Air carrier crew uses omega without monitoring VOR as backup. Flies 15 mi south of course.

Attributes
ACN	138081
Time
Date	199002
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : fak
State Reference	VA
Altitude	msl bound lower : 33000 msl bound upper : 33000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other descent other
Route In Use	arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 10000
ASRS Report	138081
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While en route to lga had been using omega RNAV with VOR back-up and all was well until center called to ask if we were on the nanci 2 STAR? We said yes and center said he showed us 15 mi south of course. We had been distracted as we flew over flat rock and not monitored the VOR back-up. The omega indicated right on course and we had checked the waypoints. Before departure, center gave us a vector to somto intersection and we flew the remainder on VOR. No violation was indicated by center. Our company certified omega for en route only. I have seen many cases of the omega track not that of the airways, by miles, and now only use it with strict VOR back-up. As captain I take responsibility for not having the first officer follow the VOR with me at all times.

Original NASA ASRS Text

Title: ACR CREW USES OMEGA WITHOUT MONITORING VOR AS BACKUP. FLIES 15 MI SOUTH OF COURSE.

Narrative: WHILE ENRTE TO LGA HAD BEEN USING OMEGA RNAV WITH VOR BACK-UP AND ALL WAS WELL UNTIL CENTER CALLED TO ASK IF WE WERE ON THE NANCI 2 STAR? WE SAID YES AND CENTER SAID HE SHOWED US 15 MI S OF COURSE. WE HAD BEEN DISTRACTED AS WE FLEW OVER FLAT ROCK AND NOT MONITORED THE VOR BACK-UP. THE OMEGA INDICATED RIGHT ON COURSE AND WE HAD CHECKED THE WAYPOINTS. BEFORE DEP, CENTER GAVE US A VECTOR TO SOMTO INTXN AND WE FLEW THE REMAINDER ON VOR. NO VIOLATION WAS INDICATED BY CENTER. OUR COMPANY CERTIFIED OMEGA FOR ENRTE ONLY. I HAVE SEEN MANY CASES OF THE OMEGA TRACK NOT THAT OF THE AIRWAYS, BY MILES, AND NOW ONLY USE IT WITH STRICT VOR BACK-UP. AS CAPT I TAKE RESPONSIBILITY FOR NOT HAVING THE F/O FOLLOW THE VOR WITH ME AT ALL TIMES.

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.