1、NASA TECHNICAL NOTE NASA TN 0-6098 .-# - -c./ :E -= z_ -iii LOA N CO Y: RETUI :ci AFWL (OOGL) - _:. 0: -K1RTL.AND AFS, I _ IX) CJ A COMPARISON OF AIRCRAFT AND GROUND VEHICLE STOPPING PERFORMANCE ON DRY, WET, FLOODED, SLUSH-, SNOW-, AND ICE-COVERED RUNWAYS Final Report on Project Combat Traction, a J
2、oint USAF-NASA Program by Thomas J. Yager, W. Pelham Phillips, and Walter B. Horne Langley Research Center and Howard C. Sparks Aeronautical Systems Division Wright-Patterson Air Force Base /1 :; -x u _ W I- -NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON, D. C. NOVEMBER 1970 Provided by I
3、HSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TECH LIBRARY KAFB. NM 1111 11111 11111 11 11 111111111111111 111111111111 0069461 1. Report No. I 2. Government Accession No. 3. Recipients Catalog No. NASA TN D- 6098 4. Title and Subtitle 5. Report Date A COMPARIS
4、ON OF AIRCRAFT AND GROUND VEHICLE November 1970 STOPPING P ERFORMAN CE ON DRY, WE T , FLOODED , 6. Performi ng Orga nization Code SL USH - SNOW- AND ICE- COVERED RUNWAYS 7. Author(s) 8. Performing Organization Report No. Thomas J. Yager, W. Pelham Phillips, Walter B. Horne, L-7565 and Howard C. Spar
5、ks 10. Work Unit No. 9. Performing Organization Name and Address 126-61-12-05 NASA Langley Research Center, Hampton, Va. 2336 5 11. Contract or Grant No. USAF Wright- Patterson Air Force Base, Ohio 45433 13. Type of Report and Period Covered 12. Sponsoring Agency Name and Address Technical Note Nati
6、onal Aeronautics and Space Administration 14. Sponsoring Agency Code Washington, D.C . 20546 15. Supplementary Notes Appendix D by R. W. Sugg of British Ministry of Aircraft Supply 16. Abstract A joint USAF-NASA research program has studied the stopping performance of an instrumented C-141A four - e
7、ngine jet transport and several instrumented ground vehicles on 50 runways in the United States and Europe under dry, wet, flooded, slush, snow, and ice conditions. It is shown that measurement of the stopping distance of a diagonal-braked ground vehicle provides a meaningful measure of the slipperi
8、ness of a wet run-way, and permits accurate prediction of the stopping distance of an aircraft under varied runway slipperiness conditions as well as a means for realistic calculation of crosswind limitations. It is also shown that aircraft stopping performance on a wet runway can be considerably im
9、proved either by grooving the runway or by use of a porous surface course. 17. Key Words (Suggested by Author(s) 18. Distribution Statement Runway surface treatments Unclassified - Unlimited Aircraft-grou1r1 vehicle stopping performance Runway slipperiness due to adverse weather 19. Security Oassif.
10、 (of t his report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price“ Unclassified Unclassified 196 $3.00 * For sale by the National Technical Information Service, Springfield, Virginia 22151 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-
11、,-,-Page intentionally left blank Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-CONTENTS SUMMARY INTRODUCTION . SYMBOLS ABBREVIATIONS TEST APPARATUS Test Vehicles Aircraft Ground vehicles Instrumentation . . Aircraft . Ground vehicles Other Instrum
12、entation Water depth Texture depth Photographic coverage Runway markers . Atmospheric data TEST PROCEDURES . Wet and Dry Runways. Snow-, Slush-, and Ice-Covered Runways NASA Landing Research Runway RESULTS AND DISCUSSION . . . Full-Stop Runway Braking Tests Dry-runway braking characteristics. Wet-ru
13、nway braking characteristics. Snow-, slush-, and ice-covered runway braking characteristics Limited Braking Tests at Wallops Landing Research Runway. Effects of grooving . Path-clearing effects. . . . Effects of tire-tread design Aircraft and RCR Correlation Wet and flooded runways Snow-, slush-, an
14、d ice-covered runways Comments on the RCR system . . . . . . iii Page 1 1 4 7 8 8 8 10 10 10 13 13 13 15 15 17 17 17 17 20 20 20 21 21 30 33 34 34 38 44 44 44 46 46 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Aircraft and NASA Diagonal-Braked Tes
15、t Vehicle Correlation. Artificially and naturally wet surfaces . Snow-, ice-, and slush-covered surfaces . Equi valent RCR. . . . . . . . . . . . . . . . . . . . . . . . . . British Ministry of Aviation Supply Evaluation of Runway Conditions Runway Surface Treatment Evaluation Page 48 50 50 56 61 61
16、 Conventional surface treatments (wet conditions) . 61 Conventional surface treatments (flooded or slush-covered conditions) 62 Conventional surface treatments (snow- and ice-covered conditions) 62 Unconventional surface treatments (wet or flooded conditions) 64 Unconventional surface treatments (sl
17、ush, snow, or ice conditions) 64 Unconventional surface treatments (other factors) 67 CONCLUSIONS AND RECOMMENDATIONS. . . 70 APPENDIX A - COMPILATION OF TEST DATA 72 APPENDIX B - COMPUTATION OF TEST DATA 140 Aircraft Data Reduction . . . . . . . . . . . . . 140 NASA Diagonal-Braked Test Vehicle Dat
18、a Reduction 142 APPENDIX C - CIVIL ENGINEERING DESCRIPTIONS OF RUNWAYS TESTED 145 APPENDIX D - A REPORT ON THE RESULTS FROM THE MINISTRY OF TECHNOLOGY RUNWAY FRICTION METER (MU-METER) DURING JOINT TRIALS IN THE UNITED KINGDOM WITH THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATION 15 TO 25 JULY 1969
19、- By R. W. Sugg 182 Summary . . 182 Introduction 182 Test Method 184 Test Airfields 185 Results and Discussion Conclusions Acknowledgements REFERENCES . . . iv 185 185 186 193 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A COMPARISON OF AIRCRAFT A
20、ND GROUND VEHICLE STOPPING PERFORMANCE ON DRY, WET, FLOODED, SLUSH-, SNOW-, AND ICE-COVERED RUNWAYS Final Report on Project Combat Traction, a Joint USAF-NASA Program By Thomas J. Yager, W. Pelham Phillips, and Walter B. Horne Langley Research Center and Howard C. Sparks Aeronautical Systems Divisio
21、n Wright-Patterson Air Force Base SUMMARY A joint USAF-NASA research program has studied the stopping performance of an instrumented C-141A four-engine jet transport and several instrumented ground vehicles on 50 runways in the United States and Europe under dry, wet, flooded, slush, snow, and ice c
22、onditions. It is shown that measurement of the stopping distance of a diagonal braked ground vehicle provides a meaningful measure of the slipperiness of a wet runway, and permits accurate prediction of the stopping distance of an aircraft under varied run way slipperiness conditions as well as a me
23、ans for realistic calculation of crosswind limitations. It is also shown that aircraft stopping performance on a wet runway can be considerably improved either by grooving the runway or by use of a porous surface course. INTRODUCTION wet-runway operating problems became of primary concern with the i
24、ntroduction of jet aircraft since their landing speeds are usually well above the hydroplaning speed of their tires. In addition, improved flight instruments and instrument landing systems have led to more landings being made under adverse weather conditions. The increased landing speeds coupled wit
25、h more landings being made on wet runways have resulted in more landing accidents occurring because of the lack of effective braking action. This experi ence with both military and civil jet aircraft operation indicates that the presently used Provided by IHSNot for ResaleNo reproduction or networki
26、ng permitted without license from IHS-,-,-performance prediction methods for aircraft take-off and landing accountability on wet or slippery runways are deficient in several respects. For certification of piston-engine category aircraft for civil operation, performance on dry runways is determined a
27、nd FAA regulations increase the dry landing distances thus obtained by a factor of 1.67 to provide a safety margin for operation on dry runways, and to provide for the increase in stopping distance required on a wet runway. In January 1966, the FAA instituted the 15-percent rule which increased this
28、 factor to 1.92 for jet-turbine-category aircraft operation on wet runways; thus, recognition was made of the fact that jet-engine-powered aircraft were experiencing more difficulty in stopping on wet or slippery runways than the piston-engine aircraft. This civil regulatory approach for wet-runway
29、accountability does not differentiate between runways of dif ferent slipperiness and does not account for the loss of directional control due to reduc tion in sideways traction. The U.S. Air Force uses the RCR or runway condition reading system to account for wet or slippery runway conditions. RCR n
30、umbers are obtained by making maximum braking measurements on the runway with an airport ground vehicle employing a James brake decelerometer at speeds of 20 to 30 miles per hour. The flight manual of every aircraft in the U.S. Air Force inventory contains take-off and landing distance charts based
31、on RCR numbers. Also given are crosswind limitations based on the same RCR numbers. The main problem associated with the RCR system has been that the low-speed measurements of runway slipperiness made by the ground vehicle cannot be uniquely related to the actual slipperiness experienced by the airc
32、raft at the higher speeds of the landing roll, especially on wet runways. As a result, the RCR system can considerably underestimate the actual aircraft landing distance on a wet runway. For the same reason, an unconservative crosswind limitation can be given the pilot for a landing or take-off. For
33、 the past decade, the U.S. Air Force (USAF) and National Aeronautics and Space Administration (NASA) have been cooperating extensively on research of aircraft skidding problems on wet and slippery runways. The USAF furnished aircraft tires, landing gears, wheels, and complete aircraft for study by s
34、cientists at specially equipped research facil ities of the NASA Langley Research Center and Wallops station. From this effort, along with outstanding cooperation and assistance of the FAA, NTSB, ATA, and ALPA in this country, and the Ministry of Public Works and Roads, Road Research Laboratories, a
35、nd Ministry of Aviation Supply in England, many studies were generated which greatly increased the under standing of hydroplaning and other skidding factor s. During the late fifties and early sixties, Langley Research Center conducted research on the landing loads track on full-size aircraft tires
36、which disclosed a signifi cant loss of traction and complete wheel spin-down due to hydroplaning. These results 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-were confirmed with flight tests. One important early result of this work was the devel
37、opment of the slush drag and dynamic hydroplaning equations. Extensive tests at the landing loads track showed how tire groove patterns and depth affected the ability of the tire to develop friction on wet and flooded surfaces. Friction was found to increase with an increase in the number and depth
38、of grooves. The studies, however, showed the groove patterns to be insignificant in affecting friction when less than approximately 1/16 inch of groove depth remained. In this same period, joint testing by the FAA and NASA of an instrumented four-engine jet transport also investigated hydroplaning i
39、n terms of aircraft slUSh-drag reduction and unbraked wheel spindown. Also, a study of aircraft skidding accidents had revealed that in many cases, there were elliptical areas of reverted rubber on the tire tread, It was evident that the tire had undergone a locked-wheel skid of a lengthy duration.
40、Tests at the NASA landing loads track confirmed the fact that extremely low values of friction occurred when tires contained reverted-rubber patches. Another type of hydroplaning was that associated with thin fluid films between pavement and tire and designated as viscous hydroplaning. The research
41、indicated that measures other than tire-tread design would have to be taken to solve the total runway hydroplaning problem, which was designated in three types as dynamiC hydroplaning, viscous skidding, and reverted-rubber skidding. One approach to solve the problem of low friction under dynamiC hyd
42、roplaning conditions was to direct a stream of high-pressure air in front of the tire to displace the water on the runway. Subsequent tests made by NASA on- their landing loads track and the Douglas Aircraft Company on a DC-7 showed a Significant improvement in friction under flooded conditions; how
43、ever, under wet and damp conditions, viscous and reverted-rubber skidding was still experienced. It was obvious that the solution to the problem of skidding would not come from tire or aircraft improvement alone. Attention was then focused on the pavement surface. A British study revealed that trans
44、verse grooves in the pavement surface provided signifi cant improvement in the traction of a problem runway. Tests on Similarly grooved sur faces at the NASA landing loads track under flooded, wet, and damp conditions showed that grooved surfaces greatly alleviated dynamiC hydroplaning, viscous skid
45、ding, and reverted rubber skidding. The next step was to construct a research runway at the NASA Wallops Station. Tests were conducted with three aircraft and several friction-measuring vehicles. Results of these tests and tests at Langley Research Center indicated that grooves in the runway surface
46、s did indeed improve landing characteristics. (See ref. 1.) As a result, surfaces of runways at several Air Force and civil airports were grooved. The data from the test track and the short test sections at Wallops Station, however, left many questions unanswered as to the relative merits of the dif
47、ferent surfaces and surface treatments for a full-length runway. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Project Combat Traction was initiated as a joint U.S. Air Force-NASA project consisting of two parts: (a) Full-stop brake tests were ma
48、de by an instrumented C-141A aircraft, an RCR test vehicle, and a diagonal-braked test vehicle on civil and military runways in the United States and Europe under dry, artificially wet, natural rain, ice, and snow conditions. Included in the European program were tests conducted jointly with the Bri
49、tish Ministry of Aviation Supply on Royal Air Force (RAF) and Royal Navy (RN) Bases using a Mu-meter and a Miles engineering skid trailer. (b) Limited brake tests were conducted on the landing research runway at NASA Wallops Station, with the C-141A to correlate the results with those of similar tests previously conducted on an F-4D and a Convai
