Can Planes Fly On One Engine? 12 Things You Might Not Know: Introduction
If you’re a nervous flyer or want to know more about it, you may have wondered, “Can planes fly on one engine?” and wondered if it was safe and possible.
Even though engine failure is a serious problem, commercial planes are certified, and pilots are trained to handle it safely. In this post, we’ll go into more detail about how commercial airplanes and pilots can deal with engine problems and how a plane can fly with just one engine.
Can Planes Fly On One Engine Overview
Modern turbine engines are very reliable. But if one engine stops working, the other engine can compensate for the loss of control and keep the large aircraft in the air.
There are standard operating procedures and checklists for pilots if an engine stops working. These procedures and checklists help the pilots handle the situation quickly and effectively so they can keep control of the plane. Also, pilots spend a lot of time training in airline simulators to prepare them for these situations. This training allows them to get used to the systems and procedures used when the engine stops working.
The physics of how an engine breaks down is also a big part of whether or not a plane can fly on one engine. When a plane’s engines’ breaks down, the other engine compensates for the lost power by putting out more thrust.
In real life, there have been many examples of commercial flights that have landed on one engine. These examples show how pilots handled emergencies and ensured the safety of commercial airliners.
Here are 12 things that you may not know, that pilots have to take into account before taking off.
1. Two Vs Four Engine Passenger Jet
In this post, our example is going to be a commercial twin-engine plane with jet engines that has a single engine failure, such as a Boeing 737 or Airbus A320. These are some of the most popular commercial jets in the United States and worldwide. First, most commercial planes you’re likely to fly on have two engines.
Some larger aircraft, such as the Boeing 747 and Airbus A 380, have four engines. These planes can hold over 400 passengers and are most likely to be found on international flights between high-demand cities such as New York to London.
Four-engine aircraft are becoming less common. Commercial four-engine planes like the Airbus 380 and Boeing 747 are no longer made by Airbus and Boeing.
Four-engine planes have less of a problem if one engine stops working. This is because they have more engines, giving them a bigger safety margin in case one breaks down. Planes with four engines, like the Boeing 747 and the Airbus A380, can fly with just two engines if they have to. This means that the plane can still fly and land safely even if one or two engines stop working.
2. Flight Crew Standard Operating Procedure
Standard operating procedures are in place so pilots can handle normal and emergency operations the same way every time. Even when flying with another pilot that they’ve never flown with before, standard operating procedures ensure each pilot works effectively as part of the crew.
These procedures and checklists are meant to allow the pilots to handle the situation quickly and effectively and ensure control of the airplane.
When one engine goes out on a commercial plane with two engines, the pilot will follow a set of steps called “engine-out procedures.” These steps help the crew keep control of the plane and land it safely with either just the left engine or right engine.
The crew will adhere to an orchestrated set of steps in the event of an engine failure to guarantee the safety of the flight. These actions are listed below for a typical engine failure.
3. Aviate, Navigate, and Communicate
In an emergency, pilots always use the “aviate, navigate, communicate” order of handling the aircraft. This order lists in order of importance the most important things that need to be done to make sure the flight is safe.
- Aviate: The first priority is maintaining control of the aircraft and ensuring its safe flight. This includes flying the aircraft and making necessary adjustments to the flight path, speed, and altitude. The pilot’s main focus is to keep the aircraft flying safely and avoid further hazards.
- Navigate: Once the aircraft is under control, the next priority is to navigate to a safe location. This includes determining the best course of action, such as returning to the departure airport or proceeding to an alternate airport. The pilot must also consider factors such as weather conditions, remaining fuel, and the distance to the nearest airport.
- Communicate: The final priority is communicating with air traffic control, the passengers, and the cabin crew. The pilots must inform them of the situation, provide instructions, and update them with their plans.
4. Typical steps for an engine failure on takeoff:
- Climbing to 1000 feet: The crew will climb right away to reach at least 1000 feet above the ground. The altitude is normally 1000 feet but could be higher based on mountains or other obstacles around the airport. Once above 1000 feet and in a safe area clear of obstacles, the crew can move on to the next step.
- The crew will accelerate the plane to a safe speed and retract the flaps (which add lift for takeoff and landing but also drag ), then troubleshoot and make decisions on the next steps.
- Securing the failed engine: Depending on the type of engine failure that occurred, the crew will proceed according to the emergency checklist. Securing the engine could include shutting off the fuel to the malfunctioning engine and shutting off other associated systems.
- Restarting the engine could also be an option depending on the type of failure. Some engine failures are caused by an engine flameout, where the engine is not damaged. In this case, the crew could attempt to restart the engine.
- Returning to the departure airport or continuing to a different airport: The crew will assess the situation and decide whether to return to the departure airport or continue to a different airport.
- Air traffic control and passenger communication: The crew will tell the air traffic control of the situation and communicate with them. They would also explain the situation to the passengers and provide them with instructions and assurances to help them remain calm.
For an engine failure on takeoff, pilots are required to land at the nearest suitable airport. Most of the time the crew will return to the departure airport. Some exceptions when the crew would choose a diversion airport would be for things like:
- Weather at the airport they took off from (airplanes can often take off with lower visibility and clouds than they can land). For an average mid-sized airport, a flight may only need 500 feet of visibility to takeoff but 1800 feet to land.
- Airport runway or runway conditions: if the airport runway is shorter than the crew needs to safely land with an emergency, they may decide to divert to another airport nearby with a longer runway.
In most cases, unless the airplane is close to the destination airport, an engine failure will result in a return or a diversion. The choice will be made in light of the remaining engine performance, the surrounding weather, and the distance to the closest airport.
5. Simulator Training For Passenger Planes
Pilot training on airline simulators is essential for preparing them for engine failure scenarios in different phases of flight. These simulators expose pilots to a variety of potential real-world scenarios and circumstances.
Full-motion flight simulators that accurately duplicate the systems and procedures of the aircraft are used to execute the simulations, which are created to be as realistic as possible.
These simulators are so accurate and realistic that it’s hard to tell if you’re in the flight deck of a simulator or in a passenger plane. During initial airline training for pilots, the entire training is done in a simulator. The first time a pilot flies a new aircraft is normally on an actual commercial flight with passengers. Of course, this is done under supervision and with an instructor pilot.
Engine failures during takeoff, flight, and landing are only a few of the many possibilities in the simulations. Pilots are trained to know what to do in different kinds of weather, at different heights, and at different times during the flight. The simulations also include different engine failures, such as ones that lose all power or thrust.
Here’s an example of an engine failure being practiced in an Airbus 380 full motion flight simulator
Pilots must adhere to checklists and standard operating procedures during the simulations, exactly as they would in a real-world scenario. They hone their communication skills with the passengers, the air traffic controllers, and the rest of the crew. The judgment calls that must be taken to maintain the safety of the flight are also practiced by pilots. Pilots are expected to manage the simulations’ demanding scenarios safely and appropriately.
Each simulation is followed by debriefing sessions where the pilots receive comments on their performance. The debriefing sessions allow pilots to learn from any errors and advance their abilities.
Pilots must participate in simulations frequently to keep up their skills during ongoing training, usually several times a year. Most simulator sessions focus on abnormal or emergency procedures that are rare and can’t be simulated in an actual airplane.
It’s important to note that the simulations’ level of realism is extremely high and that the simulations’ equipment is the same as the equipment found in the actual aircraft.
6. Physics Of Engine Failures
The physics of engine failure plays a significant role in the ability of a plane to fly on one engine. When an engine fails, the remaining engine can compensate for the loss of power by increasing its thrust.
Additionally, the crew and aircraft systems work together to maintain stability and control, allowing the plane to fly safely.
When an engine fails, the remaining engine increases its thrust to maintain the aircraft’s airspeed. This is known as “thrust asymmetry.” Thrust asymmetry occurs when the thrust from the remaining engines is not equal, which can cause the aircraft to yaw or roll. However, the aircraft’s control surfaces, mainly the rudder, are deflected to counter this effect and maintain stability. This allows the aircraft to continue flying safely on one engine.
Manufacturers of commercial planes make them so they can fly on one engine for a limited amount of time. This includes climbing and landing. The aircraft’s systems and procedures are designed to handle such a scenario, and the plane is certified to fly on one engine.
An important factor is an altitude at which the engine failure occurs. At high altitudes, the aircraft can continue to fly on one engine for an extended period, though it will need to descend slowly to a lower altitude where the air pressure is higher.
This is because the plane is flying in thin air, and one engine doesn’t have the power to stay at the normally high cruise altitude of around 35,000 ft. On one engine, a plane may need to descend to a maximum altitude of around 20,000 ft. While they are descending, the crew has plenty of time to determine which airport they want to divert to.
On the other hand, at low altitudes on takeoff, the crew has a higher workload harder to maintain stability and control. This is because they already have a high workload on takeoff and a long set of procedures to follow. Also, when the plane is moving slowly and has a lot of power (like when taking off), the pilot has to use more control inputs to make up for the uneven power from one engine.
In summary, the physics of engine failure plays a significant role in the ability of a plane to fly on one engine. When an engine fails, the remaining engine compensates for the loss of power by increasing thrust, and the crew works together to maintain stability and control.
Commercial airliners are designed to fly on one engine, and the aircraft’s systems and procedures are designed to handle such a scenario. The altitude at which the engine failure occurs is also important, as the crew has to work harder to maintain stability and control at low altitudes. But the pilot can use the thrust from the remaining engine to keep the plane going at a safe speed for landing.
7. V1 Speed
The critical speed at which a pilot must choose whether to proceed with or abort takeoff is V1 speed or “decision speed.” The maximum speed at which the pilot can safely abort the takeoff and bring the plane to a stop on the runway is known as V1.
The aircraft may not completely stop on the runway if the pilot chooses to abort takeoff after reaching V1 speed, so this is also the speed at which the takeoff will be continued, even if there’s an engine failure.
The pilot must decide quickly whether to proceed with the takeoff or abort it in the case of an engine failure at V1 speed. The performance of the remaining engine, the speed of the aircraft, and the distance to the runway’s end are just a few of the variables the pilot’s aircraft performance numbers will take into account. The remaining engine will provide enough thrust to compensate for the lost power if the pilot decides to proceed with the takeoff. The pilot will use the aircraft’s systems, including the rudder, ailerons, and elevators, to maintain stability and control.
Pilots rehearse engine failures at V1 speed in the flight simulator to prepare for these situations. The simulations are created to be as realistic as possible. During the simulations, pilots are shown various possibilities of engine failure at V1 speed. They are prepared to decide whether to proceed with the takeoff.
8. Aircraft Systems
An auxiliary power unit (APU), which is a small turbine engine, is a plane’s backup source of electrical and pneumatic power. The APU is used to generate power while the main engines are not working and is normally found in the tail area of the aircraft.
If a plane’s engine fails, the APU can be used to power the plane’s electrical and pneumatic systems. Lighting, avionics, and air conditioning are just a few examples of systems that can be run by the aircraft’s APU. The pressurization system, the brakes, and the de-icing system can all be powered by the pneumatic energy produced by the APU.
The primary engines can also be started using the APU. The APU can be turned off and the main engines can be used to power the aircraft once they have started.
Using the APU during an engine failure is part of the regular operating procedures.
Ram Air Turbine
A commercial airliner’s backup electrical power is provided by a small device called a ram air turbine (RAT). When the main engines aren’t running or putting out power, the RAT, which is usually in the back of the plane, is used to make electricity.
A RAT operates by spinning a turbine that produces electricity by utilizing the airflow around the aircraft. Attached to the turbine, the generator turns the mechanical energy that the turbine makes into electricity. When the plane loses its main source of power, like when the main engines stop working in flight, the RAT is immediately put into action.
The vital systems of an Airbus plane, like flight controls, navigational systems, and communication systems, are powered by the RAT in an emergency As a result, even in the event of a total power failure, the pilot can keep command of the aircraft and communicate with air traffic control.
Due to the certification ETOPS (Extended-range Twin-engine Operational Performance Standards), twin-engine commercial aircraft are permitted to fly on routes that are further from airports where they can land in the event of an engine failure.
Prior to the implementation of ETOPS, twin-engine aircraft had to stay within a specific range of an airport; this range was determined on the basis that, in the event that one engine failed, the aircraft would need to return to the airport as soon as possible. However, as technology advanced, engines grew more dependable and twin-engine aircraft were able to travel farther from airports.
Twin-engine aircraft with ETOPS certification are permitted to go for a certain number of minutes beyond an airfield. The precise type of aircraft and the route that the aircraft will be flying determine how long it is permitted to fly away from an airport.
For instance, an aircraft certified to ETOPS-120 may fly up to 120 minutes (2 hours) from an airport, whereas an aircraft certified to ETOPS-150 may fly up to 150 minutes (2 and a half hours) from an airport. Some aircraft newer receive up to a 330-minute ETOPS certification
It’s crucial to remember that the type of aircraft, altitude and weather conditions all affect how long an aircraft is permitted to fly before returning to an airport. The airplane also needs a few safety features and systems, like a redundant flight control system and a fire detection and suppression system.
It takes a lot of work to become certified for ETOPS, and the manufacturers of the aircraft must prove that the aircraft can fly safely for the required period of time with just one engine. To do this, they must simulate an engine failure and observe how the aircraft would respond.
10. Light Aircraft Regulatory Requirements
Twin Engine Aircraft:
For takeoff, commercial planes must follow strict rules and get certifications, such as being able to climb with just one engine. This protects the safety of the flight in the event of an engine failure and is a requirement for certification.
These rules and regulations governing commercial airliners do not apply to small aircraft like win-engine general aviation aircraft, sometimes called “light twins.” These aircraft are not required to demonstrate their capacity to climb on one engine and may not be able to higher takeoff weights and high temperatures.
Twin-engine, smaller aircraft are designed and manufactured to fulfill safety requirements, but there are significant differences in requirements and training between general aviation light aircraft and commercial airliners.
A general aviation single-engine plane that experiences an engine failure will be able to glide to a landing using just the lift from the airplane wings. This is usually around a 7 to 1 ratio, meaning the airplane could fly 7 nautical miles while losing 1 nautical mile (6000 ft) of altitude. For a single-engine airplane, flying at a higher altitude gives you more options for emergency landings.
11. High altitude airports
Worst-case scenarios are used to plan takeoffs and landings for commercial aircraft.
This means that even at airports in high-altitude mountainous areas, the plane must be able to climb on just one engine. Since takeoff is the most crucial part of a flight, this assures the safety of the aircraft in the event of an engine failure.
Even in the worst-case engine failure situation, the plane must be able to climb to a safe height to give the pilots ample time to troubleshoot and make a safe landing.
When it’s hot outside or you’re at a high altitude, airplanes don’t climb as well. This is because the air is thinner.
The hot temperatures and high altitudes can impact the engines’ performance and the aircraft’s systems. In these cases, it would be necessary to lower the takeoff weight to launch the airplane safely. With less weight, the plane could climb to a safe altitude in the event of an engine failure.
The criteria for the worst-case scenario also consider additional elements, including the aircraft’s weight, the weather’s state, and the runway’s length. Even in the most difficult circumstances, the plane must safely take off and climb to a safe altitude, thanks to these standards.
12. Engine Failure Statistics & Examples
Aircraft engines that fail are uncommon, but commercial aircraft are built to handle them safely. Every million flying hours, on average, a commercial airline experiences an engine failure, according to the Federal Aviation Administration (FAA). This indicates that the engine failure rate on commercial aircraft is incredibly low.
Additionally, only around 4% of all aircraft accidents are caused by engine failures, according to the National Transportation Safety Board (NTSB). Furthermore, the takeoff and landing phases, regarded as the most crucial flight periods, are when engines fail most frequently. However, because commercial aircraft are built to handle such scenarios safely, and pilots are well-trained to handle emergencies, these occurrences often have a favorable outcome.
Modern engines are also constructed to very high standards and intended to operate for thousands of hours before needing repair or replacement. The pilots can recognize and assess any issues before they become serious because of the numerous sensors and monitoring systems built into the aircraft.
Commercial aircraft have successfully continued takeoff and landing after experiencing engine failure in real life many times. A few famous examples are:
- Southwest 737: Engine failure on a Boeing 737 operated by Southwest Airlines in 2018. All onboard passengers and crew landed safely and the skilled pilot successfully landed the aircraft with only one engine, despite significant damage from the fan blades detaching from the engine.
- United Airlines Boeing 777: United Airlines flight 328 experienced an engine failure and fire after takeoff over the Denver suburbs. resulting in a safe landing back in Denver. The incident resulted in the temporary maintenance grounding of 777 aircraft with that type of engine.
- Qantas Airbus A380: An Airbus A380 operated by Qantas (a four-engine aircraft) had an engine failure in 2010 shortly after takeoff that damaged many other systems on the aircraft. The experienced pilot and crew were able to return the plane to the airport safely.
- On inspection, a turbine disc in the aircraft’s number-two engine was found to have disintegrated, causing extensive damage to the nacelle, wing, fuel system, landing gear, flight controls, and engine controls, and a fire in a fuel tank that self-extinguished.
- The subsequent investigation concluded that the failure had been caused by the breaking of a stub oil pipe, which had been manufactured improperly.
- The failure was the first of its kind for the A380, the world’s largest passenger aircraft.
- US Airways A320: There have even been successful landings with a failure of both engines:
- On January 15, 2009, US Airways Flight 1549 was a regularly scheduled passenger flight between Charlotte Douglas International Airport in Charlotte, North Carolina, and LaGuardia Airport in New York City in An Airbus A320.
- At 3:25 PM EST, the plane departed from LaGuardia Airport. The airplane had a bird strike, hitting a flock of Canada geese shortly after takeoff, which led to the failure of both engines. Chesley “Sully” Sullenberger, the Captain, and Jeffrey Skiles, the copilot, were able to perform a safe emergency landing in the Hudson River.
- Successful evacuation of the 155 passengers and crew members resulted in their rescue from the top of the wing by nearby boats and ferries. The passengers and flight attendants did not suffer any fatalities or serious injuries.
- Air Transat: One notable example of pilot error fuel starvation occurred in 2017 on an Air Transat flight. The pilots of Air Transat flight 236 which was traveling from Toronto to Lisbon, experienced fuel starvation after the pilots mismanaged the fuel, causing a landing with no engine power. This type of error was extremely rare and changes to airline policy were made as a result.
In conclusion, this essay covered the topic of commercial airplanes’ ability to fly with just one engine and the protocols and training that pilots must go through to handle such situations. Before they can take off, commercial planes must meet a number of rules and get certifications. One of these is that they must be able to fly with just one engine, even at airports in mountainous areas with a high altitudes. We also talked about how “light twins,” or tiny general aviation twin-engine aircraft, are not subject to the same rules and requirements as commercial aircraft and are not required to demonstrate the capacity to climb on one engine.
We also discussed how commercial aircraft are built to safely manage such scenarios even though engine failures are uncommon, happening only once every million flight hours on average. Modern engines are designed to very high standards, fitted with many sensors and monitoring systems to discover and diagnose any faults before they become severe. Pilots are well-trained to manage emergency circumstances.
So, the next time you fly, don’t worry about the very small chance that an engine will stop working. Commercial planes are built to handle such situations, and pilots are well-trained to handle them.
Other Aviation Questions
Here are some links to other frequently asked aviation questions, like can planes fly in the rain.