KLM pushes to resume passenger flights after tests | Hacker News Reader

KLM pushes to resume passenger flights after tests

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As I understand it the major risk is that because the ash cloud is very dry radar won't pick it up at all.

So you could fly 1000 planes and miss the cloud by luck; but if you hit it then potentially game over.

It seems a little silly that an industry with such stringent safety regulations would take that kind of risk...

BA at least say that satellite images show the cloud as smaller than the Met Office's computer model predicted it would be. Airspace was closed on the say of the latter.

Note that the Met Office's models have been way off since at least last winter...

NASA satellite images this morning match the Met Office model pretty closely.

But do they match what the model said 5 days ago it would look like in 5 days time?

Given the worst-case scenario of a failure of all engines and nothing else at cruising altitude over Europe, and assuming you have a skilled pilot, what's the probability of gliding in for a safe landing?

I'd think pretty high, since anywhere in Europe should be within safe gliding distance of a reasonable-sized airport. There are stories of landing safely under much worse conditions (eg the Gimli Glider which landed with no hydraulics or electronics and that US Airways flight into the Hudson which landed despite losing engines at low altitude).

There are at least as many stories of not landing safely, not only killing the people onboard but also on the ground. Europe is quite densely populated.

And I don't think you're within gliding distance of an airport at all, especially since they fly lower than normal to avoid the ash, and even if they are, I'm not sure what the odds of a successful dead-stick landing is. Given that most pilots have probably never tried it, I'd bet the odds of stalling out short of the runway or overrunning at high speed are pretty large.

Ultimately, it's a matter of weighting risk, and given that there seems to be no accurate assessment in combination with the shitstorm that would arise if they allowed flights to resume and a plane went down, I can't blame the authorities.

Poweroff landings are part of all flight training, even for a simple flight license. Any commercial pilot can handle it adroitly.

It is for single-engine licenses, I'm not entirely sure that they are for multi engine jets. Given the likelihood of an all-engine out, I'm not sure that's practiced much. They also don't practice ditching on water, for example. (And let me clarify that I'm not saying they couldn't set it down, I'm sure they can do that. I'm saying that it's not clear to me that you can easily manage energy so you end up at the end of the runway in a position to touch down at the right speed.)

Looking up the Gimli Glider it seems that they had a 12:1 glide ratio, so if your engines fail at 35,000 feet that should give you a range of about 128 km. I'm not sure whether it's possible, without leaving Europe, to get more than 128 km from the nearest airstrip capable of landing at least a small airliner.

Difficulties: if they're flying low to avoid the ash. Also, not all of Europe is at sea level, so if you're flying at 35,000 feet over the Alps then you might only be 25,000 feet above ground.

I think that's overly-optimisitc and only covers intra-European flights, not trans-Atlantic flights.

The longer restrictions are in place, the more airlines will push to be allowed to fly. I was due to fly from the UK to Qatar today, and I would much rather delay further than take any chances. Safety should be more important than profit.

A plane crash is pretty bad for profit (but even worse for health admittedly :-)

You talk about profit as if it's something to be ashamed of. Facts are 1) if safety really was more important to you you wouldn't fly anywhere, you'd stay safely at home and 2) if there are fewer airlines operating then you personally will need to pay more for your ticket.

Profit is nothing to be ashamed of, but saying the skies are free of ash and safe to fly in because of a couple of test flights? It seems to me that the airlines are more scared of losing money than they are of losing planes.

Flying done properly is safer than crossing the street and I'm happy to take that risk. Flying through an ash cloud is not something that generally turns out good for aircraft engines; even if an initial inspection shows that all appears fine with the aircraft and first stage fan blades, a borescope inspection may reveal clogged turbine cooling air passages (see Grindle, T., J., and Burcham, Jr., F. W., 2002, Even Minor Volcanic Ash Encounters Can Cause Major Damage to Aircraft).

If once all this is done airlines feel the need to charge more for tickets then so be it - I'm happy to pay more if it's because of safety concerns.

more scared of losing money than they are of losing planes

They're scared of ceasing to exist, i.e. bankruptcy.

Fear of bankruptcy does not make it OK to fly a plane with 200 passengers into conditions that may be unsafe.

No, but it does mean finding out what those conditions actually are (using satellite images and volunteer pilots) rather than relying computer models (guesswork at this stage).

I am currently stranded in Tokyo with a group of passengers from Finland that I will need to accommodate until the ash stops being an issue. These are the risks that entrepreneurs take, nobody could expect that some random volcano in Iceland of all places would cause 300 eur / day of losses, but life goes on.

My wife is currently stranded in Germany. As much as I miss her and want her home, there's no way I'd want her to fly through a potential ash cloud given that it doesn't show up on radar and the high risk of engine failure when you're over the North Atlantic doesn't sound like a good plan. A couple short range test flights do not mean it's safe to fly trans-Atlantic routes. When you're 40,000 feet up over freezing waters, you need to play it safe.

I still don't get the 200M losses per day. They are not paying back tickets /natural causes), nor taking care of passengers (hei, no out fault!) and I somehow doubt most people are buying tickets two days before flying.

Can someone explain?

British Airways are refunding tickets.

They're still paying salaries, plus many other operational costs. And they're foregoing revenues from these days of travel (by refunding/rescheduling passengers). So it's bound to have some impact on the bottom line.

They are paying care... they have to cover alternative travel or accomodation.

They are still paying for gates & slots in airports but are not recouping on those.

They are still paying for staff who now sit around.

They have an overhead of a communication system that is busy, combined with increasing demand for telephone support.

The only thing they're saving on is fuel, but everything else they're still covering and additionally they're covering the lowest amount they can get away with for the passengers who are stranded.

As for the passengers stranded, they have their only issues. Most would budget X on a trip that now will be rising substantially.

And that's before we touch businesses who really want their resources back earning good revenue.

Everyone is losing.

Except for some people. I live in West London and looking out and seeing a sky devoid of planes is a very very rare thing. And it's a beautiful day and I swear there are more birds than normal around. Quite lovely really.

It kinda explains this stuff here: http://news.bbc.co.uk/1/hi/uk/8624663.stm

[quote] The IATA said its estimate of a $200m daily loss of revenues was "initial and conservative". "In addition to lost revenues, airlines will incur added costs for re-routing of aircraft, care for stranded passengers and stranded aircraft at various ports," its director of corporate communications, Anthony Concil, said. KPMG was less conservative in its estimates, predicting a £200m loss in traffic revenues as a result of the UK shutdown, assuming that all ticket sales would have to be refunded to passengers. [/quote]

I'd say KPMG was rather silly, in that obviously passengers will need to get back and there's a bottle-neck at the channel tunnel and ferry ports. However as care is being paid they could actually end up paying out more than the cost of travel and make a loss even in the time after the skies open.

Air companies are process-based businesses, like chemical processing plants. They have an expensive infrastructure that costs money every day simply to exist, whether or not it is being used.

It costs less money if no planes are flying at all (just like a chemical plant presumably costs less if you shut it down), but there are still ongoing costs to meet: salaries, administrative overheads, maintenance costs, regular check-ups, etc. If you count just these, the loss is already substantial.

Then of course there's the opportunity cost. Every day that they're not flying planes, they're not earning fees from passengers. As the costs are, presumably, just a bit lower than the revenues (hopefully), this more than doubles the previous number.

Also, they are actually paying back tickets (at least EasyJet is).

And just like a chemical plant costs more than it's normal operating costs to start back up after a shutdown, an airline in a situation like this will have a major repositioning exercise to go through. Planes, people, baggage, freight, all are in the wrong places.

And Europe has 22,000 daily flights normally, 17,000 of them were cancelled Saturday. 17k flights times average number of passengers (100?) times average ticket cost ($100?) - it adds up to a lot of lost income. And as mentioned, the airlines were barely profitable as it were, and most of their costs are the same whether they are flying or not.

Analysts are saying that many/most of the airlines in Europe will be bankrupt in a couple of weeks if nothing changes, some think we will be seeing the first bankruptcies within a few days.

They are paying back tickets. They have to, at least that’s the case in Germany. I think they don’t have to pay your hotel bill because they are not to blame, but that seems to be about it.

Every plane on the ground is losing money. The only expense they are saving on is fuel, nearly everything else keeps on piling up. The losses aren't limited to airlines either, any company in the area with just in time inventory systems are in trouble.

They are repaying tickets, we were due to fly to Thailand yesterday for 2 & half weeks and weve been offered a full airline refund..tho thats only half of it with additional internal flights and hotels i now need to cancel and refund. Been planning it for months so its totally gutting.

The two biggest German airlines Lufthansa and Air Berlin are now in a full on PR war with the public authorities. It’s as if you flipped a switch, they remained silent about the whole thing until today.

I'm very glad that KLM is pushing to lift the flight bans! From what I understand, is there are no strict rules to decide when not to fly due to volcanic eruptions. The current bans are just based on calculations and now the KLM (and the two German airlines) have done tests and it shows it's safe to fly. I want to catch my flight to the Netherlands from Hong Kong this Saturday and I have full confidence in the integrity of KLM.

There's satellite data as well, e.g. picking up SO2 and I think infrared off the particles, but the only one I read about and that I therefore know can do that takes most of a week to image the entire planet.

They haven't shown that it's safe to fly, they've just shown that they could fly a few planes from A->B without them crashing. Anecdote is not the same as evidence.

I'm really surprised at how many people express little to no concern about being in a metal tube 5 miles up in what might be volcanic ash, given what ash has done to other planes.

The pilot doesn't want to die either, and the airline don't want to lose their expensive plane!

I'll happily jump on a plane as soon as airspace reopens knowing that.

I wouldn't fly on those planes.

You need some Dutch courage :-)

In Delft a student offered to take me on the back of his bike, sitting on the newspaper carrier. I expressed strong skepticism and he said, "Trust me, I'm Dutch."

Within 50 yards of starting our journey, I had been unceremoniously spilled onto the pavement, bleeding from my elbow.

I live in the Netherlands. I've sat on the back of bikes more than a hundred times and I can't remember a single time that I've fallen to point where I'm bleeding.

Ah, but how many times has someone told you "trust me, I'm Dutch"? That should have been the only warning I needed :)

Also, I assume that there is some skill to being a good backseat rider, and while I was not wiggling around, I was not actively helping steer either.

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