Feeds

Airship 'Sky Tugs' ordered from Lockheed for Canadian oilfields

P-791 military hover suck-blimp gets civil application

Intelligent flash storage arrays

The famous P-791 prototype airship - built last decade for a military transport programme which eventually came to nothing - is to give birth to new, mighty commercial versions of itself with Canadian financial backing.

Alberta-based private company Aviation Capital Enterprises says it has inked a deal with US aerospace colossus Lockheed, builder of the P-791, to "design, develop, build, flight test and Federal Aviation Administration certify a family of hybrid aircraft". The first ship, dubbed "SkyTug" and able to lift 20 tons, is to be delivered in 2012. Further versions are to scale up to "several hundred tons", apparently.

A hybrid air vehicle isn't a conventional lighter-than-air dirigible, whose weight is entirely supported by the buoyancy of its lifting gas. A hybrid's gas only counteracts part of its weight: in order to get airborne, the SkyTug will swivel its propellors downwards for vertical thrust. Once it starts flying forward its hull will generate dynamic lift just as an aeroplane's wing does, allowing the props to be swivelled horizontal for greater cruising speed.

According to Aviation Capital, the fully vertical-takeoff-and-landing (VTOL) capable SkyTug will provide "greater payload and range at a fraction of the cost of a helicopter". The larger ships that will follow apparently won't be fully VTOL - they'll require something of a run-up on the ground to generate dynamic lift and get airborne, rather as an aeroplane does.

However the big ships aren't expected to need massive runways: they'll be able to land and take off from "unimproved surfaces and water". This will be achieved by the cunning air-cushion undercarriage which is such a novel feature of the P-791: rather than wheels or skids, the airships will move about on the ground supported on air blown down through big skirt assemblies, just like a hovercraft.

The fact that a hybrid ship is heavy helps to avoid one of the main headaches of unloading an airship at a place where there's no way of taking on water ballast. A traditional airship struggles to manage such operations, as once the payload is gone the ship becomes uncontrollably buoyant and is likely to soar up through its "pressure height" - the point at which the lifting gas has expanded to fill the entire envelope - and lose most of its helium via the automatic safety valves (or burst). Helium being expensive, this is not ideal.

P-791 style ships have another ace up their sleeve for unloading, in that the hover undercarriage can be switched from blow to suck, thus sticking the ship firmly down on the ground (or sea) even if it might have become a bit flighty during unloading. This is also handy for preventing the vessel being blown around by the wind.

The P-791 itself was originally built by Lockheed in 2006 as a contender for the US military's proposed "Walrus" project, intended to deliver a brobdingnagian airship capable of hauling an entire US army combat battalion of 500+ troops - plus all their vehicles, heavy weapons and other kit - in one lift. But a heavy-lift airship needs a lot of gas, and this in turn means that "pressure height" can't be too high or the envelope will have to be unfeasibly huger still.

Thus the Walrus was specced for 10,000 feet maximum altitude, which was realistically a show-stopper for the military - even shoulder-launched missiles can reach that high, and the ship would have been a very easy target.

Choosing a cloud hosting partner with confidence

More from The Register

next story
SECRET U.S. 'SPACE WARPLANE' set to return from SPY MISSION
Robot minishuttle X-37B returns after almost 2 years in orbit
No sail: NASA spikes Sunjammer
'Solar sail' demonstrator project binned
LOHAN crash lands on CNN
Overflies Die Welt en route to lively US news vid
You can crunch it all you like, but the answer is NOT always in the data
Hear that, 'data journalists'? Our analytics prof holds forth
Experts brand LOHAN's squeaky-clean box
Phytosanitary treatment renders Vulture 2 crate fit for export
Carry On Cosmonaut: Willful Child is a poor taste Star Trek parody
Cringeworthy, crude and crass jokes abound in Steven Erikson’s sci-fi debut
Origins of SEXUAL INTERCOURSE fished out of SCOTTISH LAKE
Fossil find proves it first happened 385 million years ago
America's super-secret X-37B plane returns to Earth after nearly TWO YEARS aloft
674 days in space for US Air Force's mystery orbital vehicle
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
Win a year’s supply of chocolate
There is no techie angle to this competition so we're not going to pretend there is, but everyone loves chocolate so who cares.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Intelligent flash storage arrays
Tegile Intelligent Storage Arrays with IntelliFlash helps IT boost storage utilization and effciency while delivering unmatched storage savings and performance.