Loss of radio communication frequency creates a potential conflict while under radar vectoring.

Attributes
ACN	305003
Time
Date	199505
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ord
State Reference	IL
Altitude	msl bound lower : 4000 msl bound upper : 4000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord tower : rno
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	cruise other descent : approach
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	cruise other descent : approach
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	305003
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : far non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : became reoriented other
Consequence	Other
Miss Distance	vertical : 0
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On right downwind to runway 27R ord on heading 090 degrees, altitude 4000 ft. Ord approach (119.0) idented B-757 traffic on base that we would be following. First officer was guarding the gear horn and inadvertently switched #1 radio frequency back to the previous frequency. Upon reaching the shoreline we thought it strange that approach had not turned us on base. Shortly thereafter we saw another S80 at 4000 ft sbound. I told approach I was turning and descending just before TCASII told us to descend. Approach asked our position, then switched us back to 119.0 at which time we realized what had happened. My fix is to get rid of the gear horn at 210 KTS. It's always been a burden. Also be careful when your hand is near the radios.

Original NASA ASRS Text

Title: LOSS OF RADIO COM FREQ CREATES A POTENTIAL CONFLICT WHILE UNDER RADAR VECTORING.

Narrative: ON R DOWNWIND TO RWY 27R ORD ON HDG 090 DEGS, ALT 4000 FT. ORD APCH (119.0) IDENTED B-757 TFC ON BASE THAT WE WOULD BE FOLLOWING. FO WAS GUARDING THE GEAR HORN AND INADVERTENTLY SWITCHED #1 RADIO FREQ BACK TO THE PREVIOUS FREQ. UPON REACHING THE SHORELINE WE THOUGHT IT STRANGE THAT APCH HAD NOT TURNED US ON BASE. SHORTLY THEREAFTER WE SAW ANOTHER S80 AT 4000 FT SBOUND. I TOLD APCH I WAS TURNING AND DSNDING JUST BEFORE TCASII TOLD US TO DSND. APCH ASKED OUR POS, THEN SWITCHED US BACK TO 119.0 AT WHICH TIME WE REALIZED WHAT HAD HAPPENED. MY FIX IS TO GET RID OF THE GEAR HORN AT 210 KTS. IT'S ALWAYS BEEN A BURDEN. ALSO BE CAREFUL WHEN YOUR HAND IS NEAR THE RADIOS.

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.