by Levi Eastlick
WisDOT Bureau of Aeronautics
Published In Midwest Flyer Magazine Online October/November 2021 Issue
Do you treat takeoff and departure as seriously as an approach and landing? Many pilots seem more concerned with navigation, enroute weather, their arrival, and landing at their destination than with their takeoff and departure. This is unfortunate since the accident rate for takeoffs is about equal with that for landings. Pre-flight planning for the takeoff portion of the flight is a fundamental step too often overlooked. The takeoff plan, focused on determining if there is enough runway available and sufficient climb performance for the airplane to clear the terrain ahead, begins with calculating an accurate “weight and balance.” The key word here is “accurate!” Use a scale to weigh baggage instead of guessing because, odds are, you will guess light. Also, make sure the weight and balance data you are using is for your specific aircraft. Not all 172s weigh the same. As the saying goes, “aircraft are like pilots… they gain weight with age.”
Next, consider the airport environment and, specifically, the runway we plan to use. A call to Flight Service or logging on to your favorite aviation planning app will give you updated weather and Notices To Airmen (NOTAMs), which should give you a good awareness of available runways and the prevailing wind direction. When calculating required runway length, some pilots use “worst case” criteria as a preflight planning tool. They look at the aircraft’s performance tables to determine the required runway length for an airport at a 2,000 ft elevation with the airplane at maximum certified takeoff weight, no wind, and an air temperature at the highest degrees they will likely encounter. Then they add 50 percent for a comfort factor. If the runway is not long enough under these conditions, then a closer look is required. Jet and transport aircraft flight manuals provide a great deal more takeoff performance data than light aircraft manuals.
One useful table not available for light aircraft is the “accelerate-stop distance,” but you can get a good idea of that distance for your aircraft by adding the required takeoff distance to the landing distance, and then add 50 percent for pilot technique.
Another major factor in an aircraft’s takeoff performance is the “wind direction and speed.” Unfortunately, many takeoff accidents involve taking off into unfavorable wind conditions. When deciding which runway to use, consider that a headwind that is 10 percent of the takeoff airspeed will reduce the no wind takeoff distance by 19 percent, whereas a tailwind, which is 10 percent of the takeoff airspeed, will increase the no-wind takeoff distance by about 21 percent.
Another wind factor to consider is maintaining directional control of the aircraft during departure. While many pilots use the demonstrated crosswind component as a reference for landings, it is also a useful number to use for takeoff planning.
While most runways in Wisconsin are generally flat, do not underestimate the effect of “runway slope” on takeoff performance. A runway with an upslope of 1 percent will add 20 percent to your takeoff run. The FAA Chart Supplement is your best resource for runway gradients. Additionally, runway contamination can have a significant effect on the amount of runway required. Light aircraft manuals offer very little information on the takeoff performance from a runway with snow or standing water, so pay close attention to runway condition NOTAMs, especially in the winter.
Now that your takeoff is carefully planned, are you ready to execute the plan? This is the stage of flight where I see many pilots not focused on the risks they are about to encounter. One aspect of a safe takeoff is having an “abort plan.” Too often it seems that pilots increase power and wait for rotation speed, but do not have an abort plan, nor are they prepared for an emergency. One factor may be if takeoff speed is not reached by halfway down the runway, you will abort the takeoff. The benefit of this rule of thumb is that it will work for any length runway. There are other good reasons to power down and stay on the runway. Discuss this topic with your favorite CFI.
The most vulnerable time for an aircraft to lose power is from liftoff to at least 1,000 feet above ground level. Are you prepared and ready to react to an engine failure? Generally, the best course of action is to maintain minimum safe glide speed and land straight ahead, which usually takes an abnormally large amount of nose down input. Have you practiced for this recently (at a safe altitude of course)? Turning back to the airport is fraught with risks and a stall/spin/crash is an all-too-common outcome.
Takeoffs are deceiving since they appear relatively easy. Most flight instructors typically let new students handle all, or at least most of their first takeoff. However, the new student is only flying the aircraft; the CFI is managing all the other factors affecting the takeoff. It is essential to get into the habit of developing a firm plan of action in your mind before starting every takeoff roll. Never forget that takeoff is always optional, eventually landing is mandatory.
