AirLander take off then 2nd Flight Mishap

[etudiant]

The news that this accident originated with a snagged power line is actually somewhat reassuring. It validates the basic safety of the vehicle, even as it highlights the much more demanding aspects of airship management near the ground. The latter can be learned with experience
Against that, the instant effort to deny the fact damages the credibility of the firm.

[FlexibleResponse]

Hybrid Air Vehicles Ltd can confirm a mooring line attached to the Airlander did contact a power line outside the airfield. No damage was caused to the aircraft and this did not contribute to the heavy landing.

HAV state that the heavy landing was not caused by contact with the power line(s).

Therefore, in the absence of obvious adverse weather conditions, the accident must have been caused by one or more of the following:

1. Control system inadequate design.
2. Control system malfunction.
3. Buoyancy control malfunction.
4. Pilot error of technique, judgement or skill.
5. Other cause?

[Wageslave]

The company apparently IMMEDIATELY denied a witness report that it had struck power lines.

Why?

Corporations today really ought to be extremely conscious of how bad their image is becoming due, perhaps in part, to their seemingly limitless willingness to lie instantly about anything.

What could it cost them to say, instead, that they were investigating reports of the beast having struck a power line, rather than having to admit later on that their initial response was incorrect?

How people love to jump to conclusions and accuse others (especially evil "companies") of lying at the drop of a hat.

Perhaps the clue is in the word "immediately". If this refers to "immediately" after the accident it is highly likely that the company knew nothing of the wirestrike and as the entire ground team had witnessed it come in trailing a slack landing line (as shown in the DM's photo) and only develop a pitch down after crossing the perimeter where there are no wires it would have been utterly clear to everyone that this was impossible and would have sounded to them exactly like the sort of "witless witness" speculation we all so love to ridicule here...They also know that there are no wires in the immediate vicinity if the airfield perimeter for obvious reasons. Thus all concerned, except the pilots, would have been quite certain that no wirestrike had occurred.

It would take some time, several hours probably, before the results of the pilots' debriefing was disseminated within the company as this is always treated in confidence so some considerable delay might well be expected before mere PR wallahs knew anything about an unwitnessed and highly unlikely wirestrike some time prior to final approach especially as it doesn't/didn't seem to have been immediately connected with the incident.

For heaven's sake, lets not go around flinging about nasty accusations of "lying" before even we have all the facts? Just for once?

What possible motivation could they have to "lie"? What would be the point?
Pound to a pinch off the proverbial that statement was made before thePR officer had access to full details of the pilots' debrief and was thus made in good faith based on the info available at the time. Cut them a little slack, will you?

Why, why do so many people imagine that companies lie all the time? It just isn't rational.



It seems surprising that no video has surfaced of the wirestrike as surely dozens must have been filming it throughout it's flight? Did it make a big excursion in pitch before crossing the perimeter? If so that could have either damaged engine controls (fwd engines did not seem to be countering the pitch down) or broken equipment loose sufficient to affect the c of g.

[core_dump]

Wageslave, you're criticizing folks for not waiting for all the facts. But it's fine with you when the PR people didn't wait for all the facts? Isn't there an element of comedy to that?

[Wageslave]

There's more of an element of comedy to your reply! Me criticising folks? Ahem! You are not lying if you tell what you believe is the truth. I think Airlander had no reason whatsoever to believe, at the time, that a wirestrike had occurred out of sight. How the hell could they? Thus their PR statement was based on the as-know facts and was perfectly honest. Accusing them of lying is the opposite of that rationale as there is no evidence or logic or point for them to have done so. Thus your reply is a complete non-sequitur, a self-contradiction.

Wait for the facts? Come into the real world! They had them to everyone's best of belief. Joe Blow off the street randomly asks PR if the accident was caused by a wirestrike. Everyone had seen it come over the road with the mooring cable hanging slack. Everyone knows there are no wires in the immediate vicinity. The cable snagged nothing. Then there was an accident. As far as all who witnessed the event a wirestrike was a ludicrous suggestion, it didn't happen because they saw it didn't happen.

What on earth do you expect PR to say? "Ooh! Good theorey, I'll check and tell you in six hours" or "No, of course not, we all saw what happened, there are no wires there to hit".

No one could/would magically imagine that an apparent control accident on landing would be associated with a completely unguessed-at wirestrike in an earlier part of the flight that no one knew anything about at the time. PR are just journalists, not psychics.

Does anyone (least of all PR covering an unusual event on the spot ) go and do hours of research before answering a direct question who's answer is crystal clear because everyone saw the event? That really would deserve criticism for being super-evasive.

[cattletruck]

Nothing a few Azipod thrusters couldn't fix...if it could get them off the ground.

[oldchina]

I used JETEX


http://archivesite.jetex.org/images/motors/50/original/pic-pack-motor-50_original-ranford.jpg

[Interested Passenger]

it's all in the wording of the statement. They could say within minutes that

the crew were safe and well, there was some damage to aircraft, and whilst they didn't think they touched any power cables, we are investigating eye witness reports.

[core_dump]

Certainly they could say right away that there was no contact with a telegraph pole.

Someone more worldly, please fill me in: Why is the UK still using telegraphs?

[John Marsh]

Wageslave:
It seems surprising that no video has surfaced of the wirestrike as surely dozens must have been filming it throughout it's flight?

Has anyone on the design team thought of some onboard video cameras? Both as navigation aids and an adjunct to whatever black boxes they have installed.

[Super VC-10]

Core dump - a telegraph pole generally carries a telephone line or electricity line.

[Carbon Bootprint]

Core dump - a telegraph pole generally carries a telephone line or electricity line.I guess that sounds nice and quaint, while "utility" pole sounds so mundane... :rolleyes:

Very glad no one got hurt in the prang. I'm not really sure where this whole business will wind up, but it's a fascinating show in the meantime.

[Loose rivets]

The company apparently IMMEDIATELY denied a witness report that it had struck power lines.

Why?

fin, I think what happened was, the Daily Wail phone the company and told them the news. The reply was: NO! which I view as entirely understandable.

[A Squared]

A Squared

Given the quoted economics of the Airlander difficult to see how a positioning flight from the states, followed by a revenue flight of three hours, followed by the empty return flight would be cheaper than the Lander

Ummm, yeah. Obviously a long repositioning flight for a shrot charter is pretty unlikely to make sense in most cases. Although I have positioned empty from the Northeastern US to Santiago, to pick up a process vessel for a gold mine in Mauritania, the lack of which had halted production. The manager of the gold mine was there when we unloaded it, and he commented that it would take about 2 days to pay for the charter, which is why they were willing to pay to fly to Chile to pick it up. Anyway, that a bit of a thangent. You're kind of missing the point of my post. The point is, your post claiming the Airlander would be quicker than trying to arrange a heavy-lift aircraft is based in the idea that the Airlander is magically going to be there immediately, right exactly exactly when you need it, ready to start loading, but a heavy lift aircraft will have to be arranged and positioned. In other words, you want to compare the payload flight only of the airlander, to the whole process of arranging an ad-hoc charter when considering a heavy lift aircraft. In Ad-Hoc service the Airlander also will have to be arranged and positioned, and it will position very slowly. That was my point for commenting on how long it would take to position my aircraft to Manchester Vs the Airlander.

[parabellum]

A Squared - Yes, your point is taken and I am not overly optimistic for the long term commercial future of the Airlander. Ad hoc freight charter was one possibility but, as you say, it would need one available immediately and on site, or short positioning flight, to be viable, an unlikely scenario!:)

[oldchina]

A bunch of Anoraks?

I scoured their website for two bits of information: the blimp's economic justification and the size of the market (in units). Absent.
I get the impression of a British 1960's style project: technically driven, underfunded and lacking credible commercial management.

[Wageslave]

I get the impression of a British 1960's style project: technically driven, underfunded and lacking credible commercial management.


Kind of odd viewpoint, that - seeing as it was designed and built in the USA...

[oldchina]

Wageslave: "it was designed and built in the USA..."

True, but the Americans know when to get out.
If the business plan doesn't hold up they'll pull the plug: viz Boeing 2707.

[Heathrow Harry]

Hmmm some of us remember the CV-990... or more recently all those very light business jets that were going to revolutionise air travel for the middle classes - almost all from US manufacturers

Billions down the tube IIRC

[A Squared]

Hmmm some of us remember the CV-990... or more recently all those very light business jets that were going to revolutionise air travel for the middle classes - almost all from US manufacturers

Billions down the tube IIRC

Or the Terrafugia Transition. Even from this side of the pond, I'm left scratching my head over the idea that the US is too smart to get involved in ill-advised aviation programs.

[RAT 5]

When is it going to do an Atlantic crossing; a Pacific crossing and a round the world non-stop? They would sure gain some publicity (hopefully positive) and the R&D gained would be huge. But then again, you wouldn't try it unless it was a 95% certainty.

[A Squared]

When is it going to do an Atlantic crossing; a Pacific crossing and a round the world non-stop? They would sure gain some publicity (hopefully positive) and the R&D gained would be huge. But then again, you wouldn't try it unless it was a 95% certainty.

If you read the history of this device, it was once scheduled to do some of that/ Back when it was still a US DoD project with Northrup Grumman, it was scheduled to deploy to Afghanistan under it's own power. That was determined to be a bad idea, and the plan was changed to shipping it deflated to Afghanistan. Then sometime later the whole thing was scrapped completely. An a related note, it's a bit odd that this is being touted as the "first flight". The Airlander flew back in 2012 when it was called HAV304, and yeah, it's physically the same airframe.

[core_dump]

What "huge" R&D is to be gained by floating a silly blimp across an ocean?

[Carbon Bootprint]

...or more recently all those very light business jets that were going to revolutionise air travel for the middle classes - almost all from US manufacturers
I don't know how many of the VLJs are still viable, but a certain non-US manufacturer just recently got an FAA production cert for their "Hondajet (http://www.hondajet.com)."

(Although they apparently make them in the US, as they do with some of their cars....)

I agree there was a lot of hype when these aircraft were first announced. As they just now seem to be reaching the certification phase, I'll guess we'll see how it pans out -- for the companies that are still around, anyway.

[susier]

http://www.aero-news.net/images/content/general/2016/Klyde-Aug-26-2016.jpg

[evansb]

Now that is actually quite funny..and poignant..

[oldchina]

That's funny and relevant:
There is no "oh my God"
Humans were in charge.

[Chronus]

Jeremy Clarkson`s article in The Sunday Times today says it all. The whole thing is nothing but an expensive joke. What a complete and utter waste of a gas which is a finite resource.

[CRayner]

should know.

[Canute]

What a complete and utter waste of a gas which is a finite resource.

Yes, we must stop the waste of the 0.000001% of the worlds helium which is used in Airlander before it has a severe impact on the 90% used in party balloons.....

[cappt]

Now that we brought up Jeremy Clarkson I can't help but compare this Airlander to the Snobine Harvester of Top Gear fame. A wonderful and impressive piece of engineering marvel but useful like breasts on a boar.

[G-CPTN]

I see that the Airlander has been moved back into its hanger.

With it being only 60% buoyant, that would imply that the dead weight is 8 tonnes - or is it the full 20 tonnes?

Do you measure deadweight the same way as a ship?

[cwatters]

Is it possible they just flew too slow and stalled it?

[A Squared]

Is it possible they just flew too slow and stalled it?

Well, I wouldn't think that the "second" test flight would be conducted at a gross weight higher than the craft's buoyancy, but even if it were, presumably the device has enough vectored thrust to lift any weight in excess of buoyancy. I don't see how it would work otherwise.

[Mechta]

Quote:
Originally Posted by cwatters View Post
Is it possible they just flew too slow and stalled it?
Well, I wouldn't think that the "second" test flight would be conducted at a gross weight higher than the craft's buoyancy, but even if it were, presumably the device has enough vectored thrust to lift any weight in excess of buoyancy. I don't see how it would work otherwise.

I'm with cwatters, A stall was my first thought as soon as I saw the video. Although the wind appears to be light, any wind gradient would exacerbate the problem and make stall recovery less likely in the height available. A 500 foot operating height with a 300 foot long aircraft does not give a lot of room to play with.

If the gross weight were less than the craft's buoyancy it would be operating as an airship, not a hybrid, so it would not have come to a stop after the arrival, but would had to be held on the ground by the engines or the suction 'undercarriage; if that is working or even fitted yet.

[compressor stall]

Do you measure deadweight the same way as a ship?


Maybe not. I've zoomed in on the pic but cannot make out any plimsoll line.
:)

[minimum clean]

cwatters & Mechta:

Do you mean, first stall and then dive? Or is it, one has to imagine an “up-side-down stall”, against a positive buoancy, which means, “stalling” towards the ground, and not a dive?

To me it’s very hard to cope with overimposed static and dynamic forces at the same time, especially, if there is no constant level or reference, neither for one nor for the other.

Let’s look, what the photographs and the video could tell.

First we can see the ship passing by in what should be the downwind leg of the pattern, in a rather normal attitude.

Then we see the ship in the final approach, may be some 400 meters out, but with an overly nose-down attitude in respect to the glide path (and with the mooring line hanging down).

Last we see it arriving over the airfield, one ship-length inside the primeter fence, and with the same nose-down orientation as before.

That suggests, that the approach was made all the time nose-down. Why could it be?

The load-distribution of the airlander is: cockpit and cabin in the front, projected payload in the mid – and the fuel tanks in the aft! And then we know, it just made a 1h 40’ flight, feeding the 4X350 hp drives. That must have made it lighter and lighter at the rear end.

At the begin of the video and before starting the dive, we see the ship in this very situation. Nose down by 15 deg, GS less than 5 kt, no vertical speed visible. And the drives are running, providing a little forward and a very little downward momentum.

In the very next moment it gets out of control – but I can see no initial situation to develop a stall.

It seems more, it has to work to come down than to stay aloft.

[Methersgate]

Maybe not. I've zoomed in on the pic but cannot make out any plimsoll line.
:)
An airship is not like a ship; it's not floating on the interface, so it doesn't have a load water line, so no Plimsoll line, so no deadweight. It's like a submarine, but in a compressible fluid

[compressor stall]

Did it occur to you why I posted the smiley face?

[G0ULI]

Unlike a heavier than air aircraft, Airlander 10 can presumably be stood on its nose or tail if mismanaged, with gravity tugging downwards on everything attached to the envelope. Must make for an interesting engineering problem where every component must be braced and stressed for gravitational pull in all directions. It also suggests that all loose objects will need to be secured firmly before and during flight, just in case.

Passengers might not be to happy driving towards the ground at a very steep nose down angle, even if it is in slow motion.

As this incident has demonstrated, the craft may be lighter than air, but the is still all the inertia of mass when it comes to making a sudden stop against a solid object. I can't help feeling that an inflatable airbag towards the front of the cockpit would have allowed a more gradual deceleration and prevented any damage at all. Something similar to a large car air bag might do the trick but staying inflated for much longer. That wouldn't upset the aerodynamics and need not inflict too much of a weight penalty. Big red panic button on the pilot's panel to deploy the airbag when necessary.

[500 above]

Passengers might not be to happy driving towards the ground at a very steep nose down angle, even if it is in slow motion.

Happy or not, on an statically lighter than air airship (especially going in to a temperature inversion) that's exactly what's going to happen. In my experience of giving pax rides in airships, the pax do not expect it to behave like a fixed wing, so no issues there.

[Derfred]

Nothing on the Airlander website refers to it as "lighter than air". In fact, they seem to go to great lengths to say that it is not. Additional lift is created from the airfoil shape + forward speed and vectored thrust.

Although how it uses this airfoil shape to get airborne from a static start is a question I have not seen answered.

[G-CPTN]

Vectored thrust.

[Derfred]

How does 60% buoyancy plus 25% vectored thrust get it off the ground, exactly?

[G0ULI]

I would assume that the immense size of the aircraft coupled with vectored thrust creates a bubble of air underneath that just lifts it clear of the ground and allows acceleration enough for aerodynamic lift to be generated. A super ground effect if you like. The whole thing is designed as a lifting body.

[Mechta]

cwatters & Mechta:

Do you mean, first stall and then dive? Or is it, one has to imagine an “up-side-down stall”, against a positive buoancy, which means, “stalling” towards the ground, and not a dive?

Firstly, Airlander is not lighter than air. It uses the buoyancy of helium to reduce the amount of lift required from other sources, namely, vectored thrust at takeoff and aerodynamic lift when in forward flight.

To me it’s very hard to cope with overimposed static and dynamic forces at the same time, especially, if there is no constant level or reference, neither for one nor for the other.

You're not the only one!

Let’s look, what the photographs and the video could tell.

First we can see the ship passing by in what should be the downwind leg of the pattern, in a rather normal attitude.

Then we see the ship in the final approach, may be some 400 meters out, but with an overly nose-down attitude in respect to the glide path (and with the mooring line hanging down).

Last we see it arriving over the airfield, one ship-length inside the perimeter fence, and with the same nose-down orientation as before.

That suggests, that the approach was made all the time nose-down. Why could it be?

Assuming the pilot was performing a conventional aircraft type approach, this would consist of:

Descend with a sufficient margin of speed above stalling speed to allow for any wind gradient and possible loss of thrust.
Convert speed into height (rotate) so descent (potential energy) is converted into flight parallel with ground (kinetic energy).
Maintain nose-up attitude until forward speed & kinetic energy decays such that aerodynamic lift is insufficient to keep aircraft airborne (flare & landing).

That's what it would have to do if gliding in, however Airlander has four engines, which can deflect their airflow downwards to some extent. These allow the pilot to replace some lost aerodynamic lift at low speed with their thrust, permitting a slower airspeed at touchdown.

The load-distribution of the airlander is: cockpit and cabin in the front, projected payload in the mid – and the fuel tanks in the aft! And then we know, it just made a 1h 40’ flight, feeding the 4X500 hp drives. That must have made it lighter and lighter at the rear end.

Ballonets, which are variable size, fan-filled bags of air inside the helium-filled envelope, displace the helium and therefore the buoyancy it generates, allowing the centre of gravity to be adjusted for changes in fuel load.


At the begin of the video and before starting the dive, we see the ship in this very situation. Nose down by 15 deg, GS less than 5 kt, no vertical speed visible. And the drives are running, providing a little forward and a very little downward momentum.

At a guess, either the pilot was positioning the Airlander to start the descent, or air turbulence tipped it into this position.

In the very next moment it gets out of control – but I can see no initial situation to develop a stall.

Low initial airspeed combined with a loss of energy due to wind gradient could cause this despite the nosedown attitude.


It seems more, it has to work to come down than to stay aloft.

As mentioned earlier, Airlander is not lighter-than-air. unless it was in a thermal or other rising air, its going to come down.

[Rob Bamber]

minimum clean cwatters and Mechta

To me it looks like the CofG got in front of the centre of buoyancy. Possibly because of the fuel used up,as mc suggested. I'm guessing they must trim it by pumping gas into and out of multiple gas bags inside the envelope. So, I'd speculate the crash occurred because the trim mechanism failed, or pilot error, pumping gas the wrong way. Is it fbw?

Didn't see Mechta's last post. Does the Airlander certainly use ballonets? I would have thought it more practical to use pumps to transfer helium to a high pressure storage tank when reducing buoyancy.

[Mechta]

Rob Bamber wrote:Does the Airlander certainly use ballonets?

Yes.

Hybrid Hopes: An Inside Look At The Airlander 10 Airship | Technology content from Aviation Week (http://aviationweek.com/technology/hybrid-hopes-inside-look-airlander-10-airship)

The compartments fore and aft and either side also house ballonets, or airbags, that are used for pressure control of the vehicle. The ballonets are inflated with air on the ground, reducing the volume available for the lifting gas, making it denser. Because air is also denser than the lifting gas, inflating the ballonet reduces the overall lift while deflating it increases lift. In this way, the ballonet helps to adjust the lift as required. There is also a septum diaphragm in the ballonet compartment to prevent mixing of the helium in the upper section and air in the lower part.

“As you go up in altitude, the air wants to expand and you can’t cope with trying to contain it with the strength of the hull, so the helium pushes down on the ballonets and pushes air out through valves,” says Durham. “When you come back down the helium wants to contract, so the ship would go soggy unless you push air back into the ballonets. So each ballonet has a big valve and fan in it so can vent air in and out and run the ship at a constant delta p. It’s the one system on the vehicle that’s got no parallel to any other aircraft or helicopter,” he adds.




I would have thought it more practical to use pumps to transfer helium to a high pressure storage tank when reducing buoyancy.

Rob Bamber, The Aeros Aeroscraft, uses a system along the lines of what you describe. Technology copy - Aeros (http://aeroscraft.com/technology-copy/4580412172)

[minimum clean]

Mechta et.al.

I agree, it was not lighter than air. Had made this impression for a little time while hovering above the Airfield. But when it came down, it sat on the cushions and made no attempt to lift off again. So it shoud be proven.

On a closer look, it is visible that it came to a rest on the cabin/cockpit and only the front half of the cushions, with the aft half cushions not on the ground. That make me think, it was indeed out of trim, as the nose-down orientation in the approach indicated before.

The attitude then was excessively downwards, and I have never seen a plane come in with a negative AoA. Hence my problems to accept the stall hypothesis.

Many thanks for the Aviation Week article. It teached me a lot about the Airlander.

By one detail I was a little shocked, otherwise. The lateral engines are pivotable only by +/-20 deg!!? Despite the vanes with their additional angle, to me it seems not sufficient to make it fully maneuverable.

[CaptainSandL]

I have been trying to follow the aerodynamics but my head hurts, can anybody check my understanding and questions:
• The airlander is heavier than air
• It takes off by vectored thrust (like a Harrier?)
• Once airborne, it transitions to forward airspeed which creates lift over the body keeping it airborne.

Questions:
1. If it slows down sufficiently will it actually stall or simply sink; or are they the same thing?
2. If the above answer is stall, does it therefore have a minimum airspeed? If so what do you think it would be? Obviously I assume it depends upon weight and CG etc but a ball-park figure.

[DaveReidUK]

1. If it slows down sufficiently will it actually stall or simply sink; or are they the same thing?

If the wings are rigidly attached to the body, then for them to reach the AoA for a stall in level flight would presumably require the entire aircraft to be pitched up correspondingly.

Otherwise, as it slows down, it simply stops flying and becomes an aerostat, albeit a heavier-than-air one, with only the downward thrust from the vectored fans to (partially) offset the negative buoyancy.

[Concordski101]

Airships were traditionally lighter than air which meant you had to permanently lasso them down with an army. Airlander can effectively make itself heavier than air, hence minimal groundcrew requirement and a more rugged proposition out in the wilds.

It can hover at 0kts without stalling - there are pictures of it floating in the hangar for testing prior to opening of the doors.

It makes a rolling takeoff V1/VR 30kts:

Pilot published this big feature recently
http://www.pilotweb.aero/features/the_airship_redrawn_will_this_revolutionise_air_travel_1_463 4083

How it takes off with an extra 10T payload I don't know. You don't use the ballonets for this to suddenly make it less dense, only for trimming and controlling the internal pressure of the envelope.

We're all scratching heads a little over this. To be fair they've had decades to understand the theory and we're all playing catch up.

An earlier question related to the bow thruster above the nose, this is on the Airlander 50 CGI image but not on the 10.

The unusual attitude that was adopted prior to the incident was deliberate. I'm told by airship guys that they do this to punch through an inversion, which can critically affect the buoyancy. I wasn't there but did they go around off the first attempt & tried this second time round? Or maybe it was on the test flight plan.

The speed was low but there just wasn't a flare, only HAV will know why.

Fingers crossed to see it back up there this winter.

[Uplinker]

............Although how it uses this airfoil shape to get airborne from a static start is a question I have not seen answered.

Presumably, they use the vectored thrust fully upwards to lift the aircraft off the ground, at almost no forward speed.

At a suitable height, I guess they progressively move the vectored thrust rearwards to start the aircraft moving forward, and at a certain forward speed the body produces enough lift to take over from the vectored lift, so in full 'flight' the vectored fans only need to provide forward thrust - like a Harrier I suppose ?

Using the vectored fans at max power to produce lift must consume fuel at a huge rate though, so I guess they only do this to get airborne - the transition to forward flight and body lift then radically reduces the power required and therefore the fuel consumption?

.

[JOE-FBS]

Latest from HAV:

https://www.hybridairvehicles.com/news-and-media/news/airlander-media-statement-31st-august-2016

[Capn Bloggs]

It'll never work...

[evansb]

In the latest (October 2016) issue of Consumer Reports magazine, investigative journalist Edward Humes opined that within 80 years, "...giant solar airships and airliner sized drones will move other cargo across the globe."

So perhaps the future for airships maybe bright after all, at least for solar powered ones...

[deadheader]

"The high approach resulted in the aircraft hovering 120ft above the ground, something that was “outside the normal operating envelope”."

https://www.flightglobal.com/news/articles/airlander-developer-hav-plans-rapid-return-to-flight-429124/

[Capt Scribble]

Quite windy in my part of the country today, should be interesting to see its performance on anything but a calm day. Perhaps they should have one of those nets, that you see at golf ranges, surrounding the airfield.

[G-CPTN]

Hybrid Air Vehicles (HAV) said repairs will take about three to four months to repair and test and were confined to the hull and the front part of the cockpit, but specialist tools needed for some of the repairs had been scrapped by the US Army and needed replacing, which would "contribute significantly to the estimated overall time required".

[edmundronald]

There might be some work for these airships airlifting those huge windturbine blades to remote windfarm locations without close access roads. Airship would spend a few weeks or a couple of months on location setting up a whole bunch of windmills, bringing the blades in from a shipping or air transport hub, so the ferry time in getting the airship to the general area would be amortized.

Edmund

[G-CPTN]

Good thinking, but there is a lot of preliminary work needed (installing a concrete foundation) then intricate positioning using cranes which seems to need at least a gravel road.
The best use would be lifting the towers from the dock to the installation site (which often needs careful planning of highway routes for long vehicles).

We had a vehicle that ran off a country road and fell into a ditch (due to the length of the road vehicle negotiating a bend):-

Wind turbine recovery from Northumberland road 'hurting trade' (http://www.bbc.co.uk/news/uk-england-tyne-18254480).

[cwatters]

If it can't hover at low level would it really be suitable for errecting turbines? Can it maintain station laterally? Eg in wind that change direction?

[Mechta]

Why wouldn't it just turn to point into wind?

[G-CPTN]

I think edmundronald was just suggesting transporting the wind turbines to the site rather than lifting them into place.

[silverstrata]

You are all wrong.
When the pilot applied the brakes before landing, the helium all rushed to the front, causing it to be heavy and causing the nose to droop.

While you might jest here, a similar thing does happen. If you have a helium balloon floating in a car, and you brake hard, the balloon goes backwards. The same happens with brains - if you have a car crash the brain hits the back of the skull, not the front.

Why? Because with the floating balloon, the heavier air moves forwards and pushes the lighter helium balloon backwards. Same with brain fluids, which are heavier than brains. Not sure if any of this applies to airships, whise ballonettes should constrain the differential gas mixtures.....

[edmundronald]

I think edmundronald was just suggesting transporting the wind turbines to the site rather than lifting them into place.
Yes, I was thinking of a wind-turbine *farm* when a bunch of them may need transporting from the nearest river, port, or heavy access road. Of course the site needs infrastructure, but maybe even cranes etc could be brought in in pieces by airship.

I had no opinion on an airship replacing a heavy lift crane; in fact in view of possible wind gusts at a site selected for wind, the idea makes me nervous :)

[costalpilot]

Yes, if the Germans and US can't manage it, what chance have some Brits got?

Nice attitude.


see WW2.

[Obba]

The Airlander is being reported on CNN as 'fully assembled' and ready for flight...!


World's largest aircraft prepares to take off - CNN Video (http://edition.cnn.com/videos/aviation/2016/03/22/worlds-biggest-aircraft-airlander-10-sdg-orig.cnn/video/playlists/travel/)


Some interesting footage (albeit small), inside the cockpit and the test pilot talking about it.

[Rigga]

...old video of pre-1st flight launch

[Obba]

Sorry, I should have realised that I didn't mention the 'weirdness' of why CNN is running this article now...

[Contact Approach]

Cannot see this as being the future of air travel. Sorry to break it you.

[Capt Scribble]

The idea has been around for years and no one has made a success of it, so there is little chance now especially in a windy country.

[DaveReidUK]

At the risk of stating the obvious, you can have a successful product without it necessarily being "the future of air travel". :O

[ironbutt57]

not possible to make it solar/electric?

[Lantern10]

Well it's got plenty of surface area. Got to be worth looking into.

[g109]

Google for the German cargo lifter project, they tried it as well about 15 years ago, and they failed miserably

[Penny Washers]

I don't think that anyone has mentioned the fact that the slower you go, the less effective the controls are going to be. You end up with zero control at zero speed, and have to rely on the vectored thrust from the engines. Do they rotate to the extent that there is no thrust in a horizontal direction?

Another thought is that the Airlander might have huge problems with centre of pressure travel. Put that alongside controls of limited effect, and some odd attitudes might result.

Especially on landing.

[averow]

Sounds like a great project for a PhD candidate (seriously) : model the behavior of this hybrid beast using the latest CFD (computational fluid dynamics) advances to predict behaviors and suggest software for managing it. Someday we might be using airships to navigate Mars and Titan....modeling the behavior of such a hybrid beast in gusty England might give us some insight.

[Obba]

Google for the German cargo lifter project, they tried it as well about 15 years ago, and they failed miserably


Chin up old chap, can't let the dastardly hun beat us.


But the UK is much fatter bear in mind...


The Cargolifter (of which I assume you are referring to), is a 'standard' Led Zep bullet/low drag type. The Airlander 'seems' to be relying on the shape for lift more than the engines per se..

[noflynomore]

model the behavior of this hybrid beast using the latest CFD (computational fluid dynamics) advances to predict behaviors and suggest software for managing it.

Don't you suppose they've had scores of such doing exactly that for the last decade or more?
How do you imagine it got where it is now - by guesswork and a sliderule?

[Jetscream 32]

I flew G-BIHN the old 500 series.... there is a good reason the US gave up the Skylander as a bad bet.... airborne and mooching around its fine, and you can coerce it if you wait long enough...... but get it close to the ground and it doesn't want to play at all.... that thing needs a pair of 250ft guide lines on a mini winch - approach airfield, zero speed, winch out, winch in, connect to mast... back to the bar for Gin and medals!!

Best of luck to them but chances of success are close to remote as a commercial operation...

Renting Cardington hanger, staff, development, licensing, let alone marketing or anything else will be a cash burn of circa £1 - 2 mill GBP per annum.... If its not commercial with clients by end of 2017 then I think it will go the same was as most British a/c manufacturing for commercial types... BN / Edgely / Slingsby..... Sorry if you're employed there and wish you the very best success...... but......... it will be an amazing experience if nothing else!!

[langleybaston]

Any large buoyant object in the boundary layer is bound to be skittish in a slow sense.

As a simple experiment, the Met Office courses for graduates with 2.1s or Firsts [and the occasional PhD] went into an open field in daylight and launched simultaneously, and tracked, a red balloon, a white balloon and a blue balloon from a short and surveyed base line.

Each was tracked by theodolite. The divergences after a minute were substantial, after 2 minutes were multiples of the baseline. After 5 minutes they were separated by football pich dimensions.

The students then went indoors and were asked what conclusions they came to.
Predictability in the boundary layer is very very poor. Which is part of the reason to employ proper pilots for proper aircraft.

[PersonFromPorlock]

It occurs to me that the problems AirLander is having are analogous to those of a large ship trying to dock without the aid of a tugboat or -boats. So, what would the tugboat-analog for an AirLander be, if one is possible at all?

[Less Hair]

So what has made the US abandon the AirLander before? Limited payload? Flight behavior? Do we know?

[beardy]

I understood that the withdrawal from Afghanistan left no immediate mission and no likely future one. (Who would want to do that again?)

[averow]

Well they certainly didn't seem to be able to land it safely, so I suspect its behavior isn't well understood!

[noflynomore]

Isn't it a good thing no one took much notice of such wisdom when the Wright Bros/Codys/Bleriots/Farmans were doing their thing?

[Capt Scribble]

The Wright Bros idea was new, the airship has been around for quite a long time. The Americans, who paid a lot for the development of this vehicle, could not find a use for it and I can not imagine an economic case for something that is slow, unable to carry much, suscetible to weather and difficult to control. Were there any plus points?!

[andrasz]

Were there any plus points?!
Economics. If your only option to get something heavy but not time critical into a distant remote location is by air, the alternates will cost an arm and a leg. From the bill I had to pay for airlifting a party of 12 plus gear and supplies to a remote African mountain location with a helicopter that was based 200 miles away, I could have purchased a small house back home...

[beardy]

Capt Scribble

There was a use for it; there was no further use for it once the USA changed it's tactics and before development was complete.
The Wright brothers ideas were not new, they were a development of existing work. Nor were they 'the first.'

[601]

get something heavy but not time critical into a distant remote location is by air
A380 wings from Wales to France?

[deadheader]

The DoD cancelled the LEMV project with Northrop Grumman and HAV mainly due to macroeconomics and the politics of US National Debt at the time. The Obama Administration swung the axe, the DoD chose the cutting block. Programs that were viewed as not being strategically important, such as this, for reasons outlined by another poster above, were axed. Records show that not all DoD stakeholders agreed with all of the decisions, and this one was no exception, but cutbacks had to be made nonetheless.

Ironically, the climate of resource constraints allowed private companies to take advantage to the detriment of the US taxpayer; HAV repurchased the LEMV project for just $300k, despite reports of it costing upwards of USD $100m by that stage (admittedly not all aspects of the project were included in the sale).

The economic case has not yet been demonstrated. Nor has the operational one. And there is no obvious demand for such a vehicle. However, only father time will tell and it is worth highlighting that the AirLander is not, as some posters suggest, a rerun of yesteryear. This is brand spanking new technology, never before attempted, never before utilised, and quite possibly never to see the commercial light of day. But AirLander is no AirShip! The 2001 patents are clear on that aspect (at least!)...

[Super VC-10]

Possible use for the Airlander.

Amazon files patent for flying warehouse - BBC News (http://www.bbc.co.uk/news/technology-38458867)

[beamender99]

The flight deck is now back in place after major repairs and testing has begun inside a hangar at the airfield.

Airlander 10: Longest aircraft tested after crash repairs - BBC News (http://www.bbc.co.uk/news/uk-england-beds-bucks-herts-38853721)

[Onceapilot]

Oh good. Something to brighten-up the UK news. I do hope that no-one gets hurt though!:uhoh:

[stator vane]

The linked article mentions it can operate up to
20,000 feet! Can you imagine what the winds
would do to it? I'd never be in that thing that high!

[FakePilot]

Yes, if the Germans and US can't manage it, what chance have some Brits got?

Nice attitude.

There's relatively little oil in an airship.

[airsound]

The AAIB report has appeared in Bulletin 3/2017.
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/597862/AAIB_Bull_3-2017.pdf
scroll down to page 32

The odd thing is, it doesn’t really explain why the aircraft got into an 18º nosedown situation, although it does cover the events leading up to it.

It also saysWithout the means of providing significant vertical thrust, the aircraft is not capable of true vertical landings (in calm or very light wind conditions). Anyway, I gather that’s it for the AAIB’s involvement.

[G-CPTN]

Airlander 10 crash-landed after mooring line snagged power cables (http://www.bbc.co.uk/news/uk-england-beds-bucks-herts-39213100).

[Super VC-10]

Apparently the Airlander has taken another nosedive, according to a post on Facebook. All I know is that a link to a photo has been posted - linked below.

BREAKING NEWS: World?s biggest airliner ?nosedives into a field? after breaking free from its moorings just months after crashing on a test flight (http://bn.areclipse.com/75632#75632)

[JOE-FBS]

Complete nonsense, it hasn't been flying. It is sat happily on its mast just down the airfield from my office.

[wiggy]

Indeed, the photo seems to show it "happily on its mast", not nose diving into a field.

[JOE-FBS]

Official statements:


"We have just seen reports in the media about Airlander pitching up at the rear by a small amount. This is a normal event which one can expect to see from time to time. It is something that Airlander is designed to do."


"It didn't nosedive. It pivots on the mooring mast, and rotates and has some pitch around it too. It never "nosedives"."


https://twitter.com/airvehicles

[Super VC-10]

Thanks all, glad all is OK. I posted in good faith.

[beamender99]

The European Aviation Safety Agency has granted the craft permission to fly.
This move follows the UK Civil Aviation Authority's Permit to Fly which was received a week ago.

Airlander 10: Longest aircraft gets permission to fly again - BBC News (http://www.bbc.co.uk/news/uk-england-beds-bucks-herts-39755398)

[nohold]

Saw her outside at Cardington a couple of weeks ago, rather smart I must say:)

[nohold]

Airlander 10 takes to skies for first time since crash...

The world's largest aircraft has successfully flown for the first time since it crash-landed nine months ago.

The Airlander 10 - a combination of a plane and an airship - took off at 17:30 BST near its base at Cardington Airfield, Bedfordshire and landed safely at about 20:15 (May 10th 2017).

The £25m aircraft nosedived during a test flight on 24 August.
No-one was injured in the accident, but the airship's cockpit was effectively destroyed.

Airlander 10 takes to skies for first time since crash - BBC News (http://www.bbc.co.uk/news/uk-england-beds-bucks-herts-39873506)

[G-CPTN]

14th June 2017:-The world's longest aircraft, Airlander 10, took off from Cardington and completed its fourth test flight last night - reaching the highest altitude it has attained so far.

During the flight, which lasted about four hours, it reached 3,500ft (1,067m).The craft varied its speed to between 20 and 30 knots, measuring the acceleration and deceleration with the thousands of sensors on board.

After doing a series of landing practice runs, Hybrid Air Vehicles said Airlander was "safely on the mast following a hugely successful flight" by 22:15.

From:- BBC Local Live: Beds, Herts and Bucks - BBC News (http://www.bbc.co.uk/news/live/uk-england-beds-bucks-herts-40227933)