VOR Question

[azure]

FWIW, I always do air checks (comparing the two). It's the easiest thing to do while flying.

Of course, if both of your VORs are off, and off in the same directly then, well...

Which is probably why checking against each other in the air is only allowed a 4 degree discrepancy (IIRC). It's also why I like to do ground checks as well, or at least checks on some radial I can identify by ground reference.

But I also like to do lots of checking the two against each other in the air too, on different radials of the same VOR as well as different VORs. Both nav radios in the 172 I'm doing my instrument training in always pass the VOT at KDET to within a degree at the most, but we found yesterday that on the SVM 080 (cross radial for the LOC/ILS 15 FAF @ KDET), its NAV2 is nearly 4* off. Not beyond tolerance for an aerial check (6*), but nearly 2nm off at that distance, NOT something I'd be comfortable relying on for real.

 

[chucky]

It's also usually the easiest way to do it on the ground (if there's a VOR station you can receive on the ground) rather than taxiing around to wherever they put the ground check point (if they even have one). And since the check must be in the book before an IFR takeoff...

One thing I was wondering recently - is it legal to launch VFR, go to an airborne checkpoint and do the check, then pick up an airborne clearance? I guess you'd have to take the logbook along with you. Not that it sounds like a good idea, I'm just wondering if it's technically legal.

 

[Ted]

It's also usually the easiest way to do it on the ground (if there's a VOR station you can receive on the ground) rather than taxiing around to wherever they put the ground check point (if they even have one). And since the check must be in the book before an IFR takeoff...

Correct, but that's not an issue if you plan ahead.

"It's Saturday and my VOR check expires on Wednesday. I think I'll do it today."

 

[poadeleted20]

One thing I was wondering recently - is it legal to launch VFR, go to an airborne checkpoint and do the check, then pick up an airborne clearance?

Absolutely. Only problem is you can't do this when it's 900-2 and you're at a Class D airport like mine.

I guess you'd have to take the logbook along with you.

If that's where you record the checks, yes, but few folks do. Most folks keep it in a separate record in the airplane (see that "other record" bit in 91.171(d)). I keep a little notebook labled "Avionics Log" in the glove box for VOR checks and GPS update logging.

Not that it sounds like a good idea,

That depends only on whether you have a Plan B if the VOR's fail the check.

I'm just wondering if it's technically legal.

It is.

 

[poadeleted20]

Correct, but that's not an issue if you plan ahead.

While I know you fly your plane quite often, there have been times when I've gone 30 days without flying my own plane (yes, I know that's not good for the engine, but there have been times I simply couldn't), and I suspect many folks have the same problem.

 

[AdamZ]

Thanks for the clarification! I'm going to go over to a nearby airport on my next flight and do a VOR ground check.

Ok lets go

 

[SCCutler]

I loga VOR check airborne pretty much every time I fly XC. It gives me something to do.

 

[Ted]

I loga VOR check airborne pretty much every time I fly XC. It gives me something to do.

You mean you don't play FreeCell when flying?

 

[Rob Schaffer]

This morning I arrived at the airport at 6am to prepare for a quick early morning flight to check the VOR receivers in the plane over at NorthEast Philadelphia Airport (PNE). I was going to meet Adam this morning for the flight, but awoke to a text from him that he was feeling slightly under the weather. We’ll catch up sometime soon and make a flight together.

I called for fuel on the hand-held and gave 09L some energy juice for the morning, 10 gallons per side. Checked all the lights, setup things inside, and completed my preflight checks and walk around. Rocked the wings, and then sumped the tanks. I started up and set the radio frequencies about 6:30am. The airport was still very calm, no one else around and only some airliners overhead going to PHL. Run-up complete, I departed runway 24 to the north, leveling off at 2500 for the trip around the top edge of Willow Grove Airspace. Tracking Yardley VOR, I then called up PNE Tower with information X-Ray, stating a full stop for VOR check. They gave me the option of Runway 24 (almost straight in) or Runway 15. I opted for 15, so I could make a left base entry and it would put me much closer with less taxi time to get to Foxtrot, where the VOR mark was on the taxiway. I made a nice landing on 15, and turned off to the right to the VOR Checkpoint.

Over the checkpoint circle, I tuned 112.0 for the VOR frequency and set both VOR’s to 215* - TO. Nav 2 needled moved right to center (Lower CDI), but Nav 1 was off. I turned Nav 1 to about 219* and the needle came to center. It’s really close between 219* and putting the pin on 220*. As you can see in the photo, the setting is about 219*, but the needle isn’t perfectly straight down. But on 220*, it was about the same the other way. So, I’d conclude that before any IR Flight training shooting approaches or VOR tracking, we’ll have to have the Nav1 adjusted. I guess some initial hood time for climbs / timed turns / decents / unusual attitudes will be a good start though.

So, I jotted down the VOR record on my table in the Flight Binder and then called back tower (I was told to stay with them previously) Winds still calm, they gave me the option of RY 6 or RY 33 for departure. I chose to taxi down to RY 33 so I could depart West and head back to Wings. At the hold short, I checked the mags again and instrument settings, then called Tower “ Tower, 09L at 33, Ready for Take-off” They came back with cleared for takeoff on 33, proceed on course,.. so I took the runway and make a nice smooth departure. Leveled off at 2000 feet for the short trip to Wings, and entered the 45* downwind for 24 behind another Cessna. Good power – idle landing again from ABeam the numbers for 24, and back to parking I went. Only 1.0 today, but it was nice getting out.