News Letter 1940 Jul-Dec - Air Force Historical Studies Office
News Letter 1940 Jul-Dec - Air Force Historical Studies Office
News Letter 1940 Jul-Dec - Air Force Historical Studies Office
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homeon the stations of the Pan American<br />
<strong>Air</strong>ways. However, caution should<br />
always be employed whenusing the radio<br />
compass at these higher frequencies.<br />
The indicator needle will oscillate<br />
more and mountains will cause some<br />
course changes. However, br, following<br />
the indicator the compass w1ll always<br />
bring the airplane to the station, although<br />
the track may be devious. .'<br />
Every radio compass when operating as<br />
a compass Elmploysfull automatic volume<br />
control. The equipment therefore when,<br />
operat ing as a compass should not be ><br />
used for aural radio range reception<br />
since the automatic volume control cuts<br />
a strong signal downand brings a weak<br />
signal up, fhereby broadening the<br />
course and making off-course sigpals<br />
appear as on-course signals. For example,<br />
the airplane maybe in the "A"<br />
quBdrant. The "A" should be heard by<br />
tlle pilot 'since it is much.stronger<br />
than the "N." . Automatic vollime control,<br />
however, will cut the "A" downand<br />
bring the "N" UP.l..r esul.t Ing in .an oncourse<br />
signal, 'men SllI'alreception is<br />
desired tEe compass equipment should be<br />
operated on "RE .ANT" or "REG .LOOP ."<br />
In any position;. interconnected interphone<br />
volume controls should be turned<br />
full-on and the "audio" knob on the<br />
compass control box adjusted for comforta:ble<br />
level. " ." .. ~<br />
. , Aural reception of simultaneous. radio<br />
range signals .is only slightly affected<br />
by automatic volume control, since the<br />
carrier is always on; however, the cone<br />
of silence Lsmade much sharper with a<br />
leveling off of the build-up on both<br />
sides of the cone. The compasses must<br />
be operated on ''REC.ANT'' or ''REG.LOOP''<br />
for @Podaural course definition of all<br />
radio ranges of the.non-simultaneous<br />
variety. .<br />
, Conclusions<br />
To sum up: Wheno:perated as a compass,<br />
there is a sli@:J.td1stortion of recap- .<br />
I rantal error. This error is caused by<br />
the distortion 'of the radio waveby the<br />
airplane structure. Q)ladrantal error<br />
curves showthe correction which has to<br />
be a,pplied to the indicated radio bearing<br />
m order to obtain the correct. radio<br />
bearing. On present type ~~~ses".if<br />
the pilot does not have a antal;.<br />
error chart 'available in tlie Birplatie,<br />
he can point the air:plane toward the,d<br />
station, bring the r1ght-left indicator<br />
to zero. and read the ~etic 'compass"<br />
On future :production of radio compasses<br />
a device mll be provided for setting~<br />
up the quadrantal error on the compass<br />
itself so that a qua.dI:antal error chart<br />
will be unnecessary after the curves<br />
have been run and the error set up.",<br />
. '. ---000--- ..• 1<br />
, . , .'1'<br />
MAJORroOLITTLEREl'tJRlilSTO .'-r '''fi,<br />
ACTIVESERVICE :~"-f.'tn<br />
• , Ut,.<br />
. It 'was a matter of rejoicing smong.d<br />
the old timers at Wri~t Field to see.<br />
IIJimmy" Doolittle Major, <strong>Air</strong> Reserve',<br />
in the cafeteria in uniform once more..<br />
Major Doolittle has been called to one<br />
:lear's active 'service with the Ail' :;,<br />
Corps and reported on <strong>Jul</strong>y 1 to the',<br />
Supervisor of the Central <strong>Air</strong> Ocrps .Procurement<br />
District for duty. Assigned<br />
as an -Assistant Suoervisor of the. Central<br />
<strong>Air</strong> Co:rlJsProeurement District ;'.:.he<br />
will be 'stahoned at Indianapolis.,~<br />
. Major.Doolittle' s career, both as' an<br />
<strong>Air</strong> corps officer and as a Reserve. officer<br />
since his separation from active<br />
duty in 1930, is too well known.to 'need<br />
recounting here. From the old McCook<br />
Field ~s, he is rememberedasa test<br />
pilot whowas always so anxious to try<br />
out the newest and most radical designs<br />
of aircreft coming to the Division.that<br />
he could .searcelywait to lay hands on<br />
the controls. .<br />
Biographical notes .danced thro'wih at<br />
random contain the following' colorful<br />
lines: "First to Cross the U.S. in Less<br />
than 24 Hours - September 5, 1922; "c ,<br />
"Saved Life by Parachut e September I,<br />
1929, Cleveland; II 'II Saved.Lile by. Parachute<br />
.fune 1931, St. Loms; II "Demonstrated<br />
Curtiss Pursuit Planes to .,,,:<br />
ChiJ.ean Government, 1926; II "First American<br />
flYer to Cross Andes in Plane, '.<br />
1926; II TlFlys on Back Thro~ Sky; "'._<br />
"AwardedDistiIJgl,lished JrlYlng Cross;.},<br />
1929;" "Elected Presd.dent of the Institute<br />
of Aerona;utical'Sciences, <strong>1940</strong>."<br />
These are but a few of the events ,that<br />
flash across the "Doolittle" pages ...J<br />
Not only did Major Doolittle,reCeive<br />
a heart1.' welcomefrom all whoknew;him<br />
at Wri6at Field, but all were .glad',at<br />
the prospect of his being attlie"field<br />
frequently in connectio~ with hi~"du~<br />
tion of radio range silmals of simultaneous<br />
ranges. ALWAYS USE MAXIMUM TI'TER-<br />
PHONE VOIDMEJ AND MINIMUM .A!JDIO VOLUME .<br />
ONCOMPASS .. To receive non-simultaneflUS<br />
radio ranges :place on uBEC.A..~" or<br />
REC.LOOP." ',Incia.entally, the automatic<br />
volume.control feature which is now<br />
a part of the present type commandset<br />
is being eliminated on the new type<br />
commandset, since this feature is a<br />
source of danger when following the<br />
radio range and has disadvantages in<br />
trying to. tune in one of the two stations<br />
which are close in frequency.<br />
At the' time of installation all radio<br />
compasses are .so calibrated that the<br />
pointer is on zero for stations dead<br />
ahead. 'To take side bearings it 'isnecessary<br />
to take into account the quadhes<br />
at the nearby stahon. .....c' d!lJ;<br />
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