PI~OJECT 10073 RECORU CARD l. DATETIME GROUP l . LOCATION 12. CUNCLUSIONS 0 Was Balloon k Ric\_"J_t Tcnn 0 Probably Uolloon ----------------0 Possibly Balloon 4. TYPE OF OBSERVATION ::UCGroundVi ~uol 0 Air Vi suol a GroundRodar 0 Wos Atrcrofr 0 Probably Atrcroh 0 Po ui bl y AI rcrah 0 Air-Intercept Raoar 0 Wo" Astronurnlcol ():No iH;I/rflJ. Civilian (5) 7. l E NCT H _O...:,r_O.:...;B.;..S_E_R_V_A_T_IO-N------r-1-:I.~N~U:-:-:Mtl E R OF OOJECT S 9:--COURSE ao.--8-R-IE-f'-SU_M_M_A_R_Y OF $1CHTINO 11. COMMt;N..-s 0 Prob9bly A:,tronomlcol 0 Pouibly Astronomh;ol 0 lnsuffic:lont Ooto for Evaluation ~hapc-Lieht-Co lor -Uun s u 1.lly Brieht -Speed Observers in car r.mring !TE. Object Statiorur;r. First, thoutjlt to be A/C rut H .. \s not vlmred throue;ht right ra1.r \Iindow. Plant authorityies checked but nothing This is th~ only rJ;:<a:;l::an positional was fou: .. d t 0 account !or the si61tin3. data Biven. First n.1.gnitu<le 3tar P.igel lo,., on horizon a t 110 d cg azimut.l). See Ca::;e 21 Jan 5l -Sar.'.e location) Plane t:J Venus and Juplte r not vlsiblc in E:1st. Ho mention of di$appoarance P.ven uith r eport.. In~fficif'.nt Data for evaluJ.tion. PROJECT 10073 RECORD CARD LOCATION 11. CONCLUSIONS Oak JUdge, Was Balloon P rob obi y Boll con Po asi bl y Balloon 3. DATETIME GROUP TYPE OF OBSERVATION 0 Ground Vi suol 0 Ground-Radar Wos Aircraft 0 Probably Aircraft 0 Alrlntorcettt Raoor 0 Po ssi bl y Ai rcrolt 0 Was Astranornl col ProbQbly Astronomical D Poulbly Attronomlcal Othor Ground Target 7. LENGTH OP OBSERVATION NUMilER 07= 08JECiS D lnsuffic:lttnt Doto fQr Evaluation Three radar runs 10. aAIEf SUMMARY Of $1GHTINO Explanation is"ducting".caused by t.l-te F-82 attempted to intercept an unkno;m t nrget. Three passes \tere made at the object but since it "'as over Oak Ridge the pas s could not be completed. \'leather data indicate3 a double inversion existed in the air. ATJC FORM 329 (REV 26 lltP 52) inversion. ProbJ.ble source belr~ a gro: r.!J ~Jl'lCLASS~EtEO JU J\JtJ.J.\SS I EIE 0 SUM~ARY OF INFORMATION PREPARING OFFICE SUBJECT COOl:. f-OR USE IN lfii>IVIDUAL PARAGHAPH EVALUAriON SOURCE: OF INFOR~AliON COMPLETELY RELIABLE A CO~lFioU-41:.0 OY OTHER ~\IRCLS USUALLY hEUAULE 8 f'ROBARLY TnUE FAIRLY RELIABLE IBLYTRU NOT U$UALl Y RELlA OLE 0 DOUUTFULLY TRUE UNRfLIABL! E IMPROBABLE REI.IAoiUTY UNI<NO'Mt F T IIUI H CANNOT DE J UDGED SUMMARY OF INFORMATION : s: .. r:J:I ~'r'Jject.~ ~ ..k :!iugtl~ i''"'!'lllt!Ssee. .tGachEJd ~.~::~o .:s t.1;e cta 1.t t -- st frc~ 7irious t-'1,.,;1~ ~nd fvu..nd that 't.h e ~cu.~-3 o'? c/1a l:ltr!. rt..m~l'3 ':'ha .tedt.her .:1t 'c.ha t.i-ne o.f this L~cide."'lt-.=.s rcp01.t~;r: ::-art.l:r c.~, , 'l.> rrltlUTIO'l rui\lC~sslflED HEADQUARTERS THIRD ARMY FORT McPHERSON, GEORGIA Orl'\.co o r t!l'J A~:;istftnt Chi'lf of Stli'f' G- 2 Di\ecto1 of.' 1ntC'1li~;'.Hlc~ ~O\,rt~o~th ~ir For(~0 Inr.1o-:;ocl horo.Tith i:::: :; l'T.~ry of inCor:"...'ltjon r e obj"ct:; :;i":ht'.}d ov " r 8j1 rlt1l 1 Fob hl 'lAyton, Ont~. A'T~J: W1IS Fort~ ad i n f\~cor'Lnce wit.~ letter, Heaclnuarters U3A3', 8 S ~l') ~, Rcl)orting of in! orr~ t-,ion on uncon7ent ton~l aircr~ft." :UilC[i\SSIF]~D. HEADQUARTERS AIR MATERIEL COMMAND ltl REPLY A!)D;tJ:SS IIOTH CO MMUNICATIO N V ELO,.E TO COMMAI'tOING Ctr~c~Al, A I R t.\ATERIEL CO'M~AND, .IHTENriON FOL lOWING OfFICE SYMBOl: WRIGHT-PATTERSON AIR FORCE BASE DAYTON, OHIO l~CLiJ.A t:Cif] A-J a / J JR/ns 5 uPJ EC'l': Unconventional Aircraft, A'fi Project tJo. 10073 Direc t.or of Inte lligence Headquarters, USAF ATTN: Evaluation Divi s i on echllical Capabilit i e s Branch ffishington 25, D.C. 1. It is c onsidert~d highly probable that the rada r targe t de:: I ccted ree times by the airborne rada r set in tho F'-82 aircraft on 21 Jamnry lias a ground target in the vicjnity of t h e X-10 plc:nt. 2. The peculiar phenom~na of having the tar~et first appear at. an altitud~ above the intr:rce ptor a nd the n b el ow the Hircre1ft i s c on3idor ed to b e due to abnorr.1~l r()fr ;,ction of the rada r clectr ora3nct.ic c -.;m a t. ions. 'The airborne rada r trcmsmi.tted e ncrror vra3 r efracted to the crou nd by a flt.r~mper::tture and/or IJoisLur e d ueL" tho t was loc;'l.ied at. about the saj"'~ altitude as the ini.cl'ceptor; more details a.ro g i vr-n j n paragraph 3 b elow. . V.'hen the interceptor clos ed on the targe~, tlh~ t a r e et first appeared to b e above the interceptor unt i l t h e apex of tho b -nt r a dar "ra~ s " wa~ reached, and after that the tarcet appeare d below the interc eptor o 3. A check ,rtth the local /I!'C base weather offtce indica t ( s tha t the ~!a:Jhville weather stn ti.on r eported the following t.rj mpc1-atur c data 50Jo to gooo ft Above 11000 ft Tc:'lp eraturc Condit i on s Six deeree increase :1a l d ecrea s e i.n ta:p/incr.,as~d a l t itudt! 'l'hr ce degree incrc~ se Normal decrea~a jn tC'r p/tncre>uso~ altitude Hq AMC Form N o. 9 (ReY 8 feb 49) "'~x-cl\ C S'JI Ir"f' A ir forc..-WP.\f&- L-3 !IEP 50 l?CO.'-\ .ROUTING AND R: J~JNCO\$_$IE!Eq. . .IU 1\JATEIUEL COal:\lAHD u.~ tbu '"'"' fror lnter-otll~ nrnspoftdenre wlthl n hlq11arhra. Nombr a "l , t~mmf"nt ~on~ec:uthel1. \ 1,., aot)tO.,of nffiU l'IJ'IIIbo18 t., dt>sl.nst~ susJEcr Project 1C'073 It is sU[ eostcd tha.t substantia l J y tle foJ J owinf, t e used i n l'eplyin~ to tha i n s oi'1.r a s the r eport on th-~ rac.l i.r de tl)c t.eo L arcet is c oncerne d : 1411. It i s c onsiderec1 hie1~Jy pro :1ble tha t the radn.r tn1 .=lt det~ctod th~ ee times by ti1c alrborne r 3.cbr et in the: F'-32 ~ircr1.ft on 2] J .:;.nu . r.f uas a r;rounc1 t o.rc e t, in t.he vicinity of the X- 1 0 pla:1t. . 112 . The peculia r phe no!'le na. o..f hE"'vlng the t;.1rget f i rst o. pear ~t a n al t.i tude above the in1.erce'Dt or !md then belot-~ the aircr .. t t i s con:: leered to 1:e c}1..1e to abnormal r efract i.on of the r aGar eJ ectrorn netic en'"m::tions. The T ' 0 airrorne r a d a r tranL'1:\.:. tted ene r a wa n r e f r actt!d to i'he gr ounc by a ~'t''1lpar3ture and/ or moistu r e Llw.:t th!:t H.::!.!l l ocat e d a t a.Joui t h e ~;an~ altitude as the interceptor; mor e d(~to.:tl~ arc t:i ven i n pa.raeraph 3 belo\1. \!hen t.he interceptor c , osed on the tarcot, the t.qreP.t f':irst appeared to be aLove t .e interceptor unti l the a p e x o: t h e bent ra.d~tr ' r ays' lla s rc.:~ched, :1r.d F..ftor th3.t the tarc0t urpeareC.: belo\-J t ho in1.erceptor. 3. A check \ l i t.h the loc l 'JiC base wo!lther ofJ~ice inc'ic(').tes t h ... t the l r:1shville YOA.t r or station r eported the f ol::i.m.ring ten:_Je r a ture data for 2100 t;ST 21 J anuary 1951: 5ooo t o eoco rt 8 CCO to llOCO ft Above 11000 f t Tc'1oe1aturo Condi tior.s Ho c b::nge Six dee r e e increase Horrna l clo cre"\se in te'"'np/increassd al t .i t u de Thr e e deeree increase r:orill~l cccrcase in tcrap/increased 31. ti tude The nom;.J. o.tmOS.f>~eric torli'er~ture concl:ttio~ in t h:.1t t e!lper..,t.ure dec :-Gases near J y ljnearil y with increase in alt itude. The :bove d:.tn. ir1cicates th:...t t ";o inversion J ::.y e r s existed, o ne above the j ntc r ceptor :::!ld one bc lou o.bout the tiTi\e the a.irl::orn'3 r~d .r t.areet ov~r tha O::tk Hir~ge arc~ u a s rt1porten. o co.:1p~.eto and a.ccur..: te effects of tc::1per turo invc r r ion ' l "e not thoroue~ly un~o tstood , i t i~ c onric e rnd tha.t t h:i.s e f f ect c aunecl the cl~ t<::ction o f '1 c;round to..rGe o appear to '-1e airborne ""irGt aco"'/e an~: t he n bolo'vJ tho intvrco?to1 a s tho int~rcontor c l oged on the 2/7 /5i fr Dj r SJ?e C Invest H/C;r I.tr 5?nd !t'N:TG, 1/25/51 and Pp t o f G i.r:;ht i ne Chief, Eloct.rOlJ len Scctlo n 13 /6JA Technic~-l.l !\n i ) ::~::is }..rt vision P A-1'7 b;~ und u n l I tocl<t on hand oro c ~haut!ed.