Maximum elevation figure

The safety altitude ( engl. minimum sector altitude, MSA) indicates to the pilot, in which altitude he just can fly safely without colliding with ground objects (houses, towers, mountains, ...). In some publications there is also the wrong translation " minimum safe altitude ".

It is already doing a safety distance of 1,000 feet, 2,000 feet factored in higher ground. If the safety altitude indicated on the ticket, for example, with 1,500 ft, the surveys in this area are more than 500 ft high.

The safety altitude is specified in terms of the ICAO standard atmosphere ( barometric altitude measurement after QNH). So the pilot must take into account the local weather conditions and if necessary enter a correction value.

Flight card security altitude

Safety altitudes may be listed differently on the various flight tickets. This is explained in the legend of each map. The safety altitude is given to the one for the entire map, the other for the airways.

Example: The highest point on the entire map is 5,310 ft (eg mountain with 1750m above sea level). With a safety margin of 1,000 ft safety altitude for the entire area represented 6,310 ft. It would be rounded to the nearest safe hundreds. So is the front of the card: MSA 6400. The highest point is highlighted on the map, even with a thick border. On another flight cards, the highest point is highlighted by a particularly thick arrow pointing to the number for the highest point on the map.

The flight map is divided into individual grid squares. For each of these rectangles a safety altitude is specified with a pale blue number in the upper left corner or. Similar in another form Here, for example, a so-called MGA ( engl. minimum grid altitude ) of 4,500 ft.

Caution: In the ICAO 1:500,000 map are the numbers = 4,500 feet not for the MGA, but for the MEF ( engl. maximum elevation figure ). The MEF is calculated from the height of the highest peak in the area of a rectangle of 30 minutes ( length as well as width minutes) in feet ( ft), plus 328 ft (100 m ) Award for possible obstacles, plus 60 ft safety reserve. Then will be rounded back to full hundred feet. In the worst case, one flies over the climax with a reserve of 388 ft. This is less than the smallest permissible minimum safe altitude according to § 6 LuftVO of 500 ft.

Air road safety altitude

For each airway MTCA is specified ( engl. minimum terrain clearance altitude ).

Airport -MSA

For landings at airports, the MSA is specified on the approach chart. A befindliches in the immediate vicinity of the square beacon or the airport reference point is taken as the center of a circle with a radius of 25 NM. In this circuit, several sectors are determined by the Funkleitstrahlen (radial ) for which the different security altitudes are given.

Example: MA at the Los Angeles airport security altitude within 25 NM from the VOR ( radio beacon ) with the identifier " LAX ", which is directly at the airport. There are three different sectors of different security altitudes. The sectors are divided by radio beams emitted from VOR ( Radial). Aircraft in the northern sector (whether it to, from or pass ) must have a safety altitude of 7,700 ft comply, because there is the mountain range where the famous Hollywood sign is. Aircraft in the southeastern sector must comply with a minimum height of 2,700 ft, because of some very small hills. Aircraft in the southwestern sector must comply with 4,400 ft, as the sector in the north reaches up to the Santa Monica Mountains.

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• Air navigation