Glad to Be Alive

[Evan]

I'm okay with paying for checked bags. Why would I want to subsidize the cost of high maintenance women who take three huge suitcases for a weekend trip? One doesn't need their whole shoe tree.

Why not? You are already subsidizing the obese shoe-tree salesman who weighs the equivalent of three huge bags. How much does the average woman weigh compared to the average man? Shouldn't this allow them to check more luggage?

It's not about fairness or weight.

We should all learn to travel lighter and charging for bags encourages it.

You've obviously never taken an extended trip abroad with professional gear, or ever paid euro prices for the things you couldn't carry there.

[EconomyClass]

One of my tourist guides says never take more than fits in a backpack. They have all sorts of ways to accomplish that, but the point they make is that whatever you pack, you schlep. And in time, the schlepping starts to get to you. I guess there can be all kinds of slants on this. But it is a fact that some people are trying to bring their home with them. So they are very cool on the notion of adventure.

But if they are willing to pay the cost, why should I object. My only objection is when the first people onto the plane take their carryon stowage space and yours and the guy next to you. It is an abuse that the airline needs to discipline without mercy.

[EconomyClass]

Turbulence

When a flight encounters what Flight 967 does, when it drops so suddenly it feels like the plane is now a stone, is that loss of lift or is it a mass of air forcing the plane down with so much energy the wings become useless? Reading about this latest event, I remember the plane at Dallas years ago that was just slammed into the ground. Wings are supposed to help against that, but convection must marshal such a huge amount of energy that wings are useless.

[Gabriel]

(I don't know why I kep doing this, oh well)

Remember the AoA? The angle at which the free stream of air hits the wing? At a given speed, the lift is directly proportional to that AoA (or, more correctly, to the amplitude between the current AoA and the AoA where the lift is zero).

At cruise, planes fly at about 2 degrees of deck AoA (the AoA measured with the fuselage as the reference). Because the camber of the wing, and because the wing is fixed to the fusselage at some angle already (called decalage), in that condition the plane will be at an AoA of about 6 degrees above the zero lift AoA.

If the plane encounters a descending vertical gust, the combined wind (due to the speed of the plane plus the speed of the gust) will come not horizontally but at an angle from above, and that will effectively reduce the AoA.

If the plane is flying at say 400kts, every 7 knots of such vertical gust will reduce the AoA in 1 deg.

So, assuming that the plane is happily flying at 1G at 400kts with an AoA 6 degrees above the AoA of zero lift, this is what you get.

Vertical descending gust ========> AoA above zero lift ======> Gs
..........0 kts.............................................6..............................1
.........21 kts............................................3..............................0.5
.........42 kts............................................0...............................0 (this will be "like a stone")
.........63 kts...........................................-3............................-0.5 (this will be even worse)
.........84 kts...........................................-6.............................-1

As you see, it's not that it's something tht the wing can't deal with. If it was possible to foresee that you are about to be hit by an 84 kts vertical descending gust and you cuold increase the AoA in 6 degrees exactly when it hits, the wings would have no problem keeping the plane happily flying at 1G. But that's not possible.

[bob12312357]

I take your point, but the primary direction for rapid acceleration/deceleration in a car is in the horizontal plane. There is a lot less need (I'm not saying no need) for restraint in a vertical direction.

On an aircraft however the primary direction, in turbulence at least, is vertically, and that is where the lap restraint comes into its own. For a vertical force to be large enough to sever you the force would need to be large enough to make the whole aircraft accelerate downwards at such a rate to produce that force at the seat belt. As an aircraft has a much greater mass than a person, and force=mass x acceleration, this is extremely unlikely.

I will accept that if the aircraft hits something on landing and comes to an instant stop, that force could certainly be great enough, but even if your body were completely restrained under those conditions your organs would probably come out through any available opening anyway!

Your organs don't have 2 come out or go anywhere and your head or body doesn't ahve 2 impact anything. Between your brain smashing into your skull and your heart being ripped from the aorta theres many ways to die. There are times planes crash and the dead won't have a scratch on em. I remember one pic posted a back on the old site where a single engine flat spun into the ground, the plane was completely intact and there was no fire. The wings didn't even seperate completely off and everyone died of internal injuries. It's common for racing drivers to die of a severed Aorta. Princess Diana died of a severed Aorta.

[T.O.G.A.]

TOGA, I'd love to see 5 point harnesses in aircraft. How many people do you think would actually use them though? Even the pilots don't wear it during cruise, opting just for a lapbelt. The proximity of the sidewall to the passenger means that even a harness may not stop them hitting their head. The majority of force in inflight turbulence that causes the damage is, as mawheatley has pointed out, vertical. We have to be practical here. How about fitting a car-like seatbelt? Maybe that would help. Problem is - will it actually discourage people from wearing it in cruise? At least the lapbelt is unobstructive.

5 point restraints would be too taxing for passengers to manage. Three point belts are more familiar and protective than lap belts

[Highkeas]

...........By the way, this has very little to do with weight itself, because I easily weigh 10-20lbs less than the average American. ..........................

The limit is based on ergonomic considerations. Bags over 50 lbs create difficulty for ground staff - my wife worked as an airline CSA and she tells me that some bags or checked items needed two people to handle them.

[Gabriel]

5 point restraints would be too taxing for passengers to manage. Three point belts are more familiar and protective than lap belts

And that third point would be fixed to...?

[Evan]

The limit is based on ergonomic considerations. Bags over 50 lbs create difficulty for ground staff - my wife worked as an airline CSA and she tells me that some bags or checked items needed two people to handle them.

Yes, I pointed this out, read my post. I advocate a 50lb limit, and a required two bag allowance would make that easy to enforce.

[EconomyClass]

Yeh, we can guess that when AF447 hit the water and came to a sudden stop, the xG force just smashed everything internally. The effect in this case would be much milder because the plane didn't hit anything solid. But the human body just isn't made for some of these sudden changes. Technology puts the body in situations it didn't evolve for. And that's great till technology itself gets overwhelmed by natural forces.

[T.O.G.A.]

And that third point would be fixed to...?

Point taken...As we know, adding the third point would be an expensive mod.

However, if the FAA had accepted the NTSB's recomendation for three point restraints when it was made back in the eighties, virtually all commercial airliner seats would be three point already through attrition.

[AirRabbit]

Come on guys … you know its not about those kinds of considerations … anyone who’s been involved in the aviation industry for more than a couple of hours can easily tell that the checked bag fee is simply a way of increasing revenues – just like selling drinks, food, and, as one airline has already threatened, coin-operated toilets. Sure, the airline could easily jack up the ticket cost and do away with all those “add-ons” but that would have a direct impact on the decision making regarding from what airline potential passengers may want to purchase their ticket. The only other area that has a similar effect is departure times.

Flights are listed chronologically by departure times – flights are also listed by ticket costs for city pairs. When “the boss” tells his secretary to “book me a flight as soon after noon as you can, and make it the cheapest you can” … guess what? The flights that are listed at 12:01 will be read before the flights leaving at 12:10. From that point – all the flights leaving at 12:01 (and you can check for yourself … there are likely more than a few) will be listed by price (highest to lowest OR lowest to highest). So, the secretary chooses the lowest-to-highest listing, and guess what … the ticket that is merely pennies cheaper will be higher on the list … and therefore read first. That flight has a much better chance of being purchased than any other in the list.

I’ve seen airline managers spend an inordinate amount of time adjusting flight schedules by mere minutes to get them listed higher on the same list; or adjusting ticket prices by pennies to achieve the same kind of result. You might be surprised at how much a couple of minutes makes on a list of flights from, say, New York to London – or how much difference there can be in being close to the top of the list by dropping the price by a penny or two … forget the 50 bucks for a checked bag! No one (or virtually no one) avoids an airline because of the cost of drinks or the fact that they may have to check a 2^nd bag.