GEN 1.5  Aircraft instruments, equipment and flight documents

GEN 1.5.1   General

Aircraft operating in the Republic of Croatia airspace shall be equipped with the required radio and navigation equipment necessary for the safe conduct of the flight.Designated ATC unit may, in substantiated cases, permit flights of aircraft without VHF transmitter/receivers and transponder in controlled zones, conducting aerodrome traffic at a controlled aerodrome and acrobatic flights in controlled airspace, if safety of air traffic is not impaired.

GEN 1.5.2   Equipment to be carried

GEN 1.5.2.1   Minimum required communication, navigation and surveillance equipment for IFR flights
  1. Two VHF transmitter/receivers (frequency range: 117.975 MHZ to 137.000 MHZ and 8.33 KHZ channel spacing). Exemptions from mandatory carriage of 8.33 KHZ equipment for State aircraft are described in ENR 1.8.
  2. Two VOR receivers. Only one receiver is sufficient if the aircraft is equipped with RNAV system that is used independent from the VOR receiver
  3. One distance measuring equipment (DME)
  4. One automatic direction finder (ADF), covering the frequency range 200.000 KHZ to 526.500 KHZ with direction indicator and audio monitoring capability
  5. RNAV equipment certified for B-RNAV (RNAV 5), P-RNAV (RNAV 1) or RNP APCH operations as required for the specific route and/or approach procedures
  6. One SSR Mode S level 2 transponder with Elementary Surveillance (ELS) capability. Fixed wing aircraft with maximum certified Take-Off Mass greater than 5700 KG or maximum cruising True Air Speed greater than 250 KT must be equipped with Mode S transponder capable for Elementary Surveillance (ELS), ADS-B Out and Enhanced Surveillance (EHS). Other aircraft with maximum certified Take-Off Mass greater than 5700 KG or maximum cruising True Air Speed greater than 250 KT must be equipped with Mode S transponder capable for Elementary Surveillance (ELS) and ADS-B Out
  7. In case of approach using the instrument landing system (ILS):
    • one receiver for ILS localizer signals,
    • one receiver for ILS glide path signals,
    • one VHF receiver with an indicator for marker beacon signals, and
    • one combined indicator for ILS localizer and glide path transmitter signals
GEN 1.5.2.2   Emergency locator transmitter (ELT)

ELT is mandatory within FIR Zagreb. Any type of ELT shall be capable of simultaneously broadcasting on the frequency 121.500 MHz and 406.000 MHz.

GEN 1.5.2.3   Requirements for FM broadcast immunity of airborne receivers

Since 01 JAN 2001, the use of FM-immune ILS/VOR navigation and VHF communications receivers is required for IFR operations within Zagreb FIR.

Users of ILS/VOR navigation and VHF communications receivers that do not comply with FM immunity standards may expect to suffer interference from FM broadcast stations.

Remarks on potential interference when using ILS/VORs for instrument approach are depicted on relevant aerodromes’ charts (AIP Part III - Aerodromes).

GEN 1.5.2.4   Airborne collision avoidance systems (ACAS II)
  1. The following turbine-powered aeroplanes shall be equipped with collision avoidance logic version 7.1 of ACAS II:
    • aeroplanes with a maximum certificated take-off mass exceeding 5700 KG
    • aeroplanes authorised to carry more than 19 passengers
  2. Aircraft not referred to in point a., but which are equipped with ACAS II on a voluntary basis shall have collision avoidance logic version 7.1

GEN 1.5.3   Equipment to be carried on all internal and on certain flights

Nil

GEN 1.5.4   Reduced vertical separation minimum (RVSM) operations

In airspace where RVSM is implemented (FL290-FL410 inclusive), flight operations are permitted only to aircraft with RVSM approval and State aircraft without RVSM approval.

RVSM approved aircraft are those aircraft for which the Operator has obtained an RVSM approval, either from the State in which the operator is based, or from the State in which the aircraft is registered.

Guidance material on the airworthiness, continued airworthiness and the operational practices and procedures for the EUR RVSM airspace is provided in the EASA CS-ACNS.E.RVSM or in the Joint Aviation Authorities (JAA) Temporary Guidance Leaflet (TGL) No. 6, Revision 1 and the ICAO Regional Supplementary Procedures (Doc 7030/4 - EUR).

GEN 1.5.5   Mode S procedures - display of downlinked aircraft parameters (DAP)

The following Mode S DAPs are used in Zagreb FIR:

These aircraft parameters are downlinked from aircraft by the Mode S EHS (Enhanced Surveillance) compliant transponder. Aircraft that are equipped with Mode S ELS (Elementary Surveillance) transponder only, cannot downlink these values.

Having seen the current indicated air speed, Mach number and magnetic heading in the label, the air traffic controller generally will use these displayed values of a Mode S EHS equipped aircraft, without verbally asking.

Note 1: in certain circumstances, it may be necessary to verbally verify any of these DAPs against reading from the flight deck.

Note 2: the DRC (Downlinked Rate of Climb/Descend) value is also provided by EHS compliant aircraft, but the air traffic controller shall not use it, due to the fluctuation of the DRC value. However the DRC value is also displayed on the screen to give information about the tendency and the order of magnitude of the vertical speed.