Dec
18
A Hybrid Airship
December 18, 2009 | 6 Comments
Is it a plane, a blimp or a dirigible from out of the past? No, it’s a hybrid airship, part dirigible, and part airplane. Built by co-founders Bob Rist and Brian Martin of Ohio Airship outside of Toledo, Ohio with the help of folks laid of at Cessna and Jeep the hybrid offers some truly interesting advantages and fills some transport market gaps.
Dynalifter Prototype Front View. Click image for the largest view.
Called the Dynalifter, the airship uses lift from both helium and a short trip down the runway to gain lift from the wings. Helium provides 30 to 80 percent of the lift, depending upon the circumstances, while internal combustion provides the forward motion.
Dynalifter Load Sharing. Click image for the largest view.
Rist says two advantages of the unique design are it uses one-third the fuel a jet plane needs and it can land in short distances. “We don’t go for the hovering thing,” Rist said, “We come in like a regular airplane, we land like a regular airplane, we take off like a regular airplane. We’ve got some (model designs) that can lift 200 tons and land in 4,000 feet.”
The company expects added funding to come in January of 2010 with flights a few months later. The prototype was built for $500,000 from donated parts. Two years ago the prototype was damaged by a storm. But the company and its idea were rescued with economic development funding from The City of Toledo and help from 15 volunteers.
At this date the airship is complete with the FAA certification awaiting enough capital to run the test flights. The prototype is an ultralight aircraft capable of carrying two people and fuel, easing the path to the first FAA certification. The goal is sell ships up to 990 feet long with a cargo capacity of 250 tons. The company claims to have 20 orders, with the first ships slated for humanitarian missions like delivering water-treatment systems.
Rist said he plans to hire engineers in Toledo to build precision components that can then be assembled into complete aircraft closer to where they will be flown. “We do all the technical stuff and design, and most of the assembly can be done overseas,” he said.
Most of the skepticism surrounding new airship concepts focuses on ground handling under windy conditions. All Dynalifters have been designed to land without a mooring crew and do not require a weight transfer system under normal conditions. Conventional airships are difficult to handle on the ground. Control requires a large number of people to grab lines during landing, or it must use equipment of some kind to “catch” the airship and attach it to a mooring mast. Then, with passengers and fuel removed, the airship experiences excess buoyancy, so the ship must be over-ballasted before unloading. When fuel is burned during flight, it becomes too light to land, requiring either valving off lifting gas or use of an elaborate mechanism to recover water vapor from the engine exhaust.
The Dynalifter hybrid doesn’t have these blimp and dirigible problems because it isn’t “lighter-than-air”. With a large fraction of its weight carried by aerodynamic lift on the wings and hull, it has a substantial net download when sitting on the ground allowing it to withstand a gusty side wind. It lands like a normal aircraft, decelerating on a runway as its weight is transferred from the wings to the tires.
Ohio Airships subcontracted conceptual design engineering to defense contractors Conceptual Research Corporation, Analytical Methods, and Composite Engineering. Together, the companies completed conceptual designs for four different sizes of Dynalifters ranging from the 120 ft. Dynalifter Patroller and RV to the 990 ft. Dynalifter Freighter. The concept has been evaluated by engineering studies that included computational fluid dynamics, initial fabrication selection, and cost analysis.
Rist sees the markets in the middle ground between cargo ships and jet service — faster than a boat, cheaper than a plane, saying, “They travel at optimum at about 140 knots. As they get down to 80, you can save that much more fuel because the more the helium takes over.” Intercontinental delivery times would be comparable to second-day air service, with a transatlantic crossings taking as little as 23 hours.
The company plan is to hire engineers in Toledo to build precision components that can then be assembled into complete aircraft closer to where they will be flown. Rist says, “We do all the technical stuff and design, and most of the assembly can be done overseas.”
Ohio Airship is not the first to conceive an airplane / airship hybrid. One of Howard Hughes’ last projects was development of the heavy-lift Megalifter hybrid, but the project died with him.
The Dynalifter uses an engineered structure currently used in modern bridge construction known as “stay bridge construction.” Stay bridge construction is a method bridge builders use to distribute high loads along the length of the bridge while dramatically reducing the total weight of the bridge.
Dynalifter Internal Structure. No larger image.
One hopes the airship’s time has come back. The relative speed compared to trucks and ships along with the fuel savings compared to jet freighting offer significant advantages both in the developed and developing world. Helium displacement as part of the lift avoids the hydrogen issue of ravenous ignition and burning. The only issue seems to be things like wind sheers and other atmospheric anomalies that might over whelm the structure.
Lockheed Martin is thought to be working on a hybrid as well. The very high load capability of a hybrid with the reduced fuel use plus very short runway needs must be quite attractive to military logistics officers.
It’s good to see some competition. Even more encouraging is there’s room in flight vehicles for the little guy to get a start. Facing the Boeing, Airbus and Lockheed Martin class of capital and expertise must be daunting. Toledo and all of America can be proud of the Ohio Airship group, its supporters and volunteers. Lets see her fly!
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Hi there,
All of the companies proposing hybrid airship designs except Hybrid Air Vehicles (The descendant of Airship Industries) have never built a successful modern airship before and they have little idea what they are doing both in design or construction terms.
What is needed is investment in developing existing successful modern airships like the Skyship series rather than an attempt to reinvent the wheel by companies new to the LTA sector, who in many cases are more interested in creaming off any investment capital than building a new airship.
Regards
Joe
http://www.airshipblimp.com and
http://www.airship.me
I love how everything in the world seems to be going hybrid. I think it is so much better that way : )
Terrific work! This is the type of information that should be shared around the web. Shame on the search engines for not positioning this post higher!
Hi folks,
The worlds first full size hybrid air vehicle is now under construction by Hybrid Air Vehicles and is designated the HAV 304. The funding is from the LEMV contract and first flight will be next summer.
It is very much game over to HAV from England after they won the LEMV contract along with partner Northrop Grumman who will supply the electronics payload.
Regards JB ( http://www.hybridairship.net )
Couldnt agree more with that, very attractive article
This was novel. I wish I could read every post, but i have to go back to work now… But I’ll return.