I’m sure anyone who’s been flying a while has seen each of the following scenarios, probably more than once:

1) A flight that preflight planning indicates will be extremely difficult that ends up being trivially easy, or,

2) A flight that preflight planning indicates will be an easy flight that ends up being problematical.

I had an example of the latter yesterday.

As back story, my Sky Arrow is based at a private strip in the N GA mountains. My wife, Karen, had spent a week in Knoxville with a friend who was recovering from eye surgery, and I wanted to pick her up (we generally leave her car at McGhee/Tyson (TYS)), Knoxville’s big airport. In addition, at my last annual, we had discovered that my transponder check was overdue. I had contacted an avionics shop at TYS, and they said they could do the check. I had also called TYS tower, and they gave me permission to enter their Class C airspace sans transponder.

Leaving my house, it was about 25ºF. The sky was clear, but I drove through one small area of ground fog on the way to the airport - nothing unusual and sure to burn off as the sun heated things up. Similarly, at my airstrip the sky was clear and things were heating up nicely by the time I got in the air.

Once in the air, it was clear there was some patchy fog around - a bit over Lake Blue Ridge and, as seen below, a patch right over the Copperhill airport:



In the above photo, TYS is maybe 11 o’clock and about 50 miles, and things looked good once out of the mountains. That is, until I checked TYS wx on my 496:



Yikes!

Well, I listened to TYS Approach, and it sure seemed the field was hard IFR. Things were obviously clear to the west, so I headed over to McMinn County to wait for the fog to (hopefully) lift. I contacted TYS Approach and told them my intentions, and asked them to call me when and if their field went VFR, or at least above Special VFR minimums.

But then a fellow Cirrus pilot, Trip, had me switch to 123.45, where he advised my that Knoxville Downtown (DKX) was VFR (thanks, Trip!). So I changed plans and, at 7,500’ turned to overfly TYS enroute to DKX. My plan was to land there unless the weather improved at TYS.

This is where things got interesting. Here was my view of TYS as I came up on it:



Sure doesn’t look hard IFR, does it? I reported field in sight and requested a Special VFR clearance. Another aircraft reported field in sight, was told the field was still IFR, and he suggested that the tower “check their equipment”(!).

Anyway, Approach vectored me NW of the airport and “held” me with vectors to follow a jet on the approach. They then had me descend to 3,000’, cleared me Special VFR into the Class C, turned me inbound and cleared me to land RWY 23R.

Things looked a whole lot different from 3,000’ (about 2,000’ AGL):



Remembering that Special VFR only required 1 mile visibility and clear of clouds, I continued, the 496 pointing the way. I was prepared to break it off at any time and head back NW if things went downhill.

This was my first view of the airport:



This is actually “enhanced” a bit - the original image is actually hazier. I’d call that about 1 to 2 miles visibility.

The tower asked if I’d prefer 23L and I said I would. Here’s the view on final:



Landing was uneventful, I got the transponder checked (the folks at Horizon Avionics were very accommodating) and picked up Karen and took the “scenic” route home over Robbinsville, NC and then Andrews/Murphy, NC (KRHP) for a touch-and-go. The snow-dusted mountains were really beautiful:





Sorry if that got a little long. I just wanted to convey how quickly weather can change, not just over time but from different perspectives.