The second crash test of a small lightweight helicopter at NASA's Langley Research Center in Hampton, Va., was a smashing success, literally -- just as engineers had predicted."Three, two, one, release," said the technician on the loudspeaker at the Landing and Impact Research Facility. With that countdown the helicopter smacked hard into the concrete. Its skid gear collapsed, its windscreen cracked open and its occupants lurched forward violently, suffering potentially spine-crushing injuries according to internal data recorders. The crash test was all in the name of research to try to make helicopters safer."The goal of any research program that has an element of impact dynamics is to develop an understanding of the crash response of the vehicle," said Karen Jackson, an aerospace engineer who oversaw the test. "Once we understand that response we can look at ways to improve the crash performance."In December 2009 researchers dropped the same MD-500 at a similar angle from the same height of 35 feet (10.7 m). Inside were the same instruments that collected 160 channels of data and the same four crash test dummies. Three of the dummies were full bodies and one was a special torso model equipped with simulated internal organs. Technicians set up the same cameras to record the impact from inside and outside the helicopter.
› Dec. 2009 Test The test conditions on both days were the same too, simulating what would be a relatively severe but survivable helicopter crash. The flight path angle was about 33 degrees and the combined forward and vertical speeds were about 48 feet per second or 33 miles per hour (53.1 kph).In the first test the MD-500 skidded to a stop, with very little damage to the helicopter or its silent occupants, because its underside was outfitted with an expandable honeycomb cushion called a deployable energy absorber."It's made of Kevlar and has a unique flexible hinge design that allows the honeycomb to be packaged and remain flat until needed," said Sotiris Kellas, the Langley engineer who created the idea as a way to cushion the next generation of astronaut-carrying space capsules, but realized it could be used in other ways.
The MD-500 before and after the drop test. Credit: NASA/Sean Smith
The force of the impact shattered the MD-500's windscreen. Credit: NASA/Sean Smith
The more recent drop on March 10, 2010 involved just the helicopter. No new technology was attached. That was the point. Engineers wanted to determine exactly how efficient the deployable energy absorber had been in the earlier test and how much it might help reduce occupant injuries. So they dropped the same helicopter in the same way and measured and recorded the same conditions with the same instruments."We were fortunate enough that the helicopter survived so well the first time that we could use it again," said engineer Martin Annett.There will be no third crash test for this helicopter. It was too damaged. Researchers say the "g" forces the MD-500 experienced more than tripled those recorded in the previous test. But that doesn't mean the research is over. Engineers have gigabytes of data to analyze to confirm exactly what impact the new honeycomb cushion technology might have for helicopters in the future.The drop tests were conducted by the Subsonic Rotary Wing Project of NASA's Fundamental Aeronautics Program, and funded by the agency's Aeronautics Research Mission Directorate in Washington.
Kathy BarnstorffNASA Langley Research Center
ABOUT AMATEUR RADIO
Amateur radio service is defined in the Communication and Multimedia (Spectrum) Regulations 2000 as a radiocommunications service (covering both terrestrial and satellite) in which a station is used for the purpose of self traning, intercommunication and technical investigations carried out by authorized persons who are interested in radio technique solely with a personal aim and without any pecuniary interest.
AMATEUR RADIO OPERATOR'S CERTIFICATE
Regulation 27(1) of the Communications and Multimedia (Technical Standards) Regulations 2000 states that no person shall undertake or conduct any activity in designated skil area unless that person is certified. Amateur radio operator has been gazetted as a designated skill area category under the regulation, hence to operate an amateur radio station a person needs to have an appropriate proficiency and skill i.e. certified in this area.
INTERFERENCE
Please ensure that the radio transmision does not cause interference to any other radio services. Regulation 15(1) of the Communications and Multemedia (Technical Standards) Regulations 2000 states that no person shall intentionally design, install, operate, maintain or modify any communications equipment in a manner is likely to cause interference with, impairment, mulfunction of, or harm to any communications equipment or any other equipment.
Regulation 15(2) of the regulation denotes that a person who contravenes this regulation commits an offence and shall, on conviction, be liable to a fine not exceeding three hundred thousand ringgit (RM 300,000.00) or to imprisonment for a term of not exceeding three years or to both.
To eliminate the potential of interferences, the following procedures must be followed strictly:-
a) Ensure that suffient equipment, tools and test gear is available and can used to monitor and verify that your transmission does not cause any interference to other radio services.
b) You must responsible if your amateur radio is found to be the caused of interference. Immediate remedy action must be taken to rectify the problems in case of interference.
c) Ensure that the transmission do not exceed the level of over deviation.
d) Ensure that the radiated energy is always within the narrowest posible frequency bands for any class of emission in use.
e) The radiation of harmonics and spurious emissions should be suppressed to minimize interference.
Historical Description of Amateur Radio: From the Encyclopedia Britannica:-
Interest in amateur radio arose around the turn of the century, shortly after the Italian inventor Guglielmo Marconi successfully sent the first transatlantic wireless signal in 1901. The interference of amateur broadcasts with commercial and military transmissions led to the institution of government control in 1911. After World War I, amateurs became active in radio experimentation, contributing to developments in long-distance broadcasting and becoming the first radio operators successfully to exploit the upper medium-frequency and lower high-frequency radio bands. Over the years, amateur radio operators have also provided emergency communications during forest fires, floods, hurricanes, and other disasters. They serve as an important link between stricken communities and the outside world until normal communications are reestablished.Amateur radio operators in the United States are subject to international and federal regulations. There are five classes of licenses. Competence in the use of the International Morse Code and a knowledge of radio theory and regulation are required to obtain the advanced-level licenses. Amateur radio is allocated frequencies at the extreme high-frequency end of the medium-wave band, five groups of frequencies in the shortwave band, two groups in the veryhigh-frequency band, three in the ultrahigh-frequency band, and seven in the superhigh-frequency band for telegraphic and telephonic communication using amplitude and frequency modulation. There are restrictions on the power of the transmitters, and certain of the frequencies must be shared with due regard for the needs of other users.
The MD-500 before and after the drop test. Credit: NASA/Sean Smith
