EUROCAE ED-26 PDF

This specification covers the requirements for the performance of equipment installed in aircraft for supplying parallel coded signals to the SSR transponder (2). These signals are utilized in the transponder for transmission of altitude information on mode C when the transponder is interrogated by signals from the appropriate ground control.

In so far as the object of fitment of the equipment is that ground control shall receive sufficiently accurate altitude information to enable it to assign the aircraft to altitudes which ensure safe levels of vertical separation from any other aircraft within possible range, the scope of this specification covers both the required output performance, and required level of accuracy of static pressure measurement in the aircraft.

In the initial phase, the introduction of altitude reporting in air traffic shall be made without degradation of the present situation, that is to say, permitting retention of the present vertical separation between aircraft.

In the second phase, the equipment should have been developed to the stage necessary for allowing reduction in vertical separation, a reduction which is being sought by the various authorities.

This double am leads, for example in Chapter 3, para 3.2, to two types of altimeters in the definition of the accuracy of the equipment. In this the documents existing and those which are in the course of preparation by ICAO have been followed (See para. 2.4).

NOTE: The integrity implicit in this MPS is sufficient for its intended use with an SSR transponder. If , however, equipment designed to this MPS is used for any other purpose, e.g. anticollision warning systems, it will be necessary to relate the integrity provisions to those required for the particular purpose.

PURPOSE

This specification (1) defines the minimum performance standards for altitude measuring equipment designed to provide a digital signal to Secondary Surveillance Radar Transponders (Mode C), as a function of aircraft altitude, referenced to standard mean sea level pressure.

(1) Short title "MPS"

(2) Ref. EUROCAE MPS WE9/1-71. June 1972 and Amendment n°1 April 1974.