Meus Caros,
Mais uma vez, começaremos este nosso apontamento semanal com mais um apontamento
sobre a modalidade de Rally Aéreo.
No apontamento desta semana vamos continuar a ver, no concreto, como se desenrola o
Teste de Aterragem duma etapa de Rally Aéreo.
RALLY AÉREO – Teste de Aterragem – Parte III
De acordo com o regulamento FAI de Rally Aéreo existe sempre uma prova de
aterragem: a aterragem final. Em que condições se deverá processar esta aterragem?
Os aviões deverão aterrar dentro dum caixa de aterragem com as seguintes
características:
No próximo apontamento iremos continuar a ver mais pormenorizadamente o teste de
aterragem.
Para mais informações sobre a modalidade de Rally Aéreo visita o site da Equipa Icarus em
www.icarusrallyflying.net .4
A conjugação dos sistemas GPS / WAAS vai permitir a dispensa da instalação dos
dispendiosos sistemas de ILS em aeroportos ou aeródromos tipicamente destinados à
Aviação Geral.
Qual é o significado desta novidade? Segurança!
Efectivamente um enorme número de aeródromos passaram a dispor de um sistema que
lhes permite disponibilizar aterragens de precisão. Contudo, a mudança de sistema aviónico
não dispensa que estes aeródromos possam não ter outros meios terrestres tais como:
luzes de pista, taxiways, etc. .
FAA LOWERS WAAS APPROACH MINIMA
The FAA has just reduced WAAS approach minima to a 200-foot decision height and 1/2mile visibility. And that means pilots flying instrument approaches using GPS enhanced by
the Wide Area Augmentation System (WAAS) can get virtually the same performance as
they do now from a ground-based ILS. "AOPA has been a strong supporter of WAAS for
more than a decade," said AOPA President Phil Boyer. "We have urged both Congress and
the FAA to press ahead with the program because it improves air safety by providing the
precision vertical guidance needed especially in poor weather conditions. And it makes better
use of the nation's system of airports because thousands that currently may only be used in
good weather can become all-weather capable." Typically, a GA airport might expect minima
of 300 feet decision height and 1 mile visibility from a WAAS approach without any
improvements to ground infrastructure. To get the lowest minima possible from WAAS, the
airport will need much of the ancillary ground infrastructure required for an ILS system,
including approach lights, precision runway markings, and a parallel taxiway.
E em Portugal? Neste momento continua a haver uns tontos que bramam pela instalação de
ILS nas suas pistas. Naturalmente exclui-se aquelas pistas onde o sistema GPS / WAAS
não garante as necessidades dos ILS CAT II e CAT III!
Na Europa, enquanto se espera pelo sistema Galileo, já foi instalado o sistema EGNOS
(para saberes mais visita o site http://www.esa.int/esaNA/GGG63950NDC_index_0.html ),
equivalente ao sistema WAAS. Não te esqueças que Portugal é um dos países envolvidos
no desenvolvimento deste projecto.
Este problema da disponibilização das aproximações WAAS levanta-nos outro problema:
quantos pilotos PPA’s de Aviação Geral têm a qualificação de IR (voo por instrumentos)?
Pouquíssimos! Na Europa o IR equivale praticamente a uma licença de PCA, com todo o
seu peso. 4
Mais um avião de Aviação Geral que provavelmente será disponibilizado nos USA dentro de
pouco tempo. Curiosamente, estão vendidos 60 a um preço de quase 250.000 € a unidade,
e ainda se procura a fábrica que os irá produzir.
Trata-se dum elegante avião equipado com um motor Lycoming IO-360 debitando uma
potência na casa dos 200 hp que lhe permitirá uma velocidade de cruzeiro estimada na casa
dos 175 knots
PLANS FOR LOPRESTI FURY MOVE AHEAD
Fifty-four communities throughout the country are seeking the plant that LoPresti Speed
Merchants will build to produce its LoPresti Fury, based on the SwiftFury that was first
offered in 1989 but never built. R.J. Siegel, the Vero Beach company's vice president of
operations who is now based in Wisconsin, said the initial investment in the plant is $28
million. Interested communities have provided property and capital as incentives. The first
year's production of 60 aircraft is sold out. The aircraft will have a base price of $295,000.
Siegel predicted the aircraft will have an indicated cruise speed of 215 mph (186 knots) using
a Lycoming IO-360 engine.
Aguardemos para ver se o projecto vai mesmo para a frente. 4
Quando qualquer estrutura se põem a vibrar é importante que a vibração não atinja
frequências próximas da “Frequência de Vibração Catastrófica”. Se isso acontecer o mais
certo é a estrutura desintegrar-se. Como deves calcular é um fenómeno que nenhum piloto
está interessado em experimentar. Porém, às vezes, por pequenas avarias este tipo de
ressonância pode acontecer. Vejamos o que aconteceu a este nosso companheiro no
Alasca.
NEVER AGAIN ONLINE: FLUTTERING WITH DISASTER
Flutter and wing oscillations rendered the aircraft uncontrollable with imminent structural
failure as a probable ending: a harrowing event with a remarkable outcome. The pilot's swift
action and a good dose of luck helped him and his passengers survive the ordeal. Read how
this pilot handled an extreme emergency—a lesson he would not wish to repeat.
DENALI'S ROUGH RIDE
BY DONALD R. LEE
On Monday March 7, 2005, as a pilot for Fly Denali Inc., I departed Talkeetna, Alaska, for a
scenic flight around Mount McKinley with three passengers in a de Havilland DH-2 Beaver
aircraft, N3307S. This was a Part 135 air-taxi operation. I filed a flight plan with the flight
service station (FSS) at 10:38 a.m., Alaska Standard Time, for 1.5 hours of flight time — with
three hours of fuel and four souls on board — to circumnavigate the mountain.
I received a weather briefing and current airport advisory from the FSS. There were no pilot
reports for the back side of the mountain. There was an overcast layer at about 9,000 feet,
and I proceeded to fly in to the Great Gorge of the Ruth Glacier and turned around in the
amphitheater.
I asked and received the current Lake Minchumina and Healy weather. The north side was
clear of clouds, and I headed north — up past the Eldridge Glacier. As I climbed to 11,000
feet, it was clear of clouds and the complete north side was open. It was totally clear and just
awesome.
As I reached the area of the Muldrow Glacier around the Anderson Pass area, I leveled out
and reduced rpm from 2,000 to 1,850. The airspeed was about 115 mph indicated and
manifold pressure was 25 inches at that altitude. There was a small amount of turbulence
crossing the range, and I told my passengers that the mountain was talking to us and
instructed them to tighten their seat belts: It can quickly become very turbulent. Mount
McKinley was completely visible and very nice.
I started to feel a small wobble in the yoke and looked out at the left wing. It was vibrating at
about five oscillations per second, with 1 to 2 inches of deflection. It was similar to a bad
shopping-cart wheel. The rudder pedals started to wobble uncontrollably, and I could not
hold them with all the strength I had in my legs.
Within the next fraction of a second, the aircraft became completely uncontrollable — to say
that it was shaking violently would be an understatement!
With deflections of the wings 2.5 to 3 feet outboard of the main lift strut, I watched the wing
tips flap up and down so fast they were a blur, with the tip of the wings bending out of sight
about midaileron. The noise was deafening. It was an "oil canning" sound with loud popping
noises. My camera was flung from my jacket pocket to the floor between my feet. My
passengers were frozen in fear and were holding on to the sides of the cabin. The shaking
was so violent that it was hard to focus on any instrumentation. We were being bounced up
and down in a vertical motion so rapidly, that I felt the cheeks of my face being pulled back
and forth strongly. I had to clench my teeth so as not to bite my tongue. I slammed
everything on the throttle quadrant to full-aft position — throttle, propeller, and mixture —
killing the engine completely.
I simultaneously applied back-pressure on the yoke to slow the aircraft down and banked
about 15 degrees to try to put a slight load on the aircraft, so I would not have such a steep
angle of attack when pulling up. I depressed the push-to-talk switch and called Mayday, three
times, "The airplane is coming apart; the airplane is coming apart; N3307S." It took both my
hands on the yoke, which was bucking back and forth about 14 inches (not any side motion).
I could not arrest it or hold it still. The rudder pedals were pumping back and forth as fast as
they possibly could. The propeller never came to a complete stop. At about 50 mph the
oscillations stopped completely.
I did not stall the aircraft at any time. I leveled the wings and brought the engine back online
at 20 inches of manifold pressure and 1,600 rpm. I put in about 15 degrees of flaps and
maintained less than 90 mph for the descent back to the east. At 90 mph, I started to feel the
yoke vibrate and wobble again, and I reduced speed to 75. I made slight adjustments to the
mixture and manifold settings as I descended and had an uneventful landing back in
Talkeetna — not changing the flight configuration all the way to touchdown.
Upon examination of the aircraft, it was discovered that the wings had structural damage just
outboard of the lift strut and halfway point to the empennage. The left wing had lost one
fairing and popped all the screws out of the leading-edge fairings at the wing root. In
conclusion, the insurance company deemed the aircraft a total loss. Both wings were
damaged beyond repair. The right-wing aft attach point was completely severed and held in
place by lift of the wing.
The FAA engineering team concluded that one aileron was 17 ounces out of balance and
there was possibly a 0.003 discrepancy in a wing bushing that, when amplified to the length
of the wing, was a contributing factor. General maintenance would not have detected this —
everything was current and legal.
An FAA inspector who did the investigation stated — with no supporting data — that I had
exceeded the aircraft's VNE speed and caused this to happen, a statement that caused me
considerable hardship. I have since been totally exonerated from any wrongdoing, and I
actually have been credited with a save of the three lives and my own, with my correct and
swift response to the emergency.
Flutter is a very dangerous event, and any indication should be dealt with seriously. I'm glad
that I was able to act quickly and nurse the aircraft back to a safe landing. I've also learned
several important lessons.
Be alert to how your aircraft handles at all times. It is crucial to immediately recognize
anomalies that could be signs of an impending structural problem. There was nothing during
maintenance or preflight of the aircraft that indicated a pending problem with flutter, however
I would advise anyone with this type of aircraft to have the controls balanced. Also, should
there be any question of safe flight, act quickly and don't change the configuration until you
have landed.
Meu caro amigo, nunca te esqueças que as frequências de ressonância catastrófica podem
ser ultrapassadas fazendo, por exemplo, variar a velocidade do avião. Abaixo ou acima
duma certa velocidade o fenómeno pode desaparecer. 4
Os Mooney são uma parte integrante da Aviação Geral. Agora, foi produzida a 11.000º
unidade.
MOONEY REACHES PRODUCTION MILESTONE
Mooney Airplane Company has delivered its 11,000th production aircraft, an Ovation2 GX.
The airplane went to Dennis F. Strigl of New Jersey on February 23. Strigl bought the
airplane after he decided to get back into flying. He first flew a Mooney model back in the
1980s. Mooney delivered its first airplane in 1948 from its initial location in Wichita. In 1951
the company moved to its present location in Kerrville, Texas
Se quiseres saber mais sobre o modelo Ovation 2 GX consulta o site do fabricante em:
http://www.mooney.com/aircraft/ovation2gx/ . É um excelente avião equipado com “glass
panel” 4.
Deixa-me terminar recomendando-te que te associes à AOPA Portugal. Perguntarás, de
imediato, como o poderás fazer. Visita o site da AOPA Portugal em www.aopa.pt e manda
as tuas perguntas para o Presidente da AOPA Portugal através do seguinte e-mail address:
[email protected]. Gostaria de contar com a tua presença na nossa AOPA. 4
Entretanto visita o site da Equipa Icarus em www.icarusrallyflying.net. Há sempre novidades
tanto mais que, este, sofreu uma remodelação que trouxe “coisas” úteis para os pilotos.
Por hoje, é tudo. Não me despeço sem o meu conselho habitual: decide-te e resolve, duma
vez por todas, praticar Rally Aéreo. Praticando Rally Aéreo serás muito melhor piloto.
Um abração do
Fernando