17, No. 16 May 3, 2001 Issue
Research will lead to a crash landing
By Joe Kleinsasser
Theres going to be a plane crash in June. But dont worry. The crash is planned and there wont be any deaths or injuries.
Wichita States National Institute for Aviation Research was selected as a key player in developing a crashworthy all-composites airplane as part of NASAs Advanced General Aviation Transport Experiments program.
Only a handful of crash tests have been conducted on composite planes. Four of the earlier tests also involved NIAR.
The upcoming drop test at NASA Langley Research Center in Virginia is an important element of NASAs aviation safety program.
In early March, former NIAR researcher Steve Hooper of J.B. Dwerlkotte Associates and a systems engineer for AGATE, learned that the project was behind schedule for a drop test date at NASA Langley. He and the NASA program management developed a revised plan and immediately turned to NIAR for additional technical expertise.
John Tomblin, associate professor of aerospace engineering and NIAR researcher, says WSU was chosen "basically because of our notoriety, our ability to work under a tight time schedule, and because we are an AGATE member. For them to select a university (to help) is quite remarkable. Normally an airframe company does this kind of work."
The drop test will be conducted on a modified Lancair Columbia 300 fuselage and wing, which is a glass and graphite composite airplane.
Interestingly, all the composite materials on the plane were tested and identified at WSU about four years ago as part of another AGATE program.
Three WSU graduate students accompanied Hooper and Steve Soltis, the FAAs national resource specialist for crashworthiness, to the Lancair Aircraft Co. in Bend, Ore., to assemble the basic airframe in 10 days. The aircraft was then shipped to NIAR for modifications to enhance the crashworthiness performance.
"Its very unusual for students to have this significant of a role," says Tomblin. "Its an opportunity for the grad students to obtain hands-on experience. All the lessons learned throughout their graduate education are put to use in one project."
The recommended modifications are based on computer simulations performed by Hooper and NIAR research associate Marilyn Henderson. These simulations are one of the first applications of a systems approach to crashworthiness in the aerospace industry.
The systems approach uses the entire airframe to protect the occupants in a crash, just as the entire automobile is used to protect occupants in car crashes.
It is considerably more sophisticated than the traditional approach to aerospace crashworthiness problems, where the focus is limited to just the installed seats and restraint systems.
Hooper indicated that the goal in a crashworthiness design is to maintain a survivable cockpit space throughout the crash event, and to retain the passengers within this volume.
He also noted that the secret to success in crashworthiness projects is correctly identifying the "devil in the details."
Hooper says, "The opportunity to employ three graduate students possessing expertise in structural engineering as well as 10 years of combined experience in fabricating and testing composite materials was invaluable. They were uniquely capable of solving the nit-picky fabrication problems that are easily overlooked in projects such as this."
When the modifications are complete, the airplane will be shipped to NASA Langley Research Center where it will be drop tested from a 240-foot high tower at the Impact Dynamics Test Facility. It will hit the ground at a 30-degree nose-down pitch attitude and at the aircrafts stall speed. The test article will include four lifelike test dummies and a large number of measurement instruments.
The pendulum drop test will be recorded on high-speed video from a variety of angles including one from inside the airplane.
The results will benefit manufacturers who want to design and certify safer general aviation aircraft.
|Inside WSU is published by the Office of University Communications for Wichita State University faculty, staff and friends on biweekly Thursdays during the fall and spring semesters. Items to be considered for publication should be sent to campus box 62 or Amy.Geiszler-Jones@wichita.edu 10 days before publication.|