Carden, John R

Drake, Hubert M

English

NASA Technical Reports Server

., . 
SECURITY INFORIV1AT ION 
Copy r: 
RM rlflOG2~. J 
NACA 
RESE.ARCH MEMORANDUM 
If;) H 
o ~ ~ 
l::.::l ~ 
;-. .--l 
~T~ I 
1--: 0 
U·.' r' 
v~ 
~ ~o 
E.r1E% TOR-STABILIZER EFFECTIVENESS AND TRIM OF THE 
, --t< 
" H 
X - I AIRPLANE TO A MACH NUMBER OF 1.06 
By Hubert M. Drake and John R. Carden 
Langley Aeronadical Laboratory 
~ Langley Air Force Base, Va. 
~ CLASSIFICATION CIL~\\C;ED 
NACA - Dryden/;r.~ 
Ey au t ho r i ~y of _ ~_l?-~.I?-g~ . 51~ ______ ______ Ga Le._~::-_~'2_-:'2~ __ _ .. 
CLASSIFIED DOCUMENT 
This materlal contalns 1n!ormaUoD .llecUng lbe NaUonaJ Defense of the United Slates wIthin lbe meaning 
of the espionage laws, TiUe 18, U.S.C., Sees. 793 and 794, the transmission or revelaUon cf which in any 
manner to unauthorized person is prohibited by law. 
NATIONAL ADVISORY COMMITTEE 
FOR AERONAUTICS 
WASHINGTON 
November 1 , 1950 
https://ntrs.nasa.gov/search.jsp?R=19930086316 2020-06-17T12:41:19+00:00Z
1 
• 
• 
NACA RM L50G20 SECRET 
NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS 
RESEARCH MEMORANDUM 
ELEVATOR- STABILIZER EFFECTIVENESS AND TRIM OF THE 
X-l AIRPLANE TO A MACH NUMBER OF 1 . 06 
By Hubert M. Drake and John R. Carden 
SUMMARY 
Limited measurements of elevator- stabilizer effectiveness and trim 
of the X- l airplane with the 10- percent-thick wing and 8-percent-thick 
tail have been presented previously to a Mach number of about 0.93 . 
Subsequent flights have permitted refinement and extension of these dat a 
to higher Mach numbers. The data presented in this report were obtained 
at about 40,000 feet altitude at Mach numbers between 0.78 and 1.06 for 
normal-force coefficients between 0.26 and 0.42 . 
The data show that at Mach numbers between 0.78 and 0.92, the varia-
tion of elevator position i s gradual for all the stabilizer settings 
tested. Above a Mach number of about 0.92, trim changes are more pro-
nounced. The magnitude and direction of these trim changes and the Mach 
number at which they occur change with stabilizer incidence. The data 
indicate that s tabilizer angles of 20 and 0 .50 are the limit settings 
for which the airplane can be trimmed with the elevator alone through 
the Mach number range up to M = 1.0. Because of the high altitude of 
flight the stick forces involved were moderate, maximum values of 30 pounds 
pull and 50 pounds push being obtained. The relative e l evator-stabilizer 
effectiveness dit/dOe decreases from a value of 0.25 at a Mach number 
of 0.78 to a minimum value of 0 .05 at Mach number of 1 .0. At Mach numbers 
between 1.01 and 1.06 the effectiveness increases. The variation of ele-
vator deflection with stabilizer incidence was nonlinear between Mach 
numbers of 0.94 and 0.97. The variation of dit/doe with Mach number 
and the nonlinearity of this curve at Mach numbers between 0.94 and 0.97 
were primarily responsible for the difference between the trim curves 
obtained at the various stabilizer settings . It was found that, with 
the elevator fixed at zero, only about 0.50 of stabilizer movement would 
be required to trim through the Mach number range from 0.78 to 1 .02 but 
greater movements would be required at Mach numbers above 1 .02. 
SECRET 
2 SECRET NACA RM L50G20 
INTRODUCTION 
The variation of relative elevator-stabilizer effectiveness for the 
X-l airplane having the 10- percent- thick wing and the 8-percent - thick 
tail has been presented in r eference 1 for Mach numbers up to 0 . 93 as 
determined from limited measurements during the exploratory flights of 
the airplane. Subsequent flights, made primarily for the purposes of 
obtaining pressure distributions , have permitted refinement of these 
data and its extension to higher Mach numbers. These results are pre-
sented in thi s paper . 
n 
w 
S 
q 
SYMBOLS 
stabilizer incidence angle, degrees 
elevator angle at elevator center line, measured with respect 
to stabilizer, degrees 
elevator- wheel force, pounds 
airpl ane normal- force coefficient 
normal acceleration, gravitational units 
airplane weight , pounds 
airplane wing area, square feet 
dynamic pressure, pounds per s quare foot 
AIRPLANE AND INSTRUMENTATION 
A three- view layout of the X-l airplane utilized in the NACA transonic 
research program is shown as figure 1 . A complete description of the air-
plane is presented in reference 2. 
Instrumentation installed in the airplane includes standard NACA 
recording instruments which record indicated airspeed, altitude, three 
components of acceleration, pitching velocity, elevator and stabilizer 
position, and elevator control force. A modified SCR 584 radar unit is 
used to obtain the a irspeed calibration on each flight as described in 
reference 3 . All records are synchronized by a common timer . 
SECRET 
• 
• 
NACA RM L5OG20 SECRET 3 
The elevator angles presented herein were measured with respect to 
the stabilizer by a transmitter installed at the center line of the ele-
vator torque tube on the fuselage center line. The stabilizer angles 
were measured with respect to the fuselage center line. 
TESTS, RESULTS, AND DISCUSSION 
The data presented in this report vere obtained in level flight at 
altitudes between 38,000 and 42,000 feet and the elevator position was 
measured at the center of the elevator; therefore, tailor elevator dis-
tortion effects were not investigated and the results presented neglect 
these effects. Because of the variation in attitude, airplane weight, 
and speed during the runs, each set of data was obtained at a slightly 
different range of normal-force coefficients. The center-of-gravity 
location ranged from 20.9 to 21.8 percent of the mean aerodynamic chord 
and was neglected in the analysis. 
The variations of elevator position and force with Mach number for 
several stabilizer settings are presented in figure 2. At Mach numbers 
between 0.78 and 0.92 the data for all stabilizer settings are generally 
similar, and the trim changes are gradual and small for all but the 2.10 
stabilizer setting. Above a Mach number of 0.92 there are more abrupt 
changes in trim which are different in magnitude and direction for the 
various .stabilizer settings. The most pronounced of these trim changes 
are in the nose-down direction at a Mach number of 0.92 for 2.10 incidence 
and in the nose-up direction at a Mach number of about 0.96 for 0.50 sta-
bilizer and at about 0.99 for the other stabilizer settings. 
The data indicate that 20 to 0.50 are about the limit stabilizer 
incidences for which the airplane can be trimmed by the elevator up to 
a Mach number of 1 at normal-force coefficients near 0.3. The elevator 
limits are 140 up and 110 down. 
The friction in the elevator control is about x4 pounds. Lines have 
therefore been faired through the elevator wheel-force data and only the 
faired lines have been presented in figure 2. These data show that the 
elevator forces follow the same trends as do the positions discussed pre-
viously. Because of t he high altitude of these flights, the forces were 
moderate over the range of stabilizer incidences testedj the maximum 
elevator control forces encountered in flying to a Mach number of 0.95 
were only about 12 pounds pull and 15 pounds push. At higher Mach numbers 
greater forces are required by the larger elevator angles involved in the 
trim changes discussed previously. The largest forces encountered were 
about 30 pounds pull and 50 pounds push. 
SECRET 
-- --------
4 SECRET RACA RM L5OG20 
The data of figure 2 were converted to a constant normal-force coef-
ficient of 0 . 30 by changing the elevator angle by the increment which 
would be required to obtain 0.3 normal-force coefficient. The values 
of dOe/dCNA used to make this change were obtained from turns and pull-
ups . An estimate of the effect of the curvature of the flight path on 
the elevator angle was made and it was found to be a maximum of about 0.30 • 
These data a re replotted in figure 3 and show that, at a constant normal-
force coefficient of 0.3, the variations in elevator position with Mach 
number would be more pronounced than was indicated by the data of figure 2 
in which there were differences in normal-force coefficient between the 
various runs. 
The data of figure 3 were cross-plotted to obtain the relative 
elevator-stabilizer effectiveness dit/doe . Some examples of these cross 
plots are shown on figure 4. For Mach numbers below about 0.94 the varia-
tion of elevator position with stabilizer incidence was linear, but at 
Mach numbers between 0.93 and 1.0 the variation is not linear, lower 
effectiveness being indicated for down-elevator angles than for up angles. 
Above a Mach number of unity, insufficient data are available to determine 
the shape of the curve. 
The variation of dit/doe with Mach number is shown on figure 5. 
These data indicate that the value of dit/doe decreases from a value 
of 0.25 at a Mach number of 0.78 to a value of about 0.05 at a Mach num-
ber of 1.0. At supersonic speeds an increase in effectiveness is indi-
cated. The curve above a Mach number of 1 .01 is less well defined than 
at lower speeds since only two trim curves were used in obtaining it. 
At Mach numbers between 0.94 and 0.975 curves are shown for the slopes 
measured at elevator angles of 40 up and down. The effectiveness is 
considerably lower for down-elevator angles than for up-elevator angles. 
Examination of the curves of figure 3 in relation to the control 
effectiveness presented in figure 5 indicates that the differences in 
the magnitudes and directions of trim changes of the trim curves at 
different stabilizer settings may be accounted for by the large variation 
in dit/doe over the Mach number range and the fact that the effective-
ness varies with elevator position, as shown in figure 4, at Mach numbers 
between 0.94 and 0.97. 
The variation of stabilizer pos i tion with Mach number required for 
t rim with zero elevator angle was obtained from the cross plots of ele-
vator and stabilizer angles used to obtain figure 5 and are presented as 
figure 6. These data show that only about 0.50 movement of an all-
moveable tail would be required to trim through the Mach number range 
from 0.78 to 1.02 at CNA of 0.3. At supersonic speeds an increase in 
the stabilizer angle required is indicated. In this case, again, the 
SECRET 
• 
NACA RM L5OO20 SECREl' 5 
curve was obtained from only two trim curves above a Mach number of 1.015 
and is therefore less well defined than at lower Mach numbers. 
As pointed out previ ously, the effects of tailor elevator distortion 
are included in the variation of effectiveness shown. Some data have been 
obtained on the X-l having the 8- percent-thick wing and 6-percent-thick 
tail which indicate that twisting of the horizontal tail and elevator 
surface may occur and that the amount of twist is affected by the dynamic 
pressure, Mach number, and elevator position. It is believed, however, 
that the effect of elevator twist is secondary to the aerodynamic losses 
in elevator effectiveness in causing the variations in the trim curves 
for the different stabilizer settings . Flight measurements of tail twist 
will be necessary before the effects of such distortion on the control 
effectivness and the reasons for the trim changes experienced can be 
determined. 
CONCLUSIONS 
From the trim data obtained for the X-l airplane at about 40,000 feet 
altitude and a normal-force- coefficient range from 0.26 to 0.42 it has 
been found that: 
1 . At Ma ch numbers between 0 . 78 and 0.92 the variation of elevator 
positio~ with Mach number is gradual for all the stabilizer settings 
tested. Above a Mach number of about 0.92 the trim changes are more 
abrupt. The magnitude and direction of these trim changes and the Mach 
number at which they occur vary with stabilizer setting. 
2 . The data indicate that stabilizer angles of 0.50 and 20 are the 
limit settings for which the airplane can be trimmed for Mach numbers up 
to 1.0 with the elevator a l one . 
3. Because of the high altitude of these flights, the stick forces 
were moderate at Mach numbers below 0 . 95 but reached values of 30 pounds 
pull and 50 pounds push at higher Mach numbers. 
4. The relative elevator- stabilizer effectiveness decreases from 
about 0 . 25 at Mach number 0 . 78 to a minimum of 0.05 at Mach number 1 . 0 . 
The effectiveness then increases as Mach number is increased to M = 1 . 06. 
At Mach numbers between 0 . 94 and 0.97 the effectiveness is affected by 
elevator angle. The variation in elevator- stabilizer effectiveness and 
its nonlinearity at Mach number between 0.94 and 0 . 97 are primarily 
r esponsible for the difference between the trim curves obtained at the 
var ious stabilizer settings . 
SECRET j 
6 SECRET NACA RM L50G20 
5. With the elevator fixed at zero, about 0.50 of stabilizer movement 
would be required to trim to a Mach number of 1.02, but greater movements 
would be required above 1 .02. 
Langley Aeronautical Laboratory 
National Advisor y Committee for Aeronautics 
Langley Air Force Base, Va . 
REFERENCES 
1. Drake, Hubert M., Goodman, Harold R. , and Hoover, Herbert H.: Pre-
liminary Results of NACA Tr ans onic Flight s of the XS-l Airplane 
with lO- Percent- Thick Wing and 8- Percent-Thick Horizontal Tail. 
NACA RM L8I29, 1948 . 
2. Williams, Walter C., Forsyth, Charles M., and Brown, Beverly P.: 
Genera l Handling Qualities Results Obtained During Acceptance 
Flight Tests of the Bell X- l Airplane. NACA RM L8A09, 1948. 
3. Goodman, Harold R. , and Yancey, Roxannah B.: The Static-Pressure 
Error of Wing and Fuselage Airspeed Ins t allations of the X-l Air-
planes in Trans onic Flight . NACA RM L9G22, 1949. 
SECRET 
NACA RM L5OG20 SECRET 7 
= = 
1,....·>--------- ,28.00 ' ----------i 
~-------- 31. 0'------~~~ 
8. 02' 
J 
Figure 1 .- Three- view sketch of X-I research airplane. 
SECRET 
8 
i.,;' 
f- 1--1--
,",' 
";ljilT' 
."" i ,;, 
,,,,' 
v 
.. 
, ~ :-::: 
'" ~ i'-
k- I.-
I~ .' 1~ l i' 
'f. ::, In' 
, l,iF ' '' il~' 
,1!lIl( 
II::': 
I;. . 
I", I'" 
'iii':: ~ 
,ii I::, Ui",[ I ..... 
J!" ,',I 
Ir. '· ... 
I 'i' 
. 
,",f.-
II. 
II>-. 
J 
SECBEl' NACA RM 150020 
• " 1;;~ 
f) II' '1""',,, 
I" It!. : :, i:;:. 
1.,,1·,·, ' fll'rtllili;~ 1\ 1' 
r;. ~ 
i" I' ll i" ' 1'f;'I"" I'lt l ilTi; 
Pi!:f l'UHI\'lJ ,'! ', IHf ," !'!:: 
I'''' I"'~ F-i 1;:1 1 ~'Hli; I " I' '': " I '~I!:" I'" 
I'::, F h1l t:\i , P'" ' 1\ " !l."klU 'HE I'ii " n~' ,'I,:: .", 
I Ih i I r:~ fliit '!. ' ~ f'II' ii!il l"i! I " . lii 
.~ ,H Jilt w. 1:,;.:. 
Ii" ,.,~ '", ",' I,if" ,,'; , '" 
,d? 'E. 
' I:'" I," I."',, I':';' ,i. k, ,:;;· ,:i,,:. 
, 1"'1'" ,,~ '" :,. ";""n 
I .f 
I ' " 
l<il 
r·: ,It:! , 
1 '~ Ir;'ptq~;, i IPI. f :., l. ~ 
H'Iill. liii hi: ,· P i- I", 
't 
,1::;, ', Ii ,l 
':. I,,' I '" , ,11 ", 'W., 
" IU:l-i ~ , 
'I,!!, ~ 
Hi N' I '. 
H IJI 
';; 
I,., 1:iI,I" "i l1. 
'~ ' ~ ' , 
:. it, , (i 
,, 'bl ., P 
I'''' 
J I H 
" 
, n;'I ,,, 
1:,; .. ~ .. p, 
'<: ':. 
\' 1.1,'11:' 
I':: ," 
1" 1'"' 
, .. I." 
I .. 
,::, 
'''' 1 
:i' 
I"; , 
, . ': U I 'i 1"UI!" iU I·i, I,iu, 
, . ,'; " ' It!ii • " '~: I,;;' 
Pt, I'lii I ii' 
"I 
I i, 1m' JE,' 
I'''''' 
, .... I-i.i!·, ' 
.- . 
f-,"';'" "R!. 
Iii" , 
,ii "ii lHij 
,N 
"" 
" 
I 'i 
:. IHi!', •. 
i" ril " 
i ,i 
~ 
1/ . tt'" 
i . . . 
, 
. I~I! 
t I'n"] [':' 
HiLi H,i'd! lilt. 'I.[:.j 
"~,~l I'!' [,j 
"lim I~'I~ 
j I:; ,T 
!", ' !if 
'Hi' 
Figure 2 .- Variation of elevator angle and control force with Mach number 
at various s tabilizer settings. X- l airpl ane; pressure altitude 1 
about 40,000 feet . 
SECRET 
2 
• 
NACA RM L50020 SEC REI' 9 
h,'~ 1+ kl:,f' , i j~ 1 
U I'U I'\fit" ~1] ~ 
IE! Iff' ld 
I t! l;itt it) "+ I;lflltt I I '~ ttl 4f'frft! 11, 
iff' §:t .,.." , "'It It.,.., , tilltil -r'1 fli 
w tillY 
II 
r~ tH 
Itl ~ "JJ iF r ! If:! 
I n ,lr.,: :=?> Ir.u 
... IOOVi bft. I fti ' a, m i Itl 111 
IJtUW,J .~ It illtlA 'l I 1 jj:hl1 I ~ III ,j.j 
It± f ft' fi ffif ~j 
itt IUt! Ifli1 tfj r= :ro:J.lm= 
::I lBtl ~ I_ .... ~ t', 1!J:!t ill tb 
1:1± t:ttt l:' 1£ l i:to !fl(4.l:I ,ilifIHt lF. 
/ r...u: :i i:s'I!.* . 
ItTlifutW i'1R IFhl w 
"', a:~ ~ ' 1-;:;I-"~""" 
r; ,H, I1=;-:.; till IfftJ 
Iii!: tE : f.~ ft, r§B liffi 
:j:l:Bi~ +'''1 wrn 1J~ r,.,1. 
tf: Iill: :;'iltt!:iii+! . 
't +, 
Figure 3.- Variation of e l evator angle with Mach number for various 
s tabilizer settings at a normal - for ce coefficient of 0.3· 
SECRET 
10 SECRET NACA RM L5OO20 
Figure 4.- Effect of Mach number on varia tion of elevator angle with 
stabilizer incidence at a normal- force coefficient of 0.3. 
SECRET 
• 
~ 
(") 
g;J 
8 
• • 
+1 .,- ~-r-- ,..-, ' .. t- -+ , , I r- - • "C. LL' Ifl"'i ," !L • .., --- r- I----- , f 
-~ ~ ts~ Id .a. t2 '//, ~/ ~~, ~ 
-- - --
,r OJ "7 _. 
'L I ~ I Fe ~ :ii t ff'n, (}, ~/a .! 1-... ___ b,...I. ~ i'le.. rs r.: 'J<> ..., ~ 1>-6 ~ ~~-_. t-i ~ , F-h ~ 1tJ.J :,£' V'n 10- .~ ':'1. 1;1/1 1'- -~ te. 7.Ii!.... ~" .!! f..,. ..... -I ~ ....... ~ # .~ T r' I .... 
It • ~" .- .. - -, 
t,1 .,... .,..,. - ...,..,... l 
'" 
........ b!: l 1.: :~ -I t j: t ~ 
--~- -- _u "- - I , 
'1' PV1 
, 
"'K , 
~ 
~. ,; --; - I'- 'I T i: t 
....... 
~ ........:.... - -~ 
-
-'--
-- ~ -- - . -;--
_ .... 
----. ~ ~ -I , -.... 
"'-. 
1 T , I , , , 
1-- - ~~ -.... I--'~ "- - . -'-'-I i\: 1//1 
-
, 1"'-1'-, 
~ ( t'- . - ft.t ~ r_ :,/ .... 
-
't ~ + I 
'" 
r',:: 
" 
, 
1 + r:-~ 
-
-' ~ --1--1--- -~r--- ~ ~, --, , I""- I~: ~ 1--
-. 
h ~ 
.7 ~ ,_ C3 D ___ C3 ~ . I ~ P' 9 ~ 9 l ~" il DO ' {~ P4 I.~ !-- --
_ , __ ~ _ _ . l _ _ ~_ ~ , IN 0 ~ V/l ~/! 6, ~ M 
'-- '---'----
Figure 5.- Variation of relative elevator-stabilizer effectiveness with 
Mach number for the X-l airplane at a normal-force coefficient of 0 . 3 
and an a ltitude of about 40,000 feet . 
~s 
S. 
- -
-~ :--
~ 
L 
• (.0) 
~ (") 
:x> 
~ 
t-t 
VI 
8 
f\) 
o 
m 
t%j 
(") 
~ 
t-' 
t-' 
L 
z 
> () 
> 
t-
• 
" .. ~ 
, 
';" 
~ 
~ 
~ 
n 
~ 
f-3 
, . 1- -~~ - ---- -~~~ -- -~ .. -~+ ' ~- ~:::I =-':::--=_L =FI [- :4 1_.1::._- -r--c---~-c---_'~ .1 ____ 1 __ + r-1 
r 1 I 1- - -~-~--- - f-- - - -f---- I--c--~---r----r--
i·-J · L__ .- -- --r -- .-- -- -I-- --- - .. - I 
t -\ 1- --. ---r-r- - .--r-±-I------.1-- . +'----.. -1-----.-- r-' _.t-
1- l1-- -. ---- ---- -- I I -- ---I---- -- - _.1 __ 
I! -- .-- I---- r-I---- --- ---- J-.--
r 1 __ _ _____ '-- __ -t- -:.:-~- Iqt:: s~·d t'?'n //'?2L~bi. d"7tip -1-+--
I 1---~-r-I I .! ;g.. __ _ 1' ___ ' ' ___ L. __ -L ---1,___ -t.- 1/1 1 1 1_-/ 
~ r 1 , ,-I . . "," 1_ ·---,.---I-·-----·--------r· j' -"" / 1-
'-", - j-. ---- --- :::::=:::r.--- -.-f-- .-~ - r- - r- f - -,'- - -' .-~ I 
! L : ..  
I . 
I 
I 
~'--r--' 
1_-
--'! I 
l~ - --I----f- t:::::- ","_ .- I r-- :/ ----
-/-. ··-----t--·--r--r-- -.- . . -- -1-'- __ .. t---... L .- , tt 
.-L-.. -' ---~- -t-- - --c-' ---- I-- - I 
1~-'--· --1-- .----- -1--.-- --- -- .-- _ .. - ... ---r-'- ---r- '-1--1-~ k r-- - -- : -- -1--- - - 1---- - --+- --f--- . Z~±_~~i7__ .84 _r .. 88 9~ 9,15 /.(.0 ' 1.~4 v. c: ~t 
_-'___ ._ .. __ '-___ '--1-.. .1-1-__ ~1t7/rh ... _ QLvj.n~AM _ I 
Figure 6.- Var i ation of s t abilizer incidence requ i red for trim with Mach 
number . Elevator ang le , 00 ; normal - force coefficient, 0 . 3 ; pressure 
a ltitude, 40,000 feet . 
.. • .. 
f-J 
f\) 
m 
t:>:j 
~ 
~ 
~ 
~ 
t-t 
'8 
f\) 
o 
SECURITY INFORMATION 
SECRET 
SECRET 
' . 
... 
~ , 
I 
" 
'\ 
I I • 
, f 
.' 
, '. 


Elevator-stabilizer Effectiveness and Trim of the X-1 Airplane to a Mach Number of 1.06

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server