8/14/2019 Brazil Flight

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Aeroflot putsA330-200intoserviceAIRTRANSPORTlO

AIR TR/ANSPORT

fatalGolcollisionINVESTIGATIONOHNCROFTWASH NGTONDC

Followins the publication ofl' tn. nrr"iti* final report intothe 2006 atalmid-aircollisionbe-hveen an Embraer Legacy 600businesset and a Gol TransportesAreosBoeing 737-BOOver theAmazon, nvestigationparlicipantthe US National TransportationSafetyBoardsays he accidentwasthe result of "numerous ndividu-al and nstitutional AIC factors".Crucially, t hasnotbeen estab-Iished how the Legacy's rans-ponder had been inadvertentlydeactivated,preventing the air-bornecollision avoidance ystemfromworking.all rs+ passengemnd crew onboard C,ol light 1907 died in the29 September 006collision afterthe damaged aiflraft plunged tothe forest fl.oor from 37.000ft(11,29sm). he LegacyN6ooXL),being lor,rmon adelivery flightbyUS air taxi operator Excelaire,made an emergencyanding withdamage o its left winglet and lefthorizontal stabiliser.Brazil's in-vestigationagencyCenipa,whichheaded the investigation, pub-lished its final report ast week.

guard,alongwith other possibili-ties discussedn the report, seweas mportant reminders of humanergonomic considerations at pre-venting nadvertentcontacts n ac-tual flying situations.The NTSB says he investiga-tion "has identified many safetyissues for ATC operations, butthese issues need to be furtherhighlighted. Even hough he bodyof the [Cenipa]report acknowl-edges safety deficiencies withATC, these deficiencies are notsufficiently supportedwith analy-sis or reflected n the conclusionsor cause f the accident."The board adds: "These defi-ciencies nclude a lack of timelyATC action after the loss ofN600XI-s transponder and two-way radio communication, andfeaturesof the ATC software hatmay haveaggravatedeficienciesin altitude clearanceawarenessforN600XL."ffi "* Keeoabreast f all he atestair{;ffi;ffiH"#Sm/saftty

SAFETYDAVIDKAMINSKI-MORROW ONDON

theunit's creentwice n20s.TheLegacy'sopilothadbeencalculatingakeoffparametersromManaus,he et'sdestination,singa laptop omputern heminutesleading p o he ranspondeross.CENIPAas uled utaccidentalcontact etweenhe aptop nd heradiomanagementnit.But tclaimslight+ecordervi-dence uggestshecommanderwasassistinShecepilotwith uelconsiderationsnd ooking t ueldataon he adiomanagementnitdisplay. uelnformationnd hecollision-avoidanceystem'status

arecontainednseparate isplaypagesn heunit."Whilehe commander]asaFparentlyryingo clari! the ssue ftheairplaneuel tatus...hisadiomanagementnitwas sed na waythatchangedhe...transponder...to'standby',"t says, ndsuggestshishappenedustas hecopilotn-formedhecommandeLfteraperiod f silence,hathehad omeimportant anaus epartureata."Themost ikely xplanation...isthat he commander],hilenatten-tivelytryingtoeturn is adioman-agement nit...afteronsultinghe

fuelpage, idnotnotice ehadpushed buttonhatwould hangethe ranspondertatuso standby'."CENIPAismissesntentionaleactivations unlikely ndextensivetestjngurned pnoevidencef avi-onicsailure. ockpitecordervi-denceules ut nadvertentontactbetweenommander'sootand heradiomanagementnit, ia he n-strument anelootrest. ENIPAal-culatesheprobabilityf ransponderdeactivationhisway t oncen 192trillionlight ours:This ind fcon-dition anbeconsideredirtuallym-oossiblen he leet'sifetime."

Airtraflic Gontrolfactors cited nlnadvertentnactivationf Legacyransponderikely

"The evidence ollectedduringthis investigation sbongly sup-ports the conclusion hat this ac-cidentwascausedbyN600)G andGol 1907 ollowing ATC clearanc-es,which directedthemtooperatein opposite directions on the sameairway at the samealtifude,result-ing n a midair collision," says heNTSB n commentsappended othe Cenipareport."The lossof effective air haffcconhol was not the result of a sin-gle error,but a combination of nu-merous ndividual and nstitution-al ATC factors that reflectedsystemic shortcomings n empha-sisonpositiveATC concepts."As for the transponder ssueonthe Legacy, he NTSB says that"contributing to the accident wasthe undetected oss of flrnctionali-ty of the airbome collisionavoidance ystem echnologyasaresult of the inadvertent inactva-tion of the hansponderon boardN600XL. Further conhibuting totheaccidentwas nadequate om-munication between ATC andthe N600XL flightcrew."In May 2OO7he NTSB raised

concemsover nadvertentdeacti-vation ofcollision avoidance ys-tems, asking the US FederalAviation Administration to recom-mend that an audio warning andenhanced visual alert be inho-duced. This was followed by awamingto EmbraerERJ nd Lega-cy operators hat they could acci-dentally deactivate he hanspond-er by placing their feet on thefoohestsdirectly below the nstru-mentpanel.The NTSB says in its reportcomments hat although the foot-rest guard s "designed o preventunintended interactions" withcontrols, in flightdeck obsewa-tions with the FAA it was ob-served hat pilots "might misusethe foohests",adding:"The cap-tain's ight oot...couldmakeunin-tended contact lwith the trans-pondercontrolsl" (see raphic).It adds: "It cannot be deter-mined exactly how the accidentcrew commanded hehansponderto standby, but the possibility ofr.rnexpecteduse of the footrest

ffiraeil nyestigatmrmumf;*mwfrueilm*m ffitr#hrfiffirdrmmsrmtssilmmossBrazian nvestigationgencyCENIPAelieveshecrucialossofthe Embraeregacy'sranspondertransmissionandwith t hecolli-sion-warningystemtook place sthecommanderoughtueldatathroughheavionics.CENIPAayshis s he"most ikely"scenario fter tdrew p ivehypothetical ircumstanceso explainhesudden isappearancefthe rans-mission. ccesso he ransponderis hroughhe adiomanagementunit.Switchinghe ranspondero"standby"equireshepilottopressa soecific utton on he eftsideofflightglobal.com 16 December 2OO8 5 January 2OO9 trig|rt International | 9