Avião de Hollande atingido por um raio


21 Mar 2007
Avião de Hollande atingido por um raio e obrigado a regressar

O avião que transportava o novo presidente francês, François Hollande, para Berlim foi obrigado a regressar a Paris devido ao mau tempo, divulgou hoje o Ministério da Defesa francês.
"O avião terá sido atingido por um raio. Regressou por motivos de segurança. Neste momento, o presidente já deixou novamente" o aeroporto, afirmou um porta-voz do Ministério, citado pela agência noticiosa francesa AFP.
O chefe de Estado francês deixou o aeroporto militar de Paris a bordo de outro aparelho, que deverá chegar à capital alemã às 20:30 (hora de Lisboa).



10 Mai 2009
Madeira - Funchal
Estranho, quantos aviões são atingidos por raios, se fosse assim quantos não tinham de parar :lol:

É comum...

What happens when lightning strikes an airplane? disse:
Edward J. Rupke, senior engineer at Lightning Technologies, Inc., (LTI) in Pittsfield, Mass., provides the following explanation:

It is estimated that on average, each airplane in the U.S. commercial fleet is struck lightly by lightning more than once each year. In fact, aircraft often trigger lightning when flying through a heavily charged region of a cloud. In these instances, the lightning flash originates at the airplane and extends away in opposite directions. Although record keeping is poor, smaller business and private airplanes are thought to be struck less frequently because of their small size and because they often can avoid weather that is conducive to lightning strikes.

The last confirmed commercial plane crash in the U.S. directly attributed to lightning occurred in 1967, when lightning caused a catastrophic fuel tank explosion. Since then, much has been learned about how lightning can affect airplanes. As a result, protection techniques have improved. Today, airplanes receive a rigorous set of lightning certification tests to verify the safety of their designs.

Although passengers and crew may see a flash and hear a loud noise if lightning strikes their plane, nothing serious should happen because of the careful lightning protection engineered into the aircraft and its sensitive components. Initially, the lightning will attach to an extremity such as the nose or wing tip. The airplane then flies through the lightning flash, which reattaches itself to the fuselage at other locations while the airplane is in the electric "circuit" between the cloud regions of opposite polarity. The current will travel through the conductive exterior skin and structures of the aircraft and exit off some other extremity, such as the tail. Pilots occasionally report temporary flickering of lights or short-lived interference with instruments.

Most aircraft skins consist primarily of aluminum, which conducts electricity very well. By making sure that no gaps exist in this conductive path, the engineer can assure that most of the lightning current will remain on the exterior of the aircraft. Some modern aircraft are made of advanced composite materials, which by themselves are significantly less conductive than aluminum. In this case, the composites contain an embedded layer of conductive fibers or screens designed to carry lightning currents.

Modern passenger jets have miles of wires and dozens of computers and other instruments that control everything from the engines to the passengers' headsets. These computers, like all computers, are sometimes susceptible to upset from power surges. So, in addition to safeguarding the aircraft's exterior, the lightning protection engineer must make sure that no damaging surges or transients can reach the sensitive equipment inside the aircraft. Lightning traveling on the exterior skin of an aircraft has the potential to induce transients into wires or equipment beneath the skin. These transients are called lightning indirect effects. Careful shielding, grounding and the application of surge suppression devices avert problems caused by indirect effects in cables and equipment when necessary. Every circuit and piece of equipment that is critical or essential to the safe flight and landing of an aircraft must be verified by the manufacturers to be protected against lightning in accordance with regulations set by the Federal Aviation Administration (FAA) or a similar authority in the country of the aircraft's origin.

The other main area of concern is the fuel system, where even a tiny spark could be disastrous. Engineers thus take extreme precautions to ensure that lightning currents cannot cause sparks in any portion of an aircraft's fuel system. The aircraft skin around the fuel tanks must be thick enough to withstand a burn through. All of the structural joints and fasteners must be tightly designed to prevent sparks, because lightning current passes from one section to another. Access doors, fuel filler caps and any vents must be designed and tested to withstand lightning. All the pipes and fuel lines that carry fuel to the engines, and the engines themselves, must be protected against lightning. In addition, new fuels that produce less explosive vapors are now widely used.
The aircraft's radome¿the nose cone that contains radar and other flight instruments¿is another area to which lightning protection engineers pay special attention. In order to function, radar cannot be contained within a conductive enclosure. Instead, lightning diverter strips applied along the outer surface of the radome protect this area. These strips can consist of solid metal bars or a series of closely spaced buttons of conductive material affixed to a plastic strip that is bonded adhesively to the radome. In many ways, diverter strips function like a lightning rod on a building.

Private general aviation planes should avoid flying through or near thunderstorms. The severe turbulence found in storm cells alone should make the pilot of a small plane very wary. The FAA has a separate set of regulations governing the lightning protection of private aircraft that do not transport passengers. A basic level of protection is provided for the airframe, fuel system and engines. Traditionally, most small, commercially made aircraft have aluminum skins and do not contain computerized engine and flight controls, and they are thus inherently less susceptible to lightning; however, numerous reports of noncatastrophic damage to wing tips, propellers and navigation lights have been recorded.

The growing class of kit-built composite aircraft also raises some concerns. Because the FAA considers owner-assembled, kit-built aircraft "experimental," they are not subject to lightning protection regulations. Many kit-built planes are made of fiberglass or graphite-reinforced composites. At LTI we routinely test protected fiberglass and composite panels with simulated lightning currents. The results of these tests show that lightning can damage inadequately protected composites. Pilots of unprotected fiberglass or composite aircraft should not fly anywhere near a lightning storm or in other types of clouds, because nonthunderstorm clouds may contain sufficient electric charge to produce lightning.

Answer originally published August 20, 2001


23 Jan 2007
Há duas possíveis explicações. Ou a Merkel vociferou raios parta o Hollande, ou foi trabalho da Bruni, pois o avião em questão tinha até aqui a alcunha de "Carla One" :D

É uma "não história", como já foi afirmado, todos os dias há aviões a ser atingidos por raios, esta só foi notícia porque era com alguém importante, tretas para entreter a imprensa...
De qualquer forma, só fazer um esclarecimento. De facto o design dos aviões nas últimas décadas é feito de modo a sobreviverem a um raio (Gaiola de Faraday e outros pormaiores nos circuitos eléctricos/combustível, etc).
Mas apesar dos aviões sobreviverem, não significa que não sofram danos, aliás, raramente não devem ter algum tipo de dano mesmo que muito ligeiro, na maior parte das vezes é ligeiro. Os raios tendem a atingir as extremidades, nariz, cauda, extremidade das asas, e geralmente entram por uma extremidade e saem por outra, por vezes deixando buracos numa e noutra.
Existe uma lista de procedimento (check-list) que a tripulação tem que seguir, e se alguma coisa falhar, tem que divergir para o aeroporto mais próximo.

Por exemplo:

Circuit breakers ............................................................ ........ Check
Only reset a tripped circuit breaker if the associated service is essential to
continued safe flight. Only one attempt is allowed.

Headings ………………………………………………………… Check
Check the magnetic compass and heading system for normal indication.

Engine indication ……………………………………………… Check
Check the engines for normal indications; if an abnormal situation exists apply the
appropriate procedure.
In an engine shuts down, analyse the circumstances and consider an air-start.

Pressurisation ………………………………………………….. Check
Check the pressurisation system for normal indications.

Flight controls ………………………………………………….. Check
Check all flight controls for freedom of movement.
Verify that slats/flaps and speed brakes are functioning correctly; observe the
operating limits.

Fuel System …………………………………………………….. Check
Check the fuel system for normal operation.
Monitor fuel remaining and fuel consumption to check for fuel leaks.

Altitude …………………………………………………………… Maintain
Do not climb the aircraft after a lightning strike, unless required by performance
(climb or obstacle clearance) or operational contingencies.

If any structural damage is suspected, apply the EMERGENCY DESCENT

Aircraft other systems ………………………………………… Check
Check all aircraft instruments using a panel scan sequence.

Apply the associated emergency/abnormal procedure if any failure is discovered.
Consider landing at the nearest suitable airport if any unsafe condition is

O comandante depois da check-list, mesmo que pareça estar tudo ok, fica ao critério dele decidir o que fazer a seguir, muitas vezes opta por aterrar logo que possa. Apesar de haver umas descargas em que quase nem dão por nada, na maioria dos casos é um pouco assustador, e no geral estes eventos são muito stressantes para todos os envolvidos, sejam tripulantes seja passageiros, e todos ficam mais aliviados depois de aterrar.
Como em cruzeiro é suposto nem sequer se meterem numa trovoada, a maioria dos eventos ocorre depois de descolar ou quase a aterrar, pelo que geralmente se foi descolagem decidam retornar de imediato, ou apressar a aterragem. Se as coisas foram mesmo más e/ou suspeitas, declaram uma emergência, para terem prioridade sobre o restante tráfego. Embora todos os dias aconteça, não é propriamente uma experiência agradável para quem passou por ela.

Exemplo de danos provocados por raios:



No passado houve quedas de aviões atribuídas a raios: