Getting High in a Comanche

by Glenn Plymate,  ex-ICS 2658

A number of years ago, based in Salem, Oregon with the State Board of Aeronautics, I was scheduled to spend the day in eastern Oregon. Our regular plane, a C-182, was not available for the trip so I rented a PA-24-260 from Sam Whitney at Newberg, OR.

The flight east in the morning was VFR.  Some clouds, but no problem staying visual.  The weather at destination was mostly good all day, but colder than a gold digger's hind end in the Yukon. It was wintertime! In eastern Oregon!  Snow was on the ground. Lots of it!  And, we had some light flurries during the day.

Late in the afternoon, we were anxious to depart so went to retrieve the airplane from where it had been parked all day and get on our way back home.  Surprise! The wings were covered with heavy frost and frozen snow.  No way was I going to take off with the airfoil messed up like that.  It was a small field, no services, and no phone to get a weather briefing. What to do?  We borrowed a bucket of hot water from a house nearby to clear the frost off the wings, but the moisture would freeze to ice before we could get the surface clear.  So, I and my passenger stripped to the waist, took off our tee shirts and used them to swab the water on the wings to melt the ice. Then, we had to dry the surface before it had a chance to freeze again.  What a way to preflight and de-ice an airplane. But, in eastern Oregon and miles from nowhere, what else could we do?

We finally got the wings free from frost and ice enough to tackle the wild blue yonder so off we went into the setting sun, bound for Newberg about 360 miles away.  We were behind schedule.  There was no way to check weather but we didn't expect much change from the way it had been on the way over earlier in the day. I climbed VFR on top, as I'd done many times before in eastern Oregon, over broken clouds with bands of overcast and occasional holes. My mindset was for a VFR flight all the way home.  The usual routine.  No problem and no flight plan since there wasn't a way I could have filed, anyway.

We started out cruising at about 12,000' on top. No oxygen, but nothing to be concerned about since we were young, nonsmokers, and in reasonably good physical condition.

But, the tops kept getting higher. I could see for many miles ahead but had no way of gauging how high the clouds were in the distance.  Soon, we were at 16,000' but the tops ahead seemed benign and I thought we'd have no problem flying over them.

Wrong!

Before long we were at 18,000' and the clouds had turned to solid underneath.  Now, I'd been through high altitude chamber training and knew what bad things O2 deprivation can do for you.  It was time to do SOMETHING! Turn around, descend, or forge ahead hoping those tops would eventually abate and we'd be able to go lower.

I continued to stay above the tops and concentrated on trying to contact Seattle Center to see if I could get a clearance to descend to a lower altitude, one where I wouldn't need oxygen.  Luckily, we were able to reach Center and were able to convey the situation we were in, requested a clearance, and hoped for a speedy reply.

I was a little tense, being so high and worrying about hypoxia and the obvious consequences.  If I started feeling or showing any symptoms, my plan was to say to heck with a clearance, I was starting DOWN! I kept looking at my fingernails for any sign of blueness, didn't pay a lot of attention to my altimeter, and concentrated on staying VFR -- legal -- above the clouds.  In retrospect, expecting to be able to detect symptoms of hypoxia was DUMB!  Very dumb!  There is no way I'd feel anything.

Seattle Center finally came back with a promising response for my request, told me to "maintain VFR" and asked my altitude.  I looked at my altimeter and found it hard to believe what I saw.  Was I seeing things?  Was I in the early throes of hypoxia? I glanced at my fingernails again; they were still pink, but the altimeter showed 19,200'.

I was taking deep breaths to keep my fingernails pink, but tension was mounting as we waited for our clearance from Seattle Center. Finally, probably in fewer minutes than it seemed, we got our clearance, "Descend on course, maintain 8,000, report leaving."

WHAT A RELIEF! It was as if a huge weight had been lifted from my shoulders! The tension was gone, and the sweating stopped.  It seemed like everything was going to be okay now.  I checked my altimeter to get my "leaving" altitude and got yet another shock. It read TWENTY-THOUSAND FEET!  YIKES!  Those clouds had just kept right on climbing.

It felt so good to finally start down, I had no problem using my best, calm, professional voice as I called Seattle Center and reported, "Leaving Twenty for Eight", just like it was no big deal. Center knew we didn't have oxygen but there was nothing but routine communications from then on to suggest any unusual concerns.  We did a normal descent at 500 fpm and broke out after descending through 12,000' of solid clouds.  Twenty-four minutes on the letdown.

We felt no effect from being at that altitude and the airplane ran fine. Temperatures were very cold and that may have had a beneficial effect that would have put our density altitude somewhat lower than 20,000'.  The worst problem seemed psychological rather than physiological, knowing that being that high without oxygen can be bad for your health. 

That's the highest I've been in a single engine Comanche, and the highest I've ever been without oxygen.

Now? I never leave home without it. There's always a bottle of oxygen in the back, even if it's only a short trip around the pattern.