Pilot took action to avoid another aircraft that was turning final approach to the wrong runway.

Attributes
ACN	153987
Time
Date	199008
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : den
State Reference	CO
Altitude	msl bound lower : 8000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : den
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	landing other
Route In Use	approach : visual arrival other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	landing other
Route In Use	approach : visual arrival other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 7000 flight time type : 2000
ASRS Report	153987
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	conflict : airborne less severe non adherence : clearance other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 500 vertical : 700
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Cleared by approach control for visibility approach to runway 8L denver, (approaching from north, established on left base). Approach control pointed out traffic at 12 O'clock on visibility for runway 8R. Both aircraft started turn to final at same time. I noticed runway 8R aircraft appearing to be set up for an overshoot into runway 8L corridor. Took evasive action early to avoid conflict. Descended about 700' and shallowed turn to keep other aircraft in sight. Easily avoided runway 8R aircraft when switching to tower control heard tower confirm other aircraft cleared to land runway 8R. Continued approach and landed uneventfully. Talked with other pilot and he said he never saw me and that tower had cleared him to land on runway 8L. By not assuming that the other aircraft would turn adequately to avoid encroaching upon our designated airspace, we were able to avoid a certain catastrophic mid-air collision.

Original NASA ASRS Text

Title: PLT TOOK ACTION TO AVOID ANOTHER ACFT THAT WAS TURNING FINAL APCH TO THE WRONG RWY.

Narrative: CLRED BY APCH CTL FOR VIS APCH TO RWY 8L DENVER, (APCHING FROM N, ESTABLISHED ON L BASE). APCH CTL POINTED OUT TFC AT 12 O'CLOCK ON VIS FOR RWY 8R. BOTH ACFT STARTED TURN TO FINAL AT SAME TIME. I NOTICED RWY 8R ACFT APPEARING TO BE SET UP FOR AN OVERSHOOT INTO RWY 8L CORRIDOR. TOOK EVASIVE ACTION EARLY TO AVOID CONFLICT. DSNDED ABOUT 700' AND SHALLOWED TURN TO KEEP OTHER ACFT IN SIGHT. EASILY AVOIDED RWY 8R ACFT WHEN SWITCHING TO TWR CTL HEARD TWR CONFIRM OTHER ACFT CLRED TO LAND RWY 8R. CONTINUED APCH AND LANDED UNEVENTFULLY. TALKED WITH OTHER PLT AND HE SAID HE NEVER SAW ME AND THAT TWR HAD CLRED HIM TO LAND ON RWY 8L. BY NOT ASSUMING THAT THE OTHER ACFT WOULD TURN ADEQUATELY TO AVOID ENCROACHING UPON OUR DESIGNATED AIRSPACE, WE WERE ABLE TO AVOID A CERTAIN CATASTROPHIC MID-AIR COLLISION.

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.