Flight crew of B727, while on approach, had to take evasive action to miss another aircraft Y.

Attributes
ACN	419982
Time
Date	199811
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pxr
State Reference	AZ
Altitude	msl bound lower : 8000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : phx
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Route In Use	arrival star : star
Flight Plan	IFR
Aircraft 2
Make Model Name	PA-34-200T Turbo Seneca II
Flight Phase	cruise other
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 95 flight time total : 14000 flight time type : 95
ASRS Report	419982
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : nmac non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 350 vertical : 65
Supplementary
Primary Problem	ATC Human Performance

Narrative:

Either the other aircraft (only a guess -- a seneca ii) was being worked by another controller on another frequency or the pilot was 'toying' with the 8000 ft altitude below the floor of the class B airspace. The light tan color of the other aircraft in the smoggy, hazy sunlight against the desert brown added to the difficulty to see. The evasive maneuver of retarding the throttles while simultaneously turning left behind the other aircraft and descending slightly at 30-100 ft was commenced only after closure rate was observed to be dangerously close without any radio calls from ATC. Upon reflection, the aircraft was first observed at a distance in our 10:30 - 11 O'clock position apparently below us (although it could have been the same altitude) observed as no threat -- later observed as critically close when observed at the last.

Original NASA ASRS Text

Title: FLC OF B727, WHILE ON APCH, HAD TO TAKE EVASIVE ACTION TO MISS ANOTHER ACFT Y.

Narrative: EITHER THE OTHER ACFT (ONLY A GUESS -- A SENECA II) WAS BEING WORKED BY ANOTHER CTLR ON ANOTHER FREQ OR THE PLT WAS 'TOYING' WITH THE 8000 FT ALT BELOW THE FLOOR OF THE CLASS B AIRSPACE. THE LIGHT TAN COLOR OF THE OTHER ACFT IN THE SMOGGY, HAZY SUNLIGHT AGAINST THE DESERT BROWN ADDED TO THE DIFFICULTY TO SEE. THE EVASIVE MANEUVER OF RETARDING THE THROTTLES WHILE SIMULTANEOUSLY TURNING L BEHIND THE OTHER ACFT AND DSNDING SLIGHTLY AT 30-100 FT WAS COMMENCED ONLY AFTER CLOSURE RATE WAS OBSERVED TO BE DANGEROUSLY CLOSE WITHOUT ANY RADIO CALLS FROM ATC. UPON REFLECTION, THE ACFT WAS FIRST OBSERVED AT A DISTANCE IN OUR 10:30 - 11 O'CLOCK POS APPARENTLY BELOW US (ALTHOUGH IT COULD HAVE BEEN THE SAME ALT) OBSERVED AS NO THREAT -- LATER OBSERVED AS CRITICALLY CLOSE WHEN OBSERVED AT THE LAST.

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.