Zaon MRX Portable Collision Avoidance System

Avoid the near-misses
Price: £345.99

Have you ever seen another aircraft come close and thought, 'Where the heck did he come from?'.

That's when the idea of some sort of Traffic Collision Avoidance System(TCAS) as fitted to airliners and high-end light aircraft becomes attractive, especially in congested areas such as the South-east of the UK.

The problem is cost and complexity. A full-blown TCAS costs more than the whole panel for many light aircraft.

There are lower cost, simpler solutions and the latest is the MRX Portable Collision Avoidance System (PCAS) from US company, Zaon Flight Systems. they claim it's the world's smallest collision avoidance system and it runs independently of the aircraft's system - it sits on top of the panel.

The MRX displays range and relative altitude of the colsest 'threat' aircraft, while continuing to monitor the top ten 'threats' within a 5nm 'bubble'  around your aircraft. It informs you with a visual display and  audio warnings.

It's a passive system, which means it works by monitoring the return transponder squawks of other aircraft around you. These return signals are in response to the interrogation signals by more sophisticated radar and TCAS systems.

For example, a ground-based radar unit sees an aircraft and sends an interrogation signal. The aircraft's transponder replies and the MRX unit picks up that signal. the range is computed, the sltitude code decoded, and the angle-of-arrival is determined.

MRX will recognise interrogations from TCAS, Skywatch and other 'active' system, military protocols and Mode S transmissions.

It's amazing how so much can be packed into such a small unit. The MRX measures 65mmx107mmx17mm - smaller than a deck of cards. Information is displayed on a dimmable LED display, and it can be powered by the aircraft's electric system or by two AA batteries with a life of 8+ hours.

 Available from pilot supply shops such as Flightstore and Transair.