Small transport Z had near midair collision with air carrier Y in traffic pattern. See and avoid con...

Attributes
ACN	208829
Time
Date	199204
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : anc
State Reference	AK
Altitude	msl bound lower : 1800 msl bound upper : 2200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : anc tower : ank tower : hnl
Operator	other
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	climbout : intermediate altitude other
Route In Use	approach : visual enroute : on vectors
Flight Plan	VFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	other
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 2850 flight time type : 40
ASRS Report	208829
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	none taken : insufficient time
Consequence	Other
Miss Distance	horizontal : 0 vertical : 400
Supplementary
Primary Problem	ATC Human Performance

Narrative:

Small transport Z took off from anc runway 32 and made a left downwind departure. Tower held me on frequency until crossing shoreline and then had me switch to anc departure. This handoff was considerably later than normal. Departure called air carrier X traffic on right downwind for runway 6R and instructed me to pass behind. Air carrier X reported at 2000 ft. I reported air carrier X in sight and climbed above my planned level altitude of 2000 ft to 2200 ft to avoid wake turbulence. Almost immediately, a second air carrier Y appeared off my left wing and passed, descending, below me. I was not aware of air carrier Y and was startled. At no time did I have any crews report one in sight so I doubt air carrier Y saw me until the last moment either. I believe this could have been avoided if the original traffic call to 'follow the medium large transport on right downwind' had included a clock reference. It is my belief that the controllers desired me to follow the second medium large transport and avoid, but I attempted to do so with the first which met all the conditions the controller reported to me. Also, an earlier handoff to departure would have given more time possibly to sort things out.

Original NASA ASRS Text

Title: SMT Z HAD NMAC WITH ACR Y IN TFC PATTERN. SEE AND AVOID CONCEPT.

Narrative: SMT Z TOOK OFF FROM ANC RWY 32 AND MADE A L DOWNWIND DEP. TWR HELD ME ON FREQ UNTIL XING SHORELINE AND THEN HAD ME SWITCH TO ANC DEP. THIS HDOF WAS CONSIDERABLY LATER THAN NORMAL. DEP CALLED ACR X TFC ON R DOWNWIND FOR RWY 6R AND INSTRUCTED ME TO PASS BEHIND. ACR X RPTED AT 2000 FT. I RPTED ACR X IN SIGHT AND CLBED ABOVE MY PLANNED LEVEL ALT OF 2000 FT TO 2200 FT TO AVOID WAKE TURB. ALMOST IMMEDIATELY, A SECOND ACR Y APPEARED OFF MY L WING AND PASSED, DSNDING, BELOW ME. I WAS NOT AWARE OF ACR Y AND WAS STARTLED. AT NO TIME DID I HAVE ANY CREWS RPT ONE IN SIGHT SO I DOUBT ACR Y SAW ME UNTIL THE LAST MOMENT EITHER. I BELIEVE THIS COULD HAVE BEEN AVOIDED IF THE ORIGINAL TFC CALL TO 'FOLLOW THE MLG ON R DOWNWIND' HAD INCLUDED A CLOCK REF. IT IS MY BELIEF THAT THE CTLRS DESIRED ME TO FOLLOW THE SECOND MLG AND AVOID, BUT I ATTEMPTED TO DO SO WITH THE FIRST WHICH MET ALL THE CONDITIONS THE CTLR RPTED TO ME. ALSO, AN EARLIER HDOF TO DEP WOULD HAVE GIVEN MORE TIME POSSIBLY TO SORT THINGS OUT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Small transport Z had near midair collision with air carrier Y in traffic pattern. See and avoid concept.