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Enroute Airbus A380 wake flips Challenger business jet upside down

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Re: Enroute Airbus A380 wake flips Challenger business jet upside down

#211

Post by gingerbread-man »

wallace_f wrote: post #191
lutorm wrote: post #44

This is a reminder that the announcement that you should "keep your seat belt fastened at all times when you're in your seat" isn't just something someone made up. It's a small price to pay in case you ever encounter severe turbulence en route, but it might be one of these things that most people don't realize until it happens to them. Hitting your head against the cabin ceiling can seriously put a damper on your tri…

Can we talk about this in terms of actual statistics? How dangerous is flying without a seatbelt relative to say, driving without one?

Per the FAA (https://www.faa.gov/passengers/fly_safe/turbulence/):

- Each year, approximately 58 people in the United States are injured by turbulence while not wearing their seat belts.

- From 1980 through 2008, U.S. air carriers had 234 turbulence accidents, resulting in 298 serious injuries and three fatalities.

- Of the 298 serious injuries, 184 involved flight attendants and 114 involved passengers.

- At least two of the three fatalities involved passengers who were not wearing their seat belts while the seat belt sign was illuminated.

- Generally, two-thirds of turbulence-related accidents occur at or above 30,000 feet.

Edit: These stats do not include general aviation (private jets, etc...).

Re: Enroute Airbus A380 wake flips Challenger business jet upside down

#212

Post by gingerbread-man »

gingerbread-man wrote: post #211
wallace_f wrote: post #191

Earlier quoted context omitted.

Can we talk about this in terms of actual statistics? How dangerous is flying without a seatbelt relative to say, driving without one?

Per the FAA ( https://www.faa.gov/passengers/fly_safe/turbulence/ ): - Each year, approximately 58 people in the United States are injured by turbulence while not wearing their seat belts. - From 1980 through 2008, U.S. air carriers had 234 turbulence accidents, resulting in 298 serious injuries and three fatalities. - Of the 298 serious injuries, 184 involved flight attendants and 114 involved passengers. - At least…

For comparison, about 10,000 unrestrained motorists die in fatal vehicular accidents every year, and millions are injured. https://www.cdc.gov/motorvehiclesafety/seatbelts/facts.html

Re: Enroute Airbus A380 wake flips Challenger business jet upside down

#213

Post by throwaway7767 »

Zombieball wrote: post #138
peteretep wrote: post #134

Earlier quoted context omitted.

> anyone riding a bicycle, > even if they aren't going at > high-speed on road, should > wear a helmet "just in case" Is this a trick question? The answer is yes. In many places it's a legal requirement.

Thank you! I'm probably heavily influenced by the fact that I live in one of these places (where helmets are a legal requirement). All I could think while reading this is "yes, you definitely should always wear a helmet!!"

Out of curiosity, is cycling a common mode of transportation where you are from?

I recall seeing studies showing that helmet-laws generally coincided with low use of bicycles. Places where cycling is extremely common (like Denmark and Holland) never seem to have them, and it's uncommon to see cyclists using them unless they're doing something particularly dangerous (riding in traffic, off-road, etc).

Re: Enroute Airbus A380 wake flips Challenger business jet upside down

#214

Post by snovv_crash »

chakalakasp wrote: post #202
cyberferret wrote: post #36

Earlier quoted context omitted.

If you recall Boyle's Law from high school physics - Temperature is proportional to pressure. Aircraft wings generate an intense area of low pressure over the top of the wing (which is what essentially generates the lift). This low pressure area is magnified when flaps and slats are deployed. On a humid day, the lowering of the pressure over the wings can basically force the air temperature at that point to lower and…

BTW the low pressure generating the lift thing is a myth. The lift is caused by the fact that the air is being deflected downward and good ol' Newton's Third Law.

Yes, but by making the air move you introduce a low pressure where it moved from, and a high pressure where it moved to. They are interconnected, just like how you can determine speeds through conservation of momentum or conservation of energy.

Re: Enroute Airbus A380 wake flips Challenger business jet upside down

#215

Post by ryguytilidie »

phumbe wrote: post #7

For anyone interested, there are several great youtube videos[1-4] that show the wakes (the wingtip vortices in particular) created by various aircraft. This incident brings the Reduced Vertical Separation Minima (RVSM)[5] into question. Strategic Lateral Offset Procedure (SLOP)[6] can be used used to avoid such incidents. [1] https://www.youtube.com/watch?v=E1ESmvyAmOs [2] https://www.youtube.com/watch?v=dfY5ZQDzC5s…

Cool example of vortices on an F1 car as well: https://www.youtube.com/watch?v=ZlDnd3B1rhs

Re: Enroute Airbus A380 wake flips Challenger business jet upside down

#216

Post by gingerbread-man »

sundvor wrote: post #62
lutorm wrote: post #44

This is a reminder that the announcement that you should "keep your seat belt fastened at all times when you're in your seat" isn't just something someone made up. It's a small price to pay in case you ever encounter severe turbulence en route, but it might be one of these things that most people don't realize until it happens to them. Hitting your head against the cabin ceiling can seriously put a damper on your tri…

True.I would think this would be more of a problem for people from US states where wearing a seatbelt is not mandatory. In other parts of the world (with more sense) such as Europe, Australia, we're conditioned to always using it due to strict enforcement and as such it's not such a novelty.

Speaking as someone who has actually done seatbelt enforcement, (I worked as a cop for a year after college before getting into software development,) catching people who aren't wearing their seatbelts is really, really hard. Each seatbelt ticket written probably takes ~30 minutes of time for the issuing officer.

Re: Enroute Airbus A380 wake flips Challenger business jet upside down

#217

Post by Tarq0n »

tbabb wrote: post #119
EGreg wrote: post #103

"until the crew was able to recover the aircraft exercising raw muscle force" Any more info on that??

Under normal flight conditions, the aircraft's engine supplies hydraulic power to the flight controls (flaps, ailerons, elevator), like power steering in your car. Very necessary for big/fast aircraft, as the plane is heavy and the force of the air resisting the movement of those control surfaces is very high. If the engines fail, you still need to be able to control the plane, so there is something called a ram air…

Are there standards of strength that pilots have to meet for situations like these? What about female pilots?

Re: Enroute Airbus A380 wake flips Challenger business jet upside down

#218

Post by mnw21cam »

Zombieball wrote: post #143
cr4ig_ wrote: post #46

Earlier quoted context omitted.

I was looking at FlightRadar24 and listening to ATC while an A380 took off from Dulles near DC. Not only did they warn for wake turbulence when the plane was already well away, they held other aircraft for a runway inspection after the plane took off. I'd imagine that kind of wake could kick up some significant debris on the ground as well.

I believe warning of wake turbulence is very common after take off of any large and heavy aircraft. Wingtip vorticies can sit over a runway (or even drift over to parallel runways) for minutes after a takeoff. They are very dangerous to smaller aircrafts. The key to avoiding vorticies is to take off at a point earlier than the previous aircraft and to climb at a steeper angle (vorticies travel behind and downwards fr…

Helicopters. Indeed - there is a state known as "settling with power" https://en.wikipedia.org/wiki/Vortex_ring_state where a helicopter is sitting inside its own vortex, and is incapable of climbing straight up with full power.

Re: Enroute Airbus A380 wake flips Challenger business jet upside down

#219

Post by throwaway7767 »

tempestn wrote: post #169
ajdlinux wrote: post #116

Earlier quoted context omitted.

That happens to be the justification that my country uses to make bicycle helmets mandatory (though there's significant debate about whether it's actually helped reduce injury rates, and it fairly clearly depresses overall rates of cycling versus other modes of transport). I think the cost of wearing an aircraft seatbelt while you happen to be seated is rather lower than the cost of having to wear a bicycle helmet, t…

What's the cost? Helmets aren't that expensive. Having to carry it around? Could always lock it to the bike. Helmet hair?

Locking it to the bike isn't a good solution if you live in a place where it rains or snows a lot. So you end up having to carry it with you on errands. If you bike a lot, those small inconveniences add up.

I can't imagine fashion sense is much of a reason, that seems like a strawman argument commonly conjured up by helmet laws advocates.

Re: Enroute Airbus A380 wake flips Challenger business jet upside down

#220

Post by wallace_f »

gingerbread-man wrote: post #212
gingerbread-man wrote: post #211

Earlier quoted context omitted.

Per the FAA ( https://www.faa.gov/passengers/fly_safe/turbulence/ ): - Each year, approximately 58 people in the United States are injured by turbulence while not wearing their seat belts. - From 1980 through 2008, U.S. air carriers had 234 turbulence accidents, resulting in 298 serious injuries and three fatalities. - Of the 298 serious injuries, 184 involved flight attendants and 114 involved passengers. - At least…

For comparison, about 10,000 unrestrained motorists die in fatal vehicular accidents every year, and millions are injured. https://www.cdc.gov/motorvehiclesafety/seatbelts/facts.html

So according to this answer[1], ~1.7MM fly/day.

Making a quick guess that from '80-'08, Americans average 1MM flights/day, then odds of serious injury are ~1 in 95,000.

Odds of death are 1 in 9,333,333.

Assuming the possibility of taking 3 'average' flights/day, then you'd need to board flights non-stop for 8,523 years to die, on average. 88 years to be injured.

[1] - https://www.quora.com/How-many-people-fly-domestically-in-th...

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