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Archives: Wikis

Adverse Runway Condition

Adverse Runway Condition 1.1 Dissemination of RWY State Information SNOWTAMs and RWY reports are only provided for winter conditions and not for other hazardous RWY conditions e.g. RWY slippery when wet or combined with dust. Observations and measurements are not made at routine intervals. Information on RWY state and braking conditions as contained in SNOWTAM […]

Special Weather Phenomena

Special Weather Phenomena 1- Thunderstorms, CB / TCU Turbulence, hail, snow, lightning, sustained up- and downdrafts, icing conditions – are all present in thunderstorms. Up- and downdrafts extend far beyond the visible storm cloud. Severe turbulence can be expected up to some distance from large thunderstorms. 2- Downdraft and Microburst (MB) A downdraft is a […]

Fuel Policy (EU-OPS)

An operator must base the company fuel policy, including calculation of the amount of fuel to be on board for departure, on the planning criteria outlined in the following subparagraphs. Basic Procedure The usable fuel to be on board for departure must be the amount of: • Taxi Fuel • Trip Fuel • Contingency Fuel […]

11. Flight visibility and vision at high altitudes

Flight visibility and vision at high altitudes Flight visibility is frequently different from the surface visibility. Such differences are caused by the unequal distribution of the obscuring particles, such as smoke, haze, fog-particles with height and because the pilot sees the conditions from a different angle than does the observer on the ground. Some conditions […]

10. Variation in visual segment

Variation in visual segment In order to assimilate and interpret the visual cues which are being presented in such extremely dynamic perspective, the pilot needs two things: – A sufficient exposure time to the lights, and – A minimum visual segment during his final approach. The exposure time depends on the decision height and the […]

9. The visual segment

The visual segment From previous paragraphs we learned that no practical method exists for measuring the SVR available to the pilot at decision height and that, for low visibility approaches, RVR measured along the runway is used to provide a reasonable likelihood of visual contact on the approach at or before DH and to provide […]

8. Slant visual range

Slant visual range The operation requirement for ’slant visual range’ (SVR) has been discussed in subpara 2. Also an indication was given for the ideal situation re-availability of this kind of information. The ICAO All Weather Operations Panel is of the opinion that a possible approach to such a complete solution may be to determine […]

7. Accuracy of RVR reports

Accuracy of RVR reports As already indicated previously, an RVR report is not more than an ’assessment’ what a pilot would see form the position on a particular runway for which the RVR is issued. For the following reasons inaccuracies in the reports are unavoidable: a. Fog is seldom uniform. Transmissometer(s) may be located in […]

6. Reporting procedures of RVR reports

Reporting procedures of RVR reports RVR reports reach aircraft via ATS units and / or aeronautical broadcasts. Flight Crew Reference Guide  a. The reporting scale should consist of increments between 25 metres, when RVR is less than 150 m, 50 metres for RVR up to 800 metres, 100 metres for RVR between 800 and […]

5. Availability of RVR observations at ATS units

Availability of RVR observations at ATS units If transmissometer readings are converted into RVRs using computers, the RVR is usually presented automatically in the aerodrome control tower and approach control office using digital displays; similar displays are installed in the MET office or observing station (e.g. USA). Tables may be used to convert the transmission […]