is a transmission that frequently sends aircraft ID and position data while not being interrogated. In some Mode S transponders and ADS-B devices, the squit transmission can include up to almost 50 parameters including lat/long position, direction of flight, velocity, and more.
The Mode S aircraft identification code is listed on AC Form 8050-3, Certificate of Aircraft Registration, as the International Civil Aviation Organization (ICAO) Aircraft Address Code. If the aircraft registration does not contain this information, aircraft owners with a Mode S transponder can obtain an aircraft identification code from the FAA Aircraft Registry in Oklahoma City, Oklahoma. This may be accomplished by writing to the following FAA address:

Federal Aviation Administration
Aircraft Registration Branch AFS-750
P.O. Box 25504
Oklahoma City, OK 73125-0504

You may also call:
Utilizing more than one antenna to improve the quality and reliability of radio signal is called antenna diversity.

Heavy and/or faster aircraft utilize top and bottom antenna configurations to eliminate the possibility of signal blind spots caused by shadowing. Lighter, slower general aviation aircraft typically only have 1 antenna and do not require antenna diversity. Although not completely uniform, the transmission pattern of a typical antenna provides adequate radiation above and below in relation to most GA aircraft even when the antenna is on the bottom of the aircraft.

Yes, providing that the unit has been functioning normally, SEA can upgrade and convert the MST-67A transponder as follows:

MST-67A P/N 066-01143-0301 to 066-01143-2101 = $9550 USD

MST-67A P/N 066-01143-0601 to 066-01143-2101 = $9550 USD

MST-67A P/N 066-01143-1301 to 066-01143-2101 = $9550 USD

MST-67A P/N 066-01143-1602 to 066-01143-2101 = $6950 USD

Prices are subject to change should cost of parts needed change from OEM.

For a repair RMA or questions about any transponder service, please contact the SEA Repair Department.

As of June 2010, the MST-67A does not have Extended Squitter (ES) capabilities. Honeywell is planning to make the MST-67A ES compliant; however, there is not a timeline currently available.
Most Mode S transponders such as the Honeywell MST-67A and Collins TDR-94D include a feature that allows it to automatically determine the aircraft Registration Number (Tail Number) of U.S. registered (N numbered) aircraft. If the aircraft is U.S. registered and operated where the tail number is used as the call sign (Flight ID), then the operator does not have to manually enter the Flight ID. Therefore, a control head with Flight ID input such as the Honeywell PS-578 or Collins CTL-92E is not required.

The transponder automatically reads the Mode S address assigned to the aircraft. If the Mode S address falls within the range of addresses assigned to the U.S. by the International Civil Aeronautics Organization (ICAO), the MST-67A will automatically convert that Mode S address to the tail number of the aircraft and place it in the Flight ID register for compliance with Elementary Surveillance.

If the aircraft is operated where the Flight ID is not the tail number or the aircraft is not registered in the U.S., then a Flight ID control head is required to allow for manual entry of Flight ID. The flight ID may contain the company-assigned number for that particular flight such as an Airline name and Flight number.
Honeywell Service Bulletin MST67A-34-56 addresses a software issue related to EASA Airworthiness Directive No. 2008-0159. This European AD identifies a problem in the MST-67A. The transponder datalink does not communicate all of the surveillance parameters correctly with the Mode S Secondary Surveillance Radar (SSR). Therefore, the affected MST-67A does not fully support Mode S enhanced surveillance.

MST-67A P/N 066-01143-2001 units with serial numbers MST67A-F1450 and below are affected. MST-67A P/N 066-01143-2101 units with serial numbers MST67A-G2850 and below are affected.

Honeywell Service Bulletin MST67A-34-56 incorporates a software modification to address the enhanced data communication issues. This SB involves replacing to intergrated circuits on the IOP/DLP COM board and appropriate labeling.

Since safety and quality are of the utmost importance, Southeast Aerospace is pleased to inform its customers and prospective clients that we will incorporating the Honeywell Service Bulletin into all MST-67A P/N 066-01143-2001 and 2101 that are serviced and processed in our FAA/EASA approved repair facility. If you have an MST-67A that is affected by this Airworthiness Directive, please contact our Service Center at for more details on a quick, responsive solution.
Yes. The -2101 version provides two transponder antenna inputs or diversity. The diversity option allows selection of signal receptions from either a top or bottom mounted antenna based on the characteristics of the received signals. The -2001 version does not provide the diversity option. In the event that the diversity version -2101 must be used in place of the non-diversity version -2001, a simple input must be changed on connector J671A. Pin 89 of this connector identifies whether one or two antennas are used in the installation. Pin 89 is strapped to aircraft ground if only one antenna is used. Therefore, if installing a -2101 in a -2001 installation, no wiring changes are needed.
Yes, anytime a transponder is removed or replaced an altitude correlation between what the transponder is reporting and what is displayed on the altimeter needs to be performed. This is outlined in FAA CFR Part 91.413. This regulation indicates that following any installation or maintenance of a transponder where data correspondence error could be introduced, the integrated system has been tested, inspected, and found to comply with paragraph (c), appendix E. Furthermore, these references indicate that an integration test between the altitude reporting equipment and transponder system must be conducted.

For complete information, please refer to these FAA regulations or contact Southeast Aerospace Tech Support team at
Many avionics systems require a configuration or setup process. This process is required to interface certain avionics systems to other systems in the aircraft that will be inputting or outputting information to and from these systems. Some examples of systems that require a configuration or setup process include:


In addition, most newer technology or solid state systems require configuration via computer interface of some type. A qualified avionics technician should always refer to the appropriate manufacturer's installation manual for complete information and instructions.
TCAS II is a system used for detecting and tracking aircraft in the area of an aircraft. TCAS interrogates transponders in other aircraft and analyzes the replies to determine range, bearing, and relative altitude (if reporting) of the intruder aircraft. When the TCAS II processor determines that a potential collision hazard exists, it will issue visual and audio advisories to the pilot/copilot for appropriate vertical avoidance maneuvers. TCAS is not able to detect aircraft without an operating ATCRBS transponder (operating in Mode A and C) or a Mode S transponder.
TCAS II utilizes two types of cockpit displays, Resolution Advisory (RA) and Traffic Advisory (TA) display. The RA is incorporated into the vertical speed indicator (VSI). With illuminating red and green arcs around the dial, the VSI displays the required rate, or limitation of climb or descent, to avoid a collision. The TA display shows the intruding aircraft’s relative position and altitude with a trend arrow to indicate if it is climbing or descending greater than 500 feet per minute. The TA display may be presented on compatible weather radar indicator or MFD, dedicated TCAS display or a TA/VSI display. The TA display uses symbols and colors to identify the relative threat of each intruder. Supplementing the displays, TCAS II provides appropriate synthesized voice announcements.
For operators (usually commercial) whose Flight ID changes frequently, a control head such as Honeywell PS-578 or Collins CTL-92E provide for the entry of the Flight ID. The Flight ID may contain the company-assigned number for that particular flight such as an Airline name and Flight number. For civil operators whose Flight ID (usually the aircraft registration number) whose Flight ID does not change, a control with Flight ID input is not required.

Yes. According to Honeywell Installation Bulletin 502, the PS-578 has the same dimensions, mounting holes, and same connectors as the KFS-578A. Both controls have the same tuning functions however the PS-578 adds the ability to enter the 8 digit aircraft Flight ID. The design of each control differs as well as the internal circuitry. Some capabilities of the KFS-578 requiring part number differences were consolidated into single part numbers in the PS-578. The wiring is identical and no change in plug configuration or system wiring is required.

PLEASE NOTE - Publications are for Reference Only