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-   -   AirLander take off then 2nd Flight Mishap (https://www.pprune.org/freight-dogs/583125-airlander-take-off-then-2nd-flight-mishap.html)

Tourist 19th Aug 2016 08:14


Originally Posted by A Squared (Post 9478503)
And other people with millions to throw around have already thrown millions at it, and after seeing the results first hand, decided not to throw more millions at it.

The idea that the fact that someone is spending money on it proves it's viable is absurd.

I never suggested that it proved anything, but I do know that people who have millions to throw around usually do a bit of research before throwing it, and a variety of them have obviously thought that it is worth a punt.

It is also worth pointing out that the US military did not pull out because they decided it was useless, they pulled out because of cutbacks and part of the selling deal is that they have access to the data accumulated by Airlander. Tat would suggest that they see some potential at the very least.

Tourist 19th Aug 2016 08:20


Originally Posted by skridlov (Post 9478216)
The physics involved is beyond me but the differences in mass and surface area combined with the difference between the media in which these vessels operate would make this something of an over-simplification. wouldn't it?

I really don't know, to be honest.

All down to the relative momentum of a ship vs Sea and airship vs air I guess. At least an airship in flight only has to worry about one medium. Ships have two to worry about.

I suppose the airship has to worry about gusts which I guess equates to waves.

I'm thinking these should equate due to the very nature of bouyancy?

skridlov 19th Aug 2016 09:25

Back in the 80s I manufactured and supplied some video signal processing equipment to Airship Industries for use in that decade's version of the "airship revival". Anyone remember "Airship Industries"?

TURIN 19th Aug 2016 11:21

I think the Airlander team are made up of a few ex Airship Industries designers and engineers.

Basil 19th Aug 2016 11:35


Do you know what the fully laden fuel consumption is?
Sorry, don't know.
I lifted that data from their website.

netstruggler 19th Aug 2016 13:12


Anyone remember "Airship Industries"?

I worked at GEC Marconi's Flight Automation lab in the early 80s and we were contracted to do some flight control work for AI.


To avoid EMC issues on the long exposed cable runs to the control actuators we were looking to use fibre optics.


It turned out that running fibre optics around the outside of a large inflatable balloon introduced its own issues.

G-CPTN 19th Aug 2016 13:51


Originally Posted by TURIN (Post 9478855)
I think the Airlander team are made up of a few ex Airship Industries designers and engineers.

The airship designer pool must be little more than a puddle.

A Squared 19th Aug 2016 13:52


Originally Posted by Snyggapa (Post 9478646)
>The idea that the fact that someone is spending money on it proves it's viable is absurd.

Likewise, the idea that the fact that others have refused to spend more money on it proves that it is not viable, is equally absurd.

Unlike tourist, I wasn't offering that as any kind of proof, but as a counterpoint to his silly reasoning.

G-CPTN 19th Aug 2016 13:57

USS Akron and Macon.

A Squared 19th Aug 2016 14:14


Originally Posted by Tourist (Post 9478657)
Wow!

Must be windy on your planet, because here on earth ships that can only do 17kts seem to manage to move out the way of most nasty weather systems...:rolleyes:

Uhhh, yeah sure if a dangerous storm was the same thing in the context of an airship as it is in the context of an ocean-going ship, sure. Thing is it's not. the kind of winds which would be absolutely catastrophic for an airship wouldn't give an oceangoing ship much pause. Yeah, a ship can see a typhoon coming, usually, and chug out of the way, usually. Sometimes they aren't able. I think you're going to find that weather that is going to jeopardize an airship is a lot less severe, and will be a lot more common, and will be a bit harder to predict. Just as a guess, I would say that winds 25 kt gusting to 35 would almost certainly destroy an airship not in a hangar, but airline operations commonly continue is such weather and it would be relatively unremarkable for an ocean-going ship. Never mind that a ship will have fuel reserves measured in weeks at normal cruise which enables waiting out large storms, while a hybrid airship with a load which requires lift in excess of bouyancy will not.

Point being, reasoning that a strategy which is useful for oceangoing ships will also be viable for something so completely different as an airship is fundamentally flawed.

Piltdown Man 19th Aug 2016 14:18

A truly ridiculous qurstion, but what does an airship's loadsheet look like? Does it come out at zero, or even less? I can understand a trim sheet would be required but what else does an airship need in calculations and operational paperwork?

As for its uses, there are many. Especially as this one appears to be able to accept an under-slung load. That will enabie odd-size cargo to travel point-to-point without special provisions.

PM

skridlov 19th Aug 2016 14:22


Originally Posted by netstruggler (Post 9478967)
I worked at GEC Marconi's Flight Automation lab in the early 80s and we were contracted to do some flight control work for AI.


To avoid EMC issues on the long exposed cable runs to the control actuators we were looking to use fibre optics.


It turned out that running fibre optics around the outside of a large inflatable balloon introduced its own issues.

That's interesting as I had some problems generating a "certificate of conformity" for my DC powered signal processor, relating to RF emissions. I ended up outsourcing the tests and supplying a certificate that I really didn't fully understand. Luckily AI folded before my hardware had a chance to create problems. Not that it would have of course.

A Squared 19th Aug 2016 14:50


Originally Posted by Tourist (Post 9478660)
v It is also worth pointing out that the US military did not pull out because they decided it was useless, they pulled out because of cutbacks and part of the selling deal is that they have access to the data accumulated by Airlander. Tat would suggest that they see some potential at the very least.

Aside from the fact that the US military has at times, funded some spectacular failures, you're desperately attempting to form a conclusion that is ridiculous. To wit: "They didn't cut the program because it wasn't promising, they cut it because htey had budget cuts" as if the two are completely independent of each other.

I'll help you find your way thru your fallacy with a question: When an organization is forced to reduce spending, do they cut the programs showing the most promise, or do they cut those showing the least promise?


Beyond that, I think that you'll find that the military's primary interest in this is as a sigint platform with significant loiter time. I certainly don't dispute that it it may have some advantages in this role. Plying air commerce on a regular basis? Meh.

Tourist 19th Aug 2016 15:15


Originally Posted by A Squared (Post 9479045)
Uhhh, yeah sure if a dangerous storm was the same thing in the context of an airship as it is in the context of an ocean-going ship, sure. Thing is it's not. the kind of winds which would be absolutely catastrophic for an airship wouldn't give an oceangoing ship much pause. Yeah, a ship can see a typhoon coming, usually, and chug out of the way, usually. Sometimes they aren't able. I think you're going to find that weather that is going to jeopardize an airship is a lot less severe, and will be a lot more common, and will be a bit harder to predict. Never mind that a ship will have fuel reserves four weeks at normal cruise which enables waiting out large storms, while a hybrid airship with a load which requires lift in excess of bouyancy will not.

Point being, reasoning that a strategy which is useful for oceangoing ships will also be viable for something so completely different as an airship is fundamentally flawed.

My apologies.

I had not given your question adequate consideration, so didn't quite realise how stupid it was.

1. You state that an airship is far more vulnerable to storms than a ship. Do you have any evidence for this?
I have zero knowledge about airships, but a reasonable amount about inflatable structures. What I do know is that that type of structure which is purely maintained by pressure is extraordinarily strong. I can think of no circumstance where a storm could possibly damage the basic shape through shear forces alone.
Unlike an aircraft, for example.
As far as I can see, at altitude, the threat is purely from upset of some kind due to updrafts/downdrafts affecting different parts of the envelope and perhaps rolling/pitching them. The envelope would be fine, but I suspect the contents of the gondola would get messy at that point

The danger comes if it can be forced into the ground by the weather.

2. The fastest hurricane in the record was Emily in 1987, whose maximum speed reached 110.48 km/hr (59.61 kt or 68.65 mph) as it raced over the North Atlantic.

This would seem to suggest that a 90kt blimp could outrun it, yes?

This is what I thought until I had a bit of a think.
Why outrun anything?

What about if you just turned the engines off and drifted with the wind?
How fast does a storm move relative to the wind holding it?
A ship moves relative to the sea. It has to move over the sea to avoid a storm.
An airship need do little more than drift with the wind, as a storm moves with the air mass it is in.
As long as you stay away from the centre patch where local effects might pull you in, you would be fine, just like an aircraft really.

3. An airship with weather radar will have more not less warning of a storm as a function of height.

4. Four weeks to wait out a storm?

That is a hell of a storm! Definitely not visiting your planet. Sounds nasty.
I would think 24hrs at 90kts will give enough radius to avoid the biggest storm on earth.

Scuffers 19th Aug 2016 15:16

I am struggling to see a genuine practical use for this?

it falls in the same pointless category as the solar plane, all very clever, but ultimately pointless.

Tourist 19th Aug 2016 15:18

What about the ones I posted earlier?

Scuffers 19th Aug 2016 15:30

All easier/cheaper/better done by existing aircraft.

combine with it's massive size (and low cargo capacity), vulnerability to wind, lack of speed, fragility, etc. where is the killer application?

if you want to do surveillance, there are already a large selection of drones, all the way up to global Hawk etc.

if you want to air-lift 10 tonnes vertically, there are helicopters/tiltrotors

etc etc etc.

Tourist 19th Aug 2016 15:34

It appears that the vulnerability and fragility have taken root in the minds on the forum.
Any evidence?

Re the better done by existing, nope.

If, and it is a big if, it can be made to work it has enormous advantages over many other aircraft.

Helicopters are very range/height limited, plus 10t is the prototype. Try 50t.

Global hawk is all very well, but you need an awful lot of them to maintain permanent watch, and do you know how much they cost?!

Scuffers 19th Aug 2016 15:44

Name me a large airship that has not suffered some catastrophic disaster?

(remember what the sheds at Cardigan were built for?)

Helo wise, how high do you want to go? (and to what end?)
and just how far do you need to fly? (V22 tiltrotor can do 1,000 miles)

Global Hawk has something like a 40 hour on-station time, and a range over halfway round the planet.

Like I said, what's the killer-application?

G0ULI 19th Aug 2016 16:23

Given that AirLander 10 is effectively a proof of concept model and that much higher lift capacity can be incorporated by simply adding a couple of extra metres in the envelope height, width and length, this experiment will likely invent some completely new applications. A craft with a vertical lift capacity measured in hundreds of tons would certainly be revolutionary.

Don't regard AirLander 10 as a finished product. Think what future development can lead to. DC3 V B747, both great aircraft and both revolutionary, but that is the level of difference that needs to be considered when thinking about AirLander 10 and possible future incarnations of the type.


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