Loss Of Thrust On Takeoff

Note to readers: The scenarios, calculations, graphics, information and opinions contained in this post are not intended as flight instruction. If you want to explore any of these scenarios, try it on a flight simulator or practice with an experienced CFI at a safe altitude. The main point of this post is to get pilots thinking about what they would do in various emergency scenarios, and doing their own research and training to effect the best possible outcome if presented with a real emergency.

One of the in-flight scenarios in our Advanced Qualification Program for General Aviation (AQP4GA) training handbook deals with the loss of thrust on takeoff (LOTOT). This occurs when the aircraft loses some or all power during the initial takeoff roll or immediately after takeoff, when the aircraft is at an altitude too low to make a turn back toward the runway viable. The pilot has no choice but to glide to a landing somewhere straight ahead or within a narrow arc left or right of the departure path.

This is indeed one of the scariest scenarios a pilot can face, especially at an airport like our home airport (KCRG) where the airport property is surrounded on all sides by residential and retail development, water, power lines and other obstructions. Having flown at this airport for nearly a decade now, in my opinion, the departure from Runway 23 presents the most risk to the pilot in the LOTOT scenario. The most common takeoff clearance for Runway 23 is from taxiway F intersection, which reduces the available runway length to approximately 3,600 feet when compared to using taxiway C intersection, which offers approximately 3,800 feet.

Beyond the end of the runway, there is approximately 2,000 feet of grass infield available before the airport boundary fence abeam St. John’s Bluff Road, just north of Atlantic Blvd. Beyond the fence, the pilot is faced with about one-quarter mile of hostile terrain in all directions: busy local roads packed with cars, power lines, homes and shopping centers. If a pilot is forced to land in this area, the odds of survival are near zero and the chances of hurting people and damaging property on the ground are near 100 percent.

Craig Airport is one of the busiest Class D towers in the nation now, and the second busiest in the state of Florida, averaging 500 operations per day. That’s about 50 takeoffs and landings every hour, or nearly one every minute, all day long, seven days a week, while the tower is open. With so many pilots flying so many different kinds of aircraft — from Piper Cubs to turbine helicopters to Hawker jets — all jockeying for use of our two, 4,000-foot runways, it’s become routine for Craig Tower controllers to clear single engine aircraft to takeoff via a taxiway intersection (23/F, 32/E) to expedite the flow of traffic. While requesting full length is always at the pilot’s discretion, the controller is unlikely to oblige when there are six other single engine aircraft in the pattern and six more waiting to take off. That’s just the reality we deal with most days at Craig.

People higher up the airport food chain than me have been talking for years about the possibility of getting one or both of our runways extended to 5,000 feet, which is the minimum length for larger business jets. Even though I don’t need any more runway to fly my Cessnas, extra pavement certainly can’t hurt, as you’ll learn in the following scenarios.

I thought it would be useful to run the numbers for the LOTOT scenario in our Cessna 150 or 152, which both offer similar performance. In the diagrams below, you’ll see that if we depart Runway 23 from taxiway F intersection, and the engine quits immediately after takeoff (i.e. upon reaching the theoretical 50-foot obstacle), we should be able to land straight ahead on the remaining runway. If we get off the ground and climb at Vy to 500 feet AGL, we can easily make the “possible turn” back to the airport. But what happens if the engine quits at say 200 or 300 feet? Based on performance calculations and in-flight observations, we will have climbed to 200-300 feet AGL by the time we cross the departure end of the runway, and approximately 400 feet as we cross the airport boundary fence on runway heading.

Let’s take a look at the “best case” in this danger zone, being at 400 feet as we cross the airport boundary fence. We might be able to turn back if we’re lightly loaded and the air is cool and calm, but I’m not interested in gambling. I want a sure thing I can count on, so in my mind, I’m aiming for the northbound lanes of I-295. If traffic is light, I can land on the highway itself, or, if traffic is heavy or questionable, I can land on the median or the shoulder. Landing in this direction is most favorable if winds are out of the west-northwest. If winds are out of the south or southwest, I’d have a bit of a tailwind landing this direction, which is one of the many reasons I’d prefer to depart Runway 14, where at least I could make a 90-degree right turn and land on Runway 23.

I tested this theory in our Cessna 150 with a student, while practicing crosswind landings on Runway 32 at Jacksonville International (JAX). The distance from the treeline on the approach to Runway 32 at JAX to the beginning of the runway is approximately 1,500 feet, the same as the distance from the airport boundary fence to I-295 when departing Runway 23 at CRG. As you can see in the video we easily made the runway in this scenario, and presumably could have made I-295 if we were over the airport boundary fence at 400 feet.

But what if I’m over the departure end of Runway 23 at about 200 feet in a climb at Vy when the engine quits? I’m too low to turn around, and too low to make it to I-295. My only hope is to lower the nose, dump the flaps, and land straight ahead in the grass. The problem is, I’m way too high. Imagine you’re over the threshold of a 2,000-foot runway (represented by the grass between the departure end of Runway 23 and the airport boundary fence) at 200 feet AGL. Would you be able to get the airplane down and stopped before you reach the end of the runway?

Mathematically, it might be possible. With power at idle and flaps retracted, your rate of descent at best glide speed is approximately 500 fpm in a Cessna 150 or 152. With flaps extended, you might increase that rate of descent to close to 1,000 fpm at idle. If we assume our ground speed in the descent is 60 knots, we could lose 200 feet of altitude in approximately 1,000 feet of forward travel, in calm wind, with the flaps fully extended. A headwind would decrease the forward distance traveled. In this scenario, that leaves us with approximately 1,000 feet left to touch down and come to a stop before hitting the fence, or at least hit the fence at a slow enough speed where we’d not likely hurt ourselves or do too much damage to the airplane. The key to success in this scenario is quickly transitioning from the Vy climb pitch attitude to a descent pitch attitude, deploying full flaps and landing at the slowest possible speed above the stall. Adding a forward slip would increase your descent rate and thereby increase your available landing rollout distance, but would also dangerously destabilize the approach in a tense situation close to the ground, possibly leading to a stall-spin. Whatever you decide to do, this is definitely a scenario you’ll want to practice with an instructor, at a safe altitude, until you can nail it without thinking.

I tested this theory in a Cessna 172 with a different student, while practicing crosswind landings on Runway 26 at JAX. In fairness to the student, I had not briefed him on this in advance and did not provide much guidance in flight on how to best pull this off. I wanted to see what a regular pilot would do in this situation if the SHTF, and how it would pan out. In this scenario, we flew over the approach end of Runway 26 at 200 feet AGL, simulating being over the departure end of Runway 23 at CRG at 200 feet, with the grassy area and the airport boundary fence straight ahead. At this point, I instructed the student to reduce power to idle, extend full flaps, and land on Runway 26. As you can see in the images below, it’s unlikely that we would have made it down safely in the grass at CRG if we were at 200 feet over the departure end of Runway 23. However, since the climb performance in the Cessna 172 far exceeds that of the Cessna 150 or 152, realistically we would be significantly higher by that point and likely able to glide to I-295 or even turn back to the airport. This is exactly why these scenarios must be practiced before you’re forced to execute in a real emergency!