1 00:00:00,000 --> 00:00:06,200 So you see, using the ALDEF, Langley's test truck, and the Convair 990 to test tires and 2 00:00:06,200 --> 00:00:10,600 tire wear really helped engineers solve their problem with the shuttle runway at Kennedy 3 00:00:10,600 --> 00:00:11,600 Space Center. 4 00:00:11,600 --> 00:00:12,600 Right. 5 00:00:12,600 --> 00:00:17,520 They run tests, measure and collect data, graph the results, and predict solutions to 6 00:00:17,520 --> 00:00:18,520 their problems. 7 00:00:18,520 --> 00:00:19,520 Hmm. 8 00:00:19,520 --> 00:00:21,600 Sounds similar to what you do in your classroom? 9 00:00:21,600 --> 00:00:24,960 Does NASA Langley conduct any other extreme tests? 10 00:00:24,960 --> 00:00:26,560 Funny you should ask. 11 00:00:26,560 --> 00:00:29,200 Remember the title of today's program? 12 00:00:29,200 --> 00:00:31,720 Measurement, Ratios, and Graphing. 13 00:00:31,720 --> 00:00:33,720 3-2-1 Crash? 14 00:00:33,720 --> 00:00:40,480 Well, NASA Langley actually crashes aircraft to test them for safety right here at the 15 00:00:40,480 --> 00:00:45,920 Impact Dynamics Research Facility. 16 00:00:45,920 --> 00:00:50,080 How is technology used to collect the mathematical data in crash tests? 17 00:00:50,080 --> 00:00:53,200 Why is area important in the results of the test? 18 00:00:53,200 --> 00:00:57,040 How are ratios used to find a solution? 19 00:00:57,040 --> 00:01:00,800 The Impact Dynamics Research Facility is used to conduct full-scale crash tests of 20 00:01:00,800 --> 00:01:01,800 aircraft. 21 00:01:01,800 --> 00:01:06,080 The aircraft would be tested, suspended from the gantry, pulled back to a calculated release 22 00:01:06,080 --> 00:01:12,480 height, and then released to swing like a pendulum into the impact surface below. 23 00:01:12,480 --> 00:01:16,560 Just before crashing, the swing cables are released and the aircraft goes into free flight. 24 00:01:16,560 --> 00:01:20,000 The cables attached to the aircraft are released by pyrotechnics or explosions. 25 00:01:20,000 --> 00:01:21,000 It's pretty cool to watch. 26 00:01:21,400 --> 00:01:25,680 We crash aircraft so we can see how safe they are and develop ways to make them safer. 27 00:01:25,680 --> 00:01:29,760 IDRF is very similar to what the auto industry does with cars. 28 00:01:29,760 --> 00:01:33,960 Everyone has seen the commercials with cars being crashed into barriers and crash dummies 29 00:01:33,960 --> 00:01:35,720 responding to the forces. 30 00:01:35,720 --> 00:01:39,520 Our crash test dummies are wired with sensors and data are collected to determine the crash 31 00:01:39,520 --> 00:01:41,320 worthiness of an aircraft. 32 00:01:41,320 --> 00:01:46,040 Crash worthiness is how well an aircraft protects passengers in the event of a crash. 33 00:01:46,040 --> 00:01:50,840 We use the data from the dummies to make improvements to aircraft designs for crash 34 00:01:50,840 --> 00:01:51,840 worthiness. 35 00:01:51,840 --> 00:01:52,840 Lisa, that is just so cool. 36 00:01:52,840 --> 00:01:55,280 I mean, you get to crash things for a living. 37 00:01:55,280 --> 00:01:56,600 And we get safer aircraft. 38 00:01:56,600 --> 00:01:57,600 You're right, Ben. 39 00:01:57,600 --> 00:02:02,960 The testing and the research conducted at the IDRF can really benefit all airplane passengers. 40 00:02:02,960 --> 00:02:06,880 One of our main goals is to reduce the force on airplane passengers during a crash. 41 00:02:06,880 --> 00:02:11,120 We want to create structures and materials that dissipate or absorb the energy from a 42 00:02:11,120 --> 00:02:14,120 crash before the energy gets to the passengers. 43 00:02:14,200 --> 00:02:15,840 Take a car, for instance. 44 00:02:15,840 --> 00:02:19,080 Structures like the bumper and frame are designed to crush. 45 00:02:19,080 --> 00:02:23,840 When these parts crush, they dissipate or absorb some of the energy so that the passengers 46 00:02:23,840 --> 00:02:25,880 are less likely to be injured. 47 00:02:25,880 --> 00:02:28,400 Lisa, we all know that planes don't have bumpers. 48 00:02:28,400 --> 00:02:29,400 Right. 49 00:02:29,400 --> 00:02:32,880 However, there are parts of an aircraft that can absorb energy in a crash. 50 00:02:32,880 --> 00:02:37,120 Parts like the subfloor, which is the area under the floor, the landing gear, the seat 51 00:02:37,120 --> 00:02:39,360 and even the cushion can absorb energy. 52 00:02:39,360 --> 00:02:43,700 Restraints, like the seat belts, are also necessary to keep the passengers from flying 53 00:02:43,700 --> 00:02:45,940 through the aircraft during the crash. 54 00:02:45,940 --> 00:02:49,860 When these parts and structures are designed correctly or optimized, the passengers have 55 00:02:49,860 --> 00:02:52,180 a better chance of surviving a crash. 56 00:02:52,180 --> 00:02:57,580 But Lisa, how do you design aircraft parts to absorb energy? 57 00:02:57,580 --> 00:02:58,820 Good question. 58 00:02:58,820 --> 00:03:03,460 We use human tolerance data and crash test dummy data to develop better energy absorbing 59 00:03:03,460 --> 00:03:04,460 designs. 60 00:03:04,460 --> 00:03:07,020 You see, aircraft are made of different materials. 61 00:03:07,020 --> 00:03:10,780 Some are made of metals like aluminum and some are made of composite materials like 62 00:03:10,780 --> 00:03:12,780 graphite or fiberglass. 63 00:03:12,860 --> 00:03:17,700 A tennis racket is a good example of a graphite material and most small boats are made of 64 00:03:17,700 --> 00:03:19,060 fiberglass. 65 00:03:19,060 --> 00:03:23,380 Metals and composites perform very differently in a crash, so we have to design the parts 66 00:03:23,380 --> 00:03:26,460 to complement the materials the aircraft is made of. 67 00:03:26,460 --> 00:03:30,860 Basically, we would not design a subfloor in a composite aircraft the same way we would 68 00:03:30,860 --> 00:03:33,260 design a subfloor in a metal aircraft. 69 00:03:33,260 --> 00:03:36,100 Can you really design a subfloor that absorbs energy? 70 00:03:36,100 --> 00:03:37,100 Yes. 71 00:03:37,100 --> 00:03:40,380 In 1994, we tested a graphite aircraft called the Learfan. 72 00:03:40,900 --> 00:03:44,860 When the original aircraft was released from the gantry, it was extremely rigid and nothing 73 00:03:44,860 --> 00:03:45,860 crushed. 74 00:03:45,860 --> 00:03:50,180 According to the crash test dummy data we collected, only one of the six passengers 75 00:03:50,180 --> 00:03:51,180 survived. 76 00:03:51,180 --> 00:03:56,500 So we used that data to design a new energy absorbing, or crushable, subfloor. 77 00:03:56,500 --> 00:03:59,620 It would be like putting a bumper under the floor. 78 00:03:59,620 --> 00:04:04,060 Then we built and tested small sections of different subfloor designs until we had the 79 00:04:04,060 --> 00:04:05,300 best design. 80 00:04:05,300 --> 00:04:11,220 A second Learfan was modified by installing the newly designed subfloor and tested. 81 00:04:11,220 --> 00:04:15,780 The results showed that the new subfloor improved the Learfan's crash-worthiness by reducing 82 00:04:15,780 --> 00:04:18,020 the forces on the passengers. 83 00:04:18,020 --> 00:04:21,580 Oh, wow. 84 00:04:21,580 --> 00:04:23,180 This looks crazy. 85 00:04:23,180 --> 00:04:26,340 How do you collect the data from the crash tests? 86 00:04:26,340 --> 00:04:30,620 We use a digital data collection system that's designed to handle the impacts of a crash, 87 00:04:30,620 --> 00:04:31,620 like this one. 88 00:04:31,900 --> 00:04:36,740 All the instruments on board are wired to the data collection system and after the test, 89 00:04:36,740 --> 00:04:42,780 the data are downloaded onto a laptop computer to be analyzed by the researchers. 90 00:04:42,780 --> 00:04:45,620 In school, we analyze data and we make graphs. 91 00:04:45,620 --> 00:04:46,620 Is that what you do? 92 00:04:46,620 --> 00:04:47,620 Absolutely. 93 00:04:47,620 --> 00:04:51,060 We make graphs of the data collected and compare those to other graphs. 94 00:04:51,060 --> 00:04:56,920 This graph from an actual test conducted here at IDRF shows the ratio of g-force to time. 95 00:04:56,920 --> 00:05:00,460 You can feel the sensation of g-forces when you ride on a roller coaster. 96 00:05:00,460 --> 00:05:03,420 It's what you feel pushing you into your seat on a loop. 97 00:05:03,420 --> 00:05:05,540 As you can see, our graph has a curve shape. 98 00:05:05,540 --> 00:05:10,980 Next, we calculated the area under the curve and compared it to a human tolerance graph. 99 00:05:10,980 --> 00:05:16,260 This graph shows the maximum energy, or g-force, a human can tolerate over a specific time. 100 00:05:16,260 --> 00:05:22,780 The plot goes from 0g to 50g and back to 0g in a very short, short amount of time. 101 00:05:22,780 --> 00:05:27,740 The shaded area within the triangle is the amount of energy a human can tolerate in 100 102 00:05:27,740 --> 00:05:28,740 milliseconds. 103 00:05:28,740 --> 00:05:30,500 Next, we set up a ratio. 104 00:05:30,500 --> 00:05:35,900 By comparing the shaded area under the dummy data to the shaded area under the human tolerance 105 00:05:35,900 --> 00:05:39,180 data, we can determine if the passengers survive. 106 00:05:39,180 --> 00:05:43,460 We want this ratio to be less than or equal to 1 if passengers are to survive. 107 00:05:43,460 --> 00:05:46,340 Okay, Lisa, I have one more question for you. 108 00:05:46,340 --> 00:05:50,080 How does all the information that you collect here help aircraft safety? 109 00:05:50,080 --> 00:05:54,460 By using measurements and graphs, we present the data collected from tests at the IDRF 110 00:05:54,460 --> 00:05:58,700 to the aircraft companies and to the FAA or the Federal Aviation Administration. 111 00:05:58,700 --> 00:06:01,340 Even the aircraft companies can use the new designs of their aircraft. 112 00:06:01,340 --> 00:06:06,100 The FAA may use the information to establish new rules and regulations for aircraft safety.