How poor Aeronautical Decision Making severely limited my options
I may have had to fudge a few numbers to make it come out right, but just barely… the reason I finally convinced my amazing wife to let me pursue my lifelong passion was based on the notion that I could fly the family to visit her parents in a few hours and avoid the 13 hour one way drive, and that it would cost about the same. The cost was a bit iffy, but the convenience factor was CERTAINLY there. 13 hours with our now 20 month old and nearly 3 year old feels like about four months in a car. Love them… but they are LOUD. And we have a new baby now, adding to thy cacophony.
In a plane, throw on the headset and suddenly it’s pretty quiet no matter what!
Rushing out the door
It was the first time we attempted to make the crossing – KIDA to KEAT via some victor airways and small airports. It was early spring, so most of the freezing threat had vanished but the unstable air from the warmer southern reaches hadn’t quite made it’s way up yet, so I figured on the timing being pretty good to make the crossing. The short transit time was based on being able to cross the Frank Church wilderness that constitutes most of central Idaho. A few of the legs would require altitudes in excess of 12,500, but never for longer than was permissible (30 minutes every hour since I didn’t have oxygen). For those of you who want to chart it, the plan I filed had me leaving Idaho Falls and heading to the Salmon VOR (LKT) then over to Lewiston (KLWS) for my first rest & fuel stop, I was then going to head up to the Moscow/Pullman (KPUW) to get a view of my alma mater, the University of Idaho, then onward to the Moses Lake VOR (MWH) then to the final stop at Wenatchee (KEAT).
I had originally planned to leave early in the morning to allow plenty of time, but a check of the weather the day before the flight revealed that some clouds and low visibility were predicted to roll in during the late morning. We readied the boys quickly and piled into the Cessna 172 XP. We left around 5pm and with sunset scheduled for 7:30pm I knew I’d be flying in the darkness by the time I got to KEAT, but I was quite sure i could clear the mountains with daylight to spare. The first leg went well, although longer than expected with a good headwind. I still had plenty of reserve, my fuel stop was intentionally conservative, so I pushed on.
Finding the Clouds
Approaching the Salmon VOR I started to see some clouds in the distance; no vertical development to speak of so I wasn’t concerned with turbulence or potential thunderstorms; however about 30 minutes beyond LKT it became obvious I would need to ascend a bit to clear them and still be legal. Another 20 minutes or so and I was fully VFR OTT (on the top) – nothing but puffy white stuff below me.
I radioed Flight Watch, and after I didn’t get a response I remembered that they were likely broadcasting through the VOR – turning up the navaid volume did the trick. I asked for the visibility and clouds between myself and my first stop; the briefer let me know that the clouds extended through most of western Washington, and that an airmet for mountain obscuration was in effect for the remainder of the day, all the way from me to the Idaho border. I asked about a few alternates and found one that was beyond the edge of the clouds and still within fuel range (barely). On a hunch I asked for a full briefing, realizing that I hadn’t paid as close attention to my DUATS briefing as usual since I was mostly concerned with visibility and had made the hasty decision to leave early. In addition to the Airmet Sierra (mountain obscuration) that I was well aware of, Airmet Zulu was in effect as well — Icing. Before she even completed the briefing I was turning the plane around. VFR OTT over mountains was already making me incredibly nervous, and I should have turned around before I even got to the clouds (what if my engine cut out? where was I going to land when I couldn’t see anything for miles?), but add in potential icing and I was in no way going to risk my family’s lives.
To make matters worse, the plane started to buck every 4 or 5 minutes, a kind of shudder that felt like a misfire. Turns out the mags needed to be replaced completely – it hadn’t shown on the run-up but the problem was definitely there.
Fortunately my wife was VERY understanding as we puttered the 2 hours or so back to Idaho Falls, landing with about 45 minutes of fuel left in the tanks.
Aeronautical Decision Making
As I was driving back home, I realized that I had made a number of poor choices, each of which limited my options. In aviation it is critical to have as many options as possible, and each decision that limits those options is a decision that could lead to a forced landing – or worse.
By leaving early and hastily, I didn’t really pay attention to the weather briefing, so I wasn’t nearly as aware of conditions as I should have been when we left. By choosing to fly so late in the day, I was going to be flying over unfamiliar territory at night – limiting my options for forced landing since I didn’t know the terrain. By flying over the clouds, I further limited my options — I could try to get the rest of the way over them, or turn around – there was no forced landing unless I got incredibly lucky over some of the most rugged and mountainous terrain in the northwest and managed to miss the mountains and forests and pop out below the clouds without the help of navaids and then hope to find a clearing large enough to land.
Aeronautical Decision Making is all about limiting risks; choosing to fly in the best possible conditions where the best possible chance for success exists.
There are many models for aueronautical decision making, most of which revolve around some form of acronym or mnemonic, however the one I most often use is found in an FAA manual on the subject, it’s the ME model: Mitigate, Eliminate, Evaluate. The basic steps are as listed above – reduce risk and increase options. It also led me to develop written personal minimums: when will I fly VFR OTT? What level of cross wind am I comfortable landing in with passengers? Knowing this ahead of time, and sticking to it, has been a great boon to my decision making ability.
This article was posted in Aviation, Basics, Blog, Challenges, Cross Country, Cross Country, Flight Safety, Human Factors, Planning, Real World, Safety, Weather
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