Future Air Navigation System
The Future Air Navigation System ( FANS - System for the air navigation of the future) is a standard that was developed by the air transportation industry to make better use of the airspace and to accommodate even more aircraft. There are different generations of FANS standards, starting with simple automation processes up to futuristic approaches.
description
In its simplest form, FANS aircraft use GPS to determine their position. For this purpose, GPS has replaced older systems for determining position - the inertial navigation system based on gyroscopes . The aircraft then sends its position determined by GPS (via VHF or satellite communication - SATCOM) in the form of a short data telegram. FANS is not to be confused with ADS-B or Mode-S . These methods send out short data telegrams on the frequency 1090 MHz and can be received by all radio stations in the vicinity of the sending aircraft, while FANS uses VHF frequencies for aviation and satellite frequencies for satellite operators. The message with the position is sent to a recipient, be it air traffic control or the airline's flight control, which then forwards this information to air traffic control. The primary difference between ADS-B and FANS is that with FANS the receipt of the message is confirmed, while with ADS-B it is a broadcast and there is no confirmation of receipt. Other aircraft and radio stations cannot easily receive this information. The messages are not public, just like an email is not public.
The FANS standard requires the use of satellite communication ( Inmarsat , Iridium ) outside of the VHF range . So that is air traffic control on the position of the aircraft accurately informed as the radar detection is not as accurate and is not comprehensive worldwide (oceans, large deserts). In the past, ADS-B broadcasts from air traffic control could not be received everywhere because the range was limited to around 200 nautical miles . In the meantime, however, there are satellite providers who listen to the 1090 MHz frequency via satellite and pass the received data on to their customers. This also enables worldwide reception of ADS-B signals. Mode-S signals are only emitted by an aircraft when requested to do so by a radar beam. Should ADS-B reception via satellite prevail, then FANS telegrams for the transmission of positions would actually be unnecessary. A conversion to FANS costs between 200,000 and 400,000 US dollars, an upgrade of a transponder to ADS-B costs a few 1000 US dollars.
FANS can also be used to send other messages, e.g. B. Transmission of the fuel supply or technical parameters of the engines. And messages from flight safety can also be received. ADS-B via satellite would be an alternative, especially for business jets that rarely cross the oceans, since most wide-body aircraft have already been equipped with FANS. But most of the passenger planes (90%) are already equipped with ADS-B (as of 2018).
As an example, the pings received by the British company Inmarsat of the missing Malaysia Airlines flight 370 after its disappearance from the radar screens of the aircraft's installed FANS were broadcast via an Inmarsat satellite. The ping did not contain any position information.
Overall, this increases safety and reduces the risk of collisions in the air ( midair collision ). Before the introduction of FANS, the pilots had to give their position report orally - over oceans mostly using shortwave radio, as only shortwave allowed a radio link beyond the horizon. When reporting positions via shortwave, air traffic control must maintain a greater safety distance between the aircraft ( staggering - separation), as the inertial navigation system is less precise and the noise on the shortwave occasionally makes communication difficult or impossible. FANS is intended to replace these shortwave connections, as satellite communication works more securely and is not dependent on radio weather. However, a lot has changed in the field of shortwave in recent years. Some shortwave radio stations are now also able to offer data link applications. The so-called HF data link procedure, which was created especially for regions that are not covered by Inmarsat satellites, also enables aircraft to transmit position and ACARS messages to air traffic control and to receive messages from them. This is particularly important in the polar regions, where reception of Inmarsat geostationary satellites is not possible. In contrast, iridium can also be used in the polar regions. HF Data Link can also transmit positions that have been determined by a GPS receiver.
As a result, thanks to FANS, the graduation distance could be reduced. This in turn enables the aircraft to fly much closer to their desired route (usually the “ideal route”).
This “ideal route” is typically on the great circle (the shortest distance between two points on earth) or takes the current wind into account in order to increase the tailwind component or at least avoid strong headwinds.
Although the FANS concept originated from the ICAO , it was first introduced by the large aircraft manufacturers Boeing and Airbus . Boeing's FANS implementation is called FANS-1. Airbus' FANS implementation is called FANS-A. Airbus then called further improvements to its FANS-A FANS-A +.
Both aircraft manufacturers are working on further developments of FANS: Boeing under the name FANS-2 and Airbus under the name FANS-B.
Various ground systems have been developed by the air traffic control authorities of different countries to work with the Boeing and Airbus FANS (also known as FANS-1 / A).
Since these first FANS, the ICAO has pushed the standardization work on FANS and published it as a group of standards: CNS / ATM / - Communication, Navigation and Surveillance / Air Traffic Management.
It is expected that Boeing and Airbus will agree on the current ICAO standard in the future expansion of their proprietary FANS implementations. As a vision of the future, the flight plans should be able to be dynamically updated to accommodate new information, such as B. to be able to take into account the currently changed wind.
Milestones
A Boeing Business Jet equipped with the Future Air Navigation System (FANS) carried out the first transatlantic flight of a business jet with FANS on May 24, 2004. FANS has greatly reduced the need for verbal communication between the crew and air traffic control. After taking off in Gary , Indiana and a 4,000 NM flight, the aircraft landed in Geneva (Switzerland) - at the European Business Aviation Convention and Exhibition. The flight was part of the North Atlantic Traffic Trial Program run by the FANS Central Monitoring Agency (FCMA).
See also
- Shannon Radio , a shortwave radio station for Atlantic traffic in Ireland
Web links
- FANS for A320 and A330 / A340 Families in the Airbus FAST 48 (page 28 ff .; PDF; 13.7 MB)
Individual evidence
- ^ Aircraft surveillance versus tracking A comprehensive analysis between surveillance and tracking of aircraft
- ↑ Understanding Data Comm Systems with FANS 1 / A +, CPDLC DCL, and ATN B1
- ↑ Global ADS-B surveillance is now live
- ↑ ADS-B via Low Earth Orbiting Satellites Benefits Assessment
- ^ Future Air Navigation Systems: How Much? To invest or not invest in FANS 1 / A avionics is the question business operators of transoceanic-capable business aircraft are asking.
- ↑ Frequencies from Shannon Radio (North Atlantic) including 3016 kHz, 5598 kHz, 8906 kHz and 13306 kHz on shortwave and 127.9 MHz, 124.175 MHz on VHF
- ↑ Understanding the Future Air Navigation System (FANS) 1 / A Operations and Regulatory Requirements
- ↑ HF or HFDL (HF Data Link) which has been added especially for polar region communications