Weather decision making

[Tristar]

As a flight instructor, you make the ultimate go/no-go decision before every flight especially when students are new to the idea of weather decision making. However, it's not always thunderstorms or clear blue sky.

In the summer time scattered pop up thunderstorms seem to be the name of the game. It's tricky to decide whether they'll blow by in a few minutes or build to something that cancels a flight. We had a thunderstorm to the south of the field yesterday which was also moving directly east. I had hoped it would blow by by the time pre-flight briefing and pre-flight was done but a huge strike of lightning proved a change in plans. And as many flight instructors and even pilots have experienced, sometimes it looks like a bunch of light showers which you can navigate around but minutes later the airport is drenched so you're glad you didn't go. The difference between flight training and flying for fun is that most of the time you're staying in one spot to practice maneuvers which means there is no flying around the larger storms. Since this is a factor before many flights during the summer time, It would be impractical to cancel all of them but I do not want to teach my students that it's okay to fly around thunderstorms. So what does this lead up to? What I'd like to know is your tips of weather decision making. How do you decide whether or not to fly in scattered thunderstorms. A light rain shower isn't going to hurt you but shifting winds/rain and lightning is a problem.

 

[Areeda]

I'm kind of lucky in that we don't really have weather here in LA. I'm kidding of course.

I think it's very important to realize that you're teaching ADM when you make the go/no-go decisions. When the weather is iffy I like to sit the student down at the computer and/or telephone and guide them through the process. Occasionally we will make a decision like "it's OK to go today because worse come to worse I can fly an instrument approach back in but it's not VFR".

I know it's hard when you have to cancel on a particular person a lot. If we don't make the decision before going to the airport, I like to have a back up plan like ground on an appropriate subject, sim time or a trip to the mechanic.

Again, after you cut them loose they will make their go/no-go decisions the same way you did. So I try to make them like a new private (or instrument) pilot with good judgment would.

Joe

 

[dmccormack]

Here in Western PA this summer we've had more than our usual dose low vis, lots of thunderstorms and frequent rain -- in other words, crappy weather.

Early on we want to coach students -- "Are you sure we can't fly today? Why not?"

But as they progress we should let them make mistakes -- I've filed IFR flight plans before I showed up for the lesson. So far no one has launched when it was clearly IFR, but a few really hazy days they've learned that "VFR conditions" isn't necessarily blue skies and fair winds.

I think every Private Pilot student needs to fly in very marginal VFR conditions at least once, to make the theoretical real. It's easy to make a rule: "Never launch when the weather's marginal"

But until they actually fly in low VFR they don't know what "marginal" really means.

 

[Areeda]

Good point Dan!

I do a fair amount of oral prep for students I didn't train. A lot of times their weather decision making sounds like they would only fly 3 or 4 days a year in LA it's so conservative. Probably telling me what they think I want to hear more than what they would really do.

I didn't mean to imply that your go/no-go be overly conservative, just that I'll launch VFR even with a good probability I'll have to file IFR in the air. But not with a private student, without explaining.

Joe

 

[dmccormack]

Good point Dan!

I do a fair amount of oral prep for students I didn't train. A lot of times their weather decision making sounds like they would only fly 3 or 4 days a year in LA it's so conservative. Probably telling me what they think I want to hear more than what they would really do.

I didn't mean to imply that your go/no-go be overly conservative, just that I'll launch VFR even with a good probability I'll have to file IFR in the air. But not with a private student, without explaining.

Joe

Exactly -- the last thing we want is a student who says all the right things but does something else.

Now some people are constitutionally configured this way, and I just try to avoid them.

"I will only fly when it's Winds <5, Clg unrestricted, and vis P10!" is ludicrous. You'll be less safe as you won't be very proficient.

Better to have real limits that have been thought through, make sense, and are non-negotiable.

Now -- as far as T-storms....

If I'm flying an airplane with XM and spherics (such as StrikeFinder), I'll fly when few or even widely scattered cells are at least 20nm away. IF the cells are the pop-up variety (which we get frequently here due to prevailing winds and uplift terrain), I won't fly.

 

[TMetzinger]

As with everything else, "it all depends". If storms are isolated to scattered, and you can maintain visual separation with them, then it can be a very good educational thing to get up in the air and fly while keeping an eye on them and a safe distance. If they're coming in lines, or you're getting boiling cumulus clouds all over, then it's best to watch them from the ground.

As Dan's said - taking them through the decision process is a lesson in itself!

 

[Ted]

It's really hard to teach experience. I can't think of a single big XC I've had between May and now where storms haven't been a factor. There are a few things I look for in dealing with thunderstorms:

1) What is the size and distribution of the storms? If the storms are individual medium to large cells or a storm line that shows fairly consistent movement and growth/dissipation, then that's a lot more favorable to me than a whole bunch of tiny cells. The issue there is that the tiny cells could come together, and that hole you're trying to pop through could easily disappear.

2) How big of a hole are you looking at? I don't like popping through small holes, that's not very good margin. Most of the time, though, if storms aren't isolated enough to get around then your students probably don't want to be flying in that weather.

3) What is the radar trend showing? If the cells are growing or moving, where are they moving, how are they growing? If they're moving in a direction where they could cut you off, what're your outs? Generally to me that means either have a good out, or just don't go.

4) What's your equipment on board? Storm scope? NEXRAD? On-board RADAR? Eye-DAR? You always have the Eye-DAR (unless you're in IMC). If you have the other stuff you are at an advantage for sure, but you have to know how to use it, what its limitations are, and how to interpret the data it gives you. Otherwise it's useless. The sort of trip I'll make in my Aztec with on-board RADAR, a 496, and Eye-DAR is a lot different than what I'll do in the Archer with a stormscope. The speed of the airplane helps here, too, in terms of being able to outrun stuff.

5) Can I easily see where there's not a storm? A lot of times I've been able to see storms and very clearly see where there's not a storm. We flew in my friend's Travel Air within about 20 miles of a storm that had 60 dB returns. We saw it right out the window, it was clear where it was and wasn't. A lot of times being at higher altitude helps here, but if that means being above a cloud layer there's always the issue of getting back down to think about.

6) What are the forecasts? TAFs and especially the MOS forecasts off of aviationweather.gov I find are extremely helpful for my flight planning. The 10-30% predictions on the MOS are generally doable, although I've gone through 40% sections which are more annoying. You have to know how to interpret the graphs, which takes a bit of reading.

Since my trips tend to be 300 nm or greater XCs, this may not apply quite as much to the basic private pilot who's looking at local flying, so your students may vary. You are teaching ADM, and showing the students the appropriate resources for checking the weather, what all the data means, and how to interpret it. Also, you're passing on your knowledge and experience. Most of all, reminding the student that if there's ever a question, that he or she can always ask someone more experienced for some advice or just not go.

Hope this helps.

 

[MikePapa]

Every area in the US has different weather situations to deal with and it pays to know what some of those are. In Don Sheldon's biography, he said that when clouds started to form around Denali, he knew that nasty weather was moving his way.

For instance, in my area when the wind is out of the northwest this time of year, the weather can be very unpredictable. It usually means a low pressure system is up north and is pushing cool moist air from Colorado. Large weather systems can form very quickly and move in even if no front is involved. They are usually slow moving and scattered to widespread, so you just don't fly when they are around and they can repeat for days, but usually each day is not as bad as the last. When they pass you usually get a few days of really nice flying weather. In the spring or sometimes in the fall when a cold front is pushing down from the north and moist air is pushing up from the gulf, it's not a good time to be flying.

Pop up thunderstorms are just something you have to deal with in Texas at certain times of the year. Around here, isolated t-storms this time of year can be quite easily avoided visually. They are usually short lived also. So if one is over where you want to land, you can simply wait for it to die or move on, or land somewhere else and wait 45 mins or so. I see a lot of people getting quite close to them, but I prefer to give them a wide berth. Even small cells can produce some pretty nasty wind shear and microbursts several miles away. They almost always happen in the afternoon hours, so you can just fly in the mornings and miss most of them. The US lifted index chart is a reasonably good indicator of how bad things are likely to get once you get used to looking at them.

XM weather is a godsend and spherics are great for IFR, but neither is a substitute for weather knowledge and sound decision making skills.

 

[dmccormack]

They almost always happen in the afternoon hours, so you can just fly in the mornings and miss most of them.

You wanna fly XC in the summertime in the east?

Learn to get up early.

XM weather is a godsend and spherics are great for IFR, but neither is a substitute for weather knowledge and sound decision making skills.

I'm not sure how you'd be using those tools without weather knowledge

 

[Ted]

Every area in the US has different weather situations to deal with and it pays to know what some of those are. In Don Sheldon's biography, he said that when clouds started to form around Denali, he knew that nasty weather was moving his way.

That's a good point, I knew I was forgetting something.

XM weather is a godsend and spherics are great for IFR, but neither is a substitute for weather knowledge and sound decision making skills.

Yeah, I think too many people have them but don't understand what their capabilities and limitations are, and what the data actually means. That's the second part.

 

[Ted]

I'm not sure how you'd be using those tools without weather knowledge

Not successfully.

 

[dmccormack]

Yeah, I think too many people have them but don't understand what their capabilities and limitations are, and what the data actually means. That's the second part.

"That green blob right there is ok, that red blob there is no go...."

Actual discussion overhead in pilot longue.

 

[MikePapa]

You wanna fly XC in the summertime in the east?

Learn to get up early.

It's not much different in the south and southwest, and can be even more so when DA comes into play.

I'm not sure how you'd be using those tools without weather knowledge

Turn the XM box on and your brain off comes to mind. Many do. Some think it's a substitute for actually learning what weather flying is all about. Then when the box fails or the XM service goes down, or the local NEXRAD is out of service they are lost.

There's a lot more to it than just green = light and red = heavy or lots of dots equal bad stuff that direction. Lots of pilots still manage to get themselves into a heap of trouble even with those tools. Like everything else, if you don't understand the limitations, you might as well not have them. They are also mostly for what is happening right now, not necessarily what is happening 3 hours from now when you're at the end of a leg and you failed to use all the forecasting resources that were available before you ever took off.

 

[Ted]

"That green blob right there is ok, that red blob there is no go...."

Actual discussion overhead in pilot longue.

I've explained radar to non-pilots in similar terms before. You have to start somewhere.

 

[twdeckard]

There is another consideration in flying with your learners in challenging weather. Far better they are exposed to the conditions with a more experienced mentor than by themselves, later, with friends and family.

This is far more than trying to inculcate some go/no-go reasoning. This is about actual exposure to the conditions, flying in them, and negotiating them to a succesful landing at the intended airport or an alternate.

Weather is simply too fickle, even with the Mighty XM weather, to assume that one can always be certain the conditions are going to remain within some personal minimums. I sometimes chafe at the literature which is fixated on the get-home-itus and decision making. Not that that is not vitally important, but lets also make sure that I/we are able to fly in serious conditions at the limit of our abilities.

Some of the most valuable flying I have done was with a seasoned airline pilot mentor who was certainly calculating -- that this is at the edge of Todd's capabilities and providing just enough coaching as the circumstances required to see that we had a safe (if sometimes inconvenient conclusion). It was the ultimate Line Oriented Flight Training.

(I am writing more from the perspective as a learner, I am not an instructor).

 

[DutchessFlier]

One of the best things my CFI did for me (which are in earlier posts) was to take me up in very tough WX for a X-C flight to show me exactly what is was like in real world terms...and briefly into IMC to actually do the 180 turn back out into the clear. Those experiences are burned into my brain forever. Yeah, the WX in the northeast has been crappy all spring and summer...lots of 'no-go' decisionmaking.

 

[Ted]

My instructor also took me up in bad weather, and that experience was invaluable. It's definitely best for the students to get time in bad weather with an instructor. At this point the worst weather I've been in has been solo, but that's with some more experience. The learning that started with going up in bad weather with my instructor was the start. We did go up and dodge thunderstorms, among other things.

 

[dmccormack]

Turn the XM box on and your brain off comes to mind. Many do. Some think it's a substitute for actually learning what weather flying is all about. Then when the box fails or the XM service goes down, or the local NEXRAD is out of service they are lost.

I guess. I've always been a weather weenie so it's hard to configure a "I don't care" about any weather data (My wife doesn't like watching the weather channel when I'm around because I argue with the info-folk).

I think those of us who spend alot of times outdoors and are affected by the weather (soldiers, cyclists, motorcyclists, backpackers, canoeists, campers, etc), learn to read the sky sans help, and when we get into flying the additional data is welcome as confirmation of what we may already suspect or even know.

Less outdoorsy students should watch the weather channel, log onto weather sites frequently during the day to start to visualize patterns. This also gets them into the weather-watching habit, which for most pilots is so instinctive we forget it's a learned behavior and skill.

 

[twdeckard]

Less outdoorsy students should watch the weather channel, log onto weather sites frequently during the day to start to visualize patterns.

When I was in college I never imagined I could be a pilot, so having a roommate who was a CFI was unremarkable (although I did fly with him once). But generally I was not too inquisitive about his aviation.

Sometimes, on a lazy Saturday, he would mix a big Gin and Tonic and sit in an easy chair and watch the weather channel. Like for hours until he fell asleep. I figured it was his version of watching golf, and I suppose, I thought it little wierd.

Now where is that tonic ...

 

[Ddayle]

Here in Seattle we rarely get T-storms, but we do have many days w/low clouds & mist. Early in training my CFI asked me if i thought we shoud do some pattern work that day, 6 mile & 1500' ceiling. I thought it was OK, we were above minimums. After 3 laps of the field the tower called us in, it had gone under 3 miles. VALUABLE experience. W/O the instructor I would have landed after the first one, it was downright scary. Now although I have more skill and could perhaps fly in that crap, I have also gained the wisdom to know better. Save that till I have the IR.DaveR

 

[Ted]

Not to discount the value of formal training on weather (something I could surely use), but flight experience is definitely worth something, and makes a huge difference over nothing. Maybe the outdoorsy folk have a leg up as Dan pointed out, but having the experience to know how things tend to develop in your area is worth something. Besides, where did the people who came up with this training get it from in the first place?

That sounds remarkably like the "Singles are safer than twins because pilots don't handle engine failures" argument. Some people may not get useful flight experience that teaches them anything, or may learn the wrong lessons, but the right flight experience is worth something.

 

[dmccormack]

Not to discount the value of formal training on weather (something I could surely use), but flight experience is definitely worth something, and makes a huge difference over nothing. Maybe the outdoorsy folk have a leg up as Dan pointed out, but having the experience to know how things tend to develop in your area is worth something. Besides, where did the people who came up with this training get it from in the first place?

That sounds remarkably like the "Singles are safer than twins because pilots don't handle engine failures" argument. Some people may not get useful flight experience that teaches them anything, or may learn the wrong lessons, but the right flight experience is worth something.

Yeah. I agree -- The argument is hard to counter since -- how can "formal weather training" ever be a bad thing?

And yet from a practical go/no-go consideration, how many flights will be scrubbed, or how many times will I put myself in danger because I'm not at master's level proficiency with a Skew-T?

Probably not many, especially if I'm flying in and around a fairly familiar area, where a look at the sky, the radar, and the winds can give me a fair assessment of what to expect aloft.

From time to time I might be wrong -- for example, a few months ago I started a thread that showed LLWS over KAGC (winds were >60 at 3k, IIRC).

Now, as a frequent flier from KVVS, I can tell you from (bad) experience that any wind >30 knots at 3k from 030 through 200 is gonna be a rodeo (severe, "hope-I-live", turbulence).

But the ridge effect seems washed out by KAGC.

OK -- I learned something, but I cancelled one flight on a questionable day.

Lets it seem that I arguing against formal weather training -- I'm not!

I just don't think weather experience by a fundamentals-trained, interested observer as somehow less useful or efficacious.

 

[Ted]

Good points, Dan. I'd also worry that people who have formal weather training but lack practical experience would suffer from standard book learning without practical experience issues that are exhibited in other areas.

Point is, both have their value.

 

[gprellwitz]

Good points, Dan. I'd also worry that people who have formal weather training but lack practical experience would suffer from standard book learning without practical experience issues that are exhibited in other areas.

Point is, both have their value.

Well, you could get your formal weather training from a meteorologist, preferably one who is also a pilot. Let's see if we know anyone like that. Hmmm... Maybe Scott Dennstaedt?

Scott Dennstaedt - CFI & Former NWS Meteorologist
IFR magazine Contributing Editor
Writer for Plane & Pilot, Pilot Journal and Twin & Turbine
scott@avwxworkshops.com

Try www.avwxworkshops.com

But you're right, it is a fairly unusual skillset.

 

[Ted]

So I agree, that flight experience is useful and you will get better, but it is strictly limited to the foundation on which you were trained.

If you were trained properly, then you can correlate experience from other situations to the situation in hand. This accounts for many aspects of flying. I've been put into situations while flying that I received no training on, but dealt with them by correlating other rules.

My instructor and I have gone up and he's taught me a bunch of what he knows on weather. There's some stuff he doesn't know that I know, and a whole lot that he knows that I don't. A lot of my judgment calls then come from correlating those experiences and other experiences I've had to the situation. One thing I do believe is that his advice must have some aspects of truth, seeing as he's made it through his past 6000 hours just fine.

I find that pilots come to me for training because their foundation is lacking and they will never get this knowledge simply as they gain more experience. In fact, from a weather perspective much of the debate can be focused on how they were trained - was their training accurate and did it have a practical application? With each pilot I train, I see their core knowledge is seriously corrupt not allowing them to take advantage of the most basic guidance available. Or more concerning, are pilots using the weather guidance beyond its designed limitations or relying on general rules of thumb or old wives' tales or based on their limited perceptions.

And this is why there is value in the training you provide, which I have already stated several times is something that I would benefit from and that has value.

Are the "people" you are talking about instructors (CFIs) or are you referring to the folks who developed the AIM and other FAA handbooks? Weather professionals that provide the framework for such pilot training have built a firm foundation of knowledge (through years of education and relationships to other professionals) and continue to study the weather using scientific techniques they were taught while leveraging other professional's work. In some cases, they have made "discoveries" or are now able to accurately document the material based on their analysis of captured data or through modeling. We still have a tremendous amount to learn about icing and turbulence, for example.

I'm talking about the people who came up with the materials that you and other professionals educate themselves with. This stuff didn't just appear in a textbook one day, it was determined through analysis and experience, same as what's in the engineering textbooks that I used for my education.

Scott, you seem to be taking my comments defensively. I do not mean to be implying there isn't value in your training, and have stated otherwise several times. However, you seem to be discounting the value of experience (please correct me if I'm misinterpreting your statements), and I just can't agree with that.