Fuel drain

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Emergency lowering nozzle of an Airbus A340 -311
Emergency fuel dump of an Airbus A340-600 over the Atlantic near Nova Scotia

The fuel discharging ( fuel dumping ) is used in aircraft to a front emergency , a safety or scheduled landing by the discharge of kerosene , the weight of aircraft lower at or below the maximum landing weight.

General

At departure, the fuel tanks are filled according to the flight route and the necessary safety reserves. Sometimes the maximum take-off weight (MTOW) must also be used. The maximum landing weight of an aircraft is for many types below the maximum take-off weight. With a Boeing 747-400 , this difference can be around 100 tons. If it were necessary to land again immediately after take-off, a weight reduction that may be necessary can be achieved by releasing fuel via the rapid fuel release system.

In principle, an emergency situation must be present for the discharge of fuel. Air traffic control then assigns the pilots an area, a minimum altitude (1,800 meters) and a certain course (no closed circles). Compliance with the requirements ensures that a maximum of 8% of the fuel that is sprayed and evaporated in the air reaches the ground. That would correspond to a floor load of 0.02 grams per square meter. At higher altitudes or additional air currents, the amount measurable on the ground is lower.

According to the regulations of the ICAO , the area for the fuel dumping area should be populated as thinly as possible (for example the Odenwald , the Eifel , the Sauerland , the Westerwald or the North Sea ) and should exclude protection zones as far as possible. A list of the recorded amounts of fuel that was discharged via Germany in the years 2010 to 2016 results in a total amount of around 3,590 tons of kerosene with an average of 22 cases per year (a total of 121 cases in the period under review). Rhineland-Palatinate was hardest hit in 2017. In October 2018, the Federal Council approved the motion for a resolution by the state of Rhineland-Palatinate on mandatory reporting within 24 hours. The Minister of Transport was tasked with implementing it immediately. A list of the current fuel discharges over Germany is published by the Luftfahrt-Bundesamt .

Based on numerical simulations, it is assumed that when the fuel is sprayed it forms droplets with a size well below one millimeter. The exact size should depend, among other things, on the discharge conditions at the nozzle and the amount of kerosene released.

history

The history section is not adequately provided with evidence ( e.g. individual evidence ). Information without sufficient evidence could be removed soon. Please help Wikipedia by researching the information and including good evidence.
The 105% rule in the area of ​​history is unoccupied. - Salino01 ( discussion ) 14:01, 30 Dec. 2016 (CET)

The US aviation authority FAA issued a regulation in the 1960s that all aircraft whose maximum take-off weight (MTOW) is more than 5 percent above the maximum landing weight require a fuel emergency dump system.

Since most short-haul aircraft did not exceed this limit, they did not have a fuel emergency discharge system installed. When they got larger tanks for longer ranges over time, they too exceeded the 105 percent limit. However, because at the same time the engines were becoming safer and more powerful and the installation of emergency lowering systems was hardly possible, the FAA lifted the 105 percent rule for aircraft that can take off or go through with a failed engine . A fuel emergency drain for twin-engine machines was no longer necessary. Nowadays only four-engine aircraft have to be equipped with this system. However, many twin-engine, wide-body airliners can also be equipped with a fuel emergency discharge system at the customer's request so that they do not have to circle for too long in an emergency. In the case of smaller aircraft, there is no need to install emergency fuel drain systems from the start, so that long circles before landing can occur (see also incidents with Jet Blue ).

Alternatives

An alternative to fuel dumping is the immediate landing with a higher than allowable landing weight ( english overweight landing ), especially in medical emergencies or critical technical problems. Almost all types of aircraft are designed to be so stable that they can land with their maximum take-off weight; then, however, costly examinations and possibly the repair of damage are necessary. Probably for this reason, in November 2017, due to technical problems, shortly after taking off on a long-haul flight, a cargo plane discharged 50 tons of kerosene before returning for landing. On the other hand, an Airbus A380 ( Qantas flight 32 ) had to be landed in 2010 after an engine explosion with a weight of 50 tonnes above the maximum landing weight, because the rapid fuel dump had failed due to the explosion damage and time-consuming circling was not responsible.

Plumes of vapor through condensing water on a landing Fokker 100

Confusion with vapor plumes

Assumptions that planes generally deflate before landing are wrong. When the air humidity is high, the trailing edges of the aircraft's wings emit smoke plumes that can be mistaken for atomized kerosene. However, these clouds of vapor are only caused by condensing water. Due to the overpressure at the underpressure and the underpressure at the top of the wing , pressure equalization takes place at the wing end, which in turn leads to a temperature drop. This can cause humidity to condense.

Dump and Burn

Dump and Burn an F-111 of the RAAF on the Defense Airshow 2010

In flight operations of the General Dynamics F-111 of the Australian Air Force , a procedure called dump and burn was part of the demonstration program at public events. Dump and Burn was also demonstrated at the closing event of the Sydney Olympic Games in 2000 . This takes advantage of the fact that the F-111 has the emergency fuel drain located between the engines. Fuel is deflated for a few seconds while the engines are in afterburner mode. The fuel ignites and creates a flame several meters long behind the aircraft, while the faintly glowing afterburner flames can hardly be seen. After the decommissioning of the F-111, only the Saab Gripen is now able to Dump and Burn, which, like the F-111, demonstrates this at air shows.

The fuel discharge devices on civil airliners are mounted away from the hot exhaust jet from the engines in such a way that such an effect is avoided. The roughly arm-thick drainage pipes are located on the wing trailing edges.

criticism

After persistent criticism of the practice of kerosene draining, the Rhineland-Palatinate state parliament dealt with the matter in a public hearing in November 2017. In the same year, Bavaria's SPD parliamentary group chairman, Markus Rinderspacher, called for "transparent information management for civil and military air traffic and a measuring network that works." The online petition "Kerosene rain, no thanks. Transparency, yes please!" As of summer 2018, more than 70,000 petitioners supported within a few months. "

Individual evidence

  1. ↑ a b c d Niels Klußmann, Arnim Malik: Lexicon of aviation . Springer-Verlag, 2011, ISBN 978-3-642-22500-0 ( google.de [accessed December 29, 2016]).
  2. ↑ Frequently asked questions (FAQs) about the fuel drain. (PDF) In: lba.de. September 18, 2018, accessed October 26, 2018 .
  3. ↑ Balance - The most important thing about environmental protection and sustainability at Lufthansa. (PDF) Environment ABC (useful information and frequently used aviation abbreviations). (No longer available online.) Deutsche Lufthansa AG, pp. 51–52 , archived from the original on October 11, 2011 ; accessed on December 30, 2016 (2003/2004).
  4. ↑ Federal Office for Civil Aviation FOCA Aviation Development Department: Fuel Dumping. (PDF) Swiss Confederation, June 9, 2016, accessed on December 29, 2016 .
  5. ↑ Discharge of fuel by military aircraft and civil aircraft. (PDF) Answer of the Federal Government to the Minor Inquiry from the GREEN - Printed matter 18/9571 -. In: Drucksache 18/9917. German Bundestag, October 6, 2016, accessed December 30, 2016 .
  6. ↑ This is what happens when kerosene is sprayed into the air. In emergency situations, pilots have to drain their fuel, like just recently near Frankfurt. What exactly happens - and how dangerous is it? In: spiegel-online.de. SPIEGEL ONLINE GmbH, September 13, 2017, accessed on September 13, 2017 .
  7. ↑ Aircraft releases 92 tons of fuel In: rheinpfalz.de , July 31, 2018, accessed on August 1, 2018.
  8. ↑ Länderspiegel : Keroseneregen überm Pfälzerwald In: zdf.de , September 22, 2018, accessed on September 22, 2018.
  9. ↑ Federal Council decides Rhineland-Palatinate initiative on kerosene emergency discharge - Federal Transport Minister must implement the 24-hour deadline immediately. In: spdfraktion-rlp.de . October 19, 2018, accessed October 26, 2018 .
  10. ↑ Publication of fuel dumping in German airspace. (PDF) In: lba.de. Retrieved October 26, 2018 .
  11. ^ Karl Durant Pfeiffer: A Numerical Model to Predict the Fate of Jettisoned Aviation Fuel. (PDF) In: Thesis. United States Air Force (Air Force Institute of Technology), December 1994, accessed December 30, 2016 .
  12. ^ Aeroflot machine returns to Zurich , SRF, February 26, 2017; "After take-off, the Airbus A321 circled over Eastern Switzerland for an hour"
  13. ↑ Overweight Landings? Fuel Jettison? What to consider , Boeing AERO magazine
  14. ↑ Aircraft releases 50 tons of kerosene, "BILD" newspaper November 22, 2017. Accessed January 1, 2018 .
  15. ↑ Qantas A380 incident "The most dangerous time was after the landing" , Spiegel.de
  16. ↑ Resources and efficiency. In: dfs.de. Archived from the original on January 11, 2012 ; Retrieved November 30, 2010 .
  17. ↑ Andreas Ganter: Mainz hearing in the state parliament on kerosene discharge. In: Rheinpfalz. November 14, 2017. Retrieved November 14, 2017 .
  18. ↑ SPD demands information about kerosene discharge. In: Süddeutsche. August 23, 2017. Retrieved August 23, 2017 .
  19. ↑ David Lohmann: kerosene rain over Bavaria. In: Bayerische Staatszeitung. August 17, 2018. Retrieved August 17, 2018 .
  20. ↑ Rolf Sperber: The Palatinate is mobilizing against kerosene. In: echo-online. August 23, 2018. Retrieved August 23, 2018 .

Web links

Commons : Fuel Dumping  - collection of pictures, videos and audio files