The weather is frightful, when do you divert?

[Arnold]

This is predicated on non-emergency situations.

"On the third approach the pilot lost control of the aircraft and all aboard were killed." I first noticed a pattern of deadly third approaches during my instrument training when I read all the accident reports I could. My primary rule is to NEVER make a 3rd approach.

If you are 121/135 you almost never divert, after all the weather must be at or above min vis for you to begin the approach. But it does happen and part 91 it is even more likely as you can go "take a look." This is how I make the analysis.

On the missed approach I ask myself why I missed. There are three possible reasons for the missed and only one of them permits another attempt. First, I screwed up. Second, the weather was below what was reported or expected if no reporting. Third, something critical in the airplane broke. I only try again if I screwed up. I give myself a chance to make another attempt to get it right. After the second attempt I'm off to an easier approach. If I missed twice then I am too tired or too rusty to try a third time (see first sentence above). If the weather is too low it is too low and why bother with another approach and more fuel gone when the outcome will be the same. If it is something critical broken in the airplane then I get myself to an easier to complete approach. Why shoot an NDB when an ILS is less than 50 miles away?

What are your rules?

 

[Bill]

Kind of arbitrary, but I like the baseball rule. Three strikes and you're out, time to bug out to better weather. It doesn't hurt that my personal min fuel reserve is 1hr no matter the weather, and I'm normally carrying a good bit more.

 

[PaulS]

Personal mins, +500 feet on DA/MDA 2 miles vis. I would try one more time, but that's pretty much it for me.

 

[Tarheelpilot]

Unless there is a clearly recognizable cause for the missed that I can control from the flight deck there most likely won’t be a second approach. Flying domestically at the places I’ve worked there is no such thing a fuel for a third approach. If there’s enough for a second shot it’s because I asked for it prior to departure. Typically the plan is for one approach, divert and land with reserves intact.

 

[chemgeek]

There is no way in H-E-double-hockey-sticks I am going to fly three approaches to the same airport in my plane. I established that rule with my CFII during training. At the time we had a very iffy VOR-A approach to our home airport, so we got a lot of experience flying it right down to minimums. During one long IFR XC in actual conditions we had to actually miss the approach trying to return home. During the approach we had intermittent ground contact, just not over the airport. (But close by, according to landmarks.) We decided to make one more try (we had plenty of reserves) and if that couldn't be concluded safely, we were going to divert to Utica for the ILS there. We made it in the second time without incident. That training was a valuable lesson.

So, to this day, if there is no serious ground contact at or near the MAP on the first approach, there will be no second approach, even if fuel reserves allow. And under no circumstances will there be a third approach. EVER. I'll take my reserve fuel and seek nearest VFR or an approach that is essentially guaranteed to succeed.

 

[Larry in TN]

If you are 121/135 you almost never divert

Sure we do. More often than not, though, it is without even trying an approach that's below minimums.

I don't really keep track but it seems like my diversion rate is less than once per year. Lots more flights where a diversion is being considered but the traffic delays, or weather, turns out to be better than the worst case than we've planning for so the diversion is avoided.

If the reported visibility is at, or above, minimums we should be able to complete the approach. This is especially true when the visibility is reported by RVR. I've had a lot of very tight approaches where we were within a couple of seconds of a missed approach but very few where the weather is reported at minimums but we can't get in. I think I've diverted nearly as often for traffic congestion than for weather below minimums.

Nothing wrong with flying multiple approaches as long as the pilot's level of fatigue and stress are low. The more you fly IFR, the more resilient you'll be in such situations. If the stress building, though, divert. Always leave yourself an out and a little bit of margin for unanticipated delays.

 

[flyingron]

Sure we do. More often than not, though, it is without even trying an approach that's below minimums.

Isn't it illegal to commence an approach when weather is below minimums for commercial operators.

I remember ending up in Omaha one Thanksgiving when weather was down at Stapleton. The plane was full of first year USAFA kids who were nervous about returning late. But when we finally got in the academy was lined up with a bus to take them right down. Not the first such rodeo for the staff there.

 

[Arnold]

Sure we do. More often than not, though, it is without even trying an approach that's below minimums.

Yes diverting for weather is what I was talking about.

 

[Larry in TN]

Isn't it illegal to commence an approach when weather is below minimums for commercial operators.

It's against regulation, yes. That doesn't mean that you will always see the required visual reference as minimums when the reported visibility is sufficient. [/QUOTE]

Yes diverting for weather is what I was talking about.

When the weather is too low to fly an approach, or the traffic delays too long because of the weather, that is a diversion for weather.

 

[frfly172]

continuously check the weather while enroute if the weather is going down. I will usually divert before trying a low approach.

 

[jordane93]

The tanks are usually full when I fly GA so shooting the approach multiple times then holding and deciding what to do isn’t that difficult.