Honeywell International Inc. DMA-37B2 Manuale Utente

Page 3

10 Oct 2007

DMA-37B DME System

© Honeywell International Inc. Do not copy without express permission of Honeywell.

(1) The DMA-37B DME System is designed to provide the flight crew with accurate 

slant-range distance information in digital format as measured from the aircraft to a 

selected ground-based DME transponder. Depending upon the DME display, DMA-37B 

adds ground speed and time for the aircraft to reach the selected ground-base station at 

the current velocity can be derived from the slant-range.

(2) A DME is co-located at ground-based VHF Omnirange Distance Measuring Equipment 

(VOR-DME) and VHF Omnirange Tactical Air Navigation (VORTAC) stations. The 

DMA-37B is capable of receiving the distance measurement from military Tactical Air 

Navigation (TACAN) stations. A few DMEs are co-located with ILS systems presenting 

distance and aircraft speed to the runway as the aircraft approaches for landing.

(3) DME is used in conjunction with a primary navigation source, like VOR, to measure 

distance along a route of flight toward the VORTAC station. For some instrument 

approaches, it is used with VOR to fly where a DME arc or VOR-DME equipment is 

required for approach.

(4) The DMA-37B DME Interrogator is a very powerful scanning DME. In addition to stations 

selected by the crew, it searches automatically for up to five stations within a 

300-nautical mile range.

(5) The operating range of the DMA-37B DME System is zero to 300 nautical miles. The 

DMA-37B DME System consists of an airborne DMA-37B DME Interrogator, a mount, a 

DME indicator, and an antenna.

(6) The DMA-37B DME Interrogator design conforms to industry standards Aeronautical 

Radio Incorporated (ARINC) 709-8 Airborne Distance Measuring Equipment, Radio 

Technical Commission for Aeronautics (RTCA) document number DO-189 Minimum 

Operational Performance Standards (MOPS) for Airborne Distance Measuring 

Equipment (DME), and European Organisation for Civil Aviation Equipment 

(EUROCAE) ED-54 Minimum Operational Performance Requirements for Distance 

Measuring Equipment Interrogator, and digital guidance data conforms to ARINC 

429-14 Mark 33 Digital Information Transfer System (DITS) format.

(7) The DMA-37B DME Interrogator is fully interchangeable with the earlier ARINC 709 

DMA-37A DME Interrogator for backward compatibility.

(8) In addition, the DMA-37B provides fast scan and digital Morse Code decoding outputs, 

fault memory, and built-in test equipment (BITE) interfaces for use in a Central 

Maintenance Computer (CMC) in accordance with ARINC 604 to transfer maintenance 

data or in a Central Fault Display System (CFDS) in accordance with ARINC 604, and 

Airbus Industrie ABDO048C or McDonnell Douglas software requirements.

(1) Components of the DMA-37B DME System supplied by Honeywell are listed in Table 1. 

Table 1 lists the currently available components of the system, along with part numbers 

and equipment type numbers.