1 00:00:00,000 --> 00:00:04,000 One of the most important components of any vehicle is its tires. 2 00:00:04,000 --> 00:00:08,000 Unfortunately, tires are often overlooked and poorly maintained. 3 00:00:08,000 --> 00:00:12,000 Worn treads or even bald tires can lead to hydroplaning on wet surfaces. 4 00:00:12,000 --> 00:00:16,000 When this occurs, control of the vehicle is lost. 5 00:00:16,000 --> 00:00:20,000 NASA Langley Research Center has a special facility that makes traveling safer 6 00:00:20,000 --> 00:00:24,000 by testing new tire tread designs and road surfaces. 7 00:00:24,000 --> 00:00:28,000 Paula Baden finds out more about NASA's Aircraft Landing Dynamics Facility. 8 00:00:28,000 --> 00:00:34,000 Music 9 00:00:34,000 --> 00:00:38,000 Have you ever heard this sound? 10 00:00:38,000 --> 00:00:42,000 It's the impact of tires over grooved pavement. 11 00:00:42,000 --> 00:00:48,000 Developed at NASA Langley, grooved pavement limits hydroplaning on wet roads and runways, 12 00:00:48,000 --> 00:00:52,000 which helps automobiles, planes, and people travel safer. 13 00:00:52,000 --> 00:00:58,000 Most of this research is performed at a unique facility called the Aircraft Landing Dynamics Facility, or ALDEF. 14 00:00:58,000 --> 00:01:05,000 Besides developing grooved pavement, ALDEF tests aircraft wheels, tires, and advanced landing systems. 15 00:01:05,000 --> 00:01:10,000 The research gathered here develops safer roads, runways, and pedestrian walkways. 16 00:01:10,000 --> 00:01:16,000 I spoke to Bob Daugherty of NASA Langley Research Center to find out more about this one-of-a-kind facility. 17 00:01:16,000 --> 00:01:22,000 Well, the ALDEF is a unique facility that NASA uses to test landing gear components, tires, 18 00:01:22,000 --> 00:01:26,000 and even advanced landing gear concepts at full-scale conditions. 19 00:01:26,000 --> 00:01:30,000 The biggest advantage is this facility allows us to simulate full-scale conditions 20 00:01:30,000 --> 00:01:35,000 where it might otherwise be dangerous for a pilot or an aircraft to encounter. 21 00:01:35,000 --> 00:01:42,000 For example, if we tested this tire and it failed, here at our facility we've only lost a tire. 22 00:01:42,000 --> 00:01:48,000 We haven't risked any injury to a pilot or done any damage to a real aircraft, which gets very expensive. 23 00:01:48,000 --> 00:01:55,000 And, of course, being able to run tests over and over quickly at low cost gets you a lot of data in a very short period of time. 24 00:01:55,000 --> 00:01:59,000 The key to doing that is getting whatever component we're looking at up to speed 25 00:01:59,000 --> 00:02:03,000 and making it think that it's on an aircraft or spacecraft. 26 00:02:03,000 --> 00:02:07,000 We do that by taking this 60-ton carriage, propelling it up to the speed we want. 27 00:02:07,000 --> 00:02:11,000 We can get up to 250 miles per hour, and it only takes two seconds to do that. 28 00:02:11,000 --> 00:02:14,000 And then landing this tire, for example, on a runway, 29 00:02:14,000 --> 00:02:18,000 applying forces to it, steering it, and measuring those forces 30 00:02:18,000 --> 00:02:23,000 so that they can be simulated elsewhere in pilot training simulators and so forth. 31 00:02:23,000 --> 00:02:26,000 Well, Bob, tell me, how exactly do you propel the carriage? 32 00:02:26,000 --> 00:02:29,000 Well, that's really the neatest thing about this facility. 33 00:02:29,000 --> 00:02:32,000 Believe it or not, we use a giant squirt gun. 34 00:02:32,000 --> 00:02:37,000 We've got a pressurized water tank at the end of the track with a real high-tech valve. 35 00:02:37,000 --> 00:02:43,000 We actually shoot an 18-inch stream of water at a bucket at the back end of the carriage, 36 00:02:43,000 --> 00:02:46,000 and that actually gives us the energy to launch the carriage. 37 00:02:51,000 --> 00:02:55,000 Now, what's unique about this is it's low cost. 38 00:02:55,000 --> 00:03:01,000 If we were a rocket, we'd have to carry our fuel with us, and that's very expensive to do. 39 00:03:01,000 --> 00:03:04,000 But since we're using low-cost, low-efficiency water power, 40 00:03:04,000 --> 00:03:08,000 we store all of our pressurized water at the end of the track and shoot it at the carriage. 41 00:03:08,000 --> 00:03:14,000 All we have to do is pay for the water and the electricity, and it only costs about $25 for each run. 42 00:03:14,000 --> 00:03:19,000 So at the speed of 250 miles an hour, how do you stop this carriage? 43 00:03:19,000 --> 00:03:22,000 Well, at the end of our track, we have an arrestment system, 44 00:03:22,000 --> 00:03:26,000 and that arrestment system consists of five cables that stretch across the track, 45 00:03:26,000 --> 00:03:30,000 and we have a nose block on the front of the carriage that lines up with those cables. 46 00:03:30,000 --> 00:03:32,000 So as the carriage continues to travel, 47 00:03:32,000 --> 00:03:37,000 the cables allow us to gradually dissipate the carriage energy in the last few hundred feet. 48 00:03:37,000 --> 00:03:41,000 So, Bob, what other kinds of things have you tested at ALDEF in the past? 49 00:03:41,000 --> 00:03:44,000 Well, over the years, we've tested a lot of different things, 50 00:03:44,000 --> 00:03:49,000 but probably the biggest accomplishment here at the ALDEF has been the pioneering work done on hydroplaning. 51 00:03:49,000 --> 00:03:55,000 An aircraft or highway vehicle tire hydroplanes when water comes between a tire and pavement. 52 00:03:55,000 --> 00:04:01,000 When this happens, the tire loses contact with the pavement and is supported only by the water. 53 00:04:01,000 --> 00:04:06,000 This causes the tire to lose traction, which could then send the vehicle spinning out of control. 54 00:04:06,000 --> 00:04:12,000 Researchers at ALDEF have proven that by cutting thin grooves across concrete surfaces, 55 00:04:12,000 --> 00:04:18,000 channels or escape routes are created, which allow excess water to drain from the surface. 56 00:04:18,000 --> 00:04:23,000 This process of cutting grooves dramatically reduces the risk of hydroplaning. 57 00:04:23,000 --> 00:04:31,000 As a result, hundreds of commercial airport runways and interstate highway curves and overpasses have had these safety grooves added. 58 00:04:31,000 --> 00:04:37,000 Accidents on slippery highways are down as much as 85 percent in some areas, 59 00:04:37,000 --> 00:04:43,000 and aircraft tire friction in wet conditions has been improved by 200 to 300 percent. 60 00:04:43,000 --> 00:04:49,000 An added benefit of grooving is that the lifespan of these groove surfaces is extended by 5 to 10 years, 61 00:04:49,000 --> 00:04:53,000 resulting in significant maintenance cost savings. 62 00:04:53,000 --> 00:04:59,000 One of the things we're doing now is trying to increase the safety margin of space shuttle orbiter tires. 63 00:04:59,000 --> 00:05:06,000 NASA wants to improve that safety by increasing the load carrying capability of the orbiter tire by about 20 percent 64 00:05:06,000 --> 00:05:12,000 and increasing the speed capability by about 10 percent up to 250 knots. 65 00:05:12,000 --> 00:05:17,000 This is going to require a new tire design, and the best place to evaluate that is right here at the ALDEF. 66 00:05:17,000 --> 00:05:20,000 Rather than onboard an orbiter that costs several billion dollars, 67 00:05:20,000 --> 00:05:27,000 we're going to be looking at design considerations like the structure of the tire itself and the tread patterns 68 00:05:27,000 --> 00:05:30,000 to determine which design path to go down. 69 00:05:30,000 --> 00:05:36,000 So as long as tires have been around, Bob, it seems like we'd know by now how they behave. 70 00:05:36,000 --> 00:05:44,000 You'd think so, but as it turns out, how a tire behaves, whether it's an automobile tire, aircraft tire, or a spacecraft tire, 71 00:05:45,000 --> 00:05:53,000 is dependent on so many factors that technology is not yet at the point where we can accurately predict the behavior of each and every tire. 72 00:05:53,000 --> 00:05:58,000 So that's where the ALDEF comes in again to test these things and improve the predictions. 73 00:05:58,000 --> 00:06:06,000 We share that data with tire manufacturers so that ultimately they can provide a product that all of us can use more safely. 74 00:06:06,000 --> 00:06:11,000 The Aircraft Landing Dynamics Facility has been in continuous use since the 1960s. 75 00:06:11,000 --> 00:06:17,000 The structures there have not only made runways and roads safer for all of us, but also coined the term hydroplaning. 76 00:06:17,000 --> 00:06:20,000 Wind tunnels have been around for over 100 years. 77 00:06:20,000 --> 00:06:24,000 Even the Wright brothers used their own homemade wind tunnel to test ideas for their first flyer. 78 00:06:24,000 --> 00:06:30,000 Today, aircraft designs undergo significant wind tunnel testing before being built to full size and test flown. 79 00:06:30,000 --> 00:06:33,000 But what is a wind tunnel and how does it operate? 80 00:06:33,000 --> 00:06:37,000 For some answers, we turn to Johnny Alonzo to find out how it works.