Aborted TakeoffsBy Fred Herold, EAA 395010, NAFI 16046
How many of us had the experience of having the instructor pull the power on takeoff just after rotation; or pulled the carb heat on when we started our takeoff roll during a hot day; or even shut off one of the ignitions, causing the engine to suddenly lose power on takeoff roll? I’ll venture to say that 95 percent or more of the pilots flying today have never had that experience. Skills learned from such an exercise can be lifesaving if the need should arise to abort a takeoff.
Reasons to Abort
What would you do if your engine lost power midway through your takeoff roll? If it were an insidious reduction, you may not even notice and may comment on the sluggish performance of the plane. But did you even look at the tachometer to ensure that the engine was producing the proper rpm on the takeoff roll? Do you even know what the proper rpm setting should be for the plane you’re flying?
I would suggest that if the plane is yours, find out what the normal rpm is during the initial roll and note that number for future reference. A quick glance at the tachometer on the initial roll will confirm normal performance and not jeopardize your safety, the safety of other passengers, and the aircraft. If the aircraft is a rental, ask the instructor on your checkout flight what the normal rpm readings should be when power is applied; on your first few solo flights, hold the brakes when power is applied and ensure that the engine is producing proper power.
What do you do if performance doesn’t seem right to you? Remember, you are the pilot in command – the safety of this flight is your responsibility. If anything doesn’t seem normal, taxi back to the ramp and have a qualified mechanic check the aircraft. It’s better to be on the ground wishing you were in the air than to be in the air wishing you were on the ground.
What do you do if during the takeoff roll the engine sputters, coughs, and then runs normally? I hate to say this, but most pilots will proceed with the takeoff if the sputter happens when they first apply power and consider it a mere abnormality of the engine. A few of the more cautious ones will take it to the shop when they return and ask their mechanic to check the timing or something. The true cowards among us (I am a true coward) will abort the takeoff and have the engine and fuel checked before venturing aloft. This however does not always end your flying day. Sputtering has many faces such as a cold engine requiring a bit more time to warm up. It is best to learn what your engine is saying to you in various situations.
What do you do if the airplane starts to swerve off the runway? Reduce power to zero immediately and do the best you can to maintain directional control. At this point it’s probably best to call it a day and have the aircraft inspected. Better to be safe than sorry.
Eliminating Abort Situations
One really big mistake many pilots make is underestimating the amount of takeoff roll required to compensate for density altitude. It’s generally spelled out in the handbook that we all had read several months or maybe even years ago and had promptly forgotten. In summer months, the air is less dense; the amount of oxygen available to properly burn the fuel and produce power is greatly reduced, so the engine performs as if it’s at a higher altitude while it’s on the ground. This can dramatically increase the length of runway required to attain flying speed, which can be compounded by taking off from a grass strip where the ground is softer or the grass is tall. All of these things add up, and you could easily find yourself in the trees or running into the fence at the end of the runway. Keep these factors in mind when making your go/no-go decision, and your takeoffs should be uneventful. Have several abort points in mind as depending on conditions.
Here’s a good rule of thumb if you do opt to take off: If the aircraft isn’t at flying speed when you’re halfway down the runway, abort the takeoff roll immediately by reducing power and apply your brake(s). There’s no reason to take chances with your life to prove a point or to show how good a pilot you are. Always err on the side of good judgment. There’s a saying among old pilots that you learn good judgment by surviving bad judgment, and while that may be true, learning by such methods may mean that you won’t live to become a good judgment pilot.
Points to Ponder
- When in doubt about safety for any reason, remain on the ground. There’s always another day.
- If you have questions about aircraft performance, ask them. There’s always someone around willing to share his or her knowledge and experience with you.
- There are bold pilots, and there are old pilots, but very few old bold pilots.
- May the sky remain blue, and may the shiny side of the plane stay upright.
Fred Herold is a certificated flight instructor at Chesapeake Sport Pilot, located at Bay Bridge Airport, Stevensville, Maryland. Photo by Karen Helfert.