Vac A- 1-38 NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS WARTIME REPORT ORIGINALLY ISSUED March I9J+6 as Advance Restricted Report L5G19& COMPARISON OF TAIL AND WING-TIP SPIN-RECOVERY PARACHUTES AS DETERMINED BY TESTS IN THE LANGLEY 20 -FOOT FREE-SPINNING TUNNEL By Robert W. Kamm and Frank S. Malvestuto, Jr. Langley Memorial Aeronautical Laboratory Langley Field, Va. ' * 1 8 » *"" MAC A WASHINGTON NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were pre- viously held under a security status but are now unclassified. Some of these reports were not tech- nically edited. All have been reproduced without change in order to expedite general distribution. Ii-3tt Digitized by the Internet Archive in 2011 with funding from University of Florida, George A. Smathers Libraries with support from LYRASIS and the Sloan Foundation http://www.archive.org/details/comparisonoftailOOIang -7f i 0H5 bi NACA ARK No. L5G19a RESTRICTED NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS ADVANCE RESTRICTED REPORT COMPARISON 0? TAIL AND WING-TIP SPIN-RECOVERY PARACHUTES AS DETERMINED BY TESTS IN THE LANGLEY 20-FOOT FREE-SPINNING TUNNEL By Robert W. Karnra and Frank 3. Malvestuto, Jr. SUMMARY Tests of spin-recovery parachutes on six models of typical fighter and trainer airplanes wore conducted in the Langley 20-foot free-spinning tunnel to obtain data for correlating model and full-scale results. Parachutes attached to the tail of the models, to the outer wing tip (left wing tip for a right spin), to the inner wing tip, and to both wing tips were tested. The results indicated that parachutes of the same size and type were more effective as spin-recovery devices when they were attached to the outer wing tip in the spin than when they were attached to the tail. The diameter of the outer wing-tip parachute required for a 2- turn recovery by parachute action alone varied from )± to 7 feet. Parachutes attached to the inner wing tip would not effect recovery. When parachutes attached to both wing tips were used for recovery, the parachute diameters required were of the same order as for tail parachutes. The diameter of the tail parachute required for a 2-turn recovery by parachute action alone varied from 6.5 to 12.5 feet for the airplane designs used. INTRODUCTION In order to obtain data for a correlation between model and flight tests of spin-recovery parachutes, tests were conducted with six airplane models of single-engine design. The effectiveness of both tail and wing-tip parachutes as spin-recovery devices was determined for these models. The spin-recovery parachute is normally NACA AHR No. LSGI9a used only as a temporary emergency safety device during spin demonstrations so that rapid recoveries from uncontrollable spins may be obtained. Available flight and model test data on the use of tail parachutes as spin-recovery devices are presented in reference 1, and the results of these tests indicated that airplanes weighing between 7500 and li|_,00G pounds require tail parachutes having diameters of approximately 8 feet "(based en a drag coefficient of 1,02) and towline lengths between 20 and 50 feet In order to obtain satisfactory recoveries by the use of the parachutes alone . Results are presented herein of the investigation of the six airplane models, designated models A, B, C, B, E, and F, with spin-recovery parachutes attached either to the tail or to the wing tips of the models for the normal loading conditions. On each model, tail and wing-tip parachutes of various sizes were tested with several lengths of line connecting the parachute to the airplane. The results are analyzed to show the minimum satisfactory size of the parachute and the optimum length of the towline for spin-recovery-parachute installations. Brief additional tests were conducted to investigate the effect of mass variations on the effectiveness of the spin-recovery parachutes v/hen attached to the wing and the effect on recovery of simultaneously opening a tail parachute and neutralizing the rudder. For one model, tests were made at two equivalent spin altitudes to determine whether altitude critically affected tail - or wing- tip- parachute effectiveness . Two of the models (A and B) had been used in the investigation of tail parachutes reported in reference 1 and tests of tail parachutes were accordingly not repeated for these two models. The results obtained in the previous investigation are included however in the present paper. SYMBOLS b wing span, feet m mass of airplane, slugs Iv, I-yr, and Ig moments of inertia about the X, Y, and Z body axes, respectively, slu^-feet r ACA ARR No. L5G19a T X - T -Y mb^ Iy - X H mb 2 *z - \ inertia yawing-moment parameter inertia ...rolling -moment parameter inertia pltchingi-moment parameter mb a acute angle between vertical axis and thrust line (approximately equal bo absolute value of angle of attack at plane of s yimae try ) , de gre e s angle between span axis and horizontal, degrees V airplane true rate of descent (estimated by scaling from model values), feet per second ^ airplane- angular velocity about spin axis (estimated by scaling from model values), radians per second D drag of parachute, pounds; also diameter of parachute spread flat M q oynami c pre s s ur e p air density, slugs per cubic foot Crj drse - coefficient of" "parachute / - Q ) W S surface area, -of parachute, - square feet I C^ rolling-moment coefficient (-i \qo .oo, S wing arsa, square feet L rolling moment about. longitudinal. body axis, foot-pcunis /A ^n yaw.ing-moment coefficient f — — j N yawing moment about normal body axis, foot-pounds lj. NACA ARR No. L5G-19a APPARATUS AND MODELS The tests were performed in the Langley 20-foot free-spinning tunnel, the operation of which is similar to that of the 15-foot free -spinning tunnel described in reference 2. Models A, 3, C, and D, used in the investigation, represented typical fighter airplanes, whereas models E and p represented typical trainer-type airplanes. The design characteristics of the airplanes represented by the models are presented briefly in table I and three- view drawings of the models used in the tests in the Langley 20-foot free-spinning tunnel are presented as figures 1 to 6. The general construction of the spin models is described in reference 2. Briefly, the models, con- structed of balsa, are dimsnsionally representative of the corresponding airplane and are ballasted for dynamic similarity to the corresponding airplane by the installation of proper-size lead weights at suitable locations . The model parachutes used for most of the tests were the same ones used for the investigation reported in reference 1 and were made of parachute silk. The skirts of these parachutes were not hemmed, nor were the para- chutes made of individual panels. They were circular and when spread out on a flat surface formed a disk. Circular vent openings were cut in the center of the parachutes and were made one -twelfth of the diameter of the parachute when spread out on a flat surface in order to simulate approximately full-scale vent openings. Eight shroud lines of equal length were evenly spaced on the periphery of the parachute. The shroud-line lengths were made 1.35 times the diameter of the parachute because it has previously been found (reference 5) that with shroud lines greater than 1.25 times the diameter, the drag coefficient varies only slightly with change in shroud-line length. In order to determine whether details of construc- tion affected the action of the parachutes, a few parachutes were constructed to simulate more nearly full-scale parachutes - that is, the skirts were hemmed NAG A ARK No. L5G19a and. the parachutes were made of individual panels sewed bogether (fig. J). Ten panels and ten shroud lines were arbitrarily used for these parachutes. rptpqrr-.c The spin-testing technique used in the Langley free- spinning tunnels is described in detail in reference 2. Briefly, the models with the rudder set for the spin are launched by hand (this procedure supersedes the launching- spindle method described in reference 2) in a spinning attitude into the vertical upward air stream of the tunnel. The airspeed is adjusted to equal the normal rate of descent of the model. A remote-control mechanism is installed in the models to actuate the controls or to release the parachute for recovery attempts. For tests with the parachute mounted at the tail, most recoveries were attempted by ejecting the parachute from a container (as described in reference 1). The rudder was kept with the spin during recovery so that the effectiveness of the parachute alone could be obtained, In addition, a number of tests ware conducted in which, for recovery, the rudder was neutralized at Che same time that the parachute was opened so that the combined effect of opening the parachute and neutralizing the rudder could be evaluated. For the investigation of wing-tip parachutes, the parachutes were mounted on the upper surface of the wing near the wing tip. Figure 8 shows the type of instal- lation used. For attempted recoveries, a rubber band holding the packed model parachute to the wing was released by the remote -control mechanism and the parachute was opened merely by the action of the air stream over the wing. Tests were made to determine the parachute effec- tiveness with the loading along the wings and along the fuselage varied for several of the models. Table II presents the mass parameters of the models for the normal leading condition and for the alternate loading Iv - Iv Ty — I r ,' conditions. The parameters — — -, — — ^~ Jd > I z - I T mb 1 - mb 1 - and — ; o — are Indicative of the relative distribu- mb^ tlon of the mass along the three body axes. NAG A ARR No. L5G19a As previously mentioned, tests of both tail and wing-tip parachutes were made for one model ballasted to represent the corresponding airplane at altitudes of icf,000 and 20,000 feet. RESULTS AND PRECISION The results of the investigation are summarized in tables III to VIII and figures Q to 27. The drag coefficients of the model parachutes were found to be approximately 0.73 (based on flat area) by determining in the tunnel the rates of descent of the freely falling model parachutes with various weights attached. The full-scale-parachute diameters referred to herein were obtained by scaling up the model values, inasmuch as at the present time only limited data are available on the correct value of the drag coefficients of freely falling full-scale parachutes. Reference 3 indicates that the drag coefficient 0.73 obtained for model parachutes is within the range of values of drag coefficients 0.62 to 0.79 obtained for freely falling full-scale silk antispin parachutes. In reference 1, the parachute diameters were corrected for a difference in drag coefficient between model and full-scale para- chutes on the assumption that the drag coefficient of full-scale parachutes was 1.02. In order to select the full-scale parachute, it is therefore necessary to know the drag coefficient of the full-scale parachute and to correct the parachute diameter for any difference in drag coefficient between the full-scale parachute and the model parachute to obtain the same drag. An example showing the method used to determine the correct diameter for full-scale parachutes, based on drag coefficients of model parachutes, is given in the appendix. The parameters given in table III present the steady- spin characteristics of the models just prior to attempted recoveries. All the models used in the present Investiga- tion had previously been tested and repaired extensively. As a result, the steady-spin characteristics presented in table III are somewhat different from those obtained during the previous routine investigations of the models but are considered to be accurate enough to give depend- able results for the present investigation. I AC A ARR No. L5G-19a The steady-spin parameters presented in table III are believed to be the true values given by the model within the following limits: a, degrees il 0, degrees ±1 V, percent -2 & , percent i2 host of the recovery data plotted in the figures were obtained from film records and are believed to ,1 be the true values given by the models within Ty turn. 4 A few of the recoveries were obtained '\dj visual estimates ,1 and are believed to be accurate within Z~ turn. DISCUSSION Parachute Construction The results of brief tests that were conducted to compare the drag coefficients and effectiveness of the plain fabricated model parachutes used in the investiga- tion reported in reference 1 with, the drag coefficients and effectiveness of parachutes more nearly approximating full-scale construction, as shown in figure 7» showed that the drag coefficients of the differently constructed parachutes were similar and that the parachutes had the same effectiveness of operation during model tests, host of the tests were therefore conducted with the olain fabricated earachutes since these parachutes were readily available in all sizes. Tail Parachutes The variation of turns for recovery with tail- parachute diameter for the normal-control configuration for spinning (rudder full with the spin, elevator full up, and ailerons neutral), for the elevator-neutral position (ailerons neutral), and for the ele vator-down position (ailerons neutral) are presented in figures 9 10, and 11, respecti vely. Recoveries were attempted b ejecting the parachute from a cylinder installed near the tail. In figures 0, 10, 11, and the following graphs, the arrows on the ends of some of the curves / > 8 NACA ARK No. L5G19a mean that the model did not recover in the number of turns Indicated. Parts of the curves falling between points representing a diameter that gave recovery and one that did not give recovery are dashed to indicate that the fairing of that part of the curve is questionable . For a constant towline length the turns for recovery generally decreased as the tail-parachute diameter increased. The approximate full-scale-parachute diameters required to effect a recovery from the spin in 2 turns at the normal-control configuration are summarized in table IV and varied from 6.5 to 12.5 feet. For models a, B, and G, spins with the elevator up required somewhat larger tail parachutes than did spins with the elevator neutral or down, whereas for models D, S, and F, the opposite was true (figs. 9 to 11). The explanation of this result is not apparent. The length of the towline of tail parachutes had a marked effect on the number of ferns for recovery, as may be observed from figure 12, which presents results for elevator-up spins. (Although not presented, the same type results were obtained with the elevator neutral or down. ) Towline lengths between 20 and 50 feet full scale were most satisfactory because within these limits the variation of turns for recovery with towline length was small. This result is con- sistent with the conclusion of reference 1. The effect of simultaneously opening a tail parachute and neutralizing the rudder is presented in table V for the up, neutral, and down positions of the elevator (ailerons neutral). Neutralizing the rudder in conjunction with opening the parachute was somewhat beneficial for all conditions tested. As previously mentioned, reference 1 Indicates that an 8-foot tail parachute (based on a drag coef- ficient of 0.73 instead of 1.02, the diameter of the parachute would be *y— feet instead of 8 feet) would effect a satisfactory (2-turn) recovery from the steady spin for airplanes weighing between 75^0 and li;.,000 pounds. The current tests indicate that the diameter of the tail parachute required for a satis- factory recovery from the spin is not constant nor SAC A ARR No. L5G19a does it vary directly with the weight of the airplane. For .example.., airplane C having a gross weight of 7I4-O0 pounds required a 9~f°°t tail parachute and air- plane D having a gross weight of GOll pounds required a 12.5-foot tail parachute, but airplane E having a gross weight of 9277 pounds (1266 pounds more than the gross weight of airplane D) required a J-±oot parachute for satisfactory recovery from the spin. Parachute 3 Mounted on Outer Wing Tip The wing- tip parachutes, mentioned previously, were mounted on the upper surface of the wing near the wing tip, as shown in figure 8. In some cases, the protuberance of the packed parachute affected the steady spin of the model, and for each series of tests determination of the location at which to place the parachute pack was necessary so that the steady-spin characteristics of the model were not changed. For this reason, Installing the parachutes on the surface of the wing of airplanes is not considered .advisable. The parachute packs should instead be placed inside the wing and provision should be made to eject the parachutes into the air stream. The variation of turns for recovery with parachute diameter for parachutes mounted on the outer wing tip (left wing tip In a right spin) for spins with the elevator up, neutral, and down are presented in fig- ures 13, 111, and 15, respectively. Figure 16 shows the action of the outer wing-tip parachute in effecting a recovery from, the spin. The towllne lengths were generally made approximately equal to the semispan of the airplanes. In general, for all models a larger wing- tip parachute was required to effect recovery from spins with the elevator neutral or down than from spins with the elevator up. The diameters of the outer wing-tip parachutes required to effect a recovery in 2 turns from the spin at the normal control configuration for spinning are given in table IV for all the models and varied from If. to 7 feet. The results in table IV indicate that for the models tested, a parachute attached to the outer wing tip is more effective as a spin-recovery device than the same size parachute attached to the tail. 10 NACA ARE No. L531Qa Figure 17 presents test results showing the vari- ation of turns for recovery with towline length for wing-tip parachutes for the elevator-up spins. Towline length did not appear to influence the effectiveness of the parachutes appreciably. 'Ahen no towline was used (or when the towline was very short), however, the parachutes sometimes fluttered in the wake of the wing as shown in figure 13 (frames 1I4. and 15 ) and did not function properly. If long towlines ( towline s approxi- mately equal to or greater than wing span) are used to attach the parachute to the wing tip, there is the possibility of the parachute and towline fouling the tail or fuselage of the airplane as shown in figure 19 (frames b r j> and ijij.). It is recommended, therefore, that the length of the towlines be such that when fully extended the parachute just misses both the tail and the fuselage. Parachutes mounted en Inner Wing Tip Brief tests (test results not presented) made with parachutes attached to the inner wing tip (right wing tip in a right spin) indicated that parachutes on the inner wing tip will not effect a satisfactory recovery from the spin. For some cases use of the parachutes was observed to flatten the spin. It is, therefore, very important to use care in opening the correct wing- tip parachute for attempted recoveries from spins. Parachutes Mounted en Both vVing Tips The simultaneous opening of two identical parachutes, one mounted on each wing tip, would eliminate the hazards encountered in using only one wing-tip parachute - the hazards are the possibility of opening the wrong parachute or the danger of being forced into a spin in the opposite direction by a large wing-tip parachute (see fig. 2C) if the parachute is not released immediately after recovery. The effect of parachute diameter for elevator-up, elevator- neutral, and elevator-down spins on turns for recovery attempted by simultaneously opening parachutes on both wing tips is presented in figures 21, 22, and 23, respectively^. Satisfactory recoveries from the elevator- up spins could not be effected for models A, B, B, and F with tiie largest parachutes tested. The results for models 3, B, and F were not plotted because, for the size of the NACA ARR No. L5G19a 11 parachutes investigated, recoveries could, not be obtained from spins. Models C and D required approximately 8-foot parachutes for a 2-turn recovery. The results presented in figures 21 to 2J indicate that moving the elevator full down in conjunction with opening the parachutes may he desirable in order to obtain recovery from spins by simultaneously opening parachutes mounted on both wing tips. A comparison of the results presented in table IV shows that much larger parachutes will be required to obtain satisfactory recoveries by opening parachutes mounted on both wing tips than by opening one parachute mounted on the outer wing tip. In order to obtain satisfactory recoveries by opening parachutes fastened to each wing tip, the parachute diameters may have to be as large or larger than the diameter .for tail parachutes. Figure 2lx shows the effect of towline length on turns for recovery attempted by the use of parachutes mounted on both wing tips for- the elevator-down condi- tion. As was the case for parachutes mounted on the outer wing tip, towline length generally had little effect on turns for recovery. When the towlines were too long (equal to the span), however, they frequently became tangled with each other and did not effect recovery. The results presented in figure 2).\. are for the cases in which the parachutes opened properly with- out tanarlins. Loading Variations In order to determine whether variations in loading of the models would influence the effectiveness of parachutes, tests were made on some of the models with the loading varied along the wings and fuselage. Brief tests of outer wing- tip parachutes were made on four of the models with the loading along the wings increased and on one of these four models with the loading along the fuselage increased. The results, which are summarized in table VI, indicate that extreme increases in the leading along the wings had little effect on the recoveries obtained by opening parachutes fastened to the outer wing tip for models A and E but had an adverse effect for models G and P. A moderate increase in the loading along the fuselage had little effect on recoveries of model F. 12 liAQA ARE No. L5G19a Table VII summarizes the effect of loading vari- ations on the recoveries obtained by simultaneously opening parachutes mounted on both wing tips for models C, E, and P. With the loading along the wings increased for Model C, recoveries were slower than for the normal loading condition. as mentioned previously, recoveries could not be effected for models E and F in their normal loading conditions, and increasing the loading along the wings of these models had no noticeable effect en recovery A moderate increase in loading along the fuselage had no appreciable effect on the recoveries of model F. Brief tests were made with model 3 to determine the effect of loading variations on recoveries attempted by simultaneously opening a tail parachute and neutralizing the rudder. The results are presented in table VIII and show that moderate increases or decreases of mass along the fuselage and wings did not appreciably affect the recoveries. Effect of Test Altitude Brief tests i^ere conducted with model E to determine whether variations in test altitude would influence the effectiveness of spin-recovery parachutes for this air- plane. The model was tested at simulated test altitudes of 10,000 and 20,000 feet. The results are presented in figures Zy to 27. Based on these meager results, there appears to be little effect of altitude on the optimum size of wing-tip or tail parachute required for satisf actory recovery. The test altitude also had little effect on the variation of turns for recovery with -cowline length for parachutes attached to the tail. Action of Spin-Recovery Parachutes Tall parachutes .- The action of tail parachutes in effecting recoveries from spins has been discussed in reference 1. Briefly, with long towlines (towlines longer than 50 feet, full scale) the parachute towlines tend to Incline toward the spin axis. With short tow- lines (less than 20 feet, full scale) the parachute towlines tend to remain alined with the fuselage axis. With towlines between 20 and 5^' feet long, the parachutes usually ride approximately over the tail of the model, although they may oscillate from this position. NACA ARR No. L5G19a 13 Reference 1 indicates that as the towline may usually incline away from the plane of symmetry toward the inner wing tip, the parachute exerts yawing as well as pitching moments out that the effectiveness of the parachute results more from the antispin yawing moment than from the pitching moment produced. Outer wing- tip parachutes .- The typical action of a parachute fastened to the outer wing tip in effecting recovery is shown in figure lo . Frame 15 of figure i6 and frames 22 and 34- of figure 19 show that the parachute towline tended to incline awa;/ from the fuselage axis toward the vertical axis. Frame 20 of figure l6 and frames lo and 2-3 of figure 19 shew that the parachute towline generally tended to remain parallel to the X-Z plane of the model, although the parachute did oscillate. The motion-picture records of all the tests indicate that both roiling and yawing moments were set up by the parachute. As a matter of interest, the esti- mated yawing and rolling moments contributed by parachutes were compared with corresponding moments contributed by rudder reversal and full aileron deflection. The moments resulting from rudder and aileron deflection were computed by use of average moment-coefficient values for angles of attack in the spinning range obtained from force tests on models of other airplanes. For cases in which the outer wing-tip parachute was effective, the rolling- moment coefficient Cj due to the parachute was in the direction to roll the .model into the spin and varied from 0.010 to 0.015, which is less than one-half the typical rolling-moment coefficient of 0.03 developed by full aileron deflection. The yawing -moment coeffi- cient C n due to the parachute was approximately equal to the typical yawing-moment coefficient of 0.015, which would be expected from full reversal of the rudder. The effectiveness of wing- tip parachutes appears to result therefore more from the yawing moments set up by the parachute than from the rolling moments. Reference [l states that when the mass of an air- plane is distributed chiefly along the fuselage, setting the ailerons with the spin will assist recoveries obtained by rudder reversal, whereas when the mass is distributed chiefly along the wing, setting the ailerons with the spin may greatly retard recoveries. ft parachute attached to the o^ter wing tip, by inducing a pro-spin rolling moment, is in effect simulating the aileron- with-spin configuration of the airplane. It would be llj. NACA ARR No. L5< expected, therefore, that recoveries obtained by the use of an outer wing-tip parachute would be retarded by extending mass along the wing of the airplane, if the yawing moment due to the parachute and the yawing moment due to rudder reversal are approximately equal. This adverse effect of extending mass along the wing was obtained for models C and P, whereas for models A and E very little effect on turns for recovery was obtained by change in distribution of mass. CONCLUSIONS Results of tests of spin-recovery parachutes made on six models of typical fighter and trainer airplanes to obtain data for correlating model and full-scale results indicatedthe following conclusions: 1. Parachutes were more effective as spin-recovery devices when they were attached to the outer wing tip in the spin than when they were attached to the tail. The diameter of the tail parachute required for a 2-turn recovery by parachute action alone varied from 6.5 to 12,5 feet, whereas the diameter of the outer wing-tip parachute required for a 2-turn iiencovery by parachute action alone varied, from-ii. to 7 feet. 2. When a parachute, jitta.ch.ed to the inner wing tip in the spin: was opened, the parachute- would not effect recovery. 3. 'Mien parachutes attached, to both wing tips were used, -the parachute diameters required, were approximately the same size as for tail ^aarachutes. !(-. For wing-— tip parachutes it ia reccxmnended that the towline length be .such, that -men fully extended the parachute Just misses both the tail and fuselage. 5. For tail parachutes the towline should be beirwee_n 2.0, and 50 feet long. 6. Neutral. i .zing the* rudder at the same time that .the iaii parachute was opened gave faster recoveries than were -obtained by open ing the parachute alone. KACA ARR No. L5C-lQa 15 7. ?or two of the four models tested with varied mass distribution, extension of mas3 along the wings had an adverse effect on recoveries attempted by opening parachutes attached to the outer wing tip. 8. Tests conducted with one model at two equivalent test altitudes (10,000 and 20,000 ft) showed no noticeable effect of a change in altitude on the optimum size of wing-tip or tail parachute required for satisfactory recovery. Langley Memorial Aeronautical Laboratory National Advisory Committee for Aeronautics Langley Field, Va. 16 NACA ARR No. L5G19a APPENDIX MS07HOD 0? CORRECTING PARACHUTE SIZE FOR DIFFERENCES IN DRAG COEFFICIENTS The model tests Indicate that for model C, for example, a: 9»0-f° o ' t parachute fastened to the tail will be required to effect a recovery in 2 turns by merely opening the parachute. This diameter is "based on a drag coefficient Cd of 0.73 for the parachute. If it Is planned to use a parachute of similar shape but of different material so that the parachute has a drag coefficient of O.56, the area must be larger in the ratio of 0.73/0. 5^. The parachute diameter must therefore be larger in the ratio l! * , - l.lij-, which \l O.56 gives a parachute diameter of 10. 'J feet. MAC A AHR No. L5G19a 17 REFERENCES 1. Seidman, Oscar, and Karam, Robert W.: Anti spin-Tail- Parachute Installations. NACA RB, Feb. 19^3. 2. Zimmerman, C. H.: Preliminary Tests in the N.A.C.A. Free-Spinning Wind Tunnel. NACA Rep. No. 557, 1936. 3. '/food, John H.: Determination of Towline Tension and Stability of Spin-Recovery Parachutes. NACA ARR No. L6A15, 19i|6. i|. Neihouse, A. I.: A Mass-Distribution Criterion for Predicting the Effect of Control Manipulation on the Recovery from a Spin. NACA ARR, Aug. 19^2. NACA ARR No. L5G19a 18 M w < Eh w Em co w EH CO •J w Q o a fx. o CO o M E-» OT M W En o <: w o a o g 60 a •H O o .S3, 1 N p eg rH it CM -2 rH 3 rH O CM rH CO vO M rH 4J 0J - H 3 f\J -g CO H t— o NN. CM CM rH rC\ CM H rH -P •> « » « «k « OJ *H KN ON vo t— -d -=t *-» rH 1 t— O r-« NN. ON H X P OJ V0 CM O O LfN -d CO ON CM ON VO f- t-H rH -P * • • » •> «» » «H rr\ CO LP* -d CM CM — ' r-l « bO bO-H CO rf\ rf\ rTv Os C- rH • • • • • • (Jti\ CM NN. vO *N t>- CO •h d 5 _d rT\ rr\ rO. H rH ^ o rH ^. -P o -d- O O o CM bO «tf *h • • • • • • d © o UN W> vO ON VO •Hf( O 1 o C- rH rTN K\ C^ ^ Ctf 01 rev CM CM CM CM 3 -p co -d O rT\ O o • • • • • • ft«i-i o H -d t— % H CO-^ -d- -d" KN KN. -d- 43 "* fl • • «h 9k k © - — rH ON t— CO -d -d C5 £ rH © O o " o o o o -P P -— o o o o o o ro -P +a o o o o o o 7 >9 9.0 8 >6.5 >6 NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS NACA ARR No. L5G19a 22 I CO EH o H PL! o CO o s M CO o Eh O W 09 © 43 43 © X) ■s cs +> 8 n o >43 -d > o 43 rvj 43 * ^-d © *d «H|OJ •H|OJ > O ft, O aj O fn h0 r-l iH H iH ■H W MrH 2 O 43 C\J 43 43 O «rH © © 43 EH >> a p, o o H OJ O O O "1 > ^ 43 43 43 43 43 © w HlOJ ^1 H|OJ l-l H ro4J- o H ^ IF HJOJ ed $ eo o 43 © 43 H ob* O 43 H cF © -cJ f»»43 O OB iH CM W OJ O CO _d/ ^ ^ ro O U 43 U © a) 43 o H J^ o o O n a > 2 43 43 43 43 © © U bO o fl rH|OJ H cF H^M HjO, *M *H a H J^ Turns y ope K\ o 43 — » "*f* OJ Hlrvj ^1 S s gf ft o* o O J3 ^3 o 8 x> > 3-' ■p 43 o 43 43 43 © 43 "& "V rH £ o 2 o 3 r-»KM © i-i aS © o fl^ — 03 «H +> 43 OJ OJ to, rr\ ro ir\ rH 1 pH bO«M OJ OJ -=j- -d- -d- rO ro. H * fl — iH O © £^ © © H 43 U CO p © 0,d.43^ CO oo CO o co O tf\ •J O © 43 • • • • » • • 1 cd S«h CO 00 CO r- CO f- vO rH m a^- r-} cd *H £ P"C © § rH < PQ o o Q w fc < © O m C O •H 43 O © co- co o H OS < 5 o& CO O •H M « to >w CQ ^^ fH « co «< s o w M H Eh Eh o H Eh 05 a g co « & CO S3 o CO w 05 © £ o M o M 05 S3 w is < 05 PL, o as o ID p 00 ry, J3 ft p « 60 fl 2 55 ,d CP «H »H r-l » Sh P ® a) p pp .C — o o O o o p P P P P p OS > r-l rH t-t rH|C\l ■s o r-l rH at W U a) &h • tO-d 51 H a fc. at U S • S3 K^d" ^ rNL* Hj^VI •-Mcu •O-rl rH u o O O O O t»> as o P P p P p fn h p *3 as > rH r-l rH|_C\| r-Myd- H|_d- O 4> ® o fl rH ® w fn TJ fH S O *-i a §• l-l| <\J *M-d- rH|CM 3 (h *N-d- H r^T rH Eh o--^ r-l|H rH >>M t>.M t>>H r-.H C tv5X3 N £> NX) N X3 too M P M P M P W P S3 H ■d c "O S3 ■d S3 -O S3 tf ■d a> a> •a d t> a> •d *£& « a> iJ 5 SB x h a « fn ft Jh Ih ft o M O H O H O M O SO e o CO o O «-i nj -OCV »H f\J •d aj • s rH ft m m 03 03 03 h ■H < fl aS P a Sh aS HQ5 I 3 U 05 a> T) ^g T) S3 e O PtJ h Bq Tt 5U S *§ s Sh o O o p t O a> J3 p O n g P O o rH ® •o *H o a § r-j as NACA ARR No. L5G19a Fig. 1 9.60 '-M r Ul" & elevator hinge Thrust line t rudder hinge NATIONAL ADVISORY COMMITTEE FOB AERONAUTICS Figure 1.- Drawing of model A used In the teste In the Langley 20-foot free-spinning tunnel. Normal loading condition. Fig. 2 NACA ARR No. L5G19a £ elevator hinge £ f/ap hinge .79" Thrust line Chord p/ane £ rudder hinge NATIONAL ADVISORY COMMITTEE F0» AERONAUTICS Figure 2.- Drawing of model B ueed In the tests In the Langley 20-foot free-eplnnlng tunnel. Normal loading condition. NACA ARR No. L5G19a Fig. 3 u 3 cd w o CL .— 1 ■H T3 (D cd cd CL ■p CD >> 01 u ■P T3 CL • 1 CO CD u c CJ cd O CD cd i— i ■H +3 -i cd CD cd CL — "3 1 £! O C o ~ E o r-H CD cd CJ CO 1 rH ^H 3 > ■p cd • CD Cn ■P O 3 -C iH CJ CD cd T3 u O cd s Q- 1 r^H 1 CD t> X} O CD s 3 - — do cd NACA ARR No. L5G19a Fig. 8 c o ■H «3 +3 CO c •H 0) •P 3 X! O a u aj (X (X bo C u ■H CD cu bo NACA ARR No. L5G19a Fig. 9 -+ — i 1 JO — / u >- H " 3 -o < J !£ o I- ec - _l o < "■ Z ul 2£ ll o u / / S^^ N K V <>) <£> ft) 1 0. t CQ u Q Uj k ^ o + x '□ o < / Q / / "\ y / > / / r I* ' 1 ^^ / / < 1 ^ f / u 1- <* / • \< / / / / 1% \ ^ ^' s N /> \ .-% »" -< ^ -* < > i _ H — ■ — — <-~ "■*■" N ;^"3 ^ 1 *: 1 i) a-* • <1 m K K 0) J. or) «m Fig. 10 NACA ARR No. L5G19a 1 X I ! r ! o i x i X a * i Is >5 A A X 5> vl t> s I ^ I* 1 > (V) ^ NACA ARR No. L5G19a Fig. 11 IA U ->- 1- o| - Z UJ M 8 ||£ « s * 9 * * ■| <* «Q VJ Qk kj l< "^ + X P <> < Q 1 < i > : z i t\ U J 7 ^ \\ / y ii o<; ^ \y 1 jjs \ \ <*'■ •? / ^- y / / T~~~ _ — :- ^ /-■ ^ <• s *=--' ,.-; - — - — • — — Ch Qo K ?y ta/V /Darac/rufe. Co/pf/~o/s sef at /-etc/o'er- w/'ffij a/'/orcyps /?euf/-afj e/eyczfor u/d. NACA ARR No. L5G19a Fig. 13 NATIONAL ADVISORY COMMITTEE FOP AERONAUTICS 3 4 5" 6 7 8 9 /-u/Zsca/e oZ/a/r?efer scaZecZ up f/~o/r? /node/ sZze, ff F/gure/3rT/?e var/af/o/? of fur/?s for recovery wZfZi wZ/7y-fZ/0- / oan7c/?uZe cZZa/77cZ or? oaZer vr//?y t/p. Co/pfro/s seZ af /-^cftfe/^ w/ZZ? / az/a/^ojos /?eccf/~aZ } eZeisaZo/- u/D. Fig. 14 NACA ARR No. L5G19a s ?! [$2 AirplQi ne Tow/trie /e/icrf/? (ft) o A /o(6/4) + S Zo(6/£) * c /7(d/Z) O £ Z/(6/z) A F 2o(6/2) / 'ore < \ l/U./ / «. - a \ \ - A \ V \ y* ^ s te -c \ t ^ ^s r6 s-* > \^ - £ r ^ ^ m NATIONAL ADVISORY COHMITTEE FOR AERONAUT ., .j 1 1 4- 5 G 7 8 9 fu/Z-sca/e dic/weter sca/ed up fro/r? mode/ s/ze } ff F/yure /J- —The isar/af/0/7 of fur/7? for r-e'cov&ry w/t/? w//?yt- /-//y-paracfu/e c//o~/r>efer; recovery affe/npfed by opes)//)

eu fra/ t e/erafor r>eu.fr-/)arac/?ufe d/arvefer; recovery a /fe/??p fed £y ope/?/r>yf paracAufe /nous? fed cv? oaf er w/rty t/jo. Corfro/s set at rudder w/f/?, a//ero/?s r?eufra/, eferafor don/?. NACA ARR No. L5G19a Fig. 16 p to >s CO 2 ; <^ □ -c X n • NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS s /o f~u//sca/e d/'a/nefer sca/ed u/d fra/7? /node/ s/ze, ft F/'grure 22rT/?e \sar/af/o/? of /V>w for recor&ry w/f/y i^//7^-f//3-parac/?ufe d/a/nefer; recovery affe/z?/ofed 6y s/'/?7C//f&/?eous/y o/De/?//^ /Dcrr~ac/?ufes /r?ou/?fed os7 £of/? W/S7

ure23r77>e var/crf/os? of /ur/?s for* recovery w/'f/> w/P7^r-f//) -parachute d/d/vpefer; recovery af/e/pPyOfed 6y s/sp?u/t<7/?eous/j o/Oe/?//?^ /xzra ct?ufes /7?ou/?Ved o/? f?of/? w//? \ 7i zsf < /QOt 7/M. 9 Of t V > s ^ ^ K — Test Q/fifudej 20000 ft J NATION COMMITTEE 20 40 60 SO /OO f~u//-sca/e fow/)ne /e/?qf/?j ft f/gure 26.-7?7e effecf of fesf a/f/fude or? f/?e iras-/&f/or? of ftsrvTS* for- r~ecov€ , r-y w/f/? ?otv//ne length for model E; recovery affe/7ipted by opening f-Qi 7 parachute. Pa >rachut~e diameter^ feet ; controls set at rudder w/fh 3 a Herons neutral, e/evat-ors up. NACA ARR No. L5G19a Fig. 27 oo 6 3. I 1 — r 1 *" AT ore an 6 th Ij 1 1 1 1 s-7< est c \Q0t 7/ A/ 7 u c/de J f \ 1 / ' I \ \ \ \ \ NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS \\ -7ej/ a/t/tude. 10,6 00 1 c f I 2 J A S 6 7 Fo //-scale d/amefet 300/00/ up from mode/ s/zej ft f~(yure27,— The effect of test altitudQ on the [/or /of/ on of turns for recovery with parachute diameter for model Bj recovery attempted by open/no paracr?c/7e mounted on outer w/'ngt/p. lb yv line length ^54.5 feet; confrofs set at rudder with, a'/lerons n&utru/j elevator up- UNIVERSITY OF FLORIDA 3 1262 08104 953 7