Information AboutNap-of-the-earth |
| CATEGORIES ABOUT NAP-OF-THE-EARTH | |
| aerial warfare | |
| aviation terminology | |
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Nap-of-the-earth (NOE) is very low-level Flight to avoid detection and attack by an enemy when in a high-threat environment. Geographical features are used as cover, exploiting valleys and folds in the ground by flying in them rather than over them to avoid "skylining" to an enemy and to keep below radar cover. Other terms such as "ground-hugging" or "flying under the Radar " are also used. Purpose of NOE. NOE is used to minimise detection by hostile aircraft, by AWACS surveillance and control systems, or by ground-based radar. A high-flying aircraft would be detected by such systems at long range, allowing an air defense system time to react, alert SAM and AAA systems and scramble fighter (Air Defence) aircraft. Using NOE flight, the approach may be undetected, the aircraft "pops up" to attack the target and then turns to escape before the enemy can respond. Doppler radar has the potential to detect NOE flight but the incoming aircraft has to be within radar range in the first place and low flying minimises this possibility. Sensors for NOE. Most NOE flying is by day using visual reference by pilots experienced in low flying. Data from a Radar Altimeter or Terrain-following Radar system is also used, the latter enabling low flying in adverse weather where it would not be possible by visual reference and manual pilot control. At night, intensifier systems or infra-red can be used. "Night Vision Goggles" (NVGs) are visual intensifiers working in the near-IR area at a wavelength of about 1 micrometre and Forward-Looking Infra Red (FLIR, or Thermal Imaging (TI)) works at about 10 micrometres. NVGs require some ambient "light" such as from the moon or ground lights, FLIR is entirely passive and produces a picture based on the heat distribution of the area being observed. Helicopter NOE flying. The lowest NOE flying is by Helicopter s because they have lower speeds and more maneuverability than fixed-wing aircraft, particularly fast-jets. Helicopers can fly at "tree-top" level, even below the height of surrounding trees where there are clear areas, flying under wires (such as elecricity cables) rather than over them. Attack helicopters can "hide" behind trees or buildings, "popping up" just enough to use their (rotor mast-mounted) radar or other sensors and then exposing themselves a litle more in order to launch their weapons. Escape can then be made by further NOE flying. Heights above ground. Heights Above Ground Level (AGL) in NOE and low flying generally vary with the aircraft speed, manoueverability and the ruggedness of the terrain. As mentioned above, helicopters can fly very low indeed in the right circumstances, down to a few feet below the skids or wheels. Fast jets are more constrained and at a typical low-flying speed of 450 knots (800 km/h), 200 feet (60 m) is not unusual and 50 feet (15 m) is possible in relatively flat terrain. Power wires are a danger to all aircraft flying at low level and "wire strikes" are not uncommon. Special maps are produced that plot the routes of these wires but these are difficult to keep up-to-date. Pilots are trained to scan for the pylons or power-poles that support these wires, because they can be seen at a distance where the wires themselves, cannot. Other types of wires that are a hazard to low flying aircraft are for cable cars in the mountains, and wires used in logging operations which are used in lowering cut timber to collection points. SEE ALSO |
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