GOVT. DOC.

TECHNICAL NOTES

NATIONAL ADVISORY COMMITTEE FO~ AERONAUTICS

No . 608

FREE-SPIlnnw i7IND-TUlIJIIl"EL TESTS OF A LO\7- \7ING MONOPLANE

WITH SYSTEMATIC CHANGES IN WINGS AND TAILS

I. BASIC LOADING CONDITION

By Oscar Seidman and A. I . Neihouse Langley Memorial Aeronautical Laboratory

Washington August 1937

BUS,f\I:SS. SC/E.NCt. & TE.CHNOLOGY DEP'T.

https://ntrs.nasa.gov/search.jsp?R=19930081399 2018-02-10T03:53:35+00:00Z

NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

TECHNICAL NOTE NO . 60 8

FREE-SPINNING WIND-TUNNEL TESTS OF A LOW-WING MONOPLANE

WITH SYSTEI.IATIC CHANGES I N WINGS AND TAILS

I . BASIC LOADING CONDITION

By Oscar Seidman and A. I . Ne ihouse

SUMMARY

A series of tests was made in the N . A', C.A . free ­spinning tunnel to determine the efr-ect of systematic changes in wing and tail arrangement upon steady- spinning and recovery characteristics of a conventional low-wing monoplane model for a basic loading condition. Eight wings and three tails , covering a wide range of aerodynam­ic characteristics , were independently ballasted so as to be interchangeable with no change in mass distribution, For each of the 24 wing-tail combinations, observations were made of steady spins fo r four control settings and of recoveries for five control manipulations . The results are presented in the fo rm of charts comparing the spin characteristics .

The results showed that, with a poor tail arrangement, wing plan form and tip shape had considerable effect on the spinning characteristics, A wing with rectangular plan form gave noticeably steeper sp ins and faster recov­eries thun the same wing with Army tips. Poorest recov­eries uere obtained for a wing with 5 : 2 plan-form taper and no thickness taper ; rapid recoverie s were obtained uith a uing having 2 : 1 taper in both plan form and thick­ness. For al l the wings tested, satisfactory recoveries could be obtained by the use of a tail with a deepened fusel~ge and a raised stabilizer . Holding the elevators up resulted in the steepest spins from which, by reversal of both controls, the most rauid recoveries were obtained. Steepest spins were generally~ though not always, associ­ated nith most rapid recov e ry, but there appeared to be no relation betueen the sideslip of the steady spin and the turns required for recovery .

2 N. A.C.A. Technical Note No. 608

INTRODUCTION

As a result of extensive research performed in recent ye cr s in fl igh t, on sp inning balanc e s. and in fr e e- spinning ~ind tunnels, a consideraole body of data (references 1 to 14 as ~ell as unpublished results from the N. A.C.A. free­spinning tunnel) has been accumulated rega~ding the effects of inertial and dimens~onal modifications on the spinning properties of specific airplanes. The information availa­ble ~t present is not, ho~ever, sufficient to predict ac­curately the spinning characteristics of an untried air­plane design and actual full-scale or model testing must be resortcd to, unless the design incorporates extreme features known to be beneficial in the spin.

In order to secure more comprehensive data that might form the basis for developing design criterions, the N.A . C. A. has undertaken a systematic investigation of ~hich the tests horein reported constitute the first part . The general plan is to determi nc, by major independent varia­tions, uh ich of the dimensional and mass charact e ristics most greatly affect the spin. The effects of some minor changes u ill subsequently be invest igated.

It is planned to supplement the preliminary investi ­gation of a lo w- wing monoplane by brief tests to sho~ com­parative effects with a high-wing monoplane and ultimately to extend the investigation to biplanes as uel l.

The major ~in€ variables selected include tip shape, section, plan fo rm, and flaps . The prog ram included tests of an Ar my standard tapered wing (ref erence 15) that com­bines changes in plan form an<l thickness . The three test­ed tail arrangements range from a combination utilizing full-length rudder and raised stabilizer on a consid erab ly deepened fuselage , designed to be extrem ely officient in providing yawing moment for recovery, to a more nearly conventional typo "with rudder completely above a shallow fuselage and badly shielded by the horizontal surfaces .

The present repor t gives results of tests of eight wings and three tails for the basic loading condition .

The basic loading condition is representative of an average of values for 21 Am er ican ro_ l~lanes for which the moments of in ert ia were available . Eight other loading conditions to be inv estigated involve independent varia-

-~~" --

N.A.C.A. Technical Note No. 608 3

tions of relative density, center-of-gravity location, and moments of inertia. The range to be covered is based on tho values for these airplanes .

APPARATUS AND METHOD~

A general description of model construction and spin­test technique in the N.A.C.A. free-spinning tunnel is given in reference 11 . Since the publication of reference 11 it has been found possible to expedite testing by l~unch­ing models directly by hand, obviating the uso of the launching spindle.

The models are mado of balsn, reinforced nith spruce and bamboo. In order to secure lightness, tho, fuselago and nings are hollowed out as necessary, external contours being m~intained by means of silk tissue paper on reinforc­ing ribs. The desired loading is attained by the proper distribution of load noights .

As can be seen in figures 1 to 5, the uing and tail units rrero independently removable and interchangeable to permit the testing of any combination . The wings and tails n ere also in(lependently ballasted so that exchange of units could be made '.7ithout change in mass distribU­tion.

A clock,Tork delay-action mechanism was , installed to actuate the controls for recovery, simulating the rapid motions that would be imparted by a pilot.

The low-wing monoplane model uas not , scaled from any particular airplane but was designed simply to be a rep­resentative low-wing cabin monoplane with cowled radial engine and uith landing gear retracted. Over-all dimen­sions arc given in figure 1 .

For convenience in making compurisons the model may bo considered to be a 1/15-scale nodel of either a fighter or a four-place cabin airplane, tested at an altitude of 6,000 feet. In this case the full - scale characteristics nith the baaic loading and tail C would be:

rTeight (w) 4,720 lb .

Moan chord (c) 75 in.

4 N. A.C . A. Tochnic~l Note No . 608

Spc,n (b) . . . 37 . 5 ft.

Wing area (8) 234 . 4 sq . ft .

Aspect ratio .• 6

Distance from c . g . to elevator hinge . . . . . . 16 . 6 ft.

Di stance from c . g . to rudder hinge 16 . 9 ft .

Fin area 6 . 8 sq~ ft .

Rudder area 6.9 sq . ft.

Stc,bilizer area . 19 . 8 sq . ft ,

Elevator area 12 . 9 sq . ft .

Control travel Rudder: ±30 0

Elevator: 300 up,

20 0 down

Pr i ncipal moments of inertia.:

A • 2,760 slug- ft . 2

B 3,970 sl ug-ft . 2

6,150 91 ug-ft . 2 c .

x/ c

z/ c

. . . . . . . . . . . . . 0 . 25

. . . . 0

The quantity x/c is the ratio of the distance of the center of gravity back of the leading edge of the mean chord to the mean chord ; and z/c is the ratio of the di s ­tance of the center of gravity below the thrust line to the mean chord .

Figures 1 and 4 show (wing 1) and the smallest wing is of N.A . C.A. 23012 form and Ar my tips . (The scribed in reference 16 . )

the model with the basic wing tail (tail C) i nstalled . This section with rectangular plan tip contour is der i ved as de-

In co mm on with the seven other

II

N.A.e.A. Technical Note No. 608 5

wings tested, it had an area of 150 square inches, a span of 30 inches, and no dihedral, t~ist, or s~eepback.

Th e seven remaining wings (figs. 2 and 5) have varied di mens ional characteristics as follows:

Uing 2: N.A.C.A. 23012 section, rectangular with Army tips. 20 percent split flaps deflect­ed 60 0 •

Ui n g 3: N.A.C.A. 23012 section. rectangular with rec­tangular tips.

Uing 4: N.A.e.A. 23012 section, rectangular with faired tips.

Uing 5: N.A.C.A. 0009 section, rectangular with Army tips.

Uing 6: N.A.e.A. 6718 sectioh. rectangular uith Army tips.

Ui ng 7: N.A.e.A. 23012 section, 5:2 taper with Army tips.

Ui ng 8 : N.A.e.A. 23018-09 section, Army standard plan form (square centor section; 2:1 taper in both p lan form and thickness. and rounded tip).

The t hree tails tested are de s ignated A, B, and O. The conventional ~rrangement of a shallow fuselage with rud der co ~p le t ely above the tail cone is represent ed by ta i l C. The di mensional characteristics of this tail a rec

Ve r t ica l t a il a roa, 6 uercent uing area (3 percent rudder an d 3 perc ent - fin).

Fuse l age si de ar ea, back of leading edge of stabiliz­er, 2 p ercent u ing area.

Vert i cal t~il l ength (from qua rt er-chord point to rudde r hinge axis). 45 percent uing span.

Ho r i zo n tal tail area, 14 percont wing area (5.5 p er­c on t e l evator and 8.5 p e rcent stabilizer).

Ho r i z on t a l tail len g th (from quarter-chord point to elevator hinge a xi s), 44 parc ent wing span.

6 N.A.C . A. Technical Note No . 608

Tail E (figs . 3 and 5) was derived from tail C by in­creasing the fuselage depth , raising the stabilizer and elevators, and installing approximately the original fin and rud d er atop the deepened fuselage.

For tail E with the same tail lengths as tail C, the ( i mensional characteristics are:

Vert ic e l tail area, 6 percent wing area .

Fuselage side a rea, 5 . 5 percent wing area .

Horizontal tail area , 14 percent wing area .

Tail A ( figs . 3 Rnd 5), with same tail lengths as for E and C, uas similar to tail B except for full - length rudder construction and slight ly increased elevator cut- ou t :

Vertical tail a rea, 8 . 0 percent u ing area (5 percent rudder and 3 pe rcent fin).

Fuselage side area, 3 . 4 percent wing area .

Horizontal tail area, 14 pe rcent wing area.

The model loading (f o r the equivalent test altitude of 6 , 000 feet) corresponded to the following mass-distri­buti on parameters at zero altitude (p:::: 0 . 002378 ) :

NbC!

g(C-:-A:)

1L::2 C - A

x/ c

z/ c

::::

::::

::::

::::

::::

::::

IV

gpSb

61

0.64

:::: 7

8 . 7 (where kX is the radius

of gyration about the X axis)

0 . 25

o

, I . [

B.A.C.A. Technical No t e No . 600 7

RESULTS AND PRECISI ON

For ea ch \7ing and tail cODoination, sp i n tests \Tere nacle for fou r cont r o l settings :

(a) rudd e r 30 0 \T it h the sp in and e l evato r s neutral.

('.J ) rud c1_er 30 0 wi th the sp in and e l evat or s 20 0 dO\Tn .

( c) rudder 300 IT i t ~1 the sp in and elevators 30 0 up.

( d) rudde r neut ral an d. e l eva tors neutral.

Recov ery fron c ondi tion s (a) and ( D ) was attenpted oy r e ­versal of the rudder, · frOD (c) by co np l ete reversal of both controls and also by neutralizing Doth controls, and fron Cd) by cov i nG Doth c ont rols to fu lly deflected against the spin . All tests \Te r e fo r right spins .

The a1161e of attack a , angl e of sideslip f3 (posi­tive im-:ard i n a ri ght spin ), turn s fo r recov e ry, sp i n co­e ffici e~t DO/21 , and ra te of descent 1 a r e plotted in 1 2 c h art s (f i g s . 6 t 0 1 7) g r 0 up e d s 0 a s top e r 1:1 i t rea dy conp ar i son of the effe cts of tip shape , sect i on , p l an forD, flaps, and Ar ny \T i ng .

The data on these charts are oel i eved to r ep r esent the true node l valu es ITithin the follou i ng li c its (see ref ­erence 11):

Tur ns fo r r ecove ry

Do 2V

v

±3 percent

. ± 2 pe rc ent

For certain spins that are d i ff i cult to control ' in the tunnel, ouing to h i gh a ir speed or \Tandering notion, the foregoing liDits Day be exceoded .

8 N. A . C. A. Technical Note No. 608

DISCUSSION

~~~_TI11h_~i1-A_iflg~~_Q_1Q_21.- A comparison of the results given in figure 6 for tail A and different ~ings (for rudder 30 0 with and elevators neutral) shows that the rectangular wing s with rectangula~ or faired tips (wings 3 and 4) gave the steepest spins (~= 47 0 compared with 60 0 for the flattest) and the fastest recoveries (l- l/e turns) . The wing of N. A.C . A . 671B section (wing 6) gave the least outward sideslip ; the wing with 5 : 2 taper (T"!hug 7) and the ~ing with flaps (wing 2) gave the slowest recoveries (4 turns) .

Uith elevators 20 0 down (fig. 7) ihe spins uere very . similar to those for elevators neutral . Elevators up (fig . 8 ) definitely steepened the spins (by about BO for the f latter spins ) and gave rapid recoveries by reversal of both controls . With controls neutral (fig . 9) a spin could be obtained only \-lith the 5 : 2 taper wing, the model recovering of its own accord when forced into a spin for all oth e r cases.

For all control settings, rectangUlar and faired tips gave the ste epest spins and best recoveries (no more than 1- 1/ 2 turns). The wing of N. A. C. A . 6718 section gave the lea st outward sideslip of all wings and a slightly lower angle of at tack than the two comparable wings of N. A. C. A. 23012 and of N. A. C.A. 0009 sections, but airfoil section had no o.ppo.r on t effect on the turn s for recovery . Th e poorest recoveries were obtained for the ~ing with flaps and the ~ing of 5: 2 taper but the Army tapered ~ing (wing 8) ~as similar in behavior to the basic rectangular N. A. C. A. 23012 wing uith Army tips (wing 1) .

~~~1~_~11Q_tai!_~_ifig~~_!Q_1Q_!~1 . - Figure 10 gives results for the various wings ~ith tail ~ for rudder uith the spin and elevators neutral and sho~s general agreement uith the results for tail A (fig . 6) except that the spins were roughly 100 steeper . This result is not unexpected as t~e control position might be interpreted as resulting from n eutralizing th e lower half of the full - length rudder of t C'. il A.

As uith tail A, the rectangUlar and faired tips gave the steepest spins. Although the rate of descent was too great for co mp le ~e testing of the model, it is believed that recovery would have been rapid .

I " I

N.A. C.A. Technical Note No . 608 9

With elevato rs down (fig . 11) the spins were similar to those for e l evators neutral . (Th e r ectangular win g with fai red tips appear ed to g ive a critical spin condi­tion: the model would sometimes continue to spin but gen­erally uould recover of its OITn acco r d after a n um ber of turns . ) Deflecting the elevators up (f i g . 12) steepened the spin, making it, in gene r al, too fast and oscillatory to be maintained in the tunnel .

With both controls neutral, tail B is almost identi­cal in configuration and d i mensions with tail A except for the slightly larg er elevato r cut - out of tail A. As might be anticipated, the steady- spin results in figure 13 are almost identical wi th the corresponding r esult s given fo r tail A in f i gure 9 : a spin could be obtained only fo r the Case of the wing of 5 : 2 tape r. It is worth noting that, with tail B, for b ot h contro l s neut r al , several of the wings (1, 6 , and 8) appear ed to g i ve inconsistent results and additional tests we r e the r efo re pe rformed . It was ob­served that , although ~ steady spin cou l d sometimes be obtained by the use of ext reme care in l aunching, the model generally would not spin . Th e apparent s li gh t infe ri or­ity of tail B as compared wi th tail A i s possibly attrib­utable to the relati~e l y la r ger rudder - shielding effect due to the smal ler e levator cut-out of ta i l B.

For all control se tt ing s the r ectangular wing with rectangular or fa ir ed ti ps again gav e the steepest spins and the qUickest recoveries and the N.A. C. A. 6718 wi ng gave the least outward s id eslip . For controls with the spin t~ere was little other effec t of section, and the f~aps a Gain retarded r 8cove ry~ As before, the wing of 5 : 2 taper gave poo r est recovery, but the Ar my standard tapered wing was satisfact ory .

! e s i2_~ilQ_ t a i1:_.Q_ifi5.~~_1:1_1Q_~LZJ . - Wi t h t ail 0 the effects of individual wi ng d i ffe r ences were more appar ent . Figure 14 (rudder with and elevato r s neutral) aga i n shous th e $teepest spins (a = 40°) and quickest r ecove ri es ( 2 turns) for roctangular wings with ro6tan gular or fa ir ed tips. By c ompar ison the Army tip (a = 60 0 and 10 -turn recov e ry) was cons i de r a bly poore r.

As before , the N. A. C.A. 6718 wi ng g a ve the least out­ward sideslin . The re is a defin it e effect of section on r ecovery, N. A. C.A. 0009 being the best ( 5 turns) and N.A. C.A . 6718 the wo rst (no r ecove r y) although the angle of attack Was smalle r for the B. A. C.A . 6718 than for the

10 N.A.C .A. Technical Note No . 608

other t'\70 sections. The 5:2 taper and flaps are aGain ad­verse, g iving no recovery .

Elevator-doun spins (fi g . 15) uere very sinilar to elevator- neutral spins except that recovery wa s, in gener­al, soneuhat faster . Deflecting the elevators up (fig. 16) steepened the sp in, naking it difficult, in sone cases, to test the nodel in the tunnel . (Recovery uas cons i der­ablY.Dore rapid uhen the controls were reversed than TIhen theY . TIe r e nerely neutralized.) With both controls neutral (fi g . 17), spins could not be obtained for the uings \lith rectangular and faired tips.

For all control settings the rectangular wings \lith rectangular or faired tips gave the steepest spins and nost rapid recoveries . The N.A. C.A. 0009 wing gave fair recov eries , but the remaining nings \'Tere unsatisfactory with tail C, except for the c ase of conplete reversal of both controls from fully deflected u ith to fully deflected against the sp in, a procedure that gave good rec overies for all except the '.'r ing n i th flaps .

CONCLUSIONS

By a comparative analysis of the data presented, the gene r a l effects of wing or tail arrangement and of con­trol position and the apparent relationships between spin characteristics may be determined for the bas ic loading condition .

1 . ~i~_£h9ne.- Rectangular and fa ir ed tips g ive the steepest spins (ex, < 48 0 ) and the most rapid recoveries (turns < . 2- 1/2) . The Army tip g ives consistently flatter spins (ex, to 60 0 ) and slower recoveries (to 10 turns) . There is no consistent eff8ct of tip shape on sideslip .

2 . ~~QtiQQ .- With tail C the N.A.C.A. 6718 wi ng ' Gives a steeper spin than the other two sections but no recovery; the N.A. C.A. 0009 section gives fair recovery , and the 23012 section s ives poor recovery . The N.A. C.A. 6718 s?ction consistently g iv es the lea~ outward sideslip.

3 . !~~E~'- Flaps tend to retard recovery .

•

NIAIC.A. Technic~l Note No. 608

4 . ~l£~_fQrm~- The wing of 5:2 taper consistently g ives th e poorest recoveries.

5 . ~~~~_Q1anQQ~~_~i~g~- The Ar ny st ~ndard wing i s equal to or sli Ghtly better than the rect~ngular wing with Army tips .

11

For controls with the sp i n, t~il E g i ves steeper spins than tail A and recovery 'is Gen e r a lly satisfac tory for eithe r tail . Ta il C gene r a lly Gives slower r e cover­ies than ei th e r tails 'A or B .

1 . For c e rtain win g s, recovery is sli ghtly more rap­i d from spins with e l evat ors down than from spins with el­evators neutr~l, but in ~ene ral there is little differ­ence.

2 . Hol d ing elevators up results in the steepest spins from w~ich , by r eve rsal of both controls, ~re ob­t ained the nos t r ap i d recove ries •

1. Steep spins arc associated with high r a t e of de­scent and low Ob/2V.

, 2 . The re appenrs to b e no direct relationship between si d eslip of the steady sp in an d tu r ns r equ ired for r ecov­ery .

3 . t ail C, i es .

Except for the cas e of the N.A.C.A. 6718 wi ng wit h steeper spins are ass ociated with f as t e r recov e r-

Lnneley Memorial Ae ronnutic a l La bor ato ry, National A~v i so ry Co nm i ttee fo~ Ae ronautics,

Lan g ley Field , Va ., July 15, 1937.

12 N. A. C . A. Technical Note No . 608

REFEREN CES

1 . Stephens, A. V.: Free- Flight Sp i nn i ng Exper i ments with Single- Seate r Aircraft H and Bristol F i ghter Models . R . & M. No . 1404, British A. R . C. , 1931.

2 . Irving, H. B . , Batson , A. S . , and Stephens, A. V .:

3 .

Spinning Experiments on a Single Seate r Fi ghter with Deepened Body and Raised Tailplane . R . & M. No . 1421 , British A. R . C., 1932 .

Stephens, A. V" and Franc i s, R . H. : Tests of an Interceptor Fighter . B r i tis h A. R. C" 1934 .

Model Sp i nn i ng R . & M. No . 1578,

4 . Stephens, A. V.: Re c ent Resear ch on Spinn i ng . R . A. S . Jour . , vo l. XXX VII , no . 275, Nov . 1 933 , pp . 944 - 955 .

5 . Bamber , M. J . , and Zi I;'lme r Jaan, C. H.: Effect of Stab i­lizer Location upon Pitching and Yawing Moments in Spins as Shown by Tests with the Spinn i ng Balance . TI N. No . 474, N.A. C. A., 1933 .

6 . SCUdder, N. F .: A Flight I nvest i gat i on of the Effect of Aass Distr i bution and Control Setting on the Spinning of the XN2Y - l Airplane . T . R. No . 484, N • A • C • A . , 19 34 •

7 . Stephens, A. V.: Das Trudeln von Flugzeugen . Luft ­fahrtforschung, Bd . 11, Nr . 5, 25 Okt . 1934 , S . 140- 149 .

8 . Francis, R . H.: Interim Report on Systematic Model Research in Free Spins : Low Wing Monoplanes . R . & M. No . 1714, British A. R . C., 1936 .

9 . Scudder, N. F . , and Se i dman, Os c ar : A Flight Investi ­gation of the Spinn i ng of the F4B- 2 Biplane wi th Various Loads and Tail Surfaces . T . R . No . 529, N • A • C • A. , 19 35 •

10 . Irving, H. B . , Batson , A. S . , and War sap , J . H,: The Contribution of the Body and Ta il of an Aeroplane to the Yawing Moment i n a Spin . R . & M. No . 16 89 , British A. R. C., 1936 .

. I

N. A. C.A. Technicnl Note No . 60 8 13

11. Zi nncrmnn, C. H.: Prclininary Tests in the N.A.C.A. Fr e e-Spinning Wind Tunnel. T . R . No . 557, N.A.C.A., 1936.

12. Zinne rnan, C. H. : Effect in C~angcs in Tail Arrnne c­Den t upon the Spinning of a Low-Wing Monoplane Model. T.N . No. 570, N.A.C.A . , 1936.

13. Baub e r, M. J.: Aerodynanic Effects of a Split Flap on the Spinn ing Characteristics of a Monoplane Ho d e 1 • T • N • No . 515, N. A . C • A . , 19 34 •

1 4 . ]anb er, M. J., and House. R . 0 . : Spinning Characteris­tics of the XN2Y-l Airplane Obtained froD the Sp i n ­n i n g Ba lo." ce and Conpared with Results fron the Spi un ing Tunnel and froD Flight Tests. T . R. No. 607 . N.A.C.A •• 1937 .

15. hlat'riel Division, U. S . ArDY Air Corps : Handbook of Instructions for Airplane Designers . Eighth edi­tion, revision 6, vol . I, llarch 1934, p. 76f.

16 • S h 0 r tal, J 0 s ep h A .: E f f e c t 0 f Tip S hap e an d D i h e d r a 1 o ~ Lateral-Stability Characteristics . T . R. No. 54 [3, N . A. • C • A., 19 35 •

N.A.C.A. Technical Note No. 608 Fig. 1

r s.3"L

3.12"

t

5.34"

"'---------1 U /-----'-------

~---------- 30" ··----------iIoI

~~_. 201l--~.\

.~-fG_;_~±"

Figure 1.- Low-wing monoplane model with detachable tail and wing.

r -

N.A.C.A. Technical Note No. 608 Fig. 2

1~ ___ --=-30_11 ___ .~si_34_" _J_ .1 ;'; ........:::::::.---------------::------::::::;:::::---~-__r_. - J

Wing 1- 23012 rectangular with Army tips. f o flaps at 60 • Wing 2- 23012 with 20 percent full-span split

Lrr--=--------.-s}o-" ---"} .60"

------------------==:J ~.') ·- - -2-3-0-1-2-rectangular with rectangula r tips. T48

11

c: Wing 3-

23012 rectangular with faired tips. i \ ==- -+-,'

Wing 4--==::::::::

Wing 5- 0009 rectangular with Army tips (plan same asl}. -L

...,--z:::::::=---_-_-_-_-_-~_--_-_-_-_-_-_-_-.:__-_-__ -_-_-_-_-_--_-_-.:__-_-_-_-_-_-_-~_-_-_~---= '-1. 02"

( ti). Wing 6- 6718 rectangula r wi th Army tips plan same as 1 ..

-~

17.3011

: 2. 92"

--------______ · __ -------- -IT ~ . 88~~_t . .... ~::::::::-============~~~:============:::;::?:;;:?:--' +-: 3 5

tt

Wing 7- 23012 5:2 taper with Army tips.

6.36 11 -- ..-:l , , ,

3 18" I •

----------______ ~ __ --------~-~_r

Wing 8- 23018-09 standard Army wing (2:1 t aper, square center).

Figure 2.- Wings used on low-wing monoplane. N.A.C.A. wing s ections.

.291t

::;?!J+/'

N.A.C.A. Technical Note No . 608 Fig . 3

T.L.

L - -

Tail A Tail B Tail C

Figure 3.- Tails used on low-wing monoplane.

(a) Front view.

(b) Plan view. Figure 4. -

(c) Side view, showing detachable parts .

(1) Wings 1 and 2, (2) Wings 3 . (4) Wing 6, (5) Wing 7

(d) Low-wing mono~lane Low-wing monoplane mOdel.

!

2

3

4

S

6

and 4, (3) Wing 5, (6) Wing 8 •

w1nga.

:z: · >-· (") · »-· 1-3 (1)

0

~ .... 0 I» ...... ~ 0 e+-(1)

~ 0 • ()) 0 (X)

!:oj .... ~ . ~

2 .

(b) (1) Tail A, deep fuselage and long rudder. (2) Tail B. deep fuselage and short rudder. (3) Tail C. shallow fuselage and short rudder.

(a) (1) Rectaneular wing with A~ tips. (2) Rectangular wing with interchangeable rectangular and (3) 5:2 tapered wing with A~ tips. faired tips. (4) 2:1 A~ standRrd tapered wi~ with square center.

Figure 5.- Interchangeable wings and tails of low-wi~g monoplane model.

~ • » • o · » · 1-3 ro ()

E .... () Il' t-'

z o ct­,& z o

()) o (Xl

t:g .... IJtl • (]l

N.A.C.A. Technical Note No. 608 Fig. 6

Effect Tip shape N.A.C.A. Plan Flap of ~ airfoil form Fool setting p. .,.. flO

P. 'M .p section Q) • m rd ~ ..... l.p I P. ~OF-l ..... .p

~F-I 'd §FooI as 'laS):

Upon Q) N .p oro'd

>- .paS F-I ,.... m co .paS ·M ~ >-a OM ..... 0 0 r-i Or-i N 0 <OaiS Fool Q);:j as ti) 0 t'- ~~

.. 0 0 • to .p f-i

< ~flO I%. N 0 CD III 0 CD ~ C\1 00<

60 V, 40 ft.

~ r- ~. r- r- ,.. -sec. 20

0

60 I'"' ... I'"' l1li I'"' I'"'

I'"'

nb 40 f---

2V 20

0 RUA der move d fro III 3 )0 w .t ht P 30 :>8 ga.i net t 18 e lin.

20

15 Turns for 10 -recov-ery 5 r n

0 r r r r [ n n r n

10 ~,

~eg. 0 L L L L L - l. L l. L 1:::

1---10 ---60 I'"' "" r- r-

r- ~ _J a., 40 -- - . deg.

20

"U

Figure 6 .-The effect of various wings on the spin charac­teristics. Baeic loading condi"tion; tail A, rudder 300 wi th, elevators 00 , ailerons 00 (Wing has rectangular plan form, Army tips, N.A.C.A.23012 section, except as noted.)

N .A. C .A. Technical Note }10. 608 Fig. 7

Effect Tip shape N.A.C.A. Plan Flap of ~ airfoil form J.f setting

~ .... bO ~ .... ~ section Q) .0)'dS::: .... I~ I ~ ~OJ.f .... +' ~J.f 'd ~~ as • I as ~

Upon Q) C\1 ~ OCD'd

~ ""aJ F-i rI 0) <Xl ~(Ij ·MS:::» OM .... 0 0 M OM C\1 0 C<OaJa

F-4 Q);j aJ ~ 0 r::-- ~&, .- 0 0 .t')~~

< P::bO P:. C\1 0 co Ii) 0 co ~C\J mc<

60 V,

40 ft. I""

I"" I"" I""

sec. 20

0

60 I""

r- r-.nb 40 -2V 20

0 Ru ~der mov~ d fre ~ 3 bo , iJih [to 3P< a€ lain ~t the spi~

20

15 Turns for 10 recov-ery 5 r

0 r ,... r r r r r n [l r

10 ~,

~eg. 0 1: L L L 1 L L L. L 1 L

f-----lO

60 --1---- ~-I-. I""

a., 40 I"" j

deg. 20

-()

Figure 7 . -The effect of various wings on the spin charac­teristics _ Baeic loading condi1iion; tall A, rudder 30° wi th, elevators 200 down, ailerons 00 (Wing has rectangular plan form, Army tips, N.A.C.A.230l2 section, except as noted.)

,

N.A.C.A. Technical Note No. 608 Fig. 8

Effect Tip shape N.A.C.A. Plan Flap of p. airfoil form F-f setting p. ..-4 flO

P. .,-f ..., section Q) ·m'ds:! ..-i I....., I PI ~OF-f..-f .p ~F-f 'd

aF-f aI • I aJ ~

Upon Q) C\l .p OOO'd

ii ..paJ F-f M CP 00 .pal • M ~ >-OM ..-4 0 0 M Or-! C\l 0 ~Oroa

F-f Q)::i aJ to') 0 t'- ~~ " . 0 0 • to ..p F-f -< ~flO ~ C\l 0 CD LC) 0 CD l2'f C\l co <

60 V, 40 ft. r-

.., -sec. 20

0

60

'ob 40 -2V 20

0 rmRUd der g~ 10 w ~th to 0 ; ~lev a.t :>rs 30c p tc 00

c::l Roo del' o w th to :3 0 a.Q.:ai lS ~: ~le't fa. :OTS 20 300 up ~c 20 J d ~wn.

15 Turns for 10 recov-ery 5

~ 0 Fl p!:II ,. E ~ ~ f4 ~

10 ~,

~eg. 0 L ... L ... ..., LJ ... L ~ LJ

f---10

60 ,.- ----I- -,

cr., 40 --- I--

deg. 20

-0 Figure 8 .-The effect of various wings on the spin charac­teristics. Basic loading condition; tail A, rudder 300 with, elevators 300 up ,ailerons 00 (Wing has rectangular plan form, Army tips, N.A.C.A.23012 section, except as noted.)

I

N.A.C.A. Technical Note No. 608 Fig. 9

Effect Tip shape N-.A.C.A. Plan Flap of Pt airfoil form F-t setting

Pt of'i bO Pt of'i of.3 section Q) • (J') "d Q ..... 10f.3 I Pt ~OF-t .....

of.3 . a F-t "d ~F-t '" • I '" Ii: Upon

Q) C\l of.3 OOO"d

~ of.3cd F-t ,.-i (J') co of.3'" .,.-i s:: ~ O,.-i ..... 0 0 ,.-i O,.-i C\l 0 <o",a

F-t Q);:j cd C') 0 r:-- ~~ .. 0 0 • C') of.3 F-t

« ~bO rz. C\l 0 co LO ° CD !2; C\l CD ca:

60 V, 40 ft. ,... --sec. ao

0

60

.o.b 40 -av 20

0 Ru id er rot: 0° of 0 ~Oo I ~g ~in t· . , 20

El 3'" 9.to ~ f, om be t ~ 20 OWl .

15 ~ ~ s:: Turns s:: s:l s:l s:: s:: s:: Q .... .... .... .... .... .... .... .... ....

for 10 m ;: ~ ~ ~ . ~ ~ ~ ~ ~

recov-5 .~ " '-'" ery g g g 8 0 0 0 g 0 0

p p ~ r s:: s:: 0 -~ ~ ~ ~I ~ ~ ;g a "d

~ :: ;::i .~ .~ g 10 ~ ~ ~ ~ ~ ~ ~ ~ ~ ¥

13, p.eg. 0 L

-------10

60 , r-

a., 40 - .--- .

deg. 20

-0 I I

Figure 9 .-The effect of various wings on the spin charac­teristics. Basic loading condi1ion; tail A, rudder 00 with, elevators 00 , ailerons 0° (Wing has rectangular plan form, Army tips, N.A.C. A.23012 section, except as noted.)

f

N.A.C.A. Technical Note No. 608 Fig. 10

Effect Tip shape N.A.C.A. Plan Flap of Pc airfoil form F-f setting

PI ..... bD PI 'M .p section Q) .m rg s:: ..... I~ I P. ~ o ..... .p s:: 'd ~F-f aJ • I aJ ~

Upon aJF-f (!) C\1 .p oenrd ~ ~aJ F-f r-i m en .pro ' r-i ~»

Orl ..... 0 0 rI Orl C\1 0 <OcdS F-f Q);j cd t') 0 to- ~~

.. 0 0 • t') .p F-f .cr; D::M ~ C\1 0 co U') 0 co l2fC\1W<

60 V, 40 ft. I"'" r- r-

-sec. 20

0 1-Q) Q)

60 a s E 2 .p -.nb 40 ~ ~

2V 20 Cf..t Cf..t

.p .p

0 ro cd

~ ~ Rl. ki~~ Ir m t>~ ~d frou 00 wit P . bI tc 10 $:I b-~ ~_n' It. 20 0 q Z 15

Turns t t for 10 ~ ~ recov- 0 q r r-

ery 5 Q) .~ r I> r r r r r r

0 r-I r;1 10

. ~ c

..... -~ ~,

.p f-i

~eg. 0 L ~ ~ L L L L L L L

f---10

.- ----- i- I--60 r-.... r- r-

a., 40 ---I , deg.

20

--u Figure 10 .-The effect of various wings on the spin charac­teristics. Basic loading condi1ion; tail B, rudder 30° with, elevators 00 , ailerons 00 (Wing has rectangular plan form, Army tips, N.A.C.A.23012 section, except as noted.)

M.A.C.A. Technical Note No. 608 Fig. 11

Effect Tip shape N.A.C.A. Plan Flap of A airfoil form J-I setting

A ·M flO P4 ·M -P section Q) • Q) 'd s::

or-f I-P I A ~ 0 J-Ior-f +> ~J-I to

@J-I ed 'ledfC

Upon Q) C\l +> oro'd

~ +>ed J-I M (» ro +>m oMS::» OM .,... 0 0 M OM C\l 0 <OedS

J-I <IJ;:j ed til 0 ~ ~~ .. 0 0 o t') +> J-I

« ~bO f:q C\l 0 <D LO 0 <D Z C\2 CD <

60 V,

40 ft. ~ r---sec. 20

0

60 r- -nb 40 f-

-2V 20

0 Ru ~der mOVE d fre m 3 pow ~t ~ t 0 3C 0 aga ins ~ ~he ~pin

20 ,

15 Turns s:: s::

or-f or-f for 10 ~ ~,

-recov- ..., ery 5 - n n 0 0 r r n s:: s:: r r r 0 rtj 'd

3 3 10 ~ ~

~, ~eg. 0 L L L u L L L L L 1----10

.~-.-1- .. -~. 60 I ~ r-

a.., 40 -- -- r- ;

deg. 20

"V

Figure 11 .-The effect of various wings on the spin cha!ac­teristics. Basic loading condi~ion; tail B, rudder 300 with, elevators 200 down, ailerons 00 (Wing has rectangular plan form, Army tips, N.A.C.A.23012 section, except as noted.)

I •

N.A.C.A. Technical Note No. 608 Fig. 12

Effect Tip shape N.A.C.A. Plan Flap of Pt airfoil form F-4 setting

Pt 'M bO Pt 'M ~ section Q) ·m'd s::

..-i I~ I Pt ~o F-4'M ~ @~ 'd

@F-4 m • I m Ii:

Upon Q) ro .p oen'd

~ .pm F-i r-i (J) en ~m • r-i s:= >. Or-i ..-i 0 0 r-i Or-i C\l 0 <OroS

F-4 Q);j cO ~ 0 ~ ~~ .. 0 0 • C') ~ F-i

~ ~bO rr.. C\l 0 <D l!) 0 <D zroco<

60 V, 40 ft. --sec. 20

0 .. ~ 'i> ~ a1 .,j

'Q ~ r-I r-i r-I rl

~ Q)

~ ~ ~ 60

q 8 ~ i:t E ~ q

2 2 E E ] .!:

~ 2 E ~ E ~ .p .i; ..p

.ab 40 ~ ~ ~ F-I H s::

~ ~ H P H -2V 2 2 fLO fLO ..-i ~ fLO ..-i P

20 4-

-~ to

0 ~ ~ ~ : ~ ~ ~ ~ ~ ~ Q)

~ Q) Q) Q) ,q

~ ~ Q) .G Q)

20 t;l bi ~ b! f;1 0 ~ 0 ~

..... ~

.p

0 0 0 0 0 ;:-

0 0 0 0 0 ~ ~ ~ 0 0 l;> 0

15 ~

0 Turns t .r- ~ ~ ~ i: :> ::; :: ~ for 10 .

..-i ..-i ..-I .... .... ~ (j 'B 'M r-i ..-I

recov- 0 0 0 0 0 g :,j g 5 0 0 0 0 0 ..-I 0 0

ery .~ ~ ~ ~ r::t --0

~ r-i r-I () r-I

<D ~ (J) Q) CD Q)

:> :> :> :> :>, :> :> 0 :> 0

r-I r-i r-I ~

r-I 0 r-I r-i r-I ~

r-i

~ ~ ~ ~ ~ ~ ~ ~ ~ 10

i ..-i -M oM 'M oM :f

.,-t ..-t oM

.~ , .t: f f -E f .: f "f j:l "f L

~eg. 0 Q) Q) ID ID <l> ~ :. <l) <l) ~ Q)

po. po. po. ~ po. po. po. po.

"----10

60 -j=-~- 1---

,

C1.., 40 I , deg. I

20

() , I

Figure 12 .-The effect of various wings on the spin charac­teristics. Basic loading condi~ion; tail B, rudder 300 with, elevators 300 up , ailerons 00 (Wing has rectangular plan form, Army tips, N.A.C.A.23012 section, except as noted.)

..

N.A.C.A. Technical Note No. 608 Fi g. 13

Effect Tip shape N.A.C.A. Plan Flap of Pt airfoil form H setting p. .,.. bO

P. 'M +=> section v o (J') '0 s:: .,.. I+=> I P. <2l0H.,.. +=> ~H '0 aH aj • I aj ~

Upon v ro .p O(])'O

t>. .paj H M (J') (]) .pm OMS::» IS OM .,.. 0 0 M Or-i ro 0 <OmS H V::i m t<) 0 t'- ~~

.. 0 0 • t<) +=> H < ~bO rx. ro 0 CD U) 0 CD ZroCD<

60 V, 40 ft. --sec. 20 -

0

60

~b 40 ZV 20

0 R1.lA id ~r rOIl o~

2 g ~ ~Ou :~ 8 in~ t· , El ~v :lot 0 s f rom o 2 dov rn. 20

15 s:: s:: s:: s:t s:: s:t s:: s:t s:t s:t Turns ..... .,-1 ~ ~ .,.. ..... oM .,.. oM .,..

for 10 en ,

ti:i m .~

CD CD 00 CD 00 co 00

recov-5

L .. : L .. , .. "

" ,~

ery 0 0 0 0 8 0 0 0 0 0 s:: s:: s:t s:t s:: s:: s:t s:: s::

0 ~' ~ ~ ~ ~ ~ ~' ~ ~

'tj

.~ ::i g 10 ~ ~ -:? ~ ~ ~ ~ ~ ~ ~ IS=

13, deg. 0 L

r----10

60 1---I-I-' -~'

,

a.., 40 --I- I deg. I

20

- I 1..)

I .1

Figure 13 .-The effect of various wings on the spin cha rac­teristics. Basic loading condi~ion; tail B, rudder 00 with, elevators 00 , ailerons 00 (Wing has rectangular plan form, Army tips, N.A.C.A.Z3012 section, except as noted.)

I -..

N.A.C.A. Technical Note No. 608 Fig. 14

Effect Tip shape N.A.C.A. Plan Flap of Pt airfoil form H setting

Pt of"1 bO Pt of"1 ~ section d) • (7) 'd j:l

or4 I~ I Pt ~o Hof"1 ~ ~H 'd ~~ cd '1 cd II:

Upon d) C\l ~ Ooord

~ ~cd H r-! (j) ex:> ~cd • r-! j:l » Or-! of"1 0 0 r-I Or-i C\l 0 <OedS

k ~~ cd t4) 0 c-- ~~ ., 0 0 ·t4)~H

< rx. N 0 CD t{) 0 CD l2;Nm<

60 V, 40 ft. I'" I'"

- ~ ~ roo I"'"

sec. 20

0

60 I'"

I'"

.(1b 40 2V

20

0 RU! ",der move d fro m 3 )Owj t tp 30 :> ~a :ins he I pin

20

15 Turns ~ for 10 recov-ery 5

0 r1 n

10 ~,

~eg. 0 U LJ 1: L LJ ... L ... L ... 1:

1----10

60 --~--f- f---

cr., 40 -- --deg.

20

-"U

Figure 14 .-The effect of various wings on the spin charac­teristics. Basic loading condi1ion; tail 0, rudder 300 with, elevators 00 , ailerons 00 (Wing has rectangular plan form, Army tips, N.A. C.A. 2301-2 section, except as noted.)

..

N.A.O.A. Technioal Note No. 608 Fig. 15

Effect Tip shape N.A.O.A. Plan Flap of Qj airfoil form ... setting

Pt "'" ~ Pt .... ~ section d) • en ~ s:: "'" I~ I Pt ~o .... ~ ~~ 'd ~~ cd • I cd •

Upon Q) C\l ~ oro'd

~ ~cd ~ r-f en ro ~cd • r-f s:: >-g~ "'" 0 0 r-f

~~ C\l 0 C<Oaia

~ as t") 0 ~ .- 0 0 .t")~~

c< ~~ r.r. C\l 0 (!) lI) 0 (!) ~C\l [0<

60 V, 40 ft. r-'I .... ,. ,. ,. r-'I - r- r-sec. 20

0

60 ;;; r-

~b 40 W 20

0 ~u eder move ~ fro In 3 ~Ow:1 t to 30 P B.aa. lins tihe pin -g'

20

15 Turns .. ~

for 10 l"ecov- ~ , .., ery 5

0 n r

10 13,

~eg. 0 _L l . L L L L. L .... t.:

1----10

60 r -r-

Cl., 40 f-

deg. 20

-0 Figure 15 .-The effect of various wings on the spin charac­teristios. Basic loading condi~ion; tail 0, rudder 300 with, elevators 200 down, ailerons 00 (Wing has rectangular plan form, Army tips, N.A.O.A.23012 section, except as noted.)

...

N.A.O.A. Technical Note No. 608 Fig. 16

Effect Tip shape N.A.O.A. Plan Flap of ~ airfoil form f-4 setting

IJ. """ be IJ. .... .p section (I) .en~s::

""" l.p I ~ ~o ..-f

.p ~f-4 'd ~~ • I cd •

Upon (I) CQ .p OQ)'tj

~ .paS f-4 M en Q) .paS ·M a >-OM .... 0 0 M

~~ CQ 0 <0 a

~ ~~ cd ~ 0 l:>- .. 0 0 • tt:) .p f-4 < rz. C\l 0 CD It) 0 to l2; C\l r.o <.:

60 V, 40 ft. r'"

,.. ,.. .. -sec. ao

0 ~ ~ !'!

: ~ ~ 60 ~

1 -; ~ fnb 40 ~

~ -'-(1) ,.. ; 2v ao '2

a a a. 0

~-= der ~~

IV W ttll to o~ b I£le~ a.t Drs 3C ~p tc W. der o w th to 3 a,gai le t; ~le a ~ors

ao 30" up ~( 20 V dl ~wn.

15 ,:. Turns :. :.. .. !> for 10

~ .p ~ ~ recov- ~ 5 0 m ;.;

ery ~ ~; ~ 0

0 "Qj (I) ~ ~ p p q.f P

M ~ !Il r-: 10

~ 0 ~ c fJ, - '!:! - ..-I

~eg. 0 : f.t L ~

... - 1.1 .~ : f---lO ~ ~

'Q; ~ rd 60 iE iE ~ iX1

a., 40 ,-r-deg.

ao I -"V

Figure 16 .-The effect of various wings on the spin charac­teristics. Basic loading condi1ion; tail 0, rudder 300 with, elevators 300 up , ailerons 00 (Wing has rectangular plan form, Army tips, N.A.O.A.a301a section, except as noted.)

N.A.C.A. Technical Note No. 608 Fig. 17

Effect Tip shape N.A.O.A. Plan Flap of ~ airfoil form f.f setting

.CP'S~ ~ or1 ~ ..... ~ section d)

or1 I~ I ~ ~o or1 +> ~ 'd ~H as ·laSlC

Upon aSH d) C\l +> OOJ'd

~ +>as H r-f CP OJ +>as • r-f ~ >-> Or-f or1 0 0 r-f Or-f C\l 0 ~oata

f.f £f1 at ti) 0 t- ~&, .. 0 0 • ti) ~ f.f ~ F.. C\l 0 (() tn 0 (() :<?4 C\l ID ~

60 V, 40 ft. I""' ,.. ~

,.. -Bec. 20

0

60 ~

~ ~ ~

~b 40 2V 20

0 tRU( "der from Co to 3 ~o ~ g in at, ~] eva liorE rom 00

20 to 2 0 iOwn .

15 Turns s:: s:l '" '" for 10 g ~ .. recov- ~

ery 5 6 .p n 0

0 ~ ~

~ rO

10 rj

0 0

13, i:= ~

~eg. 0 L L. L L L. L ... L

~-10

---60 - ~

I"" I'"

a., 40 f-

deg. 20

- I "\)

Figure 17 .-The effect of various wings on the spin charac­teristics. Baeic loading condi-tion; tail 0, rudder 00 with, elevators 00 , ailerons 00 (Wing has rectangular plan form, Army tips, N.A.O.A.230l2 section, except as noted.)