Archived Aerospace Sector News - Pre-2007
Out-Of-Autoclave (OOA) Prepreg Development - March 2006
(Reprinted by permission of Ray Publishing Inc. from "Autoclave Quality Outside the Autoclave?" a feature article appearing in the March 2006 issue of High-Performance Composites magazine. Copyright 2006 Ray Publishing Inc.)
High quality aerodynamic surfaces are the result of The New Piper Aircraft Inc.'s ( Vero Beach , Florida ) utilisation of oven-cured prepregs for the exterior fairings of its Meridian and Malibu aircraft. Piper wanted to reduce weight and improve surface finish of these fairings, which previously were made using wet lay up techniques. Cost targets for the new design were met by selecting oven curing over the autoclave, recalls David Nesbitt, president of Matrix Composites Inc. (Rockledge , Fla.), which designed and manufactures the fairings for Piper. "In autoclave machine time and reduced process materials cost, there is an estimated 25% decrease in overall part price," Nesbitt says, "the tooling is easier and less expensive to fabricate as well".
A prepreg designed for oven cure was a key technology for achieving the required surface quality without incurring large secondary finishing costs. Using Advanced Composite Group Inc.'s (Tulsa, Oklahoma) LTM®24ST single-side film prepreg, which consists of T-300 carbon 2x2 twill with epoxy resin, "We are achieving as-moulded surface finishes that are comparable to those achieved using the autoclave process," Nesbitt reports. "Surface porosity has been eliminated, reducing the post operation time required to produce a high-quality painted surface."
LTM®24ST is fully capable of meeting the performance demands for these lightly loaded fairings, says ACG's aerospace market sector manager Chris Ridgard, who readily admits that this prepreg's out life, toughness, porosity and mechanical performance are not designed for highly loaded structures. But the company's new generation of oven-cured prepregs are so designed, he reports. In its development efforts for high-performance applications, ACG learned lessons about the differences between prepregs targeted for the oven versus the autoclave.
"We mistakenly believed in the early days that low viscosity was a good thing for oven cure," Ridgard recalls. But with low viscosity, the resin can flow prematurely and lock off escape paths for entrapped air and volatiles, which are critical for out-of-autoclave processing. By comparison, these gases will dissolve into the resin under autoclave pressures. These same distinctions mean that the degree of impregnation is far more critical in oven-cure than in autoclave prepregs, and impregnation must be more carefully controlled.
ACG's latest prepreg lines, MTM®45-1 and MTM®46, are producing fibre volumes equivalent to autoclave prepregs and near-zero void content under oven processing conditions, Ridgard reports. Both product lines offer a minimum cure temperature of 82°C. MTM®45-1 is designed for maximum wet-service temperature of 121°C while the less expensive MTM®46 has a maximum wet service temperature of 82°C. Under a contract with the Air Force Research Laboratory (Wright-Patterson AFB, Ohio ) and in collaboration with the NASA/FAA National Center for Advanced Materials Performance (NCAMP) programme, ACG is developing B-basis values for these two products, using an approach similar to the Federal Aviation Administration's AGATE (Advanced General Aviation Technology Experiment) methodology.
For further details contact ACG Sales Department.
All Composites For 210mph Four Seat FX-210 - March 2006
Four Winds of Florida (USA) have designed the FX-210 and FX-250 to be amongst the fastest and most versatile kit airplanes available.
Throughout the plane's development Four Winds' goal was always to make one of the safest and best airplanes in the industry, employing the most advanced composite materials and technology.
The streamlined yet spacious fuselage has been designed, tooled and built exclusively using composite prepreg materials supplied by ACG Inc, Tulsa.
ACG has worked with Four Winds for the last 6 years, supporting their projects through the supply of specifically developed composite materials and wide ranging technical assistance. During this time their superb kit airplanes have literally 'taken off'! ACG's ranges of low (LTM®) and variable (VTM®) temperature curing materials are ideal for such large structures.
With excellent processability and mechanical performance, these products combine the benefit of low temperature cures, with Tg developments that step well ahead of cure temperature.
For the FX-210 and FX-250, VTM®240 series prepregs are used to build the complete aircraft structure, fuselage, wings and control surfaces. LTM®30 series prepregs are supplied for reliable tooling that is compatible with the composite structures made from them.
Prepreg materials have eliminated so much of the mess of wet lay up that it is now even more desirable to build your own airplane, and Four Winds specialise in assistance with customer build programmes.
For more information visit the Four Winds web site at: www.fourwinds.com.
For further details contact ACG Sales Department.
Globalflyer Achieves Second Record - February 2006
The record breaking Virgin Atlantic GlobalFlyer completed its 19,880 nautical mile Around the World flight on March 3rd 2005. Then on 11 February 2006 it was announced that Steve Fossett received the Guinness World Record for the Longest Non Stop flight along with Richard Branson's praise of his remarkable achievements. Although an electrical malfunction shortened the flight by 45 minutes the facts are that a total flight distance of 26,389.3 miles was covered in 76 hours and 45 minutes. The all composite structure withstood a challenging take off from Kennedy Space Centre, severe turbulence over India and ice as Steve Fossett prepared to land, first at Kent International Airport and then at Bournemouth Airport.
Designed by Burt Rutan and manufactured by Scaled Composites (California), the GlobalFlyer was produced by the same team behind the X-Prize winning SpaceShipOne. Although both high-profile projects were well funded, the use of ACG's LTM® prepregs enabled both cost and manufacturing time to be kept to a minimum, whilst at the same time guaranteeing structural performance. The aircraft has a 114ft wing span giving 400 sq.ft of wing area. When fully fuelled the aircraft is 83% fuel by weight, a record in its own right no doubt. The carbon/epoxy LTM® prepreg materials used for the structure of this aircraft compliment the aerodynamics and configuration of Rutan's design, the stiffest carbon fibre prepregs being used in the wing construction.
The Virgin Atlantic GlobalFlyer is an outstanding aircraft that has brought together innovative design and the most advanced composite materials technology to achieve two extraordinary world records. For more information on this remarkable aircraft go to the Virgin GlobalFlyer web site: www.virginatlanticglobalflyer.com
For further details contact ACG Sales Department.
Unique Aerospace Projects Use LTM - October 2005
Scaled Composites and ACG are linked through two unique aerospace projects, GlobalFlyer and SpaceShipOne. The Virgin Atlantic GlobalFlyer, designed and built by Scaled Composites, California , completed a record non-stop flight around the world of 19,880 nautical miles on 3 March 2005.
The main structures of this 35m wingspan aircraft were manufactured entirely using LTM45 series composite prepreg materials provided by Advanced Composites Group Inc. These materials are ideal for such one-off projects because of their low temperature, out-of-autoclave cure capabilities and have proved their performance on other aircraft built by Scaled Composites.
Another unique aircraft, also built by Scaled Composites using ACG's out of autoclave technology, is SpaceShipOne. Last October it successfully met all the conditions required to win the prestigious X Prize. In July 2005 it was announced that Burt Rutan (President, Scaled Composites) and Sir Richard Branson (founder, Virgin Group Companies) have formed The Spaceship Company to jointly manufacture and market spaceships for the new sub-orbital personal spaceflight industry. This follows on from the launch of Virgin Galactic, the company that will license the technology to develop the world's first privately funded spaceships to carry commercial passengers on space flights.
Image courtesy of Scaled Composites.
For further details contact ACG Sales Department.
ACG in ALCAS - October 2005
Structures), the objective of which is to develop the next generation of low-cost, lightweight aircraft structures from advanced composite materials.
Financially supported under the European 6th Framework Research & Development Initiative, ALCAS, which commenced in February of this year, comprises 59 partner organisations engaged in a 4-year collaborative programme. The project is lead by Airbus UK, with almost all the main European aerospace prime and tier 1 manufacturers participating, together with a wide variety of test and design organisations, research establishments and universities.
The primary objectives of the programme are to reduce the weight, and therefore the operating costs, of the next generation of both large civil airliners and business jets through the cost effective, full application of carbon fibre composites to the aircraft primary structures.
ACG are working in the business jet section of the project, which is lead by Dassault Aviation and includes major aerospace companies such as SAAB, Alenia, CASA and Stork-Fokker. Within this part of the programme, ACG will be designing and manufacturing composite tooling for both the rear fuselage section and the wing of a Dassault Falcon series aircraft. In addition to the tooling activities, which will call upon knowledge and expertise acquired during the FUBACOMP project, ACG will also design and manufacture structural components, such as the lower wing covers and rear engine mounting frame. These parts will be manufactured using ACG's latest aerospace matrix resin systems, such as MTM®44-1 and MVR444, developed during the course of earlier collaborative projects such as CASCADE.
Project work in ACG will utilise the resources and facilities of both the ACG Technology Centre and ACC.
For further details contact ACG Sales Department.
SpaceShipOne Makes Historic Space Flight - October 2004
The Scaled Composites team made history on October 4th 2004 by flying the first ever commercial aircraft and pilot into space twice within the space of two weeks while carrying the equivalent weight of two passengers. The rocket powered SpaceShipOne, piloted by Brian Binnie, and the White Knight carrier plane, were built at the Mojave, California facility of Scaled Composites. This flight, together with the previous flight by pilot Mike Melvill on September 29th, met the conditions required to win the prestigious X prize. The project, known as Tier 1, was started in 2001 with funding from investor Paul G. Allen. Burt Rutan, founder of Scaled Composites and designer of SpaceShipOne, can now add another world-first achievement in aviation to several records already under his belt.
The airframe of SpaceShipOne was built using LTM45®EL prepregs manufactured by the Advanced Composites Group (ACG) in Tulsa, Oklahoma. The low temperature curing, high service temperature prepregs permit the use of low cost tooling and manufacturing techniques and have been successfully used by Scaled Composites and others for a number of years to build prototype and limited production aircraft. ACG is in the process of introducing the next generation of low temperature cure prepregs, including a material known as MTM®45, which will deliver improved performance while still permitting cure at low temperatures. The material will also be supported by a full design data set which is being produced with oversight and approval by the FAA. Further information on these and other products may be found in our catalogue.
For further details contact ACG Sales Department.
SpaceShipOne - June 2004
The Advanced Composites Group is pleased to be a part of the Paul Allen/Scaled Composites team in the development of the first private manned space capability, as a supplier of our LTM45®EL composite prepreg materials. Scaled selected our LTM prepreg product, manufactured in Tulsa Oklahoma, to enhance their goal of developing a safe space vehicle at the minimum possible flight operating cost. We look forward to furthering our participation that will lead to a new industry of affordable space tourism.