of the turning, believing that the aircraft is maintaining straight flight.: 125 in a 1954 study (180 – degree turn experiment), the university of illinois institute of aviation found that 19 out of 20 non-instrument-rated subject pilots went into a graveyard spiral soon after entering simulated instrument conditions. the 20th pilot also lost control of his aircraft, but in another maneuver. the average time between onset of instrument conditions and loss of control was 178 seconds. spatial disorientation can also affect instrument-rated pilots in certain conditions. a powerful tumbling sensation (vertigo) can result if the pilot moves his or her head too much during instrument flight. this is called the coriolis illusion. because the semicircular canals are set in three different axes of rotation, if the aviator suddenly moves their head during a rotational acceleration, one canal may abruptly start to detect an angular acceleration while another ceases, resulting in a tumbling sensation.: 9 visual illusions even with good visibility, misleading visual inputs such as sloping cloud decks, unfamiliar runway grades, or false horizons can also form optical illusions, resulting in the pilot misjudging the vertical orientation, aircraft speed or altitude, and/or distance and depth perception; these could even combine with nonvisual illusions from the vestibular and proprioceptive systems to produce an even more powerful illusion. examples selected list of aviation accidents attributed to spatial disorientation datelocationaccident/flightnotes & refs. feb 3, 1959clear lake, iowa, usathe day the music died crash of beechcraft bonanza that killed buddy holly, ritchie valens, and "the big bopper" j. p. richardson; pilot was not qualified for instrumented flight but took off into deteriorating weather because the passengers were important. forensic evidence showed the aircraft was in a steep right bank (90°), nose-down attitude at 3,000 ft/min (910 m/min) when it crashed. mar 5, 1963camden, tennessee, usa1963 camden pa-24 crash four deaths, including singer patsy cline. jul 31, 1964brentwood, nashville, tennessee, usa1964 beechcraft debonair crash it is believed that singer jim reeves was suffering from spatial disorientation when his beechcraft aircraft crashed in the brentwood area of nashville, tennessee, during a violent thunderstorm on july 31, 1964, claiming the lives of both reeves and his pianist dean manuel. jan 1, 1978arabian sea, near santacruz airport, bombay, indiaair india flight 855 oct 21, 1978bass strait, australiadisappearance of frederick valentich jun 6, 1992darién gap, near tucutí, panamacopa airlines flight 201 jul 16, 1999atlantic ocean, off the west coast of martha's vineyard, massachusetts, usajohn f. kennedy jr. plane crash crash occurred during a night flight over water near martha's vineyard. subsequent investigation pointed to spatial disorientation as a probable cause of the accident. because of pilot john f. kennedy jr.'s fame, the cause of the crash led to extensive reporting of spatial disorientation in the press in 1999. jan 10, 2000niederhasli, switzerlandcrossair flight 498 aug 23, 2000persian gulf, near bahrain international airport, bahraingulf air flight 072 oct 16, 2000hillsboro, missouri, usa2000 cessna 335 crash left-side attitude indicator failed and pilot kept turning his head to cross-check the right-side (co-pilot position) attitude indicator, leading to spatial disorientation; the crash killed missouri governor mel carnahan. jan 3, 2004red sea, near sharm el sheikh international airport, egyptflash airlines flight 604 disputed cause: possible pilot error (from spatial disorientation) or mechanical/software malfunctions mar 15, 2005near campbeltown, argyll, scotland2005 loganair islander accident jan 1, 2007makassar strait off majene, sulawesi, indonesiaadam air flight 574 due to the crew's focus on troubleshooting a problem with the ins, they had disconnected the autopilot without noticing and did not realize that they were in a descent until recovery was improbable. the g forces on the aircraft were stressing the hull of the aircraft and further disoriented the crew until the aircraft broke up in mid-air. may 5, 2007douala international airport, cameroonkenya airways flight 507 nov 30, 2007türbetepe, keçiborlu, isparta province, turkeyatlasjet flight 4203 sep 14, 2008perm, russiaaeroflot flight 821 jun 1, 2009over atlantic ocean, near waypoint tasilair france flight 447 may 12, 2010tripoli international airport, libyaafriqiyah airways flight 771 aug 24, 2010near shikharpur, nepalagni air flight 101 oct 1, 2012upper kandanga, queensland, australia2012 queensland dh.84 dragon crash vintage aircraft named riama mar 19, 2016 rostov-on-don, russia flydubai flight 981 feb 23, 2019trinity bay, texas, usaatlas air flight 3591 the crash of the boeing 767 cargo jet was caused by the inappropriate response by the first officer as the pilot flying to an inadvertent activation of the plane's go-around mode at a high altitude (6,200 feet), which led to his spatial disorientation. apr 9, 2019near aomori prefecture, japan2019 jasdf f-35 crash first crash of an f-35a; pilot descended rapidly during a simultaneous left-hand turn. jan 26, 2020calabasas, california, usa2020 calabasas helicopter crash ara zobayan, the helicopter pilot in the fatal accident that killed kobe bryant along with his daughter gianna and six others on january 26, 2020, was determined to have likely experienced spatial disorientation according to ntsb investigation.