Static test of Harvard II wings

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Static test of Harvard II wings

I

CONFIDENTIAL

Copy

No···-·-···-NATIONAL RESEARCH CouNCIL oF CANADA

STATIC TEST OF :··J;l.RVARD 11 WINGS

REPORT MM-44

BY

R. D. HiSCOCKS

DIVISION OF MECHANI C A L ENGINEERING

OTTAWA MARCH, 1942

6 pages .. 0 • • (!I c c f) 0 e :'1 Ｑ ｾ＠ Graph Sheets .. • .. Drawing s •.... . ｾ＠ .. Photographs •.

f9 r.

NATIONAL RES EARCH LA'S ORATORIES OTTA1,'iTA, CAN 'lDA

R E P 0 R T C ｏｾｔｆ＠ ｊｊＲｾｎｩｬａｌ＠ R 1epor t N o . . . . , • ••• MM-44 Date • . ｾｾＹｾｖｾｾﾥＬｴＹＱＲ＠ Book Serial No •.•• Page ••.•. :1, •••• , ••• A d' 2

Ｎｴｾｰ ｰ･ ｮ＠ le e s . . .• .. . Di vision of Mechanical Engineering

For Depa r tme nt of NationaJ. Defe nce, Air Service

Referen ce - Request dated 20 June, 1941

AMAE/DAE 1021-20 - 3 NRC F ile 12-Nl-103

North American Harvard II NA66 Type Record Reuort 1678 . Sub j ect - Static Test of Harvard II Wings

Author - D. Hi s cocks

Ｏ ｩ ＬｊＱｶｴｾ

Ｍ

Approved. /

Y::[f#.l: .. ... .

, Director.

'

.

-../(

At the request of the Denartment of National ｄ･ｦ･ｮ｣ｾａｩｲ＠

Se::·;,i_ :;c" st a tic load tests wer e conducted on two Har vard II

s ta r boar·d mainpl a nes in the High Angle of Attack and Cent re of

Pressur e Back condi tions. Th e ob ject of these tests was to

observe the c onditions und e r wh ich ｾ ｲｩｮｫｬｩｮｧ＠ ｯ｣｣ｵｲ ｾ ･､＠ in the

uppe r skin of t he ma inplane and the nature and permanence of

t l:le ｷｲｩ ｅ Ｚｾﾷ ｬ ･ｳ Ｌ＠ For purnoses of comparison, the tests were

conducted on t wo wings, one new and one which it was suspected had be en overlo aded in fli ght Danoeuvres.

It is concluded f r om these tests that the wrinkling ; t 2none na i n both wings is norma l for a stressed skin structure and tha t t he wings comply with curr ent airworthiness requirements for t he conditio ns examined .

Tests 'Ner·e conducte d at the reEJuest .of the Department

of National Defence, Air Service, in ｯｾ､･ｲ＠ to. examine the

buckling phe nomena i n the Harvard v ing skin for the High Angle of Att ack (HAA) and Ce ntr e of Pr e ssure Back (CPB) loading

conditions .

The load calculations were performed ｾｹ＠ the

De partme nt of Na tional Defence, Air Service, and are given in

the Anpendixc In order to anply a factor of 1.2 to the proof

load the tests were conducted to a total of 90% of t he specified ultima te lo ad, t h e specified ultimate factor in each case being 9.

P8.ge No. 2

Report No. MM-44

ａＲＱＲｾｮｴｵｳ＠

The general arrangement is indicated in Figs. 1 and 2. The angles at the wing root were bolted to a face

plate supported on a welded 12" I beam s tr·ncture. During

loading operations a reaction wa s supulied at the wing tip by a beam suspended from a ten ton crane.

Ailerons were not used in the tests, ap propriate loads being applied directly to the hinge bracket s •

. In order to ｰｲ･ｾ･ｮｴ＠ shot bags sliding off the

inclined wing surface a "picket fence" (Fig. 1) wa s brace d

from the floor for the HAA tests, The b ags were also restrained

by strips of webbing laid ｣ｨｯｲ､ ｾｲｲ ｩｳ･＠ and spanw1se • .

Deflections were ｭ･ ｾ ｳｵｲ･､＠ by strain gauge s ｾ･｡､ｩｮｧ＠

to ＮＰＰｾ＠ ｦｾＮ＠ and 16cated as inrlica t ed in Fig. 17.

Test ｐｲｯ｣･､ｾ＠

Loads were applied in ste ps of 0.1, 0.5,

0.7, 0.8,

0.9

of the specified ultimate load. After eac h increment

strain gauge- readings were ｲ･｣ｯｲ ｾ ･､＠ and the general appearance

of t he wing surface examined. Photographs were taken and the

deflection of the test stand measured at interva ls.

ｑｑｾｶ｡ｴｩｯＡｬﾧＮ＠

(a) Jiigh_Anr,le of_At,iack_Q.Q!lditj..Q!l

0.1 load - No appreciable wrinkling

0.5

load -Skin buckles between stiffeners from

0.5

chord to

the rear web. Tension field for ming aft of rear web. Some

buckling at midspan near leading ed ce (Fig. 4)

0.7

load - General increase in size of buckles toward root s e ction.

Forward of 0.5 chord buckles forming where stiffeners "stop

off" (Figs.

5

and 6)

0.8

load -As above, severe buc kl ing aft of

0.5

c. (Fig.

7)

0.9

load - As above, no evidence of stringer buckling (Figs.

8

and

9)

Upon removal of load there ｾ ｡ｳ＠ no evidence of per nanent

wrinkles in the skin. Slight distortion occurred in the re a r shear web at the flap cut out.

(b) ｾｧｮｴｲｧ｟ｑｦ｟ｅｲｧｾｧｲ･｟ＲＲﾣｴ｟ｾｑｮｾｩｴｩﾣｮ＠

Page No.

3

Renort ND. r.,Jll -44

0.1 load - Slight ｷ｡ｾｩｮ･ｳｳＬ＠ no ･ｮｾｲ･｣ｩ｡ｾｬ･＠ ｾｵ｣ｫｬｩｮｧ＠ (Fig. 10)

0.5

ｬｯｾ､Ｍ ｃｯｮｳｩ､･ｲｾ｢ｬ･＠ buckling aft of the

0.5

c. location

(Fig. 11)

0.7 load - "s above (Fig. 12 and 13)

0. 8 load - As above tension field vrrinkles growing in severity

0.9 load - ts Rbove

At the noint marked in Fig. 16 a uermanent buckle

persisted efter the load was removed. The rear web joining

the unper and lower wing surface at the flau cut out was permanently buckled also.

No distinction is made in the above observations

between the new v·ing and the used ｾ ｩｮｧＮ＠ There are unfortunate

gaps in ｴｾ･＠ uhotogranhic evidence but as far as could be

·observed in the tests the qua.li ta ti ve ＧｬＩ･ Ｑ _{ｬ ｡ｾｲｩｯｵｲ＠ of both v-dng s}

was identical.

. St rain gauge readings are tabulated on Pages 5 and 6

and the results indica ted· granhically in Figs. 18-26.

It is not considered that the ":,>icket fence"

introduced any measura1_{Jle error in ｴｾ･＠ ｈｊ｜Ｎｾ ｟＠ loCJding as the}

structure could be easily shaken by ｾ｡ｮ､＠ and probab ly

removed enti rely even at maximum load.

Due to . 1_{Jending in the test stand the . maximum}

deflection at the tip was apuroximately 1" for the HAA loading and

0.8"

for the CPB Condition. Twist in the nlane of the

root ｾ･｡ｳｵｲ･､＠ at the leading and trailing edges was approxinately

2 minutes ｈａｾ＠ and

6

minutes CPB. These deflections, which are

probably less than those ｾｨｩ｣ｨ＠ would occur with the wing attached

to the stub section on the a.ircraft will Modify the stress distribution at the wing root accordingly.

ｾｑｄﾣＱＱｬｬｩｩＲｄＲＮ＠

(1) It .is concluded that the vrinkling in ｴｾ･ｳ･＠ wings

is normal for a stressed skin structure .

(2) Buckl ing does not anpear to extend beyond the

elastic range under the ｈｾｾ＠ loading excent locally in the web

Page No. 4

Report No. MM-44

(3) In the CPB condition one local region in the

skin apparently exceeds the elastic limit in buckling. This

buckling occurs at the intersection of a discontinuous snanwise stiffene r and the root aileron Ping section rib.

(4) In the CPB condition the ｾ･｢＠ at the flap cut

out is ｣ｯｭｾｬ･ｴ･ｬｹ＠ buckled.

li§.!!ill.!:k§.

(1) Under service conditions an examination of the rear

web at the flap cut out or of the ｵｾｰ･ｲ＠ surface skin at the

root aileron wing section should reveel if a Harvard wing has been severely strained in the FAA or CPB attitude.

(2) Omission of the lightening holes in the web at the

flap cut out would render the structure more effective in shear.

(3) As the spanwise stiffener which passes near the region

of the permanent buckle (Fig. 16) does not continue on to the wing tip it appears that failure was occasioned by the inability of the skin to transfer the load from this stiffener to the

adjacent one. Therefore, a continuous stiffener or local

reinforcement should be an improvement.

(4) The loads used in the HAA tests are approximately 17%

in excess of those stipulated in U.S. airworthiness requirements. Most of the excess is due to the British Convention of

acknowledging only that portion of the wing outboard of the fuselage effective in producing lift. Loads are plotted for

comparison in Fig. 28. A and D are the shear and bending

moment curves for the loads used in the test, B and

E

are from

the type record and C and

F

were calculated in the National

Research Laboratories subsequent to the tests by the Schrenk method (Approximation Method for Obtaining the Spanwise Lift

ｄｩｳｴｲｩ｢ｵｴｩｯｮｾ＠ by

0.

Schrenk Jourft

R.

Ae. S , , Oct. 1940,

pp

331- 336J.

(5) The considerati6ns under (4) also anply to the CPB

tests. In addition a factor of

9

with a rearward centre of

pressure shift from the HAA location of 0.1 c. produces a very

severe load condition. The usual British factor for acrobatic

Fraction of Ultimate Load

0,1

0.5

0.7

0.8

0.9

zero after Test

0.1

0.5

0.7

0,8

0.9

zero after Test 1

2547

2538

2536

2533

2531

2547

931

924

921

918

917

930

2

₃

4

₅

2120 1445 1217 2043

2056 1312

970 1792

2026 1238

844 1659

2009 1200

774 1590

1991 1156

697 1510

2129 1472 1268 2093

C. P .!..J?__. =-NEYv_VriNG

2082 2883 1828 1853

2026 2750 1575 1580

2001

2687 1452 1437

1988

1384 1358

1973

1313 1274

2095

1877 1897

Page

No.

5

Report

No.

ｾ ｬｦｦｩ［Ｚ ＭＴＴ＠ 6 7 8

209 8 1059 1645

1958

996 1641

1883

960 1638

1843

940 1637

1797

916 1636

2123 1068 1644

2444 1676

735

2282 1589

731

2193 1537

728

2143 1507

726

2088 1473

725

2462 1678

₇₃₃

•

Page No. 6

1eport No. lv'IM-.44

ＭＭＭＭＭ ＮＭＭＮＮＮＮＮＭｾＭＭＭＭＭＭＭＭＭＭＭＭＭＭＭＭＭＭＭＭ

- -·---

-Fraction of ｑｾ｟ｴｬｬＡｉｄｑﾧＮＡ＠ U1ti:nate Load 1 2 ₃ 4 5 6 7 8

--- .

0.1 2222 1180 2083 1106 2124 2424 1057 1679 0.5 2215 1127 1967 865 1891 2296 998 1676 0.7 2212 1100 1905 73 8 1765 2226 964 1674 o.8 2210 1085 1872 670 1695 2187 944 1673 0.9 2209 1068 )..833 591 1617 2142 921 1672 Zero after Test 2222 1186 2099 1146 2161 2441 1061 1677 C .P ＬﾣＱｾＭ］｟Ａｉｓ ｅｄ＠ 1 '1ING O.l 2238 2299 1665 1659 1852 2161 372 943 0.5 2231 2245 1542 1401 1587 2005 272 937 0.7 2228 2218 1478 1262 1446 1919 222 935

o.B

2226 2205 1446 1195 13?0 1872 198 933 0.9 2223 2191 1411 1121

1288

1819 167 931 Zero after Test 2239 2313

1719

19o8

2186 944

EM

Fi.E..!...1

BAA

Used '"ing

0.9 Specified Ultimate Load

Page No . 7

ｅｴｧ｟ｾ｟ｧ｟＠

CPE

New Ｑ_{ｾ Ｇｩｮｧ＠}

0.7 Specified Ultinate Load

Page No .

8

Fig..!.._}

. BAA

Used ·;!ing

Zero Load

PageNo.

9

ｅｩｒｾＭＱ＠

HAA

Userl I,'.Jine

0.5

Sn e cified Ultimate Load

Page No. 10

ｅｩｧＮＮＡＮＭＭｾ＠

HAA

Used '·ring

0.7 Specified Ultimate Load

Page No, 11

Eig_.! ___

.Q

HArt

New ·; ing

Page No. 12

Report No. l\Il/f -44

[_ig-!_ __ .7_

H . .

ｬｾｳ･､＠ ·vlint:

0.8

Specified Ultimate Load

Pa(?'e r-ro.

13

ｅＱ･ｾ｟Ｒ＠

Ell

Used ｾｩｮｧ＠

0.9 Specified Ultimate Load

Page No . 14

ｆｩｾ｟Ｒ＠

HAA

New Harvard Wing

Page No,

15

Report 1:·o . IVIM-4-4

Fig_._l_9

C?H

Used 1_7ing

0 . 1 2pe cified ｕｬｴｩｾ｡ｴ･＠ Load

Pap;e No.

16

Eig.!-_1.1

CPB

J.:"'d Wing

0.

5

Specli.i.eQ TJltinate Load

Par:e N'J . 17

44-ｅｩｾ｟ｬｧ＠

CPB Used Wing

Page No . 18

Report No . MH·-44

t),g ! , __ ;LJ

｣ｾｮ＠

t; ew ''>Ting

0 .7 Spe cified Ultimate Load

Page No.

19

Eir:_. 11

cpn

Used 'iinl'l'

P::Jge ｾ＠ -->. 20

Report T''o . 1TI'J.I-44

Ei.g_. 1.2

CP"9

Used \-ring

Pat:e No . 21

Report No. I:.IIA:-44

Ei.L3.-!...J-

ｾ＠

cr-.-:

:t-Tew 1v i ng

Page No. 22

He'Jort No. Ml.I - 44

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Page l'i"O. i

A P P E N D I X

{Calculations Supplied

by

Depart1oont of National ｾ･ｦ･ｮ｣･Ｌ＠ ｾｩｲ＠ Service)

F cos

(3 -

R cos

<f

=

0

Fsint3- Rsinf=O

From which F =

_ _

Ｔ＿ＲＰＰ

__

ＮＺＮＮｾ ］Ｇｾ＠Ｎ＠

tf

= ｬｬｾｾｯ＠

Q£nsider Engine ｏｪｬ｟ｃｾ ｮ ､ｩｴｩｯｮ＠

Same figure as above.

Vs

=

70 m/hr.

vl

= Vs

ｊｾ ﾷﾷ＠

T c: 2 X 550 X 0

----218

'J

= ｳｯ［Ｎｾ＠ = 70

19

=

.

J2

._?_O __ ｾｾＮｑ＠ F cosf3- T 0 sin'b- R ｣ｯｳｾ］＠ 0 F sinf3- T₀ cos'i'+ R ｳｩｮｾ］＠ 0 F = - I 47079}1 R = i;-(1: = 5 245 X 9 = 1.::7200

(3

=

oC.-Tan

-c:u

= 18.5 - 7.1 CL

y=

ｬｦＮＬＮｾｯ＠

From the above it wi l l be seen that the ·,;engine off;' condition is critical.

Page No. ii L

=

47200 cos D

=

4720 0 (c<-(:5) = ＨｄＨＭｾＩ＠

=

ＴＶＸＰＰ ｦｾ＠II 4830::! ,/ willS.. ｡･ｽＭＺＹＭｾＡｬＮＮﾧｬｩｬｩ｣＠ forces. JL 1

=

46800//

'

_'

=

C D x D

en

= 4830 X .170 .194

=

42300 C D

=

Coef. of drag _{of wing.}

F'

=

/468oo

2 + 42302

=

47000{

Dir is Tan -1 . 093

=

3 .30°

Outer Winr.' Inertia :Fol'Ce o = 250 x 9 = _ _ 2070:,.( ,r

Load on one wine; = 23500)

From Curve ｾ Ｑ＠ - Outer wing section carries ＸＰ ｾ＠

___________ _ .Jr_ ,

of load.

=

. 80 X 23 500 =- 18700/f II

Applied static load on wing - 18700 - 2070

=

F"

=

.::::..:::..::: 16630:0: I

----Loading distribution consid ered as in Type Record Part III Pg. 51 (See curve #1)

t Chordwise ｌｯ｡､ｩｮｾ＠ F,

=

3-9x + sx2-zx3 ＭＭＴＭｲｲＺｸｬＭｾ Ｍ Ｍ F2

=

l-3x + 8x2 -

ox5

-4\1:.x) F 3

=

2x(l-x)

Page lJo. iii

Dotted Section is actual loading.

x

=

fractio n of chord that

C.P. is from L.E.

Y!i.A£._1j...:£ = ｮ｟ ｾ｣Ｎ［ＺＮＮ＠ 4412 - Lng1e of .. ｾ ｴｴ｡｣ｫ＠ = 16.5°

C.F.

=

.310 (from ｎＮ ｌ ＮｃＮ ｾ ＮｔＮｒＮ＠ j 4 6J )

'vYing root

=

ｩｾｔＮ ＮＺＺＬＮ｣｟Ｎ ＺＬ｟＠ 22 15 - .Lng1e of Attack 18.5°

c. r .

=

.2?C (from N.A.C.A.T. R. j,;460 for section 2212)

ｗｩｰＮ｟ｧ｟｟ｾ･ｮ＠ tre C. P .

₌

.29 by interpola tion.

Fl ｔｩｾＩ＠

=

.333 F1 Root

=

.381 F1 centre = .358

Fz

Tip

=

.23 9

_...

_Fz Root

₌

.222 F ₂ centre = .229

F3 Tip = .4Z9 F3 Root = .59? F3 centre = .413

Ji.l.,.

ﾷ ＭＧｾ ｾ Ｍ Loading Chart

---·

Ｍ ＭＭ ｾ ＭＭＭ

'

Fraction of Load.

Section Total F

s

Total .1 . 5 .7 .8 .9

----1-r

880

1

ｾ＠

F1 352 176 88 88

l

I

2320 _F2

Ｍ＾ＭｾＵＲ＠

208 104 52 52

I

-F _'3 920 92 368 184 92 92

!

---

-

---.

I

-I

I

_l

I

I t Fl 860

_I

86 344 172 86 86

--

-·

I

--

f

-II

2260 500 50 200 100 50 50 \

---

-

-I

--+---

Fr 900 90 360 180 90 90 0

---- --- --.--.-

--

----

·--

.. H' _{770 77 308 151 77 77} -1

-

- - -

- -

---

1---

r---III

2150 H' .1:2 490 49 196 98 49 4 9

·-

---

- - , - -

--1i' -3 890 8 9 356 178 89 89

---

.-..

-

ＭＭＭ ｾＭ Ｍ - r-·- --_F1

｣ＭｾＫ＿ＭＱ＠

284 142 ?1 71

_

...

_._

-

-IV

1980 _F2

_{ＴＵＰｾＵ＠}

180 90 4 5 45

--

t - - -

-

---

1--· F..,. 0 820

I

82 328 164 82 82 I ··-+---·--+---1---t----+---

---t

I

F 680 1 _{68 272 136 68 68}

l:

-e--. -

ＫＭｾＭＱＭＭＭ

ＭＭＭＭｴＭＭ

...

----r---F2 430 ; 43 172 86 43 43 i

v

1900

.

ﾷ ﾷ ＭＱＭＭＭＭＭ ｾ ＭＭＭ ＭｲＭＭＭ ＭＭＭＭ

--

ＭＭ Ｍ ﾷＭＭＭＭＭｩｬＭＭＭＭｾ＠ 7 9 F 790

l

?9 316 158 79 3

--- --- r-

Ｍ ｾＭ ＭＭ

----'---F1 630

I

63 252 126 65 63 ＭＭＭＭ Ｍ ＭＭ Ｍ ｾＭＭＭＭｾ Ｍ ＭＭｾＭＭＭＭｾＭＭｪｾＭＭＭＭＭ Ｍｾ ＭＭＭＭＭＭ

VI

1760 400

I

l 40 1 60 80 40 40

i

Ｍ ＭＭ Ｍ ＭＭＭＭＭＫ Ｌ ＭＭＭＭ ＴＭＭＭＭＭＫＭＭｾｾＭＭＫＭＭＭＭＭＭ !

---:-:--

ｾＺＭｾＭ ＭＭ Ｚ［ｪＭＭ［［［ＺｾｾＭ

:-;--;---:---- --

.·r

-VII 1600 F 2 370 3? , 148, 74 c r_{I ;} · 37 , 07 -- 1 - ---- - ,__ _ __.

!

I

.. ｾ Ｍ Ｍ ＭＭＭＭＭ Ｍ Ｍ Ｍ

--Section Total F t

_s

Total . 1 . 5

I 'a g e Ａｾ ｯＮ＠ v Fr a ct i on of Loa d . .7 ＭＭｾ Ｘ＠ • 9 ｾ Ｍ ＮＳ ＭＭＭＭＭＭＬＭＭＭＭＭｾＭＭＭＭｾＭＭＭＭＭＭＭＭＭＭｾＭＭＶ Ｖ＠

Ｍ ｾＭＭｾＺ＠

-

ｾ ＿ｬＭＴＭＭＷ＠

66 0 66 264 66

VIII

1 4 10 ＭＭＭＭＫ ｾ ＭＭＭ

-·-1100

._

_

___

-.. ｾ Ｍ ＭＭＭ t1 70 47 -

--

f-· 340 34 t H' .L 2·

---H' _{.L 600 60} 3 Ｍ ｾ＠

---

-.,., _[• 2

·-

[

--.·ill 3 '70 37 ··- - ·-

----

!-

---2 60 26

---

f -4 ? 0 47

·---188

---1 36 68 3 4 34

-

·-24 0 1 20 60 60 ｾ Ｍ Ｍ

-148 ?-:1: 3 ? 3? ,_

_

___

f-104 52 _,.Jo ':l " ₂₆ ＭＭＭＭ Ｍ ｾ Ｍ

-1 '..,'"' C;C.. g,::: L:: ? 4.:7

l--

IX __ __.__

i

-·

f

-__

J_

ｲ ﾷｾｩ＠

-

... ｾ＠ .. Ｍ Ｍ ｾ＠ I

... ·1

50 5 2.0 ,

--

t---.:.._ .. . - - \ 1 0 5 5 17

ｾ＠

1 _ 4 0 4 1 6

--

t - ---

·--

60 6 24

!

'·.:···.· 1 I '; :! \: ' " - .. .

F =

v

=

s

=

c.:c:_.jh_Harvard Statie TJinsJe.st.

5245='.'= _I• 193

m/hr.

o.t S .I"• 254

sq.

ft.

CL = 2 '7 ｾｲＲ＠

ps'

.002S8 2 X X 5245 254 X ｦｧＳｾ＠ X 2;15

=

ｾＳＱＷ＠

From Pg. 13 part II of Type Record

·,Then CL "" • 217 ･ｮＬ ｾ Ｌ＠ = • 01 iv

c_

=

.038 .l) n = } I?-( = .cot DV 550

=

- - -916 X 193 550 X 1.467 ··-- ::a -1 '71 ＭｾｉＭｉ＿［Ｚ｟ｾ＠ HP output =

. "55""0

ｾＧＷＱ＠ .:: .857 a:; ｅｦｦｩ｣ｩ･ｮｯ ｾ ﾷ＠

=

TJ

From A.P. 970

..

(3

I '( = 20 oC = .5o R =NY/ = 9

-oC..=

tan -1

(3

₌ 10.45° T = 916# 0 X 5245

=

4:?100 CDTot = 9.95° CL

Forces resolve 11 and J_ to chord.

11

To

cos y + R sin

'f -

F sin

(3

= 0

j_

T sin ""( + R oos

'f -

F cos

(3

=

0 .

a

From

the d.bove F = 4'7300

Cf=

9.35°

Consider ｾｾｩＮＮｐＮＮＮｾ＠ Off;' Case

F cos

(3

=

R cos

Cf

F sin(3= R sin

f

F = R = 4'7100il

lf

=

(3

ｾ＠

10.45° Engine On L • F cos

({3

-oc.) =

46500//-DTot = F sin ( (3 - oc::)

=

8180#

Dwing

=

8180 x

c,..,_

_{lJ v'J} = ＲＱＵＰ ｴ ｾ＠ Fwing

ｾ＠

v465002 + 21502

=

46600

e

=

tan - 1 2150 = 2.65° 46500 ]glgine Off L = 4'7100 c os 9.95 = 46400 D = 4?10 G sin

s.

95 = 8130 D,:₁ a 2140 Tot '

e

=

tan-1 2140

=

2.65 46400

Page No. viii

ｾｩｴｨ･ｲ＠ condition is critical in total load on

ｾ ｯｵｮｴｩｮｧ＠ angle as ｴｾ･ ｹ＠ are so close.

1<iounting ) .. ngle

=

e

+if_ c 2.65 + .5 = ｾＡＮＮＱＵﾰ＠

and wing is :·ilOUj_1ted so that there is a + ve drag force.

Load on Out9 ___ ]{_ing

Assume L.A •. .!.. vring load sp anwise distribution From Type Recor& Pa rt III Pg . 51. {see curve II)

%

of load on outer wing

=

78 ＮＵ ＿ｾ＠

Load ... 46500 x

--;r--

78 5• ct -10 - _ 18 2

zr.::o.:t

0 0T

Outer wing Intertia. force

=

9 x 230

=

2070T,·

Actual .Applied loa c1 ::z 18250 - 2070

=

l618 0i;:

:)(.C ·

':

from De Havillancl Ste. tic VfiTI£, test 40C

F + F

=

l - 2x + 2x2

1 2

F3

=

2x (1 - x)

Consider C. ? . positions as follows {See Curve II)

Root Centre Tip

.27 .• 29 .31 . :X: in C. P .F • .39 • 41 X in C ._P .B. = ｃＮｐｾｆｾ＠ + .1 .5 34 .524 _{.516 F1} + F2 .466 '.4'76 .484 F3 Loading Diagram Additions - to make

Fraction of load indicated

. - . . _..

_{- ·--·}

ｾ･｣ｴＱｯｮ＠

of F

Load F Totals c.-1 .5 ,.6 _{·17 •A} .c

ｾ ＭＭ ﾷ ＭＭ . . Fl -t -. . . ·--I F2 1210 121 . . . ＴＸｾ＠ 1'21 121 121 12] > . . . ' . ' . ; . 22'70 F,.,. 1060 106 424 106 106 106 lOE 0 ,' '

·-

--II

_IFl

₊ - . DT2 · 11'70 l l=t 4GB 117 117 11? ＱＱｾ＠

--

ｾＭＭＭＭＭＭ . 2190

_tF3

1020 102 408 102 102 . ·102 1.' 2 .

-I

,.

ll:II

ｾＱ＠

+ 1080 108 432 108 108 108 lOE 2 20'70 tF3 990 99 396 99 99 99 9<.: IV _w1 +

ＱｾＰ＠

1103 IF2 412 103 103 103 10Z: 1---930

I

-

--

--1960 _IF3 93 372 93 £5 93 93

--f-IFl + I

v

IF2 960 96 384 95 96 95 96 .. 1830 _IF3 870 87 348 87 8? 87 87 ... Ｍ ｾ Ｍ

VI

IFl + Pf2 8'70 87 348 87 87 8? 87

ｾ＠

1660 _IF3 79 316 ?9 79 79 ?9 l i I

Page No. x

ｾｯ｡､ｩｮｧ＠ Diagram (Cont'd.)

Additions to ｲｾｫ･＠

Fraction of load indicated

-1Sect1on I of 1 F I Load F Totals .1 .5 .6 .? .8 .9 I ;

VII

_Fl + i I _j F 810 81 324 81 j 81 81 I ₈₁ 2

-t

1 550 _F3 '740 74 296 ?4 ?4 ?4 ?4

---·

-

ｾＭ Ｍ Ｍ ,__

VIII

Fl + F2 ?10 ?1 284 ?1 ?1 "71 '71 13?0 _F3 660 66 264 66 65 65 66 -Fl + f2 580 58 232 58 58 58 58 1120 _F3 54:0 54 216 54 54 54 54 1--I:Ja.-Fl + F2 80 8 32 8 8 8 8 1 - - -

-160 _{. !F3} 80 8 32 8 8 8 8