Push-through method

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Puncture process (QG) is the name of a ground-based, carried out by a simple radio direction finding of bad weather landing procedure in the German Empire from about the 1920 's to the end of the Second World War . It was used when the ground visibility required for approach and landing was only given at a very low altitude, but the cloud cover was still more than 60 to 80 meters above the ground.

history

Because this method was not practicable in some weather conditions with particularly poor visibility and too unpredictable and therefore dangerous for airports with nearby obstacles that rose up into heights, the ZZ method (QGX) was developed in Germany at the end of the 1920s Name can be traced back to the Morse code ZZ used in its application for landing clearance . However, since this procedure required an overflight of the airport and then only after some time the reversal for a seven-minute long approach controlled several times by radio direction finding, the ZZ procedure was very time-consuming and required very high concentration on the ground and among the aircraft crew. If possible, this was avoided and the push-through procedure was used.

A short time later, from about 1933 was the use of beacon or beacon, as especially the "micro-wave landing beacon" (LFF), also known as Lorenz beam is known by the company C. Lorenz AG , the decisive role in the development of the ZZ procedure and the procedures later derived from it. The engineer Ernst Ludwig Kramar , who was in charge of the company's radio navigation department, proposed automation very early on.

Procedure

First of all, the direction of the airport was determined by radio direction finding. This could be done using a third-party radio direction finding procedure from the ground, or by the crew of the aircraft with the on-board radio using the radio self-direction finding procedure (IAP - Instrument Approach Procedure) on a transmitter at the airport. As a rule, the radio station on the ground made the decision as to which of the two options should be used. Then the aircraft was piloted in the direction of the bearing point at the airport and as soon as its engine noises could be heard on the ground, information about the approach was transmitted in Morse code , corresponding to the determined direction.

Approach signals
MN - engine noise in the north MS - engine noise in the south
MNE - engine noise in the northeast MSW - engine noise in the southwest
ME - engine noise in the east MW - engine noise in the west
MSE - engine noise in the southeast MNW - engine noise in the northwest

After receiving this information, the radio station switched to reception in the air. If the ground station was able to detect an overflight, the aircraft was immediately informed in Morse code with the aviation abbreviation QFG that it was currently directly above the DF station, which was usually right next to the runway. If there were no structural or landscape obstacles of great height near the airport, it was safe to use the Q-Code QFH to give the instruction to break through the cloud cover. This signal was followed by two numbers describing an angle with a point in the direction of the bearing point, so that a favorable direction of penetration could be read from it, e.g. B. QFH 60 120 for an angle between 60 and 120 degrees. As soon as the aircraft had sight of the ground, it sent the Q code QBH and began normal sight landing. If the aircraft was visible from the ground, the direction finding station sent QGV . Accuracies of plus or minus 4 degrees were achieved at a distance of 150 kilometers.

literature

  • Frank W. Fischer: The development of air traffic control in Germany , Part I: Air traffic control in Germany before 1945 , International Advisory Group Air Navigation Services (ANSA), 2014, p. 174 f.
  • Brockhaus Encyclopedia in Twenty Volumes , Volume 5, Seventeenth completely revised edition of the Großer Brockhaus, FA Brockhaus Wiesbaden 1968, p. 175

Individual evidence

  1. ^ Carl Pirath: Airports spatial location, operation and design , Volume 11 of research results of the Transport Science Institute at the Technical University of Stuttgart , Springer-Verlag 2013, ISBN 978-3-642-90970-2 . P. 33
    ( limited preview in Google Book search)
  2. ^ Karl Herz: The technical development tendencies in electrical communications / navigation and air security , Volume 13 of the Working Group for Research of the State of North Rhine-Westphalia , Springer-Verlag 2013, ISBN 978-3-663-02952-6 . P. 40
    ( limited preview in Google Book search)
  3. ^ Frank W. Fischer: The development of air traffic control in Germany - Part I: Air traffic control in Germany before 1945 , International Advisory Group Air Navigation Services (ANSA), 2014, p. 175 f.
    ( limited preview in Google Book search)