proximity to the ground, and the maintenance of a safe flight path in these phases can be very difficult. Do not take-off if a thunderstorm is overhead or approaching. At destination, hold clear if a thunderstorm is overhead or approaching. Divert if necessary. Avoid severe thunderstorms even at the cost of diversion or an intermediate landing. If avoidance is impossible, the procedures recommended in these paragraphs should be followed. Ensure that our aeroplanes are adequately secured on the ground when severe thunderstorm activity is forecast or present. Use of weather radar - guidance to pilots ECHO CHARACTERISTICS FLIGHT LEVEL Gradient of Shape Intensity Rate of change intensity * Avoid by 10 Avoid by 5 Avoid by 5 Avoid by 10 miles: miles: miles: echoes showing echoes with echoes with echoes rapid Up to 200 hooks, sharp edges with strong change of shape, fingers and or strong gradients height scalloped intensities of intensity or intensity 200 250 Avoid all echoes by 10 miles. – 250 300 Avoid all echoes by 15 miles. – 300 Avoid all echoes by 20 miles. *: Applicable to sets with Iso-Echo or a colour display. Iso-Echo produces a hole in a strong echo when the returned signal is above a pre-set value. Where the return around a hole is narrow, there is a strong gradient of intensity. NOTE 1: If storm clouds have to be overflown, always maintain at least 5,000 ft vertical separation from cloud tops. It is difficult to estimate this separation but ATC or Met information on the altitude of the tops may be available for guidance. NOTE 2: If the aeroplane is not equipped with radar or it is inoperative, avoid by 10 miles any storm that by visual inspection is tall, growing rapidly or has an anvil top. NOTE 3: Intermittently monitor long ranges on radar to avoid getting into situations where no alternative remains but the penetration of hazardous areas NOTE 4: Avoid flying under a cumulonimbus overhang. If such flight cannot be avoided, tilt antenna full up occasionally to determine, if possible, whether precipitation (which may be hail) exists in or is falling from the overhang. Icing conditions Frost, ice, snow or slush contamination can seriously affect flight characteristics Contamination increases weight and disturbs airflow. Critical surfaces, which include upper wing surfaces, control surfaces and engine cowlings, must be free of contamination unless otherwise permitted by the aircraft manufacturer
proximity to the ground, and the maintenance of a safe flight path in these phases can be very difficult. Do not take-off if a thunderstorm is overhead or approaching. At destination, hold clear if a thunderstorm is overhead or approaching. Divert if necessary. Avoid severe thunderstorms even at the cost of diversion or an intermediate landing. If avoidance is impossible, the procedures recommended in these paragraphs should be followed. Ensure that our aeroplanes are adequately secured on the ground when severe thunderstorm activity is forecast or present. Use of weather radar - guidance to pilots FLIGHT LEVEL ECHO CHARACTERISTICS Shape Intensity Gradient of intensity * Rate of change Up to 200 Avoid by 10 echoes with hooks, fingers and scalloped Avoid by 5 miles: echoes with sharp edges or strong intensities Avoid by 5 miles: echoes with strong gradients of intensity Avoid by 10 miles: echoes showing rapid change of shape, height or intensity 200 – 250 Avoid all echoes by 10 miles. 250 – 300 Avoid all echoes by 15 miles. 300 Avoid all echoes by 20 miles. *: Applicable to sets with Iso-Echo or a colour display. Iso-Echo produces a hole in a strong echo when the returned signal is above a pre-set value. Where the return around a hole is narrow, there is a strong gradient of intensity. NOTE 1: If storm clouds have to be overflown, always maintain at least 5,000 ft vertical separation from cloud tops. It is difficult to estimate this separation but ATC or Met information on the altitude of the tops may be available for guidance. NOTE 2: If the aeroplane is not equipped with radar or it is inoperative, avoid by 10 miles any storm that by visual inspection is tall, growing rapidly or has an anvil top. NOTE 3: Intermittently monitor long ranges on radar to avoid getting into situations where no alternative remains but the penetration of hazardous areas NOTE 4: Avoid flying under a cumulonimbus overhang. If such flight cannot be avoided, tilt antenna full up occasionally to determine, if possible, whether precipitation (which may be hail) exists in or is falling from the overhang. Icing conditions Frost, ice, snow or slush contamination can seriously affect flight characteristics Contamination increases weight and disturbs airflow. Critical surfaces, which include upper wing surfaces, control surfaces and engine cowlings, must be free of contamination unless otherwise permitted by the aircraft manufacturer
OM%20template%20for%20non-complex%20NCC%20operators_August%202016.docx