Personal minima other than for approaches

AlleyCat67

AlleyCat67

Pre-takeoff checklist
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AleyCat67
Yesterday I canceled a family IFR trip because it would have required flying for 3.5 hours in solid clouds/rain, with ceilings of 900-1500 the whole way. My rationale was that (a) I'm not comfortable flying a single engine over large expanses with low ceilings in case of engine failure; (b) flying is supposed to be fun, and sitting staring at instruments for 3+ hours while getting knocked around in turbulence isn't my idea of fun. FWIW my plane has a Century I autopilot that needs some attention even when it's "working".

Anyway, we talk a lot about personal minima for approaches, but what about your personal minima for IFR en route? Other than the obvious "do not flying into embedded Tstorms", do you have some requirements for ceilings, turbulence, or duration of IMC on long trips?
 
I canceled a trip and went commercial this weekend because the attitude indicator didn’t stabilize promptly when I went for a short flight the day before the trip and I noticed one propeller blade heat wire was broken, with the second leg of the trip likely to be in clouds (from a 1000-foot or lower ceiling up to at least 14000 MSL) with a chance of icing (freezing level around 7000) for about 3 hours.

I don’t have numerical minimums for that situation, but it just didn’t feel like a vacation so I scrubbed. And then shopped for glass upgrades and autopilots from the comfort of seat 27F.

I do have one hard rule for personal minimums, and that is time. If I absolutely have to be somewhere, I leave early enough to preflight the plane, take off, have a problem halfway to the destination, turn around, put the plane away, get in the car, drive to the meeting, and still get there in time to walk in looking relaxed and confident. (A true emergency like engine failure would justify missing even a necessary meeting in almost all circumstances. I’m talking about a line of thunderstorms popping up or a radio problem that makes me turn back.)
 
Your issue wasn’t the minimums. Your issue was the plane, the pilot, the programming and the passengers
 
A decent autopilot makes a huge difference. Hand flying in imc gets pretty tiring; an hour is about my limit. It's pretty rare in my experience though that you can't find an altitude on top or between layers. I'd say about 2 hours would be my limit for babysitting the autopilot in solid imc.

I like to have ceilings at least 1000agl if I'm taking the family, and that's in flat farmland country. Flying over trees or mountains I want more. I don't have hard numbers.

Haven't had much trouble with turbulence either. Generally being above the cloud layer eliminates it. Much more issues with turbulence on a clear, hot summer day.

My real limit is that I never plan legs over 3 hours. It's a lot harder to shoot an approach when you REALLY have to pee. God forbid you have to go missed.
 
I've done quite a few trips in solid clag, but limit it to 3 hours max to ensure sufficient fuel reserves. VFR ceilings are certainly adequate for me in terms of risk. If I didn't fly over 1000 foot ceilings, I'd probably never fly anywhere IFR in my region. Inability to avoid ice or serious convection is the no-go for me. I usually find that it is possible to get between layers or on top of a low overcast most of the time. If it is possible to get between layers or on top, it is a must. If tops are above 12,000 then the weather is often not very fun to fly in a light single. In a stationary front situation with lots of stratus, flying in the clag can actually be pretty smooth and easy to trim out for level flight. Even a good single axis AP is helpful to relieve tedium.
 
Jim K said:
A decent autopilot makes a huge difference. Hand flying in imc gets pretty tiring; an hour is about my limit. It's pretty rare in my experience though that you can't find an altitude on top or between layers. I'd say about 2 hours would be my limit for babysitting the autopilot in solid imc.

I like to have ceilings at least 1000agl if I'm taking the family, and that's in flat farmland country. Flying over trees or mountains I want more. I don't have hard numbers.

Haven't had much trouble with turbulence either. Generally being above the cloud layer eliminates it. Much more issues with turbulence on a clear, hot summer day.

My real limit is that I never plan legs over 3 hours. It's a lot harder to shoot an approach when you REALLY have to pee. God forbid you have to go missed.
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Yup. In the northeast I've generally been able to climb over most non-convective IMC this Spring/Summer. But now freezing levels are getting lower, so my options for viable altitudes are shrinking.
 
AlleyCat67 said:
(b) flying is supposed to be fun, and sitting staring at instruments for 3+ hours while getting knocked around in turbulence isn't my idea of fun.
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Yup! That's about where I set the bar also. 2 hours of hand-flying "in-the-clag" is not a huge amount of fun. There'd have to be some kinda reward for enduring even that much. Good call!
 
Sounds reasonable to me. Good ADM and Risk Management is worth a premium!
 
What were the tops? I too wouldn’t have fly extensively in IMC but it’s usually nice up top.
 
texasclouds said:
What were the tops? I too wouldn’t have fly extensively in IMC but it’s usually nice up top.
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Wondering the same thing. The number of instances of trips where I couldn't get on top at 8, 10 or 12k when the ceilings were that low is very, very small.

That said, if the skew-t/log-p shows that I'll be in it the whole time, I will generally still do the trip with exceptions for icing, or convective activity).

There have certainly been 5-10 minute windows of IMC at cruise, but it's been relatively rare for it to be a whole lot more than that in a single stretch.
 
I won’t go if it’s widespread LIFR, by which I mean LIFR here, there, and everywhere in between. For one thing, it can be hard to find a legal alternate under those circumstances. If I were hand flying, I’d set my mins at 1000’ and maybe 2 miles. The speed with which you can find yourself upside down shouldn’t be ignored. When they say “advise when you have the weather at your destination and requested approach,” that can be a lot of page flipping or scroll-and-tapping, during which time you can quickly get into trouble.

Having recently installed a G500, I have the zeal of the convert. If you’re at all serious about IFR — that is, if you think you’ll fly IFR in the Midwest — you should have a good autopilot.
 
coma24 said:
Wondering the same thing. The number of instances of trips where I couldn't get on top at 8, 10 or 12k when the ceilings were that low is very, very small.

That said, if the skew-t/log-p shows that I'll be in it the whole time, I will generally still do the trip with exceptions for icing, or convective activity).

There have certainly been 5-10 minute windows of IMC at cruise, but it's been relatively rare for it to be a whole lot more than that in a single stretch.
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Since you asked… tops were forecast as variable, 9000-12000. However freezing level was at about 8000 with light/moderate icing forecast. So I wasn’t counting on being able to climb above the clag without racing ice buildup.
 
Absolutely you should consider the enroute conditions as part of your personal minimums. If I'm single engine, I want MVFR over at least most of my route, to increase the odds of surviving an engine failure. I've done 4 hours hard IMC hand flying, don't really ever feel a need to do that again. Freezing levels, cloud tops and bases should also definitely be factored into planning.
 
AlleyCat67 said:
Yesterday I canceled a family IFR trip because it would have required flying for 3.5 hours in solid clouds/rain, with ceilings of 900-1500 the whole way. My rationale was that (a) I'm not comfortable flying a single engine over large expanses with low ceilings in case of engine failure; (b) flying is supposed to be fun, and sitting staring at instruments for 3+ hours while getting knocked around in turbulence isn't my idea of fun. FWIW my plane has a Century I autopilot that needs some attention even when it's "working".

Anyway, we talk a lot about personal minima for approaches, but what about your personal minima for IFR en route? Other than the obvious "do not flying into embedded Tstorms", do you have some requirements for ceilings, turbulence, or duration of IMC on long trips?
Click to expand...

Actually, I find flying in IMC to be more relaxing than VFR. This time of year you get a lot of good IMC with high freezing levels and low chance of thunderstorms. 1000 ft ceilings should not really bother an IFR pilot. It is almost VFR. But getting tossed around for 3 hours could be tiring. Also don't forget, if you don't have better than VFR conditions at your destination, you need an alternate. With widespread low ceilings (which will generate an airmet Sierra), you may have difficulty finding an alternate within a reasonable distance.
 
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