There's a common misconception that the Hindenburg failed because of hydrogen. That's not the case (he said confidently.)
The Hindenburg burned - it didn't explode. Hydrogen doesn't burn, it explodes. What burned on the Hindenburg was the skin, a mixture of all kinds of inflamable things including silver, dope and cotton. The same materials that made WW1 airplanes somewhat risky. When you watch footage of the Hindenburg you see the skin burning, the hydrogen escaping, and it falls to the ground, because, well, gravity.
Even then it happens really slowly - some people on the airship escaped by just waiting till it reached the ground then running away.
These days we regularly use flamable materials in transport - think Avgas, petrol, and to a lesser extent diesel and jet fuel (kerosene). The "hydrogen vs helium" issue is overrated in my opinion.
>The Hindenburg burned - it didn't explode. Hydrogen doesn't burn, it explodes
If it doesn't contain its own oxygen it can't realistically "explode".
(edge cases involving novelty chemical reactions that go solid/liquid -> gas by some other means notwithstanding)
You need precise fuel and oxygen ratios to burn things. Burning is basically just runaway oxidation. Burn enough stuff fast enough and you get an explosion. Contain a fairly rapid burn and you can fudge the same pressures as an explosion (this is what happens in a spark ignited combustion engine). Both these require the fuel any oxygen to be in sufficient proximity and mixture to each other.
Airships, propane tanks and other sources of fairly pure gasses can't explode until after you break them and let the contents mix them with the atmosphere. Now, a trashbag full of pre-mixed oxygen and acetylene. That will go bang real good.
>When you watch footage of the Hindenburg you see the skin burning, the hydrogen escaping,
You see the hydrogen burning as it mixed with the atmosphere in the presence of an ignition source. The airship casing on its own doesn't have enough fuel to burn that energetically.
> The "hydrogen vs helium" issue is overrated in my opinion.
I agree but for totally different reasons that boil down to "people overrate risks they don't understand".
Something had to bring the skin up to ignition point. That may very well have been hydrogen, either above or below explosive mixes.
Static electricity (from a potential difference with the ground, St. Elmo's fire, or other sources) likely also contributed. Forensic analysis strongly supports leaking hydrogen from the aft part of the airship, given the nose-high, tail-low attitude and handling difficulties.
A myth has taken hold that the “paint” on the Hindenburg’s skin — rather than its flammable hydrogen lifting gas — was somehow responsible for the Hindenburg disaster at Lakehurst, and this myth somehow persists even though it has been debunked by photographic evidence, scientific analysis, historical research, and even the TV show MythBusters.
Helium is quite expensive right now. The US has stopped giving away the helium in its strategic reserves, and so the cost is now based in the reality of the cost to produce it.
The cost of helium is the reason you don't see the Goodyear blimps just floating around anymore.
As for the Hindenburg vs. Titanic: The titanic wasn't filmed going down. And the footage of a huge ball of fire with "Oh the humanity!" is a bit more dramatic than even the film representation of the Titanic sinking.
Back when the first ships failed causing the death of all the occupants , human lives were just not worth much , so humans kept building ships.
And also mass media wasn't there yet, so there could be no way to massively distribute content of a ship sinking and all the bodies floating around.
Same thing with planes, had we discovered flight in the Middle Ages we would have loaded 100+ people in wooden planes as fast as humanely possible because of the enthusiasm for the new technology would have vastly surpassed the fear of being harmed by it.
> The cost of helium is the reason you don't see the Goodyear blimps just floating around anymore.
What are you talking about? The Goodyear blimps are still out and about providing video for major live TV broadcasts. It's not like they drain the helium and fill it back up each time it goes out.
For what it's worth, I see six scheduled appearances in two cities, all in January and February of next year. That's not a lot, especially when I used to see them about 3-4 times a year out in Montana (AKA, the boonies).
> It's not like they drain the helium
No, but they naturally lose helium at a fairly regular rate, since there's no blimp envelope systems that can prevent all helium loss. RC blimps, as an example, lose about .5% to 1% of their helium daily. Commercial blimps appear to have a couple of months until they've lost their bouyancy.
EDIT: A single Goodyear blimp requires approximately 300 mcf (1mcf = 1,000 cubic feet) of helium, and helium prices are around $700 per mcf when sold in bulk. That puts a blimp's helium costs alone in the $200,000 range for a blimp that can carry 14 people.
Back in 2000, the price per mcf was in the $40 to $50 range.
They don't keep the schedule up to date on the website. Two of the three Goodyear blimps were up for TV broadcasts this past weekend, and every weekend since at least the beginning of September.
I've for years fantasised about being able to go on an airship cruise in my twilight years. I'm genuinely surprised it's not been seriously mooted by any companies.
The Zeppelins were not squalid or horrible, but they were incredibly spartan and not at all Luxury compared to what a cruise ship can do with a lot of mass. Here's a reproduction Hindenburg passenger cabin[1], compare with a cabin on a luxury cruise ship[2]. They're optimised for low mass more than comfort.
Then a reproduction lounge on the Hindenburg[3], compare with any of these on a cruise ship[4]. Ships are roughly as luxurious as you want to spend money to get, rivalling any hotel. (Water is ~750x denser than air, does that mean it can buoy up 750x more luxury per passenger for the same displacement vessel?)
> Put a few hundred well off people in luxury and slow air ship them to locations hard to reach by ships
The problem is that the infrastructure required for a blimp to land and takeoff might be significantly less expensive than a port but it's still many times larger than what an helicopter would need.
VIP services are banking on the new AW609 Leonardo[0]
Put a flat section on top of the airship, and land helicopters (or tilt-rotors) on it. Take the passengers (and fuel + supplies) to the airship, don't take the airship to the passengers.
Is much known about the safety of this aircraft? As I understand it, V-22 Osprey can neither auto-rotate, nor land in emergency like an airplane (because the rotors would hit the ground). Seems a bit like worst of both worlds.
> As I understand it, V-22 Osprey can neither auto-rotate, nor land in emergency like an airplane (because the rotors would hit the ground). Seems a bit like worst of both worlds.
"The V-22 is a tiltrotor and does not rely on autorotation for a survivable power-out landing. The wide separation of the engines and the ability to drive both rotors with one engine make a power-out landing extremely unlikely. However, if required, the V-22 can glide for a predictable run-on landing in airplane mode, much like a turboprop"
>As I understand it, V-22 Osprey can neither auto-rotate, nor land in emergency like an airplane (because the rotors would hit the ground). Seems a bit like worst of both worlds.
Tradeoffs.
It's worth it to them to plop a bunch of marines down with helicopter speed faster/farther than you normally can with a helicopter.
The military generally doesn't uncritically accept "but muh safety and liability" arguments like private industry does because the cost of doing things less efficiently (trying to refuel helicopters in hostile airspace, airborne operations, etc) comes with a statistical body count as well and they have some degree of sovereign immunity.
In a non-military context the pros and cons would weigh differently.
Yeah, I see that the calculus is very different for the military. I was specifically curious about civilian case. I’m already conscious of how fragile helicopters can be, hence my curiosity re this.
But from other responses it seems that these aircraft can in fact auto rotate and glide in an emergency.
1. Put a few hundred well off people in luxury and slow air ship them to locations hard to reach by ships. Maybe with both top and bottom decks
2. ???
3. Profit
Everyone thinks of Hindenburg disaster when they think of blimps, yet infamous Titanic and Costa Concordia didnt sink the cruise industry.