Flight Crew Instrument; Flight Crew Commercial; Flight Crew Multiengine
Flight Crew Last 90 Days 150; Flight Crew Total 1100; Flight Crew Type 310
Situational Awareness
Aircraft Equipment Problem Less Severe
General None Reported / Taken
ATC Equipment / Nav Facility / Buildings
While operating under visual flight rules and using the RNAV (GPS) 31 LPV guidance for reference; all GPS reception was lost. On about a 2 mile final there was an aural annunciation that stated: 'Terrain System Not Available.' That was accompanied by a 'TER N/A' on the PFD and 'NO GPS POSITION' on the MFD. The aircraft was equipped with Synthetic Vision and that reverted back to the Blue/Brown attitude indicator. Since I was in VMC and VFR; I continued the landing visually and taxied to the ramp. Once on the ramp I pulled up the 'Alerts' window on the G1000 PFD. There were multiple messages including 'GPS NAV LOST - Loss of GPS navigation. Insufficient satellites;' 'ABORT APR - Loss of GPS navigation.' 'Abort approach.' 'AHRS1 GPS - AHRS1 not receiving any GPS information.' The pilot of another aircraft which was equipped with a Garmin glass panel said that he experienced the same failure while taxing to the ramp. My concern is the fact that this was a WAAS approach on a robust system with redundant GPS receivers in a brand new aircraft. If I had been in IMC; I would have been above the MDA prior to the VDP. The missed approach segment is GPS based so I would have been unable to execute the published missed approach. The fact that a failure like this occurred; while hopefully very rare; exposes some potential problems with widely utilized and heavily relied upon GPS navigation for critical phases of flight.
The reporter states that the other aircraft that also lost GPS capability at the same time was G2000 equipped and also quite new. On the ramp the GPS begin to show more satellites available but very slowly. The system was turned off to reset and then showed a full array of satellites after about five minutes. No NOTAM's for GPS outages were in effect at the time.
C172 pilot experiences a loss of GPS reception during a VMC RNAV 31 LPV approach to HIO and continues to a landing. Had the weather been IMC the missed approach procedure would have required an operational GPS.