Overshooting and Undershooting 'Engine-Out' Landings

Tags: undershoot, overshoot, glide-path, engine-out

On too many occasions, I find applicants tend to overshoot (too high on the proper glide path) when executing a simulated engine out approach and landings especially, the no-flap. 

It is interesting to me that the tendency is to OVERSHOOT the desired glide path (be too high). What is even more interesting (and distressing) is that, on too many occasions, applicants fail to use devices and methods to correct to the proper glide path. Often, I ask “Are you high or low?” and they reply that they are high. I wait for them to use the flaps, “S” turn, slip, or, if there is adequate altitude, execute a 360 degree turn to loose excess altitude to establish the proper glide path. 

Overshooting and Undershooting 'Engine-Out' Landings

Written by: Marc Nathanson, FAA Designated Pilot Examiner

On too many occasions, I find applicants tend to overshoot (too high on the proper glide path) when executing a simulated engine out approach and landings especially, the no-flap. 

It is interesting to me that the tendency is to OVERSHOOT the desired glide path (be too high). What is even more interesting (and distressing) is that, on too many occasions, applicants fail to use devices and methods to correct to the proper glide path. Often, I ask “Are you high or low?” and they reply that they are high. I wait for them to use the flaps, “S” turn, slip, or, if there is adequate altitude, execute a 360 degree turn to loose excess altitude to establish the proper glide path. 

This tendency to overshoot indicates that instructors are not stressing this task when training their students. Knowing that engine out and no-flap tasks are required on several practical tests, instructors should be teaching this discipline to competency.

Here are some suggestions both instructors and students may use to ensure competency in the described problem areas. 

Once a student can consistently land the aircraft by maintaining the proper glide path and flying a stabilized Approach, reduce the power to idle abeam the touchdown point no later than abeam the runway numbers. Consider the touch down point to be between the 500’ and 1,000’ markers, or in the first third of the runway if such markers are not on the runway. Practice flying the aircraft to the proper glide path and landing without the use of power unless a short landing (Undershoot) results requiring the use of power. Don’t hesitate to use power if necessary!

On each attempt, the pilot should note where they begin their turn from downwind and what ground reference points they fly over and adjust their bank and ground reference points on subsequent attempts until they get it right. This means that they must understand the effects of the wind, bank angle and airspeed on the approach and how to correct for deviations from what is correct and needed. 

It is of the utmost importance pilots understand that approaches and landings are dynamic. That the wind will directly affect the ground path. Too much headwind on final (tailwind on downwind/crosswind) will result in an undershoot, whereas little wind or a tailwind on final will result in an overshoot.

It is very important to understand why an engine loses partial or complete power. I suggest using carburetor heat if in doubt that carb icing may occur-better safe than sorry. I’ll admit to a certain degree of paranoia concerning switch and lever positions especially during critical phases of flight. Is the fuel selector on the fullest tank? Is the fuel pump on or positioned correctly for takeoff and landing? Do I think to turn on the fuel pump to the proper setting (high or low if it has two settings) if the engine starts to run rough or quits? I wrote an article named “Playing the What If Game”. It’s a good idea to think about things that may go wrong and what to do when we have nothing else to do other than fly the aircraft.

On a return flight to our home base flying the MD-11 for a major cargo airline company, I decided to look at the emergency procedures for an airspeed miss-compare with the fellow I was flying with. This is a situation when the Captain’s and First Officer’s computer generated airspeed indicators on the Primary Flight Display (PFD) do not show the same airspeed due to a glitch in the Flight Management System (FMS). There is a rather lengthy procedure that must be performed to get the airspeed indicators to match and show the correct airspeed. We finished our discussion and set up for our descent into our home base. During the descent…you guessed it, we had an airspeed miss-compare! We brought out the emergency procedures again and completed all procedures correctly and in a timely manner because we had taken the time to review them minutes before the occurrence. We simply asked ourselves, “What if...”, and put forth the effort to make sure we were smart and ready. 

On another occasion, I was leading a flight of 4 F-4s to the gunnery range in Spain and the “Emergency of the Day” was hydraulic failure and using the approach end hook wire with the tail hook. Sure enough, I had a hydraulic failure requiring me to put my tail hook down and take the hook wire that day. During the debrief, my wingmen decided I shouldn’t brief any of the emergencies because they happened when I did… at least this day it did.

Pay attention to the engine run up before takeoff. Do you know what the static RPM should be when full power is applied for takeoff? I find that very few, if any, applicants know what to look for. The static RPM normally applies to aircraft with fixed pitch, non-controllable/constant speed propellers. Check the Pilot Operating Handbook (POH) for these numbers. Don’t expect the RPM to top out at 2500. It will be nearer to 2200 – 2400 RPM depending on the aircraft – engine combination. If the engine does not make the proper power before takeoff, you may be faced with a problem requiring you to land without the use of the engine. 

Learn from every approach you make while landing. Be on speed and on the proper glide path, aligned with the runway centerline and use proper crosswind controls. Practice engine out landings and be ready to go-around if it goes bad. Try again until you get it right every time. And know what you would do if you have engine problems. Get into the aircraft manual and memorize those procedures that are time sensitive such as engine failure on takeoff.

Fly Safe.