Generally we can state that for the route navigation in the CTA the requirement for full coverage of B-RNAV (basic area of navigation) above the minimum flight level is a general objective, which should be fulfilled as soon as possible. For P-RNAV (specific area) in TMA with heavy traffic the requirement for DME coverage is expected already beginning 2005, for RNP-RNAV (prescribed area) the full coverage is expected after the year 2010.

However, the respective navigation infrastructure cannot be built in a short time interval and its preparation must be divided into the next few years. Supplementing of DME must be preceded by careful assessment.

For the application of P-RNAV and later RNP-RNAV for TMA needs the number of DMA must be also supplemented, however, their positions have not yet been specified. Besides calculations and flight verifications this process will also require mobile DME sets.

Specification of necessary number of DME to secure the required level of RNAV in TMA at airports and for route navigation shall be carried out by the Flight Verification Department of the Civil Aviation Authority. For the verification of accuracy of recommended positions it will use the so-called mobile DME prepared by ANS CR, s.e. The respective localities will be selected based on the combination of mathematical calculations and flight measurements and a schedule of their furnishing with new DME will be stipulated. After the stipulation of necessary number of DME their building will be included in updated Medium-Term Development Plan of Air Navigation Services of ANS CR, s.e., and allocation of respective new frequencies shall be applied for.

The so-called mobile DME, which will serve the above-mentioned purpose, consists of the following components:

FORD automobile,

DME 435 Thales,

FAN 96 Thales antennae system,

Antennae pole with attachment to FORD automobile,

Standby supply HONDA electric centre.              

Lubomír Pelinka, DPRO/ATMS/NAV