Přesně tak, letecká záchranka je na tom hodně špatně. A to je ta česká ještě relativně nahraditelná tou pozemní. Zkus si představit ještě v podmínkách takové UK nebo severní Evropy, kde je spousta míst přístupná jedině vrtulníkem a to nejen pro případ zdravotní nouze - ostrovy, vrtné plošiny, lodě v nouzi...Chlapi tu mají opravdu hodně velkej nerv.
Už aby to bylo pryč a všechny ty hrozivé scénáře o měsících a letech chrlení popela jako při minulé erupci jsou jen teoretické. Nedokážu si dnešní svět bez letadel moc představit.
Jinak k těm turbínám apod. - ono se to týká všech letadel na zemi i ve vzduchu, není to jen tak jednoduché jako že hlavním problémem je kontakt prachu s horkými plyny ve spalovací komoře za běhu motoru a následné z toho vyplývající komplikace. Jen pro ukázku z aktuálního "Volcanic Ash Awareness" bulletinu, který vyplodil Airbus (týká se samozřejmě všech letadel):
Flying through an ash cloud should be avoided by all means due to the extreme hazard for the aircraft. Experience has shown that damage can occur to aircraft surfaces, windshields and powerplants. Aircraft ventilation, hydraulic, electronic and air data systems, can also be contaminated.
Partial or total engine power loss events caused by volcanic ash ingestion, while not frequent, are major safety concerns. Simultaneous power loss in all engines has occurred, where the crew succeeded in restarting the engines, after application of operational procedures.
As weather radar is not effective in detecting volcanic ash clouds, crews must be informed by other means of the potential or effective presence of ash clouds on air routes.
Active volcanoes are capable of sending volcanic ash up to altitudes greater than FL300 after explosive eruptions. Encounters affecting aircraft performance have occurred 2 400 NM from the ash source and up to 72 hours after an eruption.
Over 80 aircraft have reported to have flown into volcanic ash cloud between 1980 and 2000, with consequences ranging from increased wear of engines to simultaneous power loss in all engines.
Volcanic Ash Effects on Aircraft
Components Abrasion
Volcanic ash are highly abrasive particles that may damage aircraft components, particularly forward facing surface of external parts and engine components. They are made of sharp rock fragments that will easily erode plastic, metal and even glass pieces.
In service events show that aircraft may suffer from extensive damage after volcanic ash encounter. In some cases, all the following parts were removed and replaced, after they were sand blasted:
• Windshields
• Forward cabin windows
• Navigation and landing lights cover
• Wing, stabilizer and fin leading edges
• Engine nose cowls and thrust reversers
• All pitot and static probes.
Engine Performance Deterioration
Ingestion of volcanic ash by engines may cause serious deterioration of engine performance due to erosion of moving parts and/or partial or complete blocking of fuel nozzles.
Volcanic ash contains particles, whose melting point is below engine internal temperature. In-flight, these particles will immediately melt if they go through an engine. Going through the turbine, the melted materials are rapidly cooled down, stick on the turbine vanes, and disturb the flow of high-pressure combustion gases.
This disorder of the flow may stall the engine, in worst cases.
Bleed, Air Data and Electronic Systems Contamination
Volcanic ash is made of very fine particles (down to 1 micron) that can easily penetrate all but the most tightly sealed enclosures. It may carry high static charge that makes it difficult to remove from electronic components.
Ash deposit easily absorbs water and can cause arcing, short circuits and intermittent failures of electronic components.
Dense ash deposit can clog bleed system filters and may lead to total bleed loss, with associated loss of cabin pressurization. Pitot and static systems may also become obstructed by the dust.
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