Ce-560XLS captain reported GPS position warning / failure during climb out.

Attributes
ACN	1652549
Time
Date	201905
Local Time Of Day	1201-1800
Place
Locale Reference	ONT.Airport
State Reference	CA
Environment
Flight Conditions	IMC
Aircraft 1
Make Model Name	Citation Excel (C560XL)
Operating Under FAR Part	Part 135
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	GPS & Other Satellite Navigation
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Clearance Deviation - Track / Heading All Types

Narrative:

On departure flying the POM1 in FMS mode; of runway 26L on 258 heading; just prior to intercepting a 294 course inbound to pom our we received message on our pfd and FMS position uncertain. Noticed something didn't look right; I switched over to green needles and flew the 294 radial off of the pdz vo which by this time had been over flown by approx. 1 dot; I corrected picked up the radial and continued the climb to 7000 crossed pom flew the pom 294 to bucck and climbed to 14;000 [feet] for bucck which was our clearance limit alt. Nothing was ever mentioned by [ATC] about our course and we let them know we had lost our GPS and we're flying VOR to VOR and would need new routing to reflect such. Within 5 not longer than 10 mins our GPS came back both agreed on position and rnp 1.0 we continued without further incident.

Original NASA ASRS Text

Title: CE-560XLS Captain reported GPS position warning / failure during climb out.

Narrative: On departure flying the POM1 in FMS mode; of Runway 26L on 258 heading; just prior to intercepting a 294 course inbound to POM our we received MSG on our PFD and FMS Position uncertain. Noticed something didn't look right; I switched over to green needles and flew the 294 radial off of the PDZ VO which by this time had been over flown by approx. 1 dot; I corrected picked up the radial and continued the climb to 7000 crossed POM flew the POM 294 to BUCCK and climbed to 14;000 [feet] for BUCCK which was our clearance limit alt. Nothing was ever mentioned by [ATC] about our course and we let them know we had lost our GPS and we're flying VOR to VOR and would need new routing to reflect such. Within 5 not longer than 10 mins our GPS came back both agreed on position and RNP 1.0 we continued without further incident.

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.