Two different "no go" decisions

[455 Bravo Uniform]

One last month, one yesterday, both planned from KLAF to KCGF.

Last month, I had airline tix IND-ORD-CLE as backup (primary actually). Forecast all week leading up to that morning was looking great. I was feeling slightly behind on planning the night before, but nothing bad. That morning, an AIRMET for icing was in place for the first half of my trip. I delayed a bit but then decided to scrub and head to IND. Not real happy about it, because is looked totally clear. On the 1hr drive to IND, it looked great. On the flight from IND to ORD, it still looked good. And ORD to CLE, clear. Not happy. But one of my friends who is a CFI said that's exactly what you want; Said I made a good decision. So I agreed with that.

This weekend my back up was to drive. I needed to be in Cleveland before 1p, but I was not back in town from work until 7:30p the night before, and had to unclog a sink and do other crap before the next morning. Needless to say I was tired. But the forecast had looked OK over the week. I had to watch approaching forecast rain early Sun/late Sat, but that was it. But the day before, the Cleveland forecast started to look iffy. Not a show stopper, but deserved respect. Windy, cloudy, maybe snow east of my destination. Decided not worth it, gonna drive. Well as we drove that morning, the weather looked great. About 100 miles away, the sky started closing up. Ceilings got lower and lower and about 20 miles away snow started. About 10 miles away, visibility on the highway was 1/8 mile. I knew I had made a good decision.

What I learned is to just trust my training and keep the go/no-go a simple decision. Sure, I might miss opportunities to fly, enjoy, and learn...but I'll also miss opportunities to get myself in a jam and possibly one I can't get myself out of.

Both decisions had the exact same disappointment at the time they were made. Both seemed like a weak move at the time. The first could have reinforced the wimpiness of my choice were it not for some new pilot-to-experienced pilot debriefing. The second reinforced the rookie "wisdom" of my choice.

I hope this helps someone.

 

[GMascelli]

Thanks for sharing. As pilots we love to fly so a no-go always stings. I used to beat myself up over it, keep watching weather and second guess. I’ve finally learned once I make the no-go to just flush it away and go about my day.

 

[Salty]

The only time a pilot roots for bad weather is after a no go decision.

 

[steingar]

I got out of the habit of using th aircraft for business. Don’t like the idea that I HAVE to be there. But I’ve never scrubbed for icing if I could just do the flight VFR.

 

[Ravioli]

I found I can alter the weather by scheduling an overnight trip to Shreveport, LA. I've tried at least a dozen times to fly over the boats for a night and the weather has grounded me every time.

I'll likely finish the IR before I get there

 

[jimhorner]

One last month, one yesterday, both planned from KLAF to KCGF.

Last month, I had airline tix IND-ORD-CLE as backup (primary actually). Forecast all week leading up to that morning was looking great. I was feeling slightly behind on planning the night before, but nothing bad. That morning, an AIRMET for icing was in place for the first half of my trip. I delayed a bit but then decided to scrub and head to IND. Not real happy about it, because is looked totally clear. On the 1hr drive to IND, it looked great. On the flight from IND to ORD, it still looked good. And ORD to CLE, clear. Not happy. But one of my friends who is a CFI said that's exactly what you want; Said I made a good decision. So I agreed with that.

This weekend my back up was to drive. I needed to be in Cleveland before 1p, but I was not back in town from work until 7:30p the night before, and had to unclog a sink and do other crap before the next morning. Needless to say I was tired. But the forecast had looked OK over the week. I had to watch approaching forecast rain early Sun/late Sat, but that was it. But the day before, the Cleveland forecast started to look iffy. Not a show stopper, but deserved respect. Windy, cloudy, maybe snow east of my destination. Decided not worth it, gonna drive. Well as we drove that morning, the weather looked great. About 100 miles away, the sky started closing up. Ceilings got lower and lower and about 20 miles away snow started. About 10 miles away, visibility on the highway was 1/8 mile. I knew I had made a good decision.

What I learned is to just trust my training and keep the go/no-go a simple decision. Sure, I might miss opportunities to fly, enjoy, and learn...but I'll also miss opportunities to get myself in a jam and possibly one I can't get myself out of.

Both decisions had the exact same disappointment at the time they were made. Both seemed like a weak move at the time. The first could have reinforced the wimpiness of my choice were it not for some new pilot-to-experienced pilot debriefing. The second reinforced the rookie "wisdom" of my choice.

I hope this helps someone.

A no-go decision is never a bad decision. It’s always better to be on the ground wishing you were in the air than to be in the air wishing you were on the ground.

That being said, for the first decsion, it appears it was made based on the Icing Airmet? In my experience, the airmets seem to provide fairly coarse guidence regarding icing, and they seem to have a buffer in altitude and area. While I would not suggest ignoring them and would never fault a no-go decison made based on an airmet, there are a few other tools which I use to get more clarity on the situation.

NOAA’s icing probability plots ( http://www.aviationweather.gov/icing/fip) give a finer grained look at where icing can be expected. These allow one to look at icing proability at various altitudes and times. They take into account temperature and moisture forecasts and help to flesh out the picture given by the airmet. Not primary at all, but useful.

The second tool I use are the SkewT-logP plots. Ed Williams has an excellent two-part tutorial on Youtube called “Weather in the Vertical” about how to interpret these plots, where to find them, and also some good explanations about some weather theory.

There are apps also which allow a desired course or a specific airport or location to be input and then return the skewT-logP plot(s) for that location and course. They can also return forecast plots based on the various computer weather models. SkewT-logP plots give an idea of cloud layers, temperatures, and atmospheric instability.

The third tool to take a look at is NOAA’s freezing level tool: http://www.wrh.noaa.gov/zoa/MOBILE/frzlvl.html.

The icing plots, the skewT plots, the freezing level plots, as well as the TAFs and METARs (I do miss the area forecasts) can be used to further explore icing probabilities and help to refine the go/no-go decision.

As an example, here in the SF Bay area the other day, there was a nice low layer of stratus clouds, some light rain, and some additional higher layers. Perfect conditions to go do some instrument approaches in actual IMC to stay current. My plan was to file and fly from KSJC to KHAF on the coast and shoot 6 approaches, do at least one hold in the missed, and then land at KHAF for lunch at the Three-Zero Cafe in Half Moon Bay.

However, there was an Icing Airmet for the area, and its base was lower than the initial altitude of the approach. A look at the freezing level tool, the icing prediction tool, the skewT’s , SFO and SJC TAFs, and the current METARs convinced me that there would be no chance of icing at the altitudes I was planning to fly. I never saw the OAT go below 13 degrees C the entire flight; I was well below the freezing level. Got in my approaches no problem and spent quite a bit of time in actual IMC. If I had relied only on the AIRMET, I wouldn’t have gone.

So, although it’s never wrong to make a no-go decision, there are some tools which can provide more detailed information about the actual and forecast conditions and, as one gains experience, can help to make decisions based on more info than just the fairly coarse AIRMETs.

As a counter example, I was planning a flight back from Phoenix’s Deer Valley Airport a couple of years ago with my wife and son. We were coming back from my son’s hockey tournament. The weather in the Bay Area looked pretty unsettled. There were no AIRMETs or SIGMETs, but the icing plots, freezing level plots, skewTs and TAFs weren’t looking promising. Instead of going all the way back, I landed in Burbank, put my wife and son on a Southwest flight home, and then flew a little furher to Santa Maria where I spent the night. Definitly made the right decison. There were some Thunderstorms in the Bay area that evening, and, based on the temps, I’m sure I would have encountered icing.


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[Vance Breese]

The consequences of icing are enough to keep me very conservative in my icing no go decisions.

Most Weathermen feel they are doing well if they are right 65% of the time so I don’t cut things close.

Successfully challenging the weather does not mean I am good at weather; it only means I was lucky that time.

I have to admit that when I make a not go decision and the weatherman was wrong I have to work to avoid learning to be less conservative in my no go decisions.

A premature death would put an end to my aviation adventures and I don’t have a compelling reason to fly.

 

[luvflyin]

Maybe this should be one of those 'sticky' threads so it will always be up there at the top of the list