In this post, I’m going to chat a bit about what has been going on in the aviation industry and NASA for the last several years. Every aircraft that you see in the pic above has an all composite airframe. And you will note that neither the Boeing 787 nor the new Airbus A350 XWB (Extra Wide Body) are in this pic. That’s for two reasons – first, everyone knows that the 787 and the A350 exist and are mostly composite. Secondly, neither one of these large people mover aircraft has an all-composite airframe. Boeing comes the closest, with 80% by weight carbon fiber composite, but Airbus is a very close second. And, of course, these two companies are in brutal competition in the people and cargo transport aircraft business, so it makes sense that both have a wide body aircraft in their fleet that is mostly carbon fiber composites. And, of course, one of the largest motivators is the savings in fuel that a lighter aircraft brings you.
Which brings me to the two pics at the top of the image collage above. Both of these are of the Stratolaunch Roc which is a carrier aircraft intended to carry a hypersonic payload to an altitude that would allow for entry into low earth orbit by the payload. The company is the brain child of Paul Allen (Microsoft) and Burt Rutan (Scaled Composites), and is essentially the second collaboration of these two visionaries, the first being SpaceShipOne.
The Stratolaunch Roc is the largest aircraft by wingspan in the world. It has a wingspan of 385 feet from tip to tip, and it is capable of carrying a half a million pound payload under that center section. And, it has just completed its second captive carry test flight where it carried the actual Talon-A hypersonic aircraft for 6 hours and to 22,500 feet in altitude. That’s a pretty amazing feat. And, the Stratolaunch ROC is an all composite airframe, thanks to Burt Rutan’s company’s experience with carbon fiber composites.
This brings me to the aircraft in the bottom left of the pic above. This is the Scaled Composites ATTT (Advanced Technology Tactical Transport). This was a DARPA program initially to build and test fly a short take off and landing (STOL) aircraft that could get in and out of a battle zone and either deliver troops and supplies near the front line of a war zone or quickly extract troops and bring them to safety. This was at least part of the original ideas that Burt Rutan had for his Stratolaunch collaboration with Paul Allen. And, like most DARPA programs, the actual aircraft, while it had completed 15 test flights and did exactly what DARPA asked it to do, DARPA did not turn it into an actual production aircraft. And, while people tend to fault DARPA for not taking things into production, that really is not their charter. They are supposed to break through technological boundaries and take very high risks betting that some of the things that they come up with will make it into a weapon system. What actually happens is that for any DARPA program, successful or not, technology is developed that will eventually get incorporated into someone’s new defense program and become part of something – like Stratolaunch.
Which brings me to the bottom right pic – this is Proteus, another brain child of Burt Rutan. Under NASA funding, Scaled Composites build an aircraft with an all composite airframe that is capable of high altitude very long endurance flights. The Proteus is the current holder of several world records for altitude for an aircraft of this size. In October of 2000, Proteus flew at 63,245 feet, that is over 6 miles up where the air is extremely thin. And, of course, Burt Rutan is not without his tricks, because proteus is “optionally” piloted, and has demonstrated autonomous flight without a pilot on board.
Finally, I thought I would go toward the smaller scale of aircraft just to fill out the list from largest to smallest all composite aircraft. The center bottom two pics are very small aircraft, and both have all composite airframes. The top on is the Raptor, which was originally envisioned as a kit aircraft that you could build yourself. Unfortunately, during a test flight near the end of the required test flight program the single prototype Raptor made an emergency landing in a corn field which did enough damage to the aircraft that it caused the develop to cease its plans for production of the kits.
However, the image at the very bottom center of the pic is a single place, open cockpit ultralight sport aircraft built in the Czech Republic by InterPlane. The aircraft’s wings come off for transport, and the entire aircraft fits well into an Iso Container for shipping to the US or wherever someone wants one. But, apparently, the manufacturer InterPlane went out of business in 2016, which is pretty common among these smaller aircraft manufacturers.
As you can see, there is a tremendous amount of interest in all composite airframes for large and small aircraft alike. I expect this business is not going away, and in fact will probably boom in the near future as the prices of carbon fiber keep coming down. In the last 10 years, carbon fiber prices have dropped substantially as companies like Toray build new high speed production lines and factories in several countries where they are close to the users and developers of composite structures. And, as you may already know, even the automotive industry is adopting composite materials for secondary structure at a rapidly increasing rate. The new fuel economy standards are pushing these manufacturers to take weight out of their products to reduce fuel consumption, so composite raw material process can only go down.
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