Know Where Your Plane Belongs
Jason Blair, ATP, CFI-I, MEI-I, FAA Designated Pilot Examiner, AGI
Not every plane is best suited to operating at every airport. Some aircraft excel in different operational environments, but not in others. Knowing where your plane belongs and what operational environments increase risk can help you avoid ending up generating an insurance claim, or worse.
What happens when you want to use your aircraft outside of its normal operational parameters? Examples might be on a trip to an airport with a higher elevation or visiting a fly-in on a grass strip or taking that aircraft for a once-a-year camping trip on a short field in the “backcountry”. I have listed some things to consider when determining if you are asking your aircraft to do something for which it isn’t best suited.
I remember vividly the first time I saw a sign at an airport, I think in Laramie, Wyoming, where it read “non-turbocharged aircraft don’t fly here when temperatures are over 80 degrees”. The sign was a smart reminder of density altitude. I was there with an Aeronca Champ, but it was in March. There is no way that type of aircraft would have been appropriate to go there in August on a 90-degree day.
If you are thinking of taking that non-turbine or turbo-charged aircraft into airports with higher ground elevations, dig into the performance charts. Do this not just for extreme operations at an airport like Leadville, CO, but where you are trying to operate from an airport at ground elevations of 3000’ MSL or 4000’ MSL. These elevations occur in much of the western flatlands and areas near the Appalachian Mountains and that can become problematic. Out west, many of the runways are built longer to accommodate the takeoff and climb needs for higher altitudes. At more moderate ground elevations the runways aren’t always significantly longer but your performance may be significantly degraded. Taking off from a short runway at 4000’ MSL ground elevation on a 90-degree day might generate a density altitude (assuming standard pressure) of approximately 6500’. That can drastically change takeoff distance requirements.
Know the takeoff and climb limits of your aircraft. In most general aviation aircraft, we need to mitigate these concerns when the temperatures and ground elevations increase. It might be that we find our plane isn’t best suited for Denver’s Centennial Airport (KAPA - ground elevation 5885’ MSL) that would have a density altitude on a similar day of 8853’ or Sedona, AZ (KSEZ - ground elevation of 4831’ MSL) where density altitude under these conditions would be 7578’. If this doesn’t sound too bad to you yet, try taking your plane up to that altitude and seeing what your climb rate looks like. Then imagine needing to take off in a fully loaded aircraft at that altitude and needing to clear any obstacles. You might think twice.
Grass fields can be some cool places to visit, but not every plane will excel there. Conditions of grass fields can also vary drastically. A friend of mine bases his Baron at a grass field that is 3500’ long and has no problems. But that location has been a grass field for over 50 years, gets multiple rollings per year to pack it down, and the grass is cut short. He wouldn’t take his Baron to other grass fields without doing a good deal of homework beforehand.
Aircraft with wheel pants incur a greater potential risk for damage when operating on soft fields. Smaller tires are generally less suited to softer fields. While it might be enticing to join a group of friends taking their decked-out backcountry planes on a fall grass-field hopping weekend, your SR22 with wheel pants might not be the best plane to do it in.
See what your POH says about using aircraft on a grass or soft field. Many performance charts will indicate a need to increase takeoff calculations by somewhere between 10 to 30%. I generally add 50% to any takeoff consideration when I am going to use grass. I like the extra margin.
In general, the more drag that the aircraft is generating during a takeoff roll on a soft field runway the longer it is going to take to get off the ground. Prepare by being proficient in your soft field technique.
There are some aircraft that just don’t do well on grass. Weight is a consideration here. I regret the day I decided to take a Piper Chieftain onto a grass runway. The landing wasn’t a big problem, but once the aircraft got parked in the grass, it settled. It was heavy and hard to get back out of the parking spot when we needed to leave a couple of days later.
Bigger flaps, VGs (vortex generators), overpowered engines for airframes, and lighter airframes are just a few things you might find on aircraft designed to operate out of exceedingly short runways. Most aircraft in the general aviation fleet are not designed for this specific operational requirement. While a Cherokee Six can certainly operate safely out of a shorter runway than a Cessna Citation, it also isn’t going to be able to safely operate out of a runway more ideal for a Super Cub.
Be realistic with the aircraft you are flying and don’t force your operations into strips that are too short. Build in a safety margin. This might mean there are places you just don’t go with your aircraft.
I used to regularly fly into the College Park MD (KCGS) airport in the Washington, DC area for meetings. I was making the trip in a Cessna 182 and a Cherokee Six and both were safe for my takeoffs and landings even though the airport was a little on the short side with a 2600’ runway. Now I fly a Cessna 340 and the runway is too short. Because of the differences in operational requirements for takeoff and landing distances between these planes, I modified my behavior to use a nearby alternate airport with a 4200’ runway.
A conservative pilot should always build in a little extra margin for the runway they choose to use.
Amphibs on Pavement
Flying amphibious aircraft? Landings on pavement might be a more challenging operation. Many floatplane operators generally consider a max crosswind component they are willing to take off or land in. And that is half of what the POH indicates as a demonstrated or maximum crosswind component for the same make and model of aircraft when it is “on wheels”.
Knowing that an amphibious aircraft is more likely to weathervane, with less ability to counteract that tendency when landing on the pavement with “4 wheels” vs. a more conventional
3-wheel configuration might make a pilot think carefully about limiting their crosswind operations.
Tailwheels in Crosswinds
For all but the most proficient flyers of tailwheel aircraft, crosswind limits may be something a pilot flying tailwheel aircraft will choose to reduce. In many cases, due to the weathervaning tendency, tailwheel aircraft will be more demanding of pilot skills when operated in strong crosswind conditions compared with similar tricycle gear aircraft. There are reasons that most aircraft produced are tricycle gear.
On the other hand, if you are flying some tailwheels, you might find yourself in an aircraft more appropriately suited to soft or rougher fields based on the gear and prop clearance. It’s, again, about knowing where your plane belongs.
Know the limitations of your aircraft and don’t try to force an aircraft into places for which it is not suited.
One thing I have learned over the years from flying a variety of aircraft is that there is no perfect one. Many makes and models do well, and may even excel in certain areas, but none excels in every operational environment. Be honest with yourself about the capabilities of the aircraft you are operating and the limitations that come with it. If you conservatively respect that evaluation, it will be less likely that you have pushed your aircraft to do something for which it isn’t suited. And that makes it less likely that you will need to make that call to your insurer to make use of your insurance policy.
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Jason Blair is an active single- and multi-engine instructor and an FAA Designated Pilot Examiner with over 6,000 hours total time, over 3,000 hours of instruction given, and more than 3000 hours in aircraft as a DPE. In his role as Examiner, over 2,000 pilot certificates have been issued. He has worked for and continues to work with multiple aviation associations with a focus on pilot training and testing. His experience as a pilot and instructor spans nearly 20 years and includes over 100 makes and models of aircraft flown. Jason Blair has published works in many aviation publications, a full listing of which can be found at www.jasonblair.net.
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