GEN 1.5  Aircraft Instruments, Equipment and Flight Documents


1.1   RNAV Equipment

Aircraft, other than state aircraft, operating on the ATS routes above FL 95 within the Brussels FIR/UIR shall be equipped with, as a minimum, RNAV equipment meeting RNP 5 in accordance with the requirements set out in ICAO Doc 7030, Regional Supplementary Procedures (EUR SUPPS, chapter 4).

1.2   RNP Approach Equipment

To execute an RNP approach the use of GNSS equipment is mandatory. In case of an RNP approach to the LPV minimum, the equipment must additionally make use of the European SBAS EGNOS. These LPV approaches can be retrieved from the FMS database using the SBAS channel number as published on the relevant RNP approach chart.

In case of RNP approach, the pilot should check RAIM availability using GNSS RAIM NOTAM or other means. In case of RNP approach to LPV minimum, the pilot should check EGNOS availability using EGNOS NOTAM for the relevant airport.

The use of guidance relying on EGNOS signals is authorized for a RNP approach leading to LNAV/VNAV minima.

Barometric VNAV guidance during approach is not temperature compensated. A temperature limitation is reflected on the RNP approach chart. Operating at uncompensated altitudes will not provide expected obstacle clearance below published minimum temperatures.


2.1   8.33 KHZ Voice Channel Spacing Above FL 195

The carriage of 8.33 KHZ channel spacing radio equipment is mandatory throughout the ICAO EUR Region for flights above FL 195.

State aircraft operating within Brussels FIR/UIR are permanently exempted from the above carriage requirement, provided that they are able to communicate on UHF. In addition, all state aircraft flying OAT within the Brussels UIR, are exempted from the above-mentioned carriage requirement.

Except for UHF equipped state aircraft, non-equipped aircraft planning to enter any FIR/UIR above FL 195 in the EUR Region where no exemption has been published (refer to the AIP of the state covering the FIR/UIR concerned), must flight plan to operate below FL 195 throughout the entire EUR Region.

Note: Above FL 245 in the Brussels UIR, UHF coverage is assured. Below FL 245, regular 25 KHZ assignments will be used. State aircraft planning to cross the Brussels UIR boundary above FL 195 shall comply with the 8.33 KHZ regulations of neighbouring states and check the UHF coverage provided.

2.2   8.33 KHZ Voice Channel Spacing Below FL 195

All radios operating in the 117.975-137 MHZ band (the ‘VHF-band’ allocated to aviation) shall have the 8.33 KHZ channel spacing capability. An operator shall not operate an aircraft in airspace where carriage of radio is required unless the aircraft radio equipment has the 8.33 KHZ channel spacing capability.

State aircraft which are permanently exempted from the requirement of having radio equipment with the 8.33 KHZ channel spacing capability shall be able to communicate on UHF or on the remaining VHF 25 KHZ frequencies, where available.


Only RVSM approved aircraft and non-RVSM approved state aircraft will be permitted to operate within the EUR RVSM airspace.

Guidance material on the airworthiness, continued airworthiness and the operational practices and procedures for the EUR RVSM airspace is provided in the Joint Aviation Authorities (JAA) Temporary Guidance Leaflet (TGL) Number 6, Revision 1, and the ICAO EUR Regional Supplementary Procedures (EUR SUPPS, chapter 4).

Note 1: 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.

Note 2: Details on RVSM airspace within Brussels UIR can be found in ENR 2.1.


4.1   Elementary Surveillance

The carriage and operation of a Mode S transponder with basic functionality is mandatory in the Brussels FIR/UIR, as follows:

  • For IFR flight as GAT: a level 2 transponder is needed with elementary surveillance (including SI-code) functionality as a minimum, compliant with ICAO Annex 10. Volume IV.
  • For VFR flights, conducted in airspace where the carriage and operation of SSR transponders is mandatory: a level 2 transponder is needed with elementary surveillance (including SI-code) functionality as a minimum, compliant with ICAO Annex 10. Volume IV.

Note: Functionality must include SI-code capability and, where ACAS II is installed, also resolution and traffic advisory reporting capability.

4.2   Enhanced Surveillance

Fixed wing aircraft flying as GAT in the Brussels UIR at or above FL 245 shall be equipped with a Mode S transponder with enhanced surveillance (EHS) functionality when the aircraft has a MTOW greater then 5 700 KG and/or a maximum cruising true airspeed in excess of 250 KT.

4.2.1   Mode S Transponder

To meet EHS requirements compliant with EUROCAE Document ED-73B, as a minimum an approved level 2 Mode S transponder (specified in the declaration of design and performance (DDP) of the transponder equipment) must be installed.

4.2.2   EHS Capable Aircraft

An aircraft is considered to be EHS capable if the full list of 8 downlink parameters (DAP), as indicated below, can be supplied. Where the parameter ‘track angle rate’ cannot be supplied, it should be substituted by the ‘true airspeed’.

BDS RegisterBasic DAP Set
(if Track Angle Rate is available)
Alternative DAP Set
(if Track Angle Rate is not available)
BDS 4,0Selected AltitudeSelected Altitude
BDS 5,0Roll AngleRoll Angle
Track Angle Rate
True Track AngleTrue Track Angle
Ground SpeedGround Speed
BDS 6,0Magnetic HeadingMagnetic Heading
Indicated Airspeed (IAS) / Mach Number
Vertical Rate (Barometric rate of climb/descend or baro-inertial)Vertical Rate (Barometric rate of climb/descend or baro-inertial)
True Airspeed (provided if Track Angle Rate is not available)

Note 1: IAS and Mach Number are considered as 1 DAP. If the aircraft can provide both, it must do it.

Note 2: Mode S EHS transponder systems must be certificated in accordance with EASA Document AMC 20-13.

If the DAP conditions cannot be met, the aircraft will be considered EHS non-capable and shall apply for an exemption, see below.

4.2.3   EHS Non-Capable Aircraft

Exemption of the EHS requirements may be granted to non-Mode S EHS capable aircraft and non-Mode S EHS compliant delivery and maintenance flights with a certificate of airworthiness issued prior to 31 MAR 2005 that conduct IFR/GAT flights in notified Mode S airspace in the Brussels FIR/UIR. In these instances the aircraft must, as a minimum, be Mode S elementary surveillance (ELS) compliant.

A standard form for the Mode S EHS exemption is contained in AIC 02/2009.

Exemption requests should be addressed to the competent CAA (see GEN 1.1).

The request must reach the administration 15 working days before the first flight using the exemption arrangements.

Fixed wing aircraft with a MTOW greater than 5 700 KG and/or a maximum cruising true airspeed in excess of 250 KT, flying as GAT in the Brussels FIR/UIR at or above FL 245 with a first certificate of airworthiness (CoA) issued on or after 31 MAR 2012, regardless of the date of original type certification, must be capable of complying with Mode S EHS airborne equipment requirements for flight in European Mode S airspace notified for Mode S EHS.

State aircraft are exempt of this requirement when flying as GAT above FL 245 within the Brussels FIR/UIR, an operational Mode S ELS transponder is sufficient.

Mode S EHS transponder systems must be certificated in accordance with EASA Document AMC 20-13 or with equivalent national certification requirements.

5   ACAS Resolution advisory (RA) (SERA.11014)

ACAS II shall be used during flight except as provided in the minimum equipment list specified in Commission Regulations (EU) 965/2012, 800/2013 and 379/2014 in a mode that enables RA indications to be produced for the flight crew when undue proximity to another aircraft is detected unless inhibition of RA indication mode (using TA indication only or equivalent) is called for by an abnormal procedure or due to performance-limiting conditions.