Nick, the following is a list of USAAF aviation accidents, just for the month of July of 1947. Sorry it's so long. Every day there is some kind of aviation accident, and on most days there are more than one. This doesn't include naval aviation either.
So, the point is, instead of trying to hide a top-secret aviation accident as a flying saucer crash,
which would presumably generate all the more interest, why wouldn't the military authorities just say the test vehicle was some known aircraft that crashed, like a B-29, or a B-26, or a C-54 with passengers, etc.?
In this list of accidents an XF-12 very high performance four-engined recon aircraft is listed.
Accident-Report.com - USAF AIRCRAFT ACCIDENTS FOR 1947
DATE—NAME—AIRCRAFT
470701—FARRAR, JAMES R—B-17G
470701—MCFARLAND, ORLAND W—P-47N
470701—MCLAUGHLIN, JAMES B—AT-6D
470701—NEWQUIST, WELDON D—C-47D
470701—NONE—C-47B
470702—BICKFORD, EDWARD F—AT-6D
470702—BINDER, LEON—L-4J
470702—GLAGOLA, JOHN JR—C-54G
470702—GODFREY, HOLLIS A—P-47N
470702—NONE—C-54E
470702—REEVES, ANDREW R—AT-6D
470703—CRESSMAN, GEORGE W—AT-6F
470703—CROCKER, JOHN P—A-26C
470703—JONES, JOHN H JR—P-47N
470703—MCMASTER, ROBERT A—P-61C
470703—POWELL, GEORGE H—L-4J
470703—TOMPKINS, MILLARD F—C-47D
470703—WARD, RALPH B—C-54G
470704—ANTONI, RUDOLPH—UC-45F
470704—BOSSERMAN, HENRY C—AT-6D
470704—FLESNER, EUGENE E—B-25J
470704—GENDREIZIG, ALFRED E—AT-6C
470704—HAUSSMAN, GEORGE F—UC-45F
470704—LAFORCE, GLEN A—AT-6D
470704—MCCUNE, JOHN A—C-47D
470704—NONE—UC-45F
470704—WEBSTER, FREDERICK L—P-80A
470705—BRYSON, VERN E—AT-6D
470705—FAUSTMAN, DAVID H—AT-6D
470705—GROSS, RALPH J—AT-6F
470705—KRAYENBUHL, CRAIGIE J—P-51D
470705—TIBBETTS, RALPH M—P-51D
470706—BUZZELLI, JOSEPH C—AT-6C
470706—KISTLER, J M—SNJ
470706—PRATER, ROBERT B—L-5B
470707—BARR, ARTHUR W—L-4J
470707—HARTZOG, JAMES F—P-80A
470707—ROGERS, JOSEPH W—P-51D
470707—SMITH, JAMES B—AT-6D
470708—ADAMS, ROBERT L—AT-6F
470708—KEYES, CECIL C—C-54D
470708—LENNON, ARTHUR T—AT-11
470708—MCCOLLOM, FRANCIS N—P-51D
470708—WOODWARD, LLOYD A—C-46D
470709—BAUM, HENRY C—AT-6C
470709—COUSINS, ROY L—AT-6C
470709—CRAIG, RICHARD M—B-17G
470709—DUNCAN, JAMES M—P-47N
470709—FRISTIK, THOMAS P—B-29
470709—MARCHANT, ROBERT B—AT-6C
470709—SMITH, ALTON G—UC-45F
470710—ELLIOTT, WILLIAM W—XF-12
470710—FARRELL, ROGER J—P-51D
470710—GIBSON, LEONARD R—C-54G
470710—HAMBY, JESE M—AT-6F
470710—MOORHEAD, ELLIOTT S JR—P-51H
470710—SHAW, THOMAS P—AT-6C
470710—THOMPSON, CHARLES M—C-54D
470710—TIMM, WALDO E—AT-6C
470710—WEIR, CHARLES O—L-5G
470711—PRICE, JOHN A—R-6A
470711—ZIGLAR, FRANK C—P-47N
470712—BALDWIN, JOHN R—AT-6D
470712—BERGER, WALTER R H—C-47A
470712—JONAS, JOSEPH F—C-47B
470712—JUDD, ALBERT A JR—C-82A
470713—BRADLEY, WILLIAM—AT-6C
470713—EELLS, IRVING C—A-26C
470713—FOWLER, WILLIAM A—AT-6D
470713—HELLER, JOHN W—AT-6D
470714—BRIGGS, RICHARD C—P-51D
470714—ESKRIDGE, EDGAR E—AT-6C
470714—GILL, FREDRICK G—L-5E
470714—HORKEN, HARLEY E—P-51D
470714—JONES, DAVID A—A-26B
470714—MARTIN, ROBERT L—A-26B
470714—TRULL, ALTON M P—P-51D
470714—WINTERQUIST, ERNEST A—PT-26
470715—CHRISTIAN, SHANNON—P-51D
470715—DUTRACK, DEAN W—P-51D
470715—FRASER, CHARLES G—A-26B
470715—MORRIS, GRADY—AT-6F
470715—ORRICK, THOMAS H—P-51D
470715—PASCHALL, EDWARD D—C-47B
470715—SMITH, JACK A—AT-6D
470716—CRITCHFIELD, JAMES C—P-51D
470716—GRANTHAM, CROFT JR—AT-11
470716—HERITAGE, WALTER M—AT-6F
470716—LEHMANN, CHARLES T—C-47A
470716—TONEY, ALBERT V—P-47D
470716—ZAHMEVITZM WALTER—P-51D
470717—ALLEN, ROBERT H—UC-45F
470717—BATEMAN, JAMES A—AT-6C
470717—BILLICK, DONALD W—C-82A
470717—BIRD, EVERETT L—AT-6F
470717—CAMPBELL, JOHN R—AT-6D
470717—CLINGERMAN, WILLIAM R JR—UC-45F
470717—COBB, ROBERT H—AT-7C
470717—FERGUSON, CLAY V—AT-6D
470717—FOWLER, CLARENCE H—P-51D
470717—HORGAN, MICHAEL C—P-51D
470717—KOPROCK, JOHN P—P-47N
470717—MATHEWS, GEORGE H JR—L-5G
470717—MCCLAIN, PAUL K—AT-11
470717—MCQUAID, JAMES R—C-47B
470717—NONE—AT-6D
470717—NORRIS, WILLIAM T—P-51D
470717—PEDRAZZINI, HAROLD O—UC-45F
470717—PHILLIPS, JOHN T—P-51D
470717—RIKE, JAMES C—L-4J
470717—SMITH, STANLEY C—A-26B
470717—WAHL, CHARLES N—P-47N
470718—CHRISTENSEN, DOUGLAS H—C-54D
470718—HUSTON, VINCENT G—B-25J
470718—HYDE, WALTER D—AERONCA
470718—KAMP, WALTER B—AT-6D
470718—LOCKWOOD, LAWRENCE R—P-61B
470718—O'BRIEN, JOHN J—P-47N
470718—SMITH, CLYDE B—AT-6F
470718—SOULE, FLOYD G—P-80A
470719—NONE—C-97
470720—FENSTERMACHER, WALTER L—AT-6D
470720—GRAHAM, CHARLES S—P-47D
470720—SMITH, DALE O—UC-45F
470720—TAYLOR, KENNETH B—AT-6D
470720—THARP, CHARLES J—P-51D
470720—THOMAS, WALTER G—AT-11
470721—BANKA, LOUIS L—L-5A
470721—BURLOW, N E—ANSON
470721—CHANCE, HARRY A—AT-6C
470721—CLAPP, ROBERT D—AT-6D
470721—KEITH, JACK L—P-51D
470721—NEE, ROBERT F—P-51D
470721—O'LEARY, DANIEL R—L-4J
470721—RUARK, WILLIAM E—P-51H
470721—SNIDER, SIMON A—P-51H
470721—WRIGHT, JULIAN C—A-26C
470721—ZAHAREVITZ, WALTER—AT-6D
470722—FLEMMING, LAWRENCE E—P-80A
470722—POSTON, JAMES H—P-51D
470722—SCHUTTE, JUNE V—UC-45F
470723—BLACK, JIM—AT-6D
470723—BRUCE, ROBERT E—P-61C
470723—HOLGUIN, JOSE L—AT-6D
470723—KIRBEBY, PERCY J—P-51D
470723—LUNDBY, ROLLAND O—A-26C
470723—MCDONALD, MIDDLETON—A-26B
470723—MCLEOD, HUGH S—P-47D
470723—O'SHAUGHNESSY, THOMAS J—PT-13D
470723—SCHMIDT, DAVID F—AT-6D
470723—SHAMBECK, CLARENCE H—B-17G
470723—SPEER, FREDERICK T—A-26B
470724—CRAWFORD, WILLIAM C—AT-6C
470724—EVANS, ROBERT A—AT-6F
470724—HALE, IVAN L—C-47A
470724—MATTHEWS, PAUL A—P-51D
470724—MORRIS, TROY J—CG-15A
470724—RUARK, WILLIAM E—P-51D
470724—VICK, HERBERT—UC-45F
470725—BRACHA, VINCENT J—UC-45F
470725—DICKSON, WILLIAM J—AT-6D
470725—FOX, HAROLD P JR—C-82A
470725—NOLAN, JOHN J—B-25J
470725—PAGAN, LEON H—P-51D
470725—PEDERSEN, JAMES C—AT-6D
470725—RAY, JOHN E JR—P-47N
470725—STANTON, O N—AT-6C
470726—FALL, GERALD G JR—B-29
470726—FORREST, ROBERT T—P-47D
470726—HENDERSON, PAUL R—AT-6F
470726—LACH, EDWARD J—AT-6D
470726—LINA, LINDSAY J—AT-6D
470726—WILLDERN, ARTHUR O JR—P-47N
470727—CLOWARD, GLANNIN A—AT-6D
470727—POSTON, JAMES A—P-51D
470727—SANTOS, SHEROD A—C-47B
470728—KING, WILLIAM R JR—P-51H
470728—LANE, HOWARD M—P-47N
470728—LIGINO, STEVE—PQ-14B
470728—MCDONALD, JAMES—UC-45F
470728—RUSSELL, THOMAS P—C-47B
470728—TYREE, GUY—AT-6D
470729—ALVARADO, ALEXANDER—PT-13D
470729—BAGLEY, HUDDIE C—B-29
470729—BROWN, ROBERT B—AT-6C
470729—CATHER, ROBERT M—AT-6D
470729—DECKER, JOHN W—P-51D
470729—ECKSTEIN, BERT R—P-51D
470729—GOLDSTEIN, EUGENE E—PQ-14B
470729—HALL, WILBUR L JR—C-47A
470729—KERR, ROBERT E—AT-6D
470729—LIVERMORE, ROSS E—C-47D
470729—MCKAY, GEORGE E—C-47B
470729—MILLER, ROBERT M—L-5E
470729—NONE—P-47D
470729—O'BRIEN, JAMES F—P-47N
470729—STURMACH, JAMES P—AT-6C
470729—WILSON, ARTHUR P—C-47D
470730—BLAKE, GORDON A—UC-45F
470730—COBURN, WILLIAM P—P-51D
470730—CRUMBIE, JAMES H—AT-6C
470730—FOSTER, F WEBB—AT-6C
470730—O'BOYLE, WILLIAM J—AT-6C
470730—STEVENS, WENDELLE C—P-38L
470731—AUST, ABNER M—P-47N
470731—BEATY, ALBERT R—B-17G
470731—BROWN, JERRY E—C-47B
470731—CHUCK, WARREN S—AT-6C
470731—HAYES, ROBERT G—AT-6F
470731—MEYER, HERBERT J—AT-6D
470731—NIRMAIER, CLAYTON B—UC-45F
470731—PICKENS, JOHN L—P-51H
470731—SIGLER, KERNEY L—P-51H
470731—SMITH, CHARLES A—L-4J
470731—SMITH, WARREN W—C-47A
470731—STINEBAUGH, JAMES S—AT-6D
470731—TATS, CLYDE F—UC-45F
470731—TOMLINSON, FRANKLIN E—C-47B