Sunday, January 18, 2015

How flying a glider makes me a better airline pilot

Like any endeavor, a well rounded education makes you more insightful, if not better at it. 
Can soaring (i.e., glider flying) make you a better pilot airline pilot? I think so.

Every glider flight, whether by aerotow or winch launch, starts out with a precision flying exercise. Being connected to the airplane in front of you with a rope does command a certain degree of concentration. One must avoid the wake of the tow plane, maintain proper tension on the tow rope (the tow plane and the glider often don't encounter rising or sinking air at the same time), and maneuver to the outside in turns. 
Flying a glider requires an appreciation and understanding of a whole set of factors that an engine makes it easy to ignore. Keeping a glider aloft for hours at a time requires putting the glider in air that, on average, is going up faster than the glider is going down.  So, there are two factors: can you find air that is going up, and how you control how fast the glider is going down. 

The first requires an understanding of the micro-meteorology. 

In soaring, I found an appreciation for how it works, for seeing a cloud not just as a puffy object, but adding to it all the airflows that make it and surround it. Essentially asking "what makes that cloud that shape, and how will it change over time?"   As airline pilots, we fly through clouds all the time—mostly we just plow right through. But we're also looking for a smooth, efficient, and safe ride even if we don't have to try to harness the power of the airflow around it to stay up. The thermals, updrafts, downdrafts, and waves make those clouds and turbulence. In the same way that a lion tamer should know about lions,  I think that appreciation, that better understanding of the environment I fly in makes me a better pilot as a result. 
The second factor, how you control how fast the glider is going down, requires an understanding of aircraft performance. 

When there's no engine, efficiency is the name of the game. It would be easy if there were just one optimum speed to fly—but there isn't. There is a speed that provides a minimum sink rate—that's good for thermalling, flying tight little circles trying to get the most altitude out of the rising air. But that very slow speed (just a few knots above stall) isn't a good one to make a distance over the ground. That is another speed. But, that changes with the wind and how fast the air your in is rising or sinking. Counter-intuitively, in air that is sinking the best approach is to push the nose down! That's to go faster and get out of that sinking air quicker. One also needs to go faster with a headwind than tailwind. (When you're only going 50 mph, it really makes a big difference.)
Those same principles apply equally to a jet airplane!  For example, in the event of an engine loss at altitude, the question is: "what speed to fly". Do I need to minimize my sink rate (to avoid traffic below), make the best distance per altitude (to clear that mountain range), do I need to make the most fuel efficient diversion, or the fastest one?

All airplanes could be gliders, and there have been a few classic examples when some big ones unexpectedly became a glider. Here's three:
  • Air Transat #236  An A330 that ran out of fuel over the Atlantic and glided to a safe landing in the Azores.
  • Air Canada Flight 143 aka, "the Gimi Glider.   A Boeing 767that ran out of fuel at 41,000 feet , about halfway through its flight originating in Montreal to Edmonton, and glided to a safe landing.
  • USAirways 1549 The "Miracle on the Hudson"
In each case, the captain was an experienced glider pilot. Hard to argue with success!
Along those same lines, energy management—a key element in the instances above—is always on a glider pilot's mind. You always have to be able to make it back to the airport (or to a different airport) and a go-around is not an option!

In a recent simulator session  we ended up shortly after takeoff with no engines operating (a fire in one and failure in the other). The objective was apparently to do a ditching drill. But, why put it in the water, when you can land on the runway—which is what I did instead. (A glider pilot is always aware of when and how he can turn back to the airport in case the tow rope breaks!)

I've also found that gliders (or other small acrobatic airplanes) can be a great resource to expand a pilot's attitude envelope. This may come in quite handy in the event of an upset event.  When you're upside down for the first time, hanging by your seatbelt, and all the dirt and other objects that aren't tied down are falling up in front of you-—it can be a little disorienting! "Tunnel vision" comes to mind.  Training in aerobatic capable aircraft can prepare you to handle an extreme upset—like an inadvertent case of upside-down. The intuitive answer is not always the right one!

Then there's the aspect of no-autopilot. Somehow that should count for triple the time spent in an airplane for hour requirements! Of course there would be few times when an autopilot would be of any use, as a glider pilot is almost constantly changing speed and direction to maximize the flight.

It won't happen magically when the new glider pilot solos or gets that new ticket. It will take some time, some effort, some thinking about it, and a lot of fun along the way!


Karlene Petitt said...

Bill, This is an amazing post. And I am currently working to lower flight hours for those pilots who have glider time. I'm thinking we could grow experience the right way! With skill versus the autopilot. Automation will come, but skill is earned.

Raymond Curry said...

Nice! It's rather pleasant to hear that there modules and mechanisms that provide us the ways on how we can perfect our way to flight. It is always a blessing to have those starter rides. We should learn to ride the current before taking off to the skies, and there are a lot of ways that we can get training that suits our budget and time. Thanks for sharing that!

Raymond Curry @ Holstein Aviation