AOPA ASI Blog: Leading Edge

It is awe-inspiring the things we can do with aircraft.  Although it happens thousands of times a day, the airlines fly people to their destinations more or less on time with luggage usually arriving coincidentally or only a day later. When we think of the logistics involved of moving flights around the country and the ground handling infrastructure needed to support the airlines, it really is amazing.

However, due to the extreme efficiency of the airlines, or perhaps not, when a snow storm fouls the Northeast—not an unknown occurrence—it all falls apart. The news of a Jet Blue flight stranded on a the ramp at Bradley last week  is something from another world – not one of the more advanced countries on the planet. It’s similar to being trapped on an escalator!

I’ve often had delays in GA related to winter weather since the aircraft I usually fly don’t do ice and heavy snow is something best avoided. There is much to be learned from this situation. First, all the airlines flights going to Newark had enough fuel to get to an alternate – something that some GA pilots haven’t quite figured out even going to the primary airport. ATC did an excellent job of coping with the influx into Bradley and everyone got down safely.

It will be illuminating to see how “Blue” management and the airport deal with the fact that it collectively took them seven hours to figure out how to get people off a parked aircraft.  Built-in boarding ladders aren’t just a good idea if a Jetway is the only way to get off.  I even vaguely remember when every airport had portable stairs – before the era of the bridge.  Maybe a lifeboat system would work. It’s the basis for a great Seinfeld episode.

The airlines are stuck with going where and when they say they’re going – it’s the basis of their business. In GA we have the flexibility of NOT going with the herd and when things start to get  ugly – don’t go there! Last year, I had my worst airline delay in a decade, when after giving a safety program at the University of North Dakota, the airline system took two days to recover from a wind event. (Get used to that as the political season heats up.)  There are plenty of places one might prefer to get stranded but the distractions were minimal and the people are friendly.

In most cases disruptive weather moves off in 3 or 8 hours . GA can fly but the airlines have equipment hubbed and spoked everywhere and it can take a long time to reconfigure especially as the number of available seats declines. Airports share responsibility for imprisonment debacles and really need to figure out how to deal with international flights when Customs isn’t immediately available.  It just doesn’t seem that difficult but then I clearly don’t understand.

Last week we talked about the joys of operating in the flight levels and judging from the comments, the votes seemed to be overwhelmingly in favor of “bigger is better” or at least, easier. I recounted the wonders of the Cessna 441 at FL350 but there is one drawback to that magnificent machine.

The cabin altitude is about 11,000 feet and where slow-onset hypoxia should be considered. Some of the Foundation staff will claim that I’ve spent way too much time at altitude and am permanently hypoxic. (There are times I would agree.) However, this topic gets relatively little attention and even the FARs don’t even bring up the subject of oxygen impairment below 12,500 (5,000 at night). This blog is NOT about rapid decompression where the time of useful consciousness at those altitudes is measured in seconds.

A pulse oximeter is a wonderfully simple-to-use device that clips on a finger tip to instantly measure your oxygen saturation (sat)  and heart rate.  Ideally, at sea level, we’d all have 100% saturation and a pulse of about 60 – fat chance!  Many pilots may start in the low 90s. When your sat drops below 90%, oxygen deprivation is starting to take place. Thinking slows, and heart rate increases as the brain asks for more O2 to be pumped up.

As the sats fall, so does your ability and it can be quite insidious. After a few hours at 9,000-10,000, where many light non-pressurized aircraft fly, many of us will be hypoxic. A slight headache, fatigue, and the inability to process information as quickly as normal, are all symptoms but they vary person to person. But is it operationally significant? In more than few accident cases we see where an otherwise capable pilot made a poor decision that resulted in an accident. Why? One factor that is certainly present in some cases is slow onset hypoxia but you can’t measure O2 saturation on a corpse so the causes remain elusive and speculative.

On my flight back across the country in the C441 at FL350 last week (which we did non-stop in under 6 hours incidentally)  checking the sats was instructive. Both crew seats are equipped with quick-don masks and when my sat was dipping below 90% I’d take a few minutes to bring it back up to normal.  During these episodes it sounded like Darth Vader’s heavy breathing (Right here above planet earth but no Death Star in sight). Sitting in the back for a bit, without the benefit of oxygen,  resulted in sleepiness and my usual slight headache. The oxygen cleared it up. It’s bad enough when passengers are sleepy and a bit out of sorts. Their brains are starving for good air but for pilots this is critical.

The message is clear–if you spend much time above a cabin altitude of 8,000, your sats are going to come down—how quickly varies by individual. Healthy, fit, non-smokers will do better than others. Even if you’re not flying a turbocharged aircraft, you may want to think about  buying a pulse oximeter—they’re available for $30 – $100. After that little stocking stuffer, if the aircraft isn’t so equipped, get a portable oxygen system—your brain (and other body parts) will love it! The Air Safety Institute will be reviewing pilot misbehavior in the future due to oxygen deprivation.

Anyone have a good hypoxia story?

I’ve  enjoyed the privilege of being invited into the flight levels by friends and co-workers, sometimes as PIC and other times just a radio operator/navigator. (Remember when those used to be career fields once upon a time?–but it’s not a growth area these days.) Last week it was high and fast flight on board a friend’s Cessna 441. The trip was East coast to Vegas for NBAA and a speech, then to Prescott, AZ to visit Embry Riddle’s western campus, where I sit on a safety advisory board, then to California to visit Foundation donors and return.

A couple of observations: First, everyone reading this blog knows that GA makes trips possible that would be impossible or completely impractical on the airlines–wish some in our government could understand that. (The Foundation is working on the image education aspect for the general public.)

Secondly, flight in the flight levels is usually much easier than down low. I’m always amazed at the simple operation of turbines compared to pistons: no leaning, no shock cooling, easy starting – etc. Flying high over the mountains is much better than slogging through up and down drafts, dealing with ice and not being able to see boomers nearly as well.

There is turbulence up high but not nearly as much and it is well forecast. There is great psychological comfort in knowing that if you’re getting the bejabbers kicked out of you on takeoff or descent, it will usually be over in a few minutes. Also a highly wing loaded aircraft rides the waves better.  Down low, I’ve had flights where it’s best to resign yourself to a long and largely uncomfortable ride. Best to cancel those trips if passengers are going. Icing? Not very often at -20C.

The machines, while complex are also highly reliable with lots of redundancy–not perfect–but very good. Training tends to be much better for turbine pilots because the hull values are high so insurers want to protect their investment. Owners usually also want to protect those reliable and very expensive engines by understanding how they work. The avionics are now largely comparable between high and low altitude aircraft but I remember well both flying and teaching basic IFR in basic aircraft–no autopilot, and no flight director. The workload was a lot higher by looking multiple places for information. After seeing my first flight director the awe that I held for high end pilots largely evaporated. (“Just tuck the V-bars into the wedge son and adjust your power on the way down until getting to minimums”–but I digress. )

Next week we should talk about oxygen. In the meantime, is it your experience that bigger aircraft are generally easier to fly or not?