The Vagaries of Weather (a bit long...)

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FastEddieB
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The Vagaries of Weather (a bit long...)

Post by FastEddieB »

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:

Image

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:

Image

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:

Image

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):

Image

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:

Image

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:

Image

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:

Image

Image

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.
Fast Eddie B.
Sky Arrow 600 E-LSA • N467SA
CFI, CFII, CFIME
[email protected]
frfly172
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Post by frfly172 »

Times like this when the weather and marginal an IFR lsa would be perfect
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Bill
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Post by Bill »

Nice write-up and great photos, Eddie. I enjoyed reading about your "adventure." Thanks for sharing.
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CTflyer
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Post by CTflyer »

Thank you!

Eddie - that is one of the most interesting posts about flying I've seen here in a long time. Bravo.

Tom
ibgarrett
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Thanks for the "lesson" on how fast wx can change

Post by ibgarrett »

Thanks for the nice write-up with photos. I am wondering if you really did need to get a special VFR clearance or not? I'm working on a Sport Pilot license and obviously I won't be able to get a special VFR at anytime with that rating, but I don't want to get caught in a position where something like this happens and it appears to be VFR, but isn't.

I agree that things didn't look IFR from high above, hazy as you descended, but not quite enough to have it be IFR.

Sounds like you've got a nice community of airports down there in GA. :D

Brian
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FastEddieB
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Post by FastEddieB »

I am wondering if you really did need to get a special VFR clearance or not?
Sorry for the delay. I just revisited this post and found your question "hanging".

Yes, if the field is reporting less than 1,000 foot ceiling or less than 3 miles visibility, one cannot approach and land without a clearance - by definition the field is IFR.

Most planes, most of the time will go ahead and shoot the approach - an option that's not available unless you're instrument rated and equipped. I'm instrument rated, but my Sky Arrow is not equipped for IFR (mainly no approved nav radio at all, just a Garmin 496).

But SVFR is also handy when departing a thin overcast or broken layer, allowing you to dodge clouds as long as you can remain clear of them and maintin 1 mi visibility. Handy when morning fog is about burned off.

But I believe that these options are not available to a Sport Pilot. This flight would have still been doable, either lingering another 30 minutes or so or landing elsewhere and waiting a short while. The key is to ALWAYS have an option (or several options) and on this flight I always did.
Fast Eddie B.
Sky Arrow 600 E-LSA • N467SA
CFI, CFII, CFIME
[email protected]
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FastEddieB
Posts: 2880
Joined: Wed Jan 07, 2009 9:33 pm
Location: Lenoir City, TN/Mineral Bluff, GA

Post by FastEddieB »

I am wondering if you really did need to get a special VFR clearance or not?
Sorry for the delay. I just revisited this post and found your question "hanging".

Yes, if the field is reporting less than 1,000 foot ceiling or less than 3 miles visibility, one cannot approach and land without a clearance of some sort - by definition the field is IFR.

Most planes, most of the time will go ahead and shoot the approach - an option that's not available unless you're instrument rated and equipped. I'm instrument rated, but my Sky Arrow is not equipped for IFR (mainly no approved nav radio at all, just a Garmin 496).

But SVFR is also handy when departing a thin overcast or broken layer, allowing you to dodge clouds as long as you can remain clear of them and maintain 1 mi. visibility. Handy when morning fog is about burned off.

But I believe that these options are not available to a Sport Pilot. This flight would have still been doable, either lingering another 30 minutes or so or landing elsewhere and waiting a short while. The key is to ALWAYS have an option (or several options) and on this flight I always did.
Fast Eddie B.
Sky Arrow 600 E-LSA • N467SA
CFI, CFII, CFIME
[email protected]
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