Missing in the Mountains

A solo pilot, the sole occupant of a Piper Meridian turboprop, was cleared for the RNAV (GPS)-E approach into Steamboat Springs, CO (KSBS) just after 6 PM local time on December 10th, 2021. Civil twilight had ended, and the moon hadn’t risen yet, so it was quite dark, even in VMC above the clouds. 

Visibility at KSBS was 1 mile, and the ceiling was below minimums. The approach started on the RNAV approach “T” in the mountainous terrain surrounding the entire approach.

You see where this is going — loss of control and/or controlled flight into terrain. Given the mountains, you’d probably wager CFIT is involved, and you’d be correct. However, what’s unique about this tragedy is figuring out why it happened.

This isn’t a cut-and-dried case like many others.

After passing the final approach fix but a full mile before the missed approach point, the pilot, for an unknown reason, executed a left turn consistent with the missed approach procedure. Further, data retrieved from the onboard avionics revealed that although the pilot flew the published route in line with the instrument approach procedure, he did not adhere to the minimum required altitudes.

Well, there’s the problem, right? He flew too low. Yes, except CFIT didn't happen until after he prematurely went missed and made a U-turn toward the hold fix. 

During the turn toward the holding waypoint, the airplane did not climb. Shortly after, it impacted steep, rising terrain.  

You might wonder if he briefed the approach before departure. According to retrievable records, yes. The pilot had checked METARs for the destination and another nearby airport before departure and viewed the RNAV (GPS)-E approach procedure at the destination airport. 

That sounds like a responsible preflight briefing. But, of note, a review of the data that the pilot looked at indicated that visual flight rules conditions prevailed at the destination with light snow in the vicinity at the time it was generated. 

Based on the preflight weather briefing the pilot obtained, he was likely unaware of the IFR conditions and below-minimum weather conditions at the destination until he descended into the area and obtained the current local weather during the flight.

As the pilot was on the instrument approach, he became aware of the below-minimum weather conditions and initiated the missed approach, as inferred by the turn away from the airport similar to the missed approach procedure and the flaps and landing gear being in transition at the time of the CFIT. 

Let’s briefly summarize.

• A very modern and navigationally capable airplane flew a precise flight path but too low.
• However, it wasn’t so low that the pilot risked CFIT with the ground beneath him on the approach.
• The autopilot wasn’t found to be faulty.
• The GPS had up-to-date nav data.
• Consider, too, that the pilot had briefed the RNAV-E approach before departure.

So what the heck happened?  

Given the lack of an obvious smoking gun, the NTSB had a typical yet understandable reluctance to draw conclusions based on circumstantial evidence. It stated it was unable to determine why the pilot prematurely initiated the missed approach procedure and why the airplane failed to climb.  

The “findings” section of the report alludes to poor ADM and failure to adhere to the published approach. That’s where the NTSB left it when the case was finalized and closed.

By now, I hope you’ve thought through and visualized this scenario enough to develop a theory or two. I think there are a few main takeaways. 

The first one is simple: Check destination and alternate weather en route. 

However, based on the fact that all equipment was working, the pilot conducted parts of the approach correctly, and there’s no evidence that he panicked at the last second after realizing the situation, the broader issue may have been that his preflight planning wasn't thorough enough. Yes, we have proof he pulled up the RNAV-E plate for SBS, but if he had absorbed it, it’s possible, and even likely, that he would have been aware of his altitude discrepancy.  

Was he distracted? Clearly, but distraction comes in several flavors. We can’t know with certainty because we weren’t on his flight deck, but there’s no evidence of typical distractors like other traffic, malfunctions, constant ATC chatter, changes to the filed flight plan, etc. It’s almost like this flight was so routine and his airplane so capable that he tuned out.

What flight do you take regularly that is like that? Your action item for this week is to double down on meticulous planning and situational awareness the next time you make that flight—and the next after that.

When you plan a flight, close your eyes and see how much you can remember without looking, then check your work.

For example, you might notice changes to “perma-NOTAMs” which are what I call things like notices that a long-abandoned and overgrown runway is, in fact, still out of service. The day the airport finally decides to resurface that runway is the day you’ll have a near miss in a pattern you’ve flown for a dozen years because your attention was in the OFF position during your preflight briefing. 

If anything about the flight is novel or represents a potential challenge, chair fly or use a simulator to practice before you go. But also practice routine flights every so often. While we can't fully remove the risks of flying, these measures can greatly reduce the likelihood of those risks resulting in tragedy.