First officer reported they were receiving erroneous and unreliable VOR information during a GPS out...

Attributes
ACN	1658717
Time
Date	201906
Local Time Of Day	1801-2400
Place
Locale Reference	IAD.Airport
State Reference	DC
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Medium Large Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	GPS & Other Satellite Navigation
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Events
Anomaly	Deviation - Procedural Clearance Deviation - Track / Heading All Types

Narrative:

On the flight from iad; after takeoff; the instruction to proceed lnd VOR as part of the flight plan. After a short time after making our way to the previously mentioned navigational aid; ATC called us asking to confirm we were heading to the correct VOR. I was the pilot monitoring in the flight and because of the GPS outage; I had my needles in 'green' which is a ground base navigation as a backup for the FMS. We asked for vectors to proceed to the right direction and no issues or alerts associated. As we kept going along the route; we tried to navigate by VOR navigation only and the green needles in the two VOR's were giving us erroneous and unreliable information. ATC had to correct our course several times and at the end; the captain advised that our plane was not the only one with this issue.

Original NASA ASRS Text

Title: First Officer reported they were receiving erroneous and unreliable VOR information during a GPS outage.

Narrative: On the flight from IAD; after takeoff; the instruction to proceed LND VOR as part of the flight plan. After a short time after making our way to the previously mentioned navigational aid; ATC called us asking to confirm we were heading to the correct VOR. I was the pilot monitoring in the flight and because of the GPS outage; I had my needles in 'green' which is a ground base navigation as a backup for the FMS. We asked for vectors to proceed to the right direction and no issues or alerts associated. As we kept going along the route; we tried to navigate by VOR navigation only and the green needles in the two VOR's were giving us erroneous and unreliable information. ATC had to correct our course several times and at the end; the Captain advised that our plane was not the only one with this issue.

Data retrieved from NASA's ASRS site 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.

First officer reported they were receiving erroneous and unreliable VOR information during a GPS outage.