The Civil Aviation (Radio Navigation Aids) Regulations, 2025
2. Interpretation
2. Interpretation
In these Regulations, unless the context otherwise requires—“Act” means the Civil Aviation Act (Cap. 394);“aircraft-based augmentation system (ABAS)” means an augmentation system that augments or integrates the information obtained from the other GNSS elements with information available on board the aircraft;“air navigation services” means air traffic services, communication, navigation and surveillance, and aeronautical information services;“air Navigation services facility” means any facility used, available for use, or designed for use in aid of navigation of aircraft, including airports, landing fields, any structures, mechanisms, lights, beacons, marks, communicating systems, or other instruments or devices used or useful as an aid to the safe taking off, navigation, and landing of aircraft and any combination of such facilities;“air navigation services provider” means an independent entity established for the purpose of operating and managing air navigation services and empowered to manage and use the revenues it generated to cover its costs;“Aeronautical Information Publication (AIP)” means publication issued by or with the authority of a State and containing aeronautical information of a lasting character essential to air navigation;“alert” means an indication provided to other aircraft systems or annunciation to the pilot to identify that an operating parameter of a navigation system is out of tolerance;“alert limit” the error tolerance not to be exceeded without issuing an alert for a given parameter measurement;“altitude” means the vertical distance of a level, a point or an object considered as a point, measured from mean sea level (MSL);“ANSP” means Air Navigation Services Provider;“angular displacement sensitivity” means the ratio of measured DDM to the corresponding angular displacement from the appropriate reference line;“antenna port” means a point where the received signal power is specified. For an active antenna, the antenna port is a fictitious point between the antenna elements and the antenna pre-amplifier. For a passive antenna, the antenna port is the output of the antenna itself;“area navigation (RNAV)” means a method of navigation which permits aircraft operation on any desired flight path within the coverage of ground- or space-based navigation aids or within the limits of the capability of self-contained aids, or a combination of these;“ATSEP” means Air Traffic Safety Electronics Personnel;“Authority” means has the meaning assigned to it under section 2 of the Act;“average radius of rated coverage” means the radius of a circle having the same area as the rated coverage;“axial ratio” means the ratio, expressed in decibels, between the maximum output power and the minimum output power of an antenna to an incident linearly polarized wave as the polarization orientation is varied over all directions perpendicular to the direction of propagation;“back course sector” means the course sector which is situated on the opposite side of the localizer from the runway;“BeiDou Navigation Satellite System (BDS)” means the satellite navigation system operated by the People’s Republic of China;“BDS Open Service (BDS OS)” means the specified level of positioning, velocity and timing accuracy that is available to any BDS user on a continuous, worldwide basis;“certificate” means the certificate for the provision of Air Navigation Services issued by the Authority under the Civil Aviation (Air Navigation Services) Regulations;“channel of standard accuracy (CSA)” means the specified level of positioning, velocity and timing accuracy that is available to any GLONASS user on a continuous, worldwide basis;“CNS” means Communication, Navigation and Surveillance;“CNS Provider" means Communication, Navigation and Communication services provider;“control motion noise (CMN)” means that portion of the guidance signal error which causes control surface, wheel and column motion and could affect aircraft attitude angle during coupled flight, but does not cause aircraft displacement from the desired course and/or glide path;“core satellite constellation” means the GPS and GLONASS;“course line” means the locus of points nearest to the runway centre line in any horizontal plane at which the DDM is zero;“course sector” means a sector in a horizontal plane containing the course line and limited by the loci of points nearest to the course line at which the DDM is 0.155;“dB” means decibel;“difference in depth of modulation-DDM” means the percentage modulation depth of the larger signal minus the percentage modulation depth of the smaller signal, divided by 100;“displacement sensitivity (localizer)” means the ratio of measured DDM to the corresponding lateral displacement from the appropriate reference line;“DME” means Distance Measuring Equipment;“DME dead time” means a period immediately following the decoding of a valid interrogation during which a received interrogation will not cause a reply to be generated;“DME/N” means distance measuring equipment, primarily serving operational needs of en-route or TMA navigation, where the “N” stands for narrow spectrum characteristics;“DME/P” means the distance measuring element of the MLS, where the “P” stands for precise distance measurement. The spectrum characteristics are those of DME/N;“effective acceptance bandwidth” means the range of frequencies with respect to the assigned frequency for which reception is assured when all receiver tolerances have been taken into account;“effective adjacent channel rejection” means the rejection that is obtained at the appropriate adjacent channel frequency when all relevant receiver tolerances have been taken into account;“effective coverage” means the area surrounding an NDB within which bearings can be obtained with an accuracy sufficient for the nature of the operation concerned;“elevation” means the vertical distance of a point or a level, on or affixed to the surface of the earth, measured from mean sea level;“essential radio navigation service” means a radio navigation service whose disruption has a significant impact on operations in the affected airspace or aerodrome;“facility Performance Category I — ILS” means an ILS which provides guidance information from the coverage limit of the ILS to the point at which the localizer course line intersects the ILS glide path at a height of 30 m (100 ft) or less above the horizontal plane containing the threshold;“facility Performance Category II — ILS” means an ILS which provides guidance information from the coverage limit of the ILS to the point at which the localizer course line intersects the ILS glide path at a height of 15 m (50 ft) or less above the horizontal plane containing the threshold;“facility Performance Category III — ILS” means an ILS which, with the aid of ancillary equipment where necessary, provides guidance information from the coverage limit of the facility to, and along, the surface of the runway;“fan marker beacon” means a type of radio beacon, the emissions of which radiate in a vertical fan-shaped pattern;“final approach (FA) mode” means the condition of DME/P operation which supports flight operations in the final approach and runway regions;“front course sector” means the course sector which is situated on the same side of the localizer as the runway;“Galileo” means the satellite navigation system operated by the European Union;“Galileo Open Service (Galileo OS)” means the specified level of positioning, velocity and timing accuracy that is available to any Galileo user on a continuous, worldwide basis.“GBAS/E” means a ground-based augmentation system transmitting an elliptically-polarized VHF data broadcast;“global navigation satellite system (GNSS)” means a worldwide position and time determination system that includes one or more satellite constellations, aircraft receivers and system integrity monitoring, augmented as necessary to support the require navigation performance for the intended operation;“global navigation satellite system (GLONASS)” means the satellite navigation system operated by the Russian Federation;“global positioning system (GPS)” means the satellite navigation system operated by the United States;“GNSS position error” means the difference between the true position and the position determined by the GNSS receiver;“ground-based augmentation system (GBAS)” means an augmentation system in which the user receives augmentation information directly from a ground-based transmitter;“ground-based regional augmentation system (GRAS)” means an augmentation system in which the user receives augmentation information directly from one of a group of ground-based transmitters covering a region;“half course sector” means the sector, in a horizontal plane containing the course line and limited by the loci of points nearest to the course line at which the DDM is 0.0775;“half ILS glide path sector” means the sector in the vertical plane containing the ILS glide path and limited by the loci of points nearest to the glide path at which the DDM is 0.0875;“height” means the vertical distance of a level, a point or an object considered as a point, measured from a specified datum;“human factors principles” means principles which apply to design, certification, training, operations and maintenance and which seek safe interface between the human and other system components by proper consideration to human performance;“ILS” means Instrument Landing System;“ILS continuity of service” means that quality which relates to the rarity of radiated signal interruptions. The level of continuity of service of the localizer or the glide path is expressed in terms of the probability of not losing the radiated guidance signals;“ILS glide path” means that locus of points in the vertical plane containing the runway centre line at which the DDM is zero, which, of all such loci, is the closest to the horizontal plane;“ILS glide path angle” means the angle between a straight line which represents the mean of the ILS glide path and the horizontal;“ILS Point “A” means a point on the ILS glide path measured along the extended runway centre line in the approach direction a distance of 7.5 km (4 NM) from the threshold;“ILS Point “B” means a point on the ILS glide path measured along the extended runway centre line in the approach direction a distance of 1 050 m (3 500 ft) from the threshold;“ILS Point “C” means a point through which the downward extended straight portion of the nominal ILS glide path passes at a height of 30 m (100 ft) above the horizontal plane containing the threshold;“ILS Point “D” means a point 4 m (12 ft) above the runway centre line and 900 m (3 000 ft) from the threshold in the direction of the localizer;“ILS Point “E” means a point 4 m (12 ft) above the runway centre line and 600 m (2 000 ft) from the stop end of the runway in the direction of the threshold;“ILS reference datum Point “T” means a point at a specified height located above the intersection of the runway centre line and the threshold and through which the downward extended straight portion of the ILS glide path passes;“initial approach (IA) mode” means the condition of DME/P operation which supports those flight operations outside the final approach region and which is interoperable with DME/N;“integrity” means a measure of the trust that can be placed in the correctness of the information supplied by the total system. Integrity includes the ability of a system to provide timely and valid warnings to the user (alerts);"ionosphere-free pseudo-range” means a pseudo-range in which the first order ionosphere effect on signal propagation has been removed by a linear combination of pseudo-range measurements from signals on two distinct frequencies from the same satellite;“key down time” means the time during which a dot or dash of a Morse character is being transmitted;“LF/MF” means Low frequency/Medium Frequency;“locator” means an LF/MF NDB used as an aid to final approach;“MANSOPs” means the Manual of Air Navigation Service Operations;“mean power (of a radio transmitter)” means the average power supplied to the antenna transmission line by a transmitter during an interval of time sufficiently long compared with the lowest frequency encountered in the modulation taken under normal operating conditions;“MLS approach reference datum” means a point on the minimum glide path at a specified height above the threshold;“MLS datum point” means the point on the runway centre line closest to the phase centre of the approach elevation antenna;“mode W, X, Y, Z” means a method of coding the DME transmissions by time spacing pulses of a pulse pair, so that each frequency can be used more than once;“navigation specification” means a set of aircraft and flight crew requirements needed to support performance-based navigation operations within a defined airspace. There are two kinds of navigation specifications;“NDB” means Non-Directional Radio Beacon;“Notice to Airmen (NOTAM)” means a notice distributed by means of telecommunication containing information concerning the establishment, condition or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel concerned with flight operations;“required navigation performance (RNP) specification” means a navigation specification based on area navigation that includes the requirement for performance monitoring and alerting, designated by the prefix RNP, e.g. RNP 4, RNP APCH;“partial rise time” means the time as measured between the 5 and 30 percent amplitude points on the leading edge of the pulse envelope;“path following error (PFE)” means that portion of the guidance signal error which could cause aircraft displacement from the desired course and or glide path;“performance-based navigation (PBN)” means area navigation based on performance requirements for aircraft operating along an ATS route, on an instrument approach procedure or in a designated airspace;“pressure-altitude” means an atmospheric pressure expressed in terms of altitude which corresponds to that pressure in the Standard Atmosphere;“protected service volume” means a part of the facility coverage where the facility provides a particular service in accordance with relevant SARPs and within which the facility is afforded frequency protection;“pseudo-range” means the difference between the time of transmission by a satellite and reception by a GNSS receiver multiplied by the speed of light in a vacuum, including bias due to the difference between a GNSS receiver and satellite time reference;“pulse amplitude” means the maximum voltage of the pulse envelope;“pulse code” means the method of differentiating between modes W, X, Y and Z and between FA and IA modes;“pulse decay time” means the time as measured between the 90 and 10 per cent amplitude points on the trailing edge of the pulse envelope;“pulse duration” means the time interval between the 50 per cent amplitude point on leading and trailing edges of the pulse envelope;“pulse rise time” means the time as measured between the 10 and 90 per cent amplitude points on the leading edge of the pulse envelope;“radio navigation service” means a service providing guidance information or position data for the efficient and safe operation of aircraft supported by one or more radio navigation aids;“rated coverage” means the area surrounding an NDB within which the strength of the vertical field of the ground wave exceeds the minimum value specified for the geographical area in which the radio beacon is situated;“receiver” means a subsystem that receives GNSS signals and includes one or more sensors;“reply efficiency” means the ratio of replies transmitted by the transponder to the total of received valid interrogations;“reserved (bits/words/fields)” means bits/words/fields that are not allocated, but which are reserved for a particular GNSS application;“search” means the condition which exists when the DME interrogator is attempting to acquire and lock onto the response to its own interrogations from the selected transponder;“satellite-based augmentation system (SBAS)” means a wide coverage augmentation system in which the user receives augmentation information from a satellite-based transmitter;“Smax” means maximum desired VHF data broadcast signal power at the VHF data broadcast receiver input;“spare (bits, words or fields)” means bits/words/fields that are not allocated or reserved, and which are available for future allocation;“standard positioning service (SPS)” means the specified level of positioning, velocity and timing accuracy that is available to any global positioning system (GPS) user on a continuous, worldwide basis;“system efficiency” means the ratio of valid replies processed by the interrogator to the total of its own interrogations;“time-to-alert” means the maximum allowable time elapsed from the onset of the navigation system being out of tolerance until the equipment enunciates the alert;“track” means the condition which exists when the DME interrogator has locked onto replies in response to its own interrogations, and is continuously providing a distance measurement;“touchdown” means the point where the nominal glide path intercepts the runway;“transmission rate” means the average number of pulse pairs transmitted from the transponder per second;“Tribunal” means the has the meaning assigned to it under section 2 of the Act;“two-frequency glide path system” means an ILS glide path in which coverage is achieved by the use of two independent radiation field patterns spaced on separate carrier frequencies within the particular glide path channel;“two-frequency localizer system” means a localizer system in which coverage is achieved by the use of two independent radiation field patterns spaced on separate carrier frequencies within the particular localizer VHF channel;“UHF” means Ultra High Frequency;“virtual origin” means the point at which the straight line through the 30 per cent and 5 per cent amplitude points on the pulse leading edge intersects the 0 percent amplitude axis;“VOR” means Very High Frequency (VHF) Omnidirectional radio Range; and“Z marker beacon” means type of radio beacon, the emissions of which radiate in a vertical cone-shaped pattern.Source: Kenya Law