1、NASA TECHNICAL NOTE=O!ZI-.,.,=ZNASA TN D-6866CASE FILECOPYSUMMARY OF DESIGN CONSIDERATIONSFOR AIRPLANE SPIN-RECOVERYPARACHUTE SYSTEMSby Sanger M. Burk, Jr.Langley Research CenterHampton, Va. 23365NATIONALAERONAUTICSAND SPACEADMINISTRATION WASHINGTON,D. C. AUGUST 1972Provided by IHSNot for ResaleNo r
2、eproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1. Report No, 2. GovernmentAccessionNo. 3. RecipientsCatalogNo.NASA TN D-68664, Title and SubtitleSUMMARY OF DESIGN CONSIDERATIONS FOR AI
3、.RPLANESPIN-RECOVERY PARACHUTE SYSTEMS7. Authors)Sanger M. Burk, Jr.9. PerformingOrganizationNameand AddressNASA Langley Research CenterHampton, Va. 2336512. SponsoringAgencyName and AddressNational Aeronautics and Space AdministrationWashington, D.C. 205465. Report DateAugust 19726. PerformingOrgan
4、izationCode8. PedormiogOrganizationReport No.L-821910. Work Unit No.136-62-02-03“11.Contract or Grant No,13. Type of Report and PeriodCoveredTechnical Note14. SponsoringAgencyCode15. SupplementaryNotes16. AbstractA compilation of design considerations applicable to spin-recovery parachute systemsfor
5、 military airplanes has been made so that the information will be readily available topersons responsible for the design of such systems. This information was obtained from astudy of available documents and from discussions with persons in both government andindustry experienced in parachute technol
6、ogy, full-scale and model spin testing, and relatedsystems.17. Key Words (Suggestedby Authoris)Spin-recovery parachute systemsParachutesSpinning18. DistributionStatementUnclassified - Unlimited19. SecurityClaccif.(of thisreportUnclassified20. SecurityClessif.(of thispage 21. No. of PagesUnclassified
7、 55Q For saleby the National Technical Information Service,Springfield, Virginia 2215122. Price*$3.00Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-CON
8、TENTSPageSUMMARY . 1INTRODUCTION 1SYMBOLS . 2TYPICAL CHARACTERISTICS OF SPIN AND RECOVERY 4Fully Developed Spin 4Spin Recovery 4SPIN-RECOVERY PARACHUTE . 5Design Approach 5Operating Environment . 6Wake Effects 6Parachute Requirements 8Parachute Type . 8Parachute Diameter and Riser Length . 8SPIN-REC
9、OVERY PARACHUTE INSTALLATION AND OPERATION 10Parachute Compartment 10Deployment Bag and Packing Methods . ilParachute Deployment Methods . 11PILOT PARACHUTE . 13Requirements and Types 13Pilot Parachute Diameter and Bridle Length 13Pilot Parachute Deployment Methods 14DEPLOYMENT MECHANISM DESIGN CONS
10、IDERATIONS 16Basic Methods of Deployment and Jettison . 16Emergency Power 17Basic Attachment Methods . 17Cockpit Control Arrangement 18SPIN-RECOVERY PARACHUTE LOADS . 19FUSELAGE LOADS 19QUALIFICATION AND MONITORING OF RECOVERY SYSTEMS 21Free-Drop Tests 21Laboratory Tests 21Airplane Ground Tow Tests
11、. 22iiiProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-PageInflight Deployment Tow Tests . 22Deployment Tests in Developed Spin 22Parachute Drag Measurements . 23Photography . 23CONCLUSIONS . , . . 24APPENDIX A - ALTERNATE SPIN-RECOVERY DEVICES . 27R
12、ockets . 27Wing-Tip-Mounted Parachutes . 29APPENDIX B - ADDITIONAL CONSIDERATIONS WITH REGARD TOTHE SPIN-RECOVERY PARACHUTE . 30Design of Parachute Compartment . 30Packing . 31REFERENCES . 33TABLE 36FIGURES . 37ivProvided by IHSNot for ResaleNo reproduction or networking permitted without license fr
13、om IHS-,-,-SUMMARY OF DESIGN CONSIDERATIONS FOR AIRPLANESPIN-RECOVERY PARACHUTE SYSTEMSBy Sanger M. Burk, Jr.Langley Research CenterSUMMARYA compilation of design considerations applicable to spin-recovery parachute sys-tems has been made so thatthe information willbe readily availabletothose respon
14、siblefor the design of such systems. The information was obtained from a study of availabledocuments and from discussions with persons in both government and industry experiencedinparachute design, full-scaleand model spin testing,and related systems. This surveyindicatedthatthe technology was best
15、defined for tacticaland trainer military airplanes,and was not considered applicableto other classes ofairplanes, especially lightgeneralaviation airplanes. Even for the military airplanes, however, there are gaps in the tech-nology where one must rely on the judgment of experts based on their relat
16、ed experience.Hence, the present paper isnot a handbook for the design of spin-recovery parachutesystems, but is simply a summary ofthe statusof the technology and a discussion ofapproaches thathave proven successful,or unsuccessful, in the past. One main conclu-sion evolves from thissurvey; thatis,
17、there are three distinctfieldsoftechnologyinvolved: parachutes, airplane spinning,and airplane systems. Specialistsinallthesefieldsshould be consulted or participateinthe design ofthe spin-recovery parachutesystem from the very beginning.INTRODUCTIONThe armed services require a contractor to demonst
18、rate by full-scale flight teststhe spin and recovery characteristics of certain types of airplanes, such as fighter, attack,and trainer airplanes, as a standard part of the flight demonstration acceptance program.(See refs. 1 and 2.) During these spin demonstrations, the airplane is generally equipp
19、edwith a tail-mounted spin-recovery parachute system as an emergency recovery device incase recovery from the spin cannot be effected by the airplane control surfaces. TheU.S. Navy recently has added a new requirement to the full-scale spin demonstrations“(ref. 2) which states that the emergency spi
20、n-recovery device must be tested in a criticalspin condition during the spin demonstration tests. Although spin-recovery parachutesystems have been used for many years, the technology for system design and qualificationProvided by IHSNot for ResaleNo reproduction or networking permitted without lice
21、nse from IHS-,-,-is very inadequatelydocumentedand few guidelines exist in this area. There have been,andcontinueto be, failures associatedwith spin-recovery parachute systems; manyofthese failures appear to be causedby the lack of understandingof the basic aerodynamiccharacteristics and mechanicsof
22、 the spin and also to lack of experiencewith spin-recovery parachute systems. This situation exists becausethere hasbeenlittle conti-nuity in the designteams over the years with respect to spin-recovery parachute systems.The purposeof this paper is to summarize the design considerations for spin-rec
23、overy parachutesystems sothat the information will be readily available to thoseresponsible for the designof such systems. The information that is presentedhereinwas obtainedfrom a study of available documents(refs. 3 to 19),and from discussionswith persons experiencedin parachutetechnology,full-sca
24、le and model spin testing, andrelated systems. Personnel from the following organizations were consulted: (1) U.S.Air Force Flight DynamicsLaboratory, (2) U.S.Naval Air SystemsCommand,(3) CessnaAircraft Company,(4) General Dynamics, Fort Worth Division, (5) GrummanAerospaceCorporation, (6) Irvin Ind
25、ustries, Inc., (7) Ling-Temco-Vought, Inc., (8) McDonnellDouglas Corporation, (9) M. Steinthal and Company,Inc., (10)Northrop Corporation,(11) Pioneer Parachute Company,and (12)NASALangley ResearchCenter.As the information was being compiled, it becameevident that in a number of areasthere is no cle
26、arly definedbasis for determining a best approachfor insuring adequateperformance of the recovery system. The present paper doesnot create newtechnologyto fill thesevoids and doesnot presume to makerecommendationsin areas where thepresent technologywill not clearly support suchrecommendations;hence,
27、 muchof thepaper discusses various aspectsof spin-recovery parachutesystem designwithout clear-cut conclusions. It wasalso apparentthat the technologywas best definedfor tacticalandtrainer military airplanes and wasnot consideredto be applicable to other classesof airplanes, especially light general
28、 aviation airplanes; therefore, the present paper islimited to applications to military airplanes.Althoughthe primary purposeof this paper is to discuss approachesin the designof tail-mounted spin-recovery parachutesystems, it wasfelt that a brief discussion onother spin-recovery devices, suchas roc
29、kets andwing-tip mountedparachutes,wouldalso be in order, since these devices are alternate systems for accomplishing the samepurpose. This information is presented in appendixA.SYMBOLSUnits used for the physical quantities in this paper are given in the InternationalSystemof Units (SI)and U.S. Cust
30、omary Units. Measurementsand calculations weremadein U.S. Customary Units. Factors relating the two systems are given in refer-2Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ence 20. A sketch of a spin-recovery parachute system with its nomenclatur
31、e is pre-sentedin figure 1.g acceleration due to gravity, 9.8 m/sec2 (32.2ft/sec 2)IX,IY momentsof inertia aboutthe X and Y bodyaxes, respectively, kg-m2(slug-ft 2)l B distance between bridle attachment point and pilot parachute skirt (see fig. 1),m (ft)l R distance between riser attachment point an
32、d spin-recovery parachute skirt(see fig. 1), m (ft)q local dynamic pressure, N/m 2 (lb/ft 2)q_ free-stream dynamic pressure, N/m 2 (lb/ft 2)r horizontal distance between spin axis and parachute attachment point, m (ft)Sp area of pilot parachute based on flat diameter, m 2 (ft 2)Ss area of spin-recov
33、ery parachute based on flat diameter, m 2 (ft 2)maximum design velocity of parachute at designated spin altitude, m/see(ft/sec)true rate of descent in spin, m/sec (ft/sec)body axesangle between fuselage reference line and vertical (approximately equal toabsolute value of angle of attack at plane of
34、symmetry), deg_rangle of sideslip, tan-1 _ss + 0 where the term tan-1 Vs_-xris positive in aleft spin and negative in a right spin, degangle of wing sweep, degair density, kg/m 3 (slug/ft 3)V mV sX, Y, Z0/APProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS
35、-,-,-anglebetweenwing spanaxis andhorizontal measuredin vertical plane,positive whenright wing is downregardless of spin direction, degf_ angular velocity about spin axis, rpsTYPICAL CHARACTERISTICSOF SPINAND RECOVERYFully DevelopedSpinThe fully developedspin is normally consideredto be the critical
36、 designconditionfor a spin-recovery parachute system. Recently, however, it hasbecomeevident that itmay be desirable under some circumstances to deploythe parachuteduring spin entrywhere the dynamic pressure maybe higher than in a fully developedspin, andconsidera-tions for this condition are discus
37、sed in more detail in a later section of the report.In the fully developedspin the airplane is in vertical descentin a fully stalled atti-tudewith the angleof attack generally between40 and90 and is rotating about the verti-cal flight-path axis. A sketch illustrating the attitude angles, spin radius
38、, and rate ofrotation of an airplane in a spin is shownin figure 2. The motion may be a steadyrota-tion or the airplane may be oscillating violently in pitch androll. Oscillations of +30 to i45 are not uncommon. Any given airplane may have several different spin modesbetween flat or steep, fast or s
39、low, and steady or oscillatory. In the steady-spin modethe aerodynamic forces and moments acting on the airplane are balanced by equal andopposite mass and inertia forces and moments so that an equilibrium condition exists.These mass and inertia forces and moments are produced by both the spinning r
40、otationand the uneven mass distribution of the airplane about its body axes. As a result, anexternally applied force or moment to a spinning airplane often causes the airplane toreact like a gyroscope rather than in the normal manner expected in straight and levelflight. The effects of these gyrosco
41、pic moments can be especially evident and importantin spin recovery, as will be discussed in the following section. (Further details on spincharacteristics of airplanes can be found in ref. 3.)Spin RecoveryThe fully developed spin is primarily a yawing motion and thus the most effectivemeans of term
42、inating it is to apply a yawing moment to oppose the rotation. Considera-tion must be given, however, to the gyroscopic moments which result from the applicationof forces or moments other than those in yaw, especially since a spin-recovery parachuteapplies a pitching moment as well as a yawing momen
43、t. The gyroscopic moments may bebeneficial or detrimental, depending upon the mass distribution of the airplane and thedirection of the applied force or moment. Because of the gyroscopic effects, applying anose-down pitching moment, for example, to a fuselage-loaded airplane (Iy IX) in a spin4Provid
44、ed by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-results in a yawingmoment in the direction of the spin rotation (prospin) andusuallycausesthe spin rotation to increase rather than causethe airplane to pitch nose down,By contrast, the application of an anti
45、spin yawingmomentwill stop the spin rotation andsimultaneously causethe airplane to nosedownout of the spin from its nose-high attitudebecauseas the spin rotation is reduced, the gyroscopic nose-uppitching momentisreduced.Thus, in order to explain the action of the parachutefor spin recovery, both t
46、heyawing momentand nose-downpitching momentappliedby the parachutemust be consid-ered. The yawingmoment, as previously mentioned,is the most effective meansfor bothstoppingthe rotation anddecreasing the angleof attack. The nose-downpitching momenthowever, is anundesirable byproduct of the parachutew
47、hich, becauseof the resultinggyroscopic effects, generally will causemost tactical airplanes to spin faster and notrecover, and may or may not causethe airplane to nosedownor decreasein angleofattack. If the parachuteis properly sized, however, the yawing momentapplied by theparachutewill stop the s
48、pin rotation in spite of the adverse pitching-moment effect. If,on the other hand,the parachute size is too small, it is possible that the airplane wouldfind a new spin equilibrium condition where the spin rate is higher and the pitch attitudeis steeper. This newattitude andspin rate shouldnot be consideredan improvement overthe original spin modebecausethe airplane could continueto spin without ever recovering.Thus, a properly sized parachutethat will producea sufficiently large antispin yawingmomentis required in order to effect a satisfactory spin recovery.It also follows from th
