Summer Flying Considerations for the Piston Powered Aircraft Operator

Everyone knows that summertime can add a layer of complexity to flying any aircraft, but it can really have adverse effects on the piston-powered aircraft and it’s operator.  Let’s take a look at the external factors in play during summertime operations.  Some are obvious, others might not be so obvious.  We’ll break them into four categories: Aircraft, Engine, Environment & People.  For this article, we’ll only focus on your aircraft and engine.

Aircraft

I’m not going to spend a ton of time going over aircraft performance as most pilots are keenly aware of how an aircraft is affected.  We know that hot weather can significantly degrade takeoff & climb performance, as well as increasing landing ground rolls due to higher true airspeeds.  Not only is the air less dense, providing a decrease in lift, but the engine (more on this later) is producing less power.  Pilots have to carefully plan for this and be aware that they’ll need more runway and more time to climb to altitude.    This is especially true in high altitude, mountainous airports and airports with terrain or obstacles in the immediate vicinity.  Always have a plan!

Do the sun and heat affect aircraft in other ways?  Absolutely. Leaving an aircraft out in the sun over time will damage the paint, transparencies (windows) and possibly the interior.  It will also destroy your tires.  Sun damage can cause “weather cracking” on the tire sidewalls and treads, ultimately weakening the tires’ structural integrity.  Excessive weather cracking should be a sign that you need to replace your tires.  Air Power, Inc. carries genuine Michelin and Goodyear tires at the best prices.  What can you do to help protect your paint, windows, interior and tires?  The obvious answer is to keep the aircraft in a hangar.  Covered tie-downs are nice, but will still expose the aircraft to the elements.  Sometimes leaving an aircraft outside, on the tie-downs, are the only option.  In that case, every effort should be made to keep the aircraft clean and waxed.  Windows should be covered to protect them and protect sun damage on the interior.  If you can, place something over the tires and wheel pants to protect them from the sun’s damaging rays.  A little bit of preventative work will keep your aircraft in top shape and help retain its’ value.

Engine

OK, we all know that high temperatures affect all aircraft engines, especially piston engines such as the Continental & Lycoming engines that are the mainstays of today’s general aviation fleet.  But why does this happen?  The higher the temperature, the less dense the air is.  Higher altitudes make it even less dense.  When flying on the rich side of peak (where all piston planes operate during takeoff and initial climb) air is the limiting factor in how much power an engine makes.  This means that there is an abundance of fuel in the cylinders and the amount of air it mixes with produces power.  Less dense air, i.e. fewer air molecules provides fewer air molecules for the fuel to bond with and, in turn, the engine will produce less power.  This is especially true of naturally aspirated aircraft engines.

So you say that you have a turbocharged engine, maybe a Continental TSIO-550 or a Lycoming TIO-540, and that the turbochargers make up for the loss in power due to high temperatures.  Wrong.  While turbocharged engines do, in fact, make up a lot of the loss in power due to high temps, they still are negatively affected.  Here are some of the ways that high temps get you, turbocharged operators, out there:

• Many of today’s turbocharged engines do not have a manual wastegate, meaning that they have a system that regulates the the amount of manifold pressure (boost) that can be put in the engine. This is a significant decrease to pilot workload.  What happens is a licensed aircraft mechanic should “set-up” the engine periodically to ensure the engine meets rated power.  Here’s the kicker though, this “set-up” only applies to the ambient conditions in which the engine was adjusted.  These are not computerized systems and cannot make adjustments on the fly.  They’re mechanical systems that require a mechanic to adjust them.  So, if you were set up to make maximum manifold pressure at your home airport in Chicago, it will not be able to make rated power when you go out to Durango, Colorado for summer vacation.  What’s worse about this scenario is that your aircraft performance charts are based on full power.  Well, you’re not making full power and have no data to lean on.  So, you need to give yourself extra room.
• Warmer air also decreases your engine detonation margin. You must properly plan for a higher airspeed climb to keep your engine cool.  Higher airspeed climbs typically mean lower climb rates.  Again, another planning factor that you need to take into consideration.  By all means, if you get into a situation where you need the altitude, go ahead and climb higher and don’t worry about your engine temperatures (within reason), but do everything you can to keep the temperatures down.

Your aircraft and engine can’t escape physics.  But what you can do is keep your aircraft in the best condition possible. Air Power, Inc. is always standing by, ready to help you and your technician with the best selection in aircraft & engine parts from OEM’s such as Cessna, Beechcraft, Continental, Lycoming, Garmin and so many more. Contact us today to learn more about our products!