Skylane 182/RG Turbo Skylane/RG
Flight Crew Glider; Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 29; Flight Crew Total 800; Flight Crew Type 35
Troubleshooting; Confusion; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Overcame Equipment Problem
Procedure; ATC Equipment / Nav Facility / Buildings
I was flying a Cessna C-182/G equipped with a Garmin panel-mounted GTN650 GPS Navigator on an IFR flight plan from ZZZ to WHP in perfectly clear sky weather. Before departing; I checked NOTAMS that stated the VNY VOR DME would be OTS (Out of Service); noting that this would not impact the use of the VOR-A approach at WHP.After departing ZZZ; the SoCal ATC Controller told me to expect the VOR-A approach into WHP; with circle to landing Runway 12. He cleared me direct GINNA; to intercept the published inbound approach course; which is the 255 radial from the VNY VOR. I was proceeding inbound to the VNY VOR on the published approach using GPS navigation. Approaching the VNY VOR; I was cleared for the approach and told to contact WHP Tower. I switched to VLOC navigation; but could not acquire a signal from the VOR. I quickly cross checked VOR1 and VOR2 for the VNY VOR signal; and I could not acquire it on either VOR. By this time I was past the VNY VOR and inbound to WHP on the very short final leg of the approach and was cleared to land by WHP Tower Controller. I continued the approach using GPS navigation on my panel mounted avionics; but the reality was that the weather was clear and +20 SM visibility; the airport was clearly in sight and I was talking to the Tower...so I continued inbound to land without conflicts or problems. I landed at XA:47 PDT. After this landing; I checked NOTAMS again and the NOTAM for the VNY VOR had been updated; and was now indicating that the VNY VOR would be OTS [until] XB:26 [that day].Although I landed 39 minutes before the VOR OTS was to be effective; I believe the VOR was in fact OTS for my approach into WHP. On this occasion there were fortunately not any problems or issues; and none of the Controllers had identified that the VOR-A approach was unavailable because of non-operating VOR. Corrective actions perhaps might be to make sure the NOTAM system is efficient and accurate as to when critical navigation equipment activates are to commence. And maintenance ground crews should absolutely conform to the details published in the NOTAMs.
C182 pilot reported VOR was out of service before the applicable NOTAM time.