Transcription
SA-429FILE NO. 1-0008AIRCRAFT ACCIDENT REPORTALASKA AIRLINES, INC.BOEIN6 727, N29696,NEAR JUNEAU, ALASKASEPTEMBER 4,1971ADOPTED: OCTOBER 13,1972 NATIONAL TRANSPORTATION SAFETY BOARDWashington, 0. C. 20591REPORT NUMBER: NTSB-"72-28L
. ReportINo.INTSB-AAR-72-28t.T i t l e and S u b t i t l eTECHNICAL REPORT STANDARD TITLE PAGE2.Government Accession No. I 3 . R e c i p i e n t ' s Catalog- No.A i r c r a f t Accident Report-Alaska Airlines, Inc., B-727, N2969, near Juneau,Alaska, September 4, 1971I.Author(s)I. Performing Organization Name and AddressNational Transportation Safety BoardBureau of Aviation SafetyWashington, D. C . 205912.Sponsoring Agency Name and Address5.Report Date.October 13, 19726.Performlna- O r -s a n i z a t i o nCode8.Performing OrganizationReport No.1D.Work U n i t No.I l . C o n t r a c t o r Grant No.13.Type o f Report andPeriod CoveredAircraft Accident ReportSeptember 4, 1971NATIONAL TRANSPORTATION SAFETY BOARDWashington, D. C . 2059114.Sponsoring Agency Code15.Supplementary NotesT h i s report contains Aircraft Safety Recommendation A-72-20516.AbstractAlaska Airlines Flight 1866, a Boeing 727, 29692, crashed while attemptinga nonprecision i n s t m e n t approach t o t h e Juneau Municipal Airport, Juneau,A l a s k a , a t approximately 1215 P.d.t., on September 4, 1971.The f l i g h t had been cleared f o r a Localizer Directional Aid (LDA) approacht o Runway 8 and had reported passing t h e f i n a l approach f i x inbound t o t h ea i r p o r t . This intersection i s located 10.2 nautical miles west of t h e a i r p o r t .No further communications were heard from t h e f l i g h t .The aircraft struck a slope i n t h e Chilkat Mountain range a t about t h e2,500-foot l e v e l on t h e approximate l o c a l i z e r course a t a position 18.5 mileswest of t h e a i r p o r t . A l l 104 passengers and seven crewmembers were injuredf a t a l l y . The a i r c r a f t was destroyed.The National Transportation Safety Board determines that t h e probable cause o ft h i s accident was a display of misleading navigational information concerning t h ef l i g h t ' s progress along t h e l o c a l i z e r course xhic r e ulted i n a premature descente w %n.gr n r r ,below obstacle clearance a l t i t u d e . The origln40? he, ewseemshgavigational information could not be determined. The Board f u r t h e r concludes that t h e crew did notuse all available navigational aids t o check t h e f l i g h t ' s progress along t h e locali z e r nor were these aids required t o be used. The crew a l s o did. not. . perform t h eAircraft Accident, nonprecision approach, misleadingnavigational information, premature descentNTSB Form 1765.2 (11/70)iiReleased t o PublicUnlimited Distribution
.TAELE OF .131.141.158 2‘2.12.2.3.x. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SynopsisInvestigationHistory of F l i g h tI n j u r i e s t o FersonsDamage t o AircraftOther DamageCrew InformaticnAircraft I n f o r m a t i o nMeteoroloqical InformationAids t o NavigationCommunicationsAerodrome and Ground F a c i l i t i e sF l i g h t RecordersAircraft WreckageFireS u r v i v a l AspectsTests and ResearchA n a l y s i s and ConclusionsAnalysisConclusions(a) F i n d i n g s(b) Probable Cause,.RecommendationsFcotnotes.AppendicesI n v e s t i g a t i o n and Hearing. AcrewInformationircraft Infcrmation. ApproachJeppesen Area.c h a r t s JuneauF . Approximate F l i g h t p a t h C h a r tAECDEGChart. CVR T r a n s c r i F tiiim e13355556669991112121221213939414142
rSA-429F i l e No. 1-0008NATIONAL TRANSPORTATION SAFETY EOARrWASHINGTON, D. C. 20591AIRCRAFT ACCIDENT SEPOSTAdouted:Oc&ber 11. 1972------ALASKA A I E L I N E S , INC.ECEING 727. N2969G.NEAR JUNEAU. ALASKASEFTEMEER 4, 1 9 7 1SYNOPSLSA l a s k a A i r l i n e s F l i g h t 1866, a Boeing 727. N2969G.c r a s h e d d u r i n g an i n s t r u m e n t approach t o J u n e a u MunicipalonA i r p o r t . Juneau. Alaska, a t approximately 1215 P.d.t.,SeFtember 4, 1971.The f l i g h t had been c l e a r e d f o r a L o c a l i z e r D i r e c t i o n a lAid (LDA) apFroach t c Eunway 0 and had r e p o r t e d p a s s i n g t h ef i n a l apFroach f i x (Barlow I n t e r s e c t i o n ) . T h i s i n t e r s e c t i o ni s l o c a t e d 10.2 n a u t i c a l miles west of t h e a i r p o r t .Nof u r t h e r communications were heard frcm t h e f l i g h t .The a i r c r a f t s t r u c k a s l o p e i n t h e C h i l k a t Mountainr a n g e a t a b o u t t h e 2,500- foct l e v e l , 18.5 miles west of t h ea i r p o r t , and apFroximately on t h e inbound l o c a l i z e r course.A l l 104 p a s s e n g e r s and t h e s e v e n crewmembers were i n j u r e df a t a l l y . The a i r c r a f t was d e s t r o y e d by i m F a c t and i s o l a t e dp o s t c r a s h fires.The National T r a n s p o r t a t i o n S a f e t y Board d e t e r m i n e s t h a tt h e p r o b a b l e c a u s e of t h i s a c c i d e n t was a d i s p l a y ofmisleading navigational information concerning t h e f l i g h t ' sp o g r e s s a l o n g t h e l o c a l i z e r c o u r s e which r e s u l t e d i n apremature d e s c e n t below c b s t a c l e c l e a r a n c e a l t i t u d e .Theo r i g i n o r n a t u r e of t h e m i s l e a d i n g n a v i g a t i o n a l i n f o r m a t i o ncould n o t be determined. The Board f u r t h e r c o n c l u d e s t h a tt h e crew d i d n o t u s e a l l a v a i l a b l e n a v i g a t i c n a l a i d s t ocheck t h e f l i q h t ' s F r o g r e s s a l o n g t h e l o c a l i z e r n o r weret h e s e a i d s r e q u i r e d t o be used.T h e crew a l s o d i d n o tperform t h e r e q u i r e d a u d i c i d e n t i f i c a t i o n of t h e p e r t i n e n tnavigational facilities.!!,
- 2 -Following t h i s a c c i d e n t , t h e Eoard recormended (NTSBS a f e t y Recommendation A-72-14) t o t h e Federal A v i a t i o nA d m i n i s t r a t i o n (FAA) t h a t t h e p u b l i c i n s t r u m e n t approachFrocedure f o r t h e LDA aFFroach t o Juneau, Alaska, Airport beamended t o reflect t h e a d d i t i o n of D i s t a n c e MeasuringEquipment (DME) a s a s o u r c e o f d e t e r m i n i n g t h e l o c a t i o n off i x e s cn t h e f i n a l aFFrCaCh c o u r s e of t h e l o c a l i z e r .1The A d m i n i s t r a t o r has c o n c u r r e d w i t h t h i s recommendationJuneau A i r p o r thave been amended t c r e f l e c t these changes.a n d t h e a p p r o p r i a t e approach charts f o r t h e.The Eoard f u r t h e r reccmmends t h a t t h e FAA c c n t i n u e testsandresearch i n t o t h e effects of Fossible e x t r a n e o u sharmonics g e n e r a t e d by a LopFler VOR t r a n s m i t t e r on a i r b o r n en a v i g a t i o n a l r e c e i v e r s and associated i n s t r u m e n t d i s p l a y s .1d111
1.1.1- 3 INVESTIGATIONHistorv of t h e F l i q h tAlaska A i r l i n e s , F l i g h t 1866 (AS66) of September 4,1971, a Boeing 727. N2969G, was a r e g u l a r l y scheduled passenger f l i g h tfrcmAnchorage,Alaska,toSeattle,Washington, w i t h i n t e r m e d i a t e s t o p s a t Cordcva, Yakutat,Juneau, and S i t k a , Alaska.The f l i g h t , o p e r a t i n g underi n s t r u m e n t f l i g h t r u l e s ( I F R ) , d e p a r t e d Anchorage a t 0913 &/a n d l a n d e d a t Cordova a t 0942.AS66 d e p a r t e d Cordova a t1034 a f t e r a d e l a y , & a r t of w h i c h was a t t r i b u t a b l e t od i f f i c u l t y i n s e c u r i n g a c a r g o compartment door. The f l i g h tlanded a t Yakutat a t 1107.While cn t h e ground, AS66 r e c e i v e d an a i r t r a f f i cc o n t r o l c l e a r a n c e t o t h e Juneau A i r F o r t v i a J e t Route 507 t ot h e P l e a s a n t I n t e r s e c t i o n , d i r e c t t o Juneau, t o m a i n t a i n9,000f e e t o r below u n t i l 15 miles s o u t h e a s t of Yakutat oncourse, t h e n c e t o climb t c and m a i n t a i n f l i q h t level (FL)230.(See Appendix E.) The f l i g h t departed Yakutat a t 1135,with 1 0 4 p a s s e n g e r s and seven crewmembers on toard.A t 1 1 4 6 , AS66 c o n t a c t e d t h e Anchorage A i r R C U t e T r a f f i cC o n t r o l Center (ARTCC) and reported l e v e l a t FL 230, 65miles east o f Yfikutat.The f l i g h t was t h e n cleared t odescend a t t h e p i l o t ' s d i s c r e t i o n t o m a i n t a i n 10,000 feetso a s t o cross t h e P l e a s a n t I n t e r s e c t i o n a t 10,000 f e e t andwas i s s u e d a c l e a r a n c e limit t o t h e Howard I n t e r s e c t i o n .(See Appendix E.)The c l e a r a n c e was acknowledged c o r r e c t l yby t h e c a p t a i n a/ and t h e c c n t r c l l e r provided t h e Juneaua l t i m e t e r s e t t i n g of 29.46 i n c h e s and requested AS66 t or e F o r t l e a v i n g 11.000 f e e t .A t 1151, AS66 r e p o r t e d l e a v i n g FL 230.Following t h i sreFort, t h e f l i q h t l s c l e a r a n c e limit was changed t o t h ePleasant I n t e r s e c t i c n . A t 1154, t h e c o n t r o l l e r i n s t r u c t e dAS66 t o m a i n t a i n 12,000 feet. Approximately 1 minute l a t e r ,t h e f l i g h t reported l e v e l a t 12,000 feet.changes t o the f l i g h t ' s o r i g i n a l c l e a r a n c e to t h eI n t e r s e c t i o n were e x p l a i n e d t oAS66bythec o n t r o l l e r as follcws:" I ' v e g o t an a i r p l a n e t h a t ' s n o tf o l l m i n q h i s c l e a r a n c e . I ' v e g o t t o f i n d o u t where he is."The c o n t r o l l e r was r e f e r r i n g t o N799Y. a P i p e r Apache whichhad d e p a r t e d Juneau a t 1 1 4 4 cn an I F R c l e a r a n c e , d e s t i n a t i o nk h i t e h o r s e , Canada.The c l e a r a n c e i s s u e d t o t h i s a i r c r a f tmade r e f e r e n c e t o Airway E l u f Seventy- Nine; t h e d e s i g n a t i o nTheHoward
- 4 t h i s airway had keen changed t o Amber F i f t e e n , and wasd e p i c t e d a s such on t h e n c u r r e n t charts.On two separateo c c a s i o n s , AS66 acted a s communications r e l a y between t h ec o n t r o l l e r and N799Y r e g a r d i n g t h i s c l e a r a n c e .ofA t 1158, AS66 reported t h a t t h e y were a t t h e P l e a s a n tI n t e r s e c t i o n , e n t e r i n g t h e h o l d i n g p a t t e r n , whereupon t h ec o n t r o l l e r recleared t h e f l i g h t t o Howard I n t e r s e c t i o n v i at h e Juneau l o c a l i z e r .I n response t o t h e c o n t r c l l e r ' s q u e r yas t o whether t h e f l i g h t was "on t o p n a t 12,000 f e e t , t h eAtc a p t a i n s t a t e d t h a t t h e f l i g h t was 99on instrument . 1 2 0 0 , t h e c c n t r c l l e r xepeated t h e f l i g h t ' s clearance t o holda t Howard I n t e r s e c t i o n and i s s u e d an expected approach timecf 1210. A t 1201, AS66 reported t h a t t h e y were a t Howard,h o l d i n g 1 2 , 0 0 0 feet.A t 1207, AS66 was q u e r i e d w i t h respect t o t h e f l i g h t ' sd i r e c t i o n of h o l d i n g and i t s p o s i t i o n i n t h e h o l d i n gpattern.When t h e c c n t r o l l e r was a d v i s e d t h a t t h e f l i g h thad j u s t completed i t s inbound t u r n and was onthelocalizer,inbound t o Howard, h e cleared AS66 f o r as t r a i g h t - i n LDA J/ approach, t o cross Howard a t or below9,000 f e e t inbound.The c a p t a i n acknowledged t h e c l e a r a n c e and reportedl e a v i n g 12,000 feet. A t 1208, i n r e s p o n s e t o t h e cont r o l l e r ' s query, r e l a t i v e t o t h e a i r c r a f t a s a l t i t u d e , t h ec a F t a i n replied, nleaving f i v e thousand f i v efourthousand f i v e hundred," whereupon t h e c o n t r o l l e ri n s t r u c t e d AS66 t o c o n t a c t Juneau Tower. C o n t a c t w i t h t h etower was e s t a b l i s h e d s h o r t l y t h e r e a f t e r when t h e c a p t a i nreported, O1Alaska s i x t y - s i x Earlow i n b o n d . '(Earlow I n t e r s e c t i o n i s located about 1 0 n a u t i c a l miles (NM) west of t h eThe Juneau Tower C o n t r o l l e r responded,Juneau Airport.)"Alaska 66, understand, a h , I d i d n ' t , ah, c o yt h e i n t e r s e c t i o n , l a n d i n g Runway 8, t h e wind 0800 a t 22 o c c a s i o n a lg u s t s t o 28, t h e altimeter now 29.47, time is 09 112. c a l lu s by Barlow.ll. . .No f u r t h e r communication was h e a r d from t h e f l i g h t ly 1223.'s e v e r a l hours later, t h e aircraft'swreckage was located 18.5 NM west of t h e a i r p o r t a t a k o u tt h e 2,500- foot l e v e l i n t h e C h i l k a t Mountain Range.Therewerethreew i t n e s s e s l o c a t e d in t h e v i c i n i t y ofoverhead j u s tt h e a c c i d e n t s i t e who h e a r d t h e a i r c r a f t f l yp r i o r t o t h e crash.
- 5 Two of t h e s e w i t n e s s e s , who were l o c a t e d a b o u t 1- 1/2miles west of t h e a c c i d e n t s i t e and a t t h e approximate2,500- foot e l e v a t i o n of t k e C h i l k a t Range, heard a lowf l y i n g j e t a i r c r a f t p a s s approximately .overhead p r o c e e d i n gi n a n e a s t e r l y d i r e c t i c n . They s t a t e d t h a t t h e y were u n a b l et o s e e t h e a i r c r a f t because of t h e r e s t r i c t e d v i s i b i l i t y ,which was e s t i m a t e d a t 60 t o 7 0 y a r d s i n f c g and l i g h t r a i n .They f u r t h e r s t a t e d t h a t t h e e n g i n e s sounded n o r n a l and t h a tt h e r e was no change i n t h e e n g i n e scunds from t k e time t h e yfirst heard t h e a i r c r a f t u n t i l t h e sound o f e x F l o s i o n s washeard approximately 1 m i n u t e l a t e r . They e s t i m a t e d t h e timeof t h e a c c i d e n t a s apFroximately 1215.The wreckage s i t ec o o r d i n a t e s were 58O 21' 42" N. and 1350 10' 12" W.rr;lwThe t h i r d w i t n e s s , l o c a t e d a b o u t o n e - h a l q s o u t h w e s t ofa c c i d e n t s i t e , heard and saw t h e a i r c r a f t p a s s cverhead.Hes t a t e d t h a t s h o r t l y t h e r e a f t e r h e ceased t o h e a r t h e e n g i n enoise and assumed t h e a i r c r a f t was c u t of h e a r i n g range. H ed i d n o t h e a r t h e a i r c r a f t c r a s h n o r d i d h e h e a r anyexplosions.1.2I n j u r i e s t o PersonsInjuriesCrewPassenqers-O t h e-r sFatal71040Nonfatal000Other000Post-mortem e x a s i n a t i o n of t h e f l i g h t c r e wmembersr e v e a l e d no e v i d e n c e of any c o n d i t i o n which c o u l d havea d v e r s e l y a f f e c t e d performance o f duty.1.3Damaqe t o A i r c r a f tThe a i r c r a f t was d e s t r o y e d by impact and i s o l a t e dpostcrash f i r e s .1.4&herCam-None1.5Crew InformationA l l crewmembers were c e r t i f i c a t e d and q u a l i f i e d t oconduct t h i s f l i g h t . (For d e t a i l e d i n f o r m a t i o n . seeAppendix B.)
- 6 -1.6T,CAAircraft I n f o r m e nThe a i r c r a f t , a Boeing 127-193, N2969G,S e r i a l NumberwasownedbyHughesAir19304,C o r p o r a t i c n and wass u k l e a s e d , v i a A i r West I n c o r p o r a t e d , t o Alaska A i r l i n e s ,Inc.,on September 25, 1970. The a i r c r a f t was certificatedAand maintained i n accordance w i t h a l l a p p l i c a b l e company andFederal A v i a t i o n A d m i n i s t r a t i o n(FWi)Froceduresandr e g u l a t i c n s . (See Appendix C For d e t a i l e d information.)!I1.11156surfaceweather o b s e r v a t i o n a t JuneauAirportwasreported as: 1,500 f e e t s c a t t e r e d ,Municipalmeasured 3,500 f e e t broken, 7,500 feet o v e r c a s t , v i s i b i l i t y15 miles, l i g h t r a i n s h o w e r s , t e m p e r a t u r e 510 F.,dew p o i n t460 F.,wind 1100 a t 1 3 k n o t s , altimeter s e t t i n g 29.46* i n c h e s , s k y coverage 1/10 s t r a t o c u m u l u s , 7/10 s t r a t o c u m u l u s ,7/10 a l t o c u m u l u s , breaks i n o v e r c a s t .There were no F i l c t reports (PIREPS) a v a i l a b l e v i aweather t e l e t y p e which were p e r t i n e n t t o t h e immediateJuneau area n e a r t h e time of t h e a c c i d e n t . However, a P I R E Pf i l e d a t 1310, c o n t a i n e d t h e following:-S i t k a p i l o t r e p o r t JuneauS i t k a 1115 TenakeeSpringsPass/Inletclosed, c e i l i n g 1,000 f e e to v e r c a s t , moderate r a i n . Chatham c e i l i n g 3,000 feeto v e r c a s t , v i s i b i l i t y 1 0 miles.There were no radar weather o b s e r v a t i o n s a v a i l a b l et i n e n t t o t h e area ccncerned w i t h t h e a c c i d e n t .per-Aids t o NavicrationThe Juneau A i r p o r t was Frovided w i t h two p u b l i c i n s t r u ment approach p r o c e d u r e s (IAF),one e n t i t l e d NDE-A (nond i r e c t i o n a l beacon) Runway 8, and t h e other, LEA ( l o c a l i z e rEunway 8.On t h i s approach o n l yd i r e c t i o n a l aid)/NCB-1l o c a l i z e r course i n f o r m a t i o n i s provided; no g l i d e p a t h i sassociated w i t h t h i s procedure.The Sisters I s l a n d VOR r /(SSR) i s used i n c o n j u n c t i o n w i t h t h e Juneau l o c a l i z e r t op r o v i d e i n t e r s e c t i o n f i x e s i n d e t e r m i n i n g t h e appropriated e s c e n t a l t i t u d e s a l o n g t h e inbound c o u r s e .Alaska A i r l i n e s , Western A i r l i n e s , and Wien C o n s o l i d a t e dAirlinesapfrovedhavebyspecialt h e FAA,fdiiM e t e o x c r i c a hich u t i l i z e t h e Juneau localizer.ifCPt1Ci
- 7 T h i s approach procedure was d e p i c t e d cn JepFesen ApproachChart 11- 9, dated J a n u a r y 15. 1971, (See Apgrcach C h a r t i nApgendix E.)A s n o t e d on t h e aFFrOaCh chart, t h e minima a p p l i c a b l e t oAlaska A i r l i n e s E-727 d a y l i g h t o p e r a t i o n s f o r a s t r a i g h t - i nl a n d i n g on Runway 0 u t i l i z i n g t h i s procedure were: minimumdescent a l t i t u d e (MEA) 1 , 0 0 0 f e e t and v i s i b i l i t y 2 miles.The approach i s conducted on a l o c a l i z e r . t r a n s m i t t i n q on aAfterfrequency cf 109.9 MHz. The inbound c o u r s e i s herei n t e r s e c t s t h e 3530 r a d i a l o f Sisters I s l a n d V O R ) , t h ei n i t i a l approach f i x , t h e f l i g h t is c o n t i n u e d v i a t h e 0 6 2 0intound l o c a l i z e r c o u r s e , w i t h a minimum a l t i t u d e o f 5 , 0 0 0f e e t f o r 3.2 NM t o t h e Rockledge I n t e r s e c t i o n (0060 r a d i a lof t h e Sisters I s l a n d VOX). A t t h i s p o i n t , d e s c e n t t o t h eMDA of 1.000 f e e t m.s.1.is authorized.The f l i g h t i s cont i n u e d inbound on t h e l o c a l i z e r course, p a s t t h e BarlowI n t e r s e c t i o n (0150 r a d i a l of Sisters I s l a n d VOR), t o t h eCoqhlan I s l a n d NEE which is t h e missed- approach p o i n t (MAP)f o r t h i s procedure.The .Coghlan I s l a n d NDE i s l o c a t e d 3.2 NM west of t h ea p p o a c h e n d of Runway 8 . T h e p r o c e d u r e requires t h a t t h i sr a d i o a i d be mcnitcred by t h e f l i g h t d u r i n g t h e approach.Visual f l i q h t must be conducted between t h e MBP and t h ea i r p o r t . The localizer antenna is l o c a t e d a b o u t 1.5 NM westof t h e runway t h r e s h c l d , and i t s c o u r s e o r i e n t a t i o n (0620)i s displaced a b o u t 200 from t h e runway heading.There arelead- inl i g h t s i n s t a l l e d t o prcvide t h e p i l o t v i s u a lguidance from t h e MAF t o t h e a i r p o r t . Should t k e l i g h t s n o tbe o p e r a t i v e , t h e v i s i b i l i t y minimum i s i n c r e a s e d from 2 t o3 siles.Colocated w i t h t h e Sisters I s l a n d VOR i s t h e SistersI s l a n d NEB. Although t h e Alaska A i r l i n e s approach chart i neffect a t t h e time of t h e a c c i d e n t refers t c "Sisters I.VOR/NDB",t h e NEB frequency (391 kc.) i s n o t mentioned ont h e c h a r t , n o r a r e t h e magnetic b e a r i n g s l i s t e d t h a td e l i n e a t e t h e Howard, Rockledge, and Barlow I n t e r s e c t i o n s .Also d e p i c t e d on t h e Alaska A i r l i n e s aFFrCaCh chart wasP o i n t Retreat NEB,l o c a t e d 3.2NM n o r t h w e s t of t h eEarlow I n t e r s e c t i o n .theDuring t h e N a t i o n a l T r a n s p o r t a t i o n Safety Ecard's p u b l i chearing ccncerning t h i s accident,theFAAPrincipalC p e r a t i o n s I n s F e c t o r a s s i g n e d t o Alaska A i r l i n e s testifiedt h a t he c o n s i d e r e d it a d e q u a t e t o u s e o n l y t h e Sisters
- 8 -I s l a n d VOR t o check progress a l o n g t h e l o c a l i z e r and t h a tt h e u s e of what h e termed redundant f a c i l i t i e s would be ad i s c r e t i o n a r y item f o r t h e p a r t i c u l a r c a p t a i n f l y i n g t h e LDAapproach.in'exthSUof an i n s t r u m e n t approach Erccedure, o n c ef o r m u l a t e d , are d e l i n e a t e d on s p e c i f i e d FAA fcrms.Theset a b u l a r and t e x t u a l data are t r a n s f o r m e d by t h e c a r t o g r a p h i cagency (cr company) t o a p i c t o r i a l d i s p l a y of t h e procedure,and are t h e sole basis f c r p r e p a r a t i o n of an I A P c h a r t of aFrocedure under FAA cognizance.ThedetailsrekhAnIScrA s p e c i a l IAP requires t h e amendment of t h e carrier'sO p e r a t i o n s S p e c i f i c a t i o n s and i s v a l i d a t e d upon r e c e i p tthereof by a r e p r e s e n t a t i v e cf t h e carrier and a F p r o v a l t y ar e p r e s e n t a t i v e of t h e A d m i n i s t r a t o r of t h e FAA, a l o n g w i t hh i s s e l e c t i o n cf an e f f e c t i v e d a t e .On J u n e 10, 1971, a namended special IAP, No. 15, was approved by t h e C h i e f ,siAirspace and Frocedures S e c t i o n , F l i g h t S t a n d a r d s D i v i s i o n ,Alaska Region of t h e FAA.On J u l y 9.1971, t h e amendedO p e r a t i o n s S p e c i f i c a t i o n was r e c e i v e d t y t h e carrier andapproved by t h e FAA P r i n c i p a l O p e r a t i o n s I n s F e c t o r a s s i g n e dt o Alaska A i r l i n e s .T h i s revised IAP i s e s s e n t i a l l y t h esame as t h e SAP dated J a n u a r y 15, 1971, e x c e p t t h a t itraises t h e minimum c r c s s i n g a l t i t u d e a t Earlow I n t e r s e c t i o nt o 3,900 f e e t and l i s t s t h e Sisters I s l a n d NEE Frequency.MDA and v i s i b i l i t y d a t a remain t h e same,The reviseds p e c i a l I A F C h a r t 11- 9, d a t e dJuly16,1971,wasd i s s e m i n a t e d t o Alaska A i r l i n e s f l i g h t c r e w s subsequent t ot h e accident.(See Appendix E.)1.On t h e day o f t h e a c c i d e n t , a l l n a v i g a t i o n a l r a d i o a i df a c i l i t i e s and s y s t e m components s e r v i n g t h e Juneauarea were f l i g h t checked by t h e FAA F l i q h t I n s p e c t i o nEistrict O f f i c e ( F I D O ) .The regorts of t h i s f l i g h t checkshowed t h a t a l l f a c i l i t i e s and components were o p e r a t i n gw i t h i n t h e i r prescribed t c l e r a n c e s .1.StfzSUraC 01ciirrtC(a:t t'I1(NFJAIC)Two separate reports of n a v i g a t i c n d i f f i c u l t i e s i n t h eJuneau area were r e c e i v e d by t h e S a f e t y Eoard f o l l o w i n g t h ea c c i d e n t . The first, a Canadian M i l i t a r y f l i g h t whicht r a v e r s e d t h e Juneau AirsFace on September 4, 1971, a tapproximately 1205, reported a VOR t e a r i n g p o i n t e r error ofbetween 5 0 0 and 7 0 0 t o t h e l e f t of t h e a c t u a l p o s i t i o n oft h e Sisters I s l a n d VOR.Similar e r r o r s were n c t e d by t h ep i l o t when p a s s i n g t h e r e v e l I s l a n d , Annette, Malcolm, andVancouver VOR s t a t i c n s .Subsequent examination of t h e VORr e c e i v e r from t h i s a i r c r a f t r e v e a l e d a n i n t e r n a l m a l f u n c t i o nwhich caused t h e reForted b e a r i n g p o i n t e r e r r o r s .T h e otherflt lr:TJet1
r-- 9 -i n c i d e n t involved a U. S. Coast Guard helicopter whichexperienced a naviqational discrepancy i n ccnnection witht h e Sisters I s l a n d VCR on September 21, 971.Similarly,subsequent examination of t h e a i r c r a f t l s VCR r e c e i v e r sr e v e a l e d an i n t e r n a l f a i l u r e a s the c a u s e of t h e problem.ACanadiana i r c r a f t (CF-LOO) , which had d e p a r t e dKhitehorse a t 1106 on t h e day of t h e a c c i d e n t , reported t oAnchoraqe ARTCC a t 1147 t h a t t h e f l i q h t had passed SistersI s l a n d a t 1 1 4 6 and was e s t i m a t i n g L e v e l I s l a n d a t 1216. T h ecrew n o t e d no f a u l t y o p e r a t i c n s or a b n o r m a l i t i e s of t h eSisters or L e v e l I s l a n d VOR's.The c o p i l c t s p e c i f i c a l l yI do n o t remember a n y t h i n g abnormal when s w i t c h i n gstated:frcm t h e Sisters VCR r a d i a l t o t h e L e v e l I s l a n d VOR r a d i a l ,such a s having t o change c o u r s e i n o r d e r t o p i c k up t h e newr a d i a l . 181.9CommunicationsThere were no reported d i f f i c u l t i e s w i t h a i r / g r o u n dcommunications between AS66 and e i t h e r t h e Anchorage ARTCCor t h e Juneau Tower. However, a review of t h e t r a n s c r i p t i o ncf recorded communicaticns fromtheAnchcrageARTCCi n d i c a t e s t h a t t h e c e n t e r c c n t r c l l e r d i d have d i f f i c u l t y i nr e c e i v i n q t r a n s m i s s i c n s from Apache N799Y which Frompted t h ec o n t r o l l e r t o u t i l i z e AS66 a s a r e l a y s t a t i o n w i t h t h a taircraft.(The t r a n s c r i p t of AS66 communication r e l a y sketween N799Y and t h e Center are i n c l u d e d i n Appendix G.T r a n s c r i p t i o n of C o c k c i t Eeccrder.)1-10Aerodrome and Ground F a c i l i t i e s I n f o r m a t i c nJuneau Municipal Airport. p u b l i s h e d e l e v a t i o n o f 18feet m.s.1.i s surrounded on t h r e e sides by mountainoust e r r a i n and opens t o a bay on t h e southwest.I t h a s onerunway, 8/26. which i s 8,456 f e e t long and 1 5 0 f e e t wide.The maqnetic v a r i a t i o n i n t h e Juneau a r e a i s 29-50 East.Because of the u n u s u a l t e r r a i n f e a t u r e s s u r r o u n d i n g t h eJuneau A i r p o r t , t h e approach area l e a d i n g t o Funway 8 i sequipped with s e q u e n t i a l flashers l e a d i n g frcm t h e MAF t ot h e runway t h r e s h o l d (3.2 NM).1.11 J l i q h t ReccrdersN2969G was equipped w i t h a United C c n t r o lGataE i v i s i o n (Sundstrand) , nodel F-542B f l i g h t d a t a r e c o r d e r(FER), s e r i a l No. 1 9 4 1 .
-10-The r e c o r d e r had been s u b j e c t e d t o mechanical damageo n l y , with moderate c r u s h i n g e v i d e n t i n b o t h sides o f t h er e a r h a l f cf t h e u n i t . T h e f o i l medium was remcved from t h emagazine and was found t o be undamaged.A l l recordedp a r a m e t e d had been a c t i v e and were c l e a r l y readable up t ot h e end cf t h e traces. T h e f l i g h t was examined hack t o t h el a s t d e p a r t u r e p o i n t , Yakutat,and no e v i d e n c e was found t os u g g e s t abnormal reccrder o p e r a t i o n .The a l t i t u d e trace showed t h a t t h e f i n a l d e s c e n t commenced a b o u t 2 minutee and 1 2 seconds prior t c impact, froman a l t i t u d e of 12,250 feet m.s.1.A d e s c e n t rate, exceedinga t times, but a v e r a g i n g 5,220 ft./min.,was6,000 ft./min.maintained t o an a l t i t u d e of a b o u t 6 , 5 0 0 feet m.s.1.Thed e s c e n t r a t e decreased a t t h i s p o i n t t o a F p r o x i m a t e l y 1,000ft./min. f o r 12 seconds and t h e n a g a i n i n c r e a s e d t o anf o r t h e remaining 54 s e c o n d s t oaverage of 4,300 ft./min.impact.The impact e l e v a t i o n , a s shown on t h e r e a d o u t ,was2,475 f e e t m.s.1.Curing t h e f i n a l d e s c e n t , a s h a l l o w r i g h tt u r n from 0600 t o 0 7 0 0 was completed. The i a p a c t h e a d i n gwas approximately 0 7 0 0 . Eeginning w i t h t h e f i n a l d e s c e n t ,t h e a i r s p e e d ranged from 216 k n o t s i n d i c a t e d airspeed ( K I A S )t o 245 XIAS and d e c r e a s e d e r r a t i c a l l y t o about 200 K I A S a timpact.Only minor f l u c t u a t i o n of t h e v e r t i c a l a c c e l e r a t i o ntrace was noted t h r o u g h o u t t h e e n t i r e p e r i o d of t h e r e a d o u t .A C o l l i n s Radic Comgany Model 642-C-1 ccckpit v o i c erecorder (CVR) was i n s t a l l e d i n N2969G. The CVR u n i t hads u s t a i n e d extreme imFact damage t o a l l s u r f a c e s ; however,except f o r a break between t h e erase and record heads, t h etape was found t o be i n good c o n d i t i o n .The e n t i r e tape,beginning w i t h t h e grcund c o n v e r s a t i o n a t Yakutat, t oimgact, was reviewed and a t r a n s c r i p t i o n of a l l r e l e v a n tcommunication and sounds a p p e a r i n g on t h e CVR t a p e was made.(See AFpendix G , which c o n t a i n s t h e t r a n s c r i p t of t h e l a s t20 minutes of c o c k p i t v o i c e recording.)Voice i d e n t i f i c a t i o n was made by p e r s o n s who werefamiliar with t h e v o i c e s of t h e f l i g h t crewmemters. Timingf o r t h e t r a n s c r i p t was accomplished by c o r r e l a t i n g a i r ground communications w i t h t h e r e c o r d i n g t h e r e o f from t h eAnchorage AR'ICC and by s u b s e q u e n t l y t i m
1. INVESTIGATION -3- 1.1 Historv of the Fliqht Alaska Airlines, Flight 1866 (AS66) of September 4, 1971, a Boeing 727. N2969G, was a regularly scheduled pas- Washington, with intermediate stops at Cordcva, Yakutat, senger flight frcm Anchorage, Alaska, to Seattle, Juneau, and Sitka, Alaska. The flight, operating under instrument flight rules (IFR), departed Anchorage at 0913 &/
