Go-NoGo Fog-2

[skidoo]

There were some interesting responses to my first fog thread. So far, more than a third were not comfortable departing in those conditions, and more than half would go ahead and depart. Some of the responses got me to wondering about the IFR pilot thought process, including this one.

"No go for me. If there is a problem that requires returning to the departure airport, how are you going to do it? A complete engine failure and how are you going to pick out a place to put it down if you can't see through the fog? IR or not, I would not be comfortable pushing the throttle forward. And, yes, I fly out of a field with a reputation for being a fog hole."

So, lets change the scenario to this.

Departure airport is CAVU but only for a 5 mile radius, effectively a hole in a fog layer that extends for 200 miles in all directions, but otherwise is CAVU above 1000 ft AGL. Beyond 200 miles it is again CAVU. Your destination is 300 miles and 100 miles beyond the fog. You have fuel for 600 miles or more.

So again, would this be a go or no go?

And, if your response to the prior thread was a no go for say a reason similar to the one given above and is a go for this one, please explain why it would be different?

 

[HPNPilot1200]

Depart IFR and cancel once the area I'm overflying is widespread VMC. We do this all the time in the northeast. Especially at ACK/MVY. Though usually it is the first scenario where the field is socked in and we're waiting for 1800 RVR to depart.

 

[Goofy]

Depends entirely on how bad you need to go. A very experienced pilot did that out of the valley here one morning, had an issue and took out some power lines coming back down. Killed 2. What's worth that possibility? Theorize all you want.

 

[Ted]

I consider this scenario to be more hazardous than the original, sipmly because you have a longer exposure time. Over a 200 mile period or so, if you have a problem that forces you to land, you may or may not be able to get into an airport, or even in a position where you can see what's beneath the clouds much before you hit it.

I'd fly it, though, provided my destination airport was forecast to be above minimums.

 

[John Collins]

In effect, you are exploring various pilot's risk tolerance. Flying is inherently risky and we make go-no go decisions all the time. Hopefully, we are able to put the risks into perspective and mitigate as much of the risk as we can. For me, the engine goes on auto rough as soon as I am over water and out of gliding distance from land, but I keep flotation equipment on board and a raft if necessary. Flying at night involves more risk than daytime flight, and I modify my route to keep more airports along the flight and I choose higher altitudes to give me more time. The same is true when flying over mountains verses the plains and valleys, I will use a course deviation to keep my exposure time to a minimum. I will fly when there are thunderstorms only when I can give them a wide berth. I avoid icing conditions and if I plan a flight where it may be a possibility, I always have an out or I won't go. I won't fly when there are known mechanical difficulties and I won't try to explain away problems.

So, would you fly if the left tank fuel gage doesn't work, but you have a fuel totalizer. I'd fix the gage. Would you fly at night? Even if you occasionally had your alternator kick off line? If your right engine alternator doesn't carry its share of the load, you've got two, what does it matter? Would you fly IFR? If so, what would your weather requirements be? Would you fly to the Bahama's in a single engine airplane? Would you cross Lake Michigan on your way to Oshkosh?

 

[Morne]

Intriguing hypothetical situation.

It would depend on if the fog were in the process of burning off or not. I have departed my airport when the fog burnt off there, even though some of the nearby countryside, including my route, were still fogged in. But, it wasn't 360-degrees and 200-miles of fog, either. If I had trouble I could get to clear ground.

I guess without knowing whether the fog is lifting or not this is still a no-go for me. 200 miles is farther than I like to gamble. And yes, I have flown over Lake Michigan (at 9500') crossing from Wisconsin to Michigan with a dandy tailwind. If you've planned well, and are watching the gauges like a hawk, the worry-gap is quite small.

 

[Rneuwirth]

I guess as a student just beginning my IR training I really don't get all the nuance contained in the question, but it seems to me if this second scenario is a no-go for an instrument pilot, he's really saying that any real IFR flight is too dangerous in a piston single.

As I understand it, the airport is clear, so any issue on take-off or soon thereafter is the same as any VFR flight, and there is no threat of storms, turbulence or icing. I don't get why the 200nm is an issue. If I can't see where to safely perform an off airport landing when the engine quits, what difference if it's 20nm or 200nm?

It seems that this scenario describes a wonderful VFR-on-top opportunity, and if that's too dangerous, then why fly IFR at all? The routings may be more circuitous, and the demands for currency are taxing.

What am I missing?

 

[Ted]

The issue between 20 nm vs. 200 nm is mostly one of exposure time. It also comes down to the concept of personal minimums. Everyone has their own "what if" scenarios that they are most comfortable with, and from that derive their own minimums from that.

In fact, the scenario depicted here is one that would be perfectly legal VFR, and one that is probably comparably low risk. If you don't trust your engine (in which case it's questionable why you're flying behind it) and you're over inhospitable terrain, then it would be a reasonable question as to whether or not you're comfortable with the potential for an engine out where you won't know what you hit until you hit it.

 

[DutchessFlier]

Again, for me, the issue in this second scenario comes down to the fact that in an emergency, being able to return to the field, if I have enough altitude to do so, or an off field landing if need be. With a 5 mile clear radius, that is much more likely to be successful than in your first scenario.

It's also amazing to me that GA part 91 IR pilots can depart in zero-zero conditions legally...not that I'm gonna go there either!

The instrument ticket actually, in many scenarios, makes your Go/No-Go decisionmaking much more difficult than it was before you achieved the rating, since your ability to fly in marginal conditions has increased by a few factors. I always err on the side of caution, but YMMV.

 

[Ted]

It's also amazing to me that GA part 91 IR pilots can depart in zero-zero conditions legally...not that I'm gonna go there either!

Let's not change that. It is nice to be given the choice to make, even though one might always choose not to.

 

[Sac Arrow]

An important question is what are the conditions of some of the airports along your route? Can you make minimums if something goes South? That would certainly be part of my planning process, even if it does not affect my ultimate decision.

I personally don't see a whole lot of difference between the stated scenario and making a 200 mile flight over water, or over inhospitable terrain. Or even to some degree a 200 mile flight at night without a lot of landing options available to you within that space. I would do it.

I agree with Ted's assessment in that if you don't trust your engine to last the flight, you probably shouldn't be flying behind it in the first place.

 

[Ted]

I agree with Ted's assessment in that if you don't trust your engine to last the flight, you probably shouldn't be flying behind it in the first place.

I have always said "Either you trust your engine or you don't." I don't fly in the twins with an engine or other major systems that I don't trust. However, it does make things more comfortable when doing a test flight after major engine work.

I've made flights in piston singles over water, with low clouds, inhospitable terrain etc. etc. At the time that I was doing so, I was comfortable with it, primarily because it was the only option available to me. I still said no to certain flights, as a combination of lack of experience and lack of equipment.

These days, I fly twins almost exclusively and am happy with the options that it affords me, as well as the improved failure modes. That doesn't mean that I think my previous flights were unsafe (well, some were, but that came down to making a bad decision), but it does mean that I'm happier with my safety margin now.