Airplanes are remarkable machines, but despite this, you will most definitely notice the loud noise they produce. So, what are the loudest airplanes?
You do not have to be close to an airport to hear the deafening roars of aircraft engines. Some airplanes can be heard from miles away. And if you have ever attended an airshow, you have witnessed them breaking the sound barrier as they display their power. Being at the center of all that action can be exhilarating.
How loud an aircraft gets will depend on several factors, such as engine type and size, speed, etc. Despite these conditions, some aircraft have been predominantly known to be the loudest airplanes. The XF-84H, Tupolev TU-95, Avro Vulcan, and F-16 are among these airplanes.
These airplanes have distinct characteristics and features that make them this loud, with some being so loud that they never made it to mass production. As much as the thundering sounds could be exciting, this is not necessarily practical in aviation.
In this article, we will take a look at a list of the loudest airplanes, delving deep into the facts behind them to see why they are so loud.
What Makes Airplanes Loud?
Generally, all airplanes produce noise to some extent, it doesn’t matter if it’s a glider or a multi-engine turbojet.
To better understand why airplanes produce so much noise, let’s take a brief look at what causes aircraft noise.
The noise produced by an airplane is majorly attributed to two things. The air flowing over the airplane's surface and the noise produced by running engines.
Air Flowing Over the Airplane’s Surface
During flight, as air passes over the aircraft's surface, it creates friction which leads to turbulent airflow. The turbulent flow of air causes sound waves, which get louder the faster the aircraft flies. This is the main reason why gliders, despite having no engines, will still produce some noise.
As the aircraft continues to fly even faster and approaches the speed of sound (supersonic speeds), the air immediately in front of the airplane (which is usually laminar at subsonic speeds) starts to compress and build in pressure.
As the aircraft reaches the speed of sound, this pressure buildup moves to the nose of the aircraft forming a high-pressure wave. Once the airplane goes past the speed of sound and breaks the sound barrier, it penetrates the pressure wave and makes a loud, booming noise called the sonic boom.
Noise From Running Engines
Engine noise is normally caused by moving parts inside the unit and the hot exhaust air leaving the engine at high speeds and interacting with the still outside air, causing friction.
Modern engines have a bypass system that mixes the fast-moving exhaust gases with slightly accelerated cold air before leaving the engine. This makes it quieter than previous jets which didn't have this technology.
Effects of Atmospheric Conditions
Atmospheric conditions also play a role in how loud we hear aircraft noise. Although this is not a result of the aircraft itself.
Temperature, humidity, cloud cover, rain, and wind direction play a role in how much aircraft noise we hear. How easy or hard it is for sound waves to move through the air is based on how weather affects sound reverberation.
Now that we have a grasp of what makes airplanes loud, let’s get into the more interesting stuff.
List and Specs of the Loudest Airplanes
Aviation is known for being a very efficient mode of transport, although it is the one that contributes most to sound pollution. With modern technology, most airplanes being produced today are focused on reducing this.
But there have been a few notable airplanes out there that have made a name for themselves for being the loudest.
1. The Republic XF-84H Thunderscreech
Depicted by most as being the loudest airplane ever manufactured, and even being featured in the Guinness Book of Records, the Republic XF-84H lives up to its reputation. This aircraft has been reported to cause seizures in a fully grown man.
Its engines were so loud that alternative ways of communication had to be used by the crew on the ground, giving it the nickname "Thunderscreech" or "Mighty Ear Banger".
The XF-84H was a test fighter airplane made by Republic Aviation and made its first flight in July 1955.
This turboprop aircraft was designed for the American military and is based on the well-known F-84F Thunderstreak.
Instead of being fitted with a jet engine, its powerplant consisted of a turbine engine coupled to supersonic propeller blades. Its sheer power was assumed to have the potential to break the airspeed record set by any propeller-driven aircraft. But due to the efficiency problems it faced and its impracticality, this never came to pass, and it was discontinued after only two units were produced.
The constant speed propeller mounted at the nose moved at speeds faster than the speed of sound, at around Mach 1.18 (905 mph; 1,457 km/h). Shock waves could be seen forming at the tips of the blades, making a sonic boom that could be heard from miles away.
On top of the thrust provided by the turboprop engine, an afterburner was installed, further increasing the aircraft’s power from 5,850 hp (4,360 kW) to 7,230 hp (5,390 kW). Although the afterburner was never used.
The airplane was fitted with dorsal yaw vanes to stop it from yawing due to the asymmetric blade effect (P-factor) of the propeller, which causes the center of thrust to move away from the center of the plane at high angles of attack.
The powerful torque from the propeller blades and the supersonic airflow at the blades threw destabilized the XF-84H so much that the manufacturer had to try out different design features, like moving the left engine intake 12 inches (30 cm) forward and redesigning the right and left flaps with differential operation, just to counteract the effects of the massive torque.
The decision to use the XT40-A-1 turboprop engine also contributed to the detriment of this aircraft, transferring to it the same problems that other airplanes fitted with the same engine, such as the XA2J Supercharger Savage and the Douglas A2D Skyshark, had experienced.
Made with the primary purpose of serving the U.S. Air Force, these disadvantages proved impractical for combat. Coupled with its long engine warm-up that could see the Thunderscreech take over 30 minutes on the runway just for the engine to warm up, and the severe vibrations created by the propeller blades saw this aircraft put out of production.
The noise produced by the XF-84H was so loud that it could reportedly be heard over 25 miles (40 km) away.
During a ground test run at Edwards Air Force Base, the effects of the aircraft severely incapacitated the chief crew member of a nearby C-47 who was busy doing his job and didn't know the tests were going on.
The noise from the T-40 engines, coupled with the effects from the propeller, was notorious for causing headaches and nausea among ground crew staff. At one point, an engineer suffered a seizure after being exposed to the powerful shock waves from the aircraft.
Operations at the control tower were not spared either when operating this aircraft. Sensitive components were at risk of being damaged by the aircraft’s powerful vibrations, which forced the air traffic controllers to communicate with the crew on the XF-84H using light signals. This forced the aircraft to be towed out to a dry lake for any further testing.
The two prototypes only flew for a cumulative flight time of 6 hours and 40 minutes during the 12 test flights that they had.
One of the test pilots, Lin Hendrix, refused to ever fly the aircraft again after just one flight. The other test pilot assigned to the project, Hank Beaird, took the Thunderscreech out for a total of 11 test flights with 10 of them ending up in forced landings.
2. Tupolev TU-95 Bear
This large turboprop aircraft was first produced in 1952 by the Soviet Union as a strategic heavy bomber, with its design based on the Boeing B-29 Superfortress. It has had over 500 units produced to date.
Four Kuznetsov NK-12 engines power up the TU-95, with each engine coupled to two contra-rotating, four-blade propellers. Each of the NK-12 engines gives this aircraft a power output of 15,000 hp (11,000 kW). Designed by a team of German prisoner engineers, this aircraft’s engine was considered to be way ahead of its time.
The decision to select a powerplant for the TU-95 was quite debated. The option of picking piston engines was thrown out because they just couldn’t give out enough power for this large aircraft, as seen in the Tupolev TU-4, and the option to use jet engines was also not viable as they consumed too much fuel to offer the desired range. This is when it was decided to go with turboprop engines, which are a balance of the two. more powerful than piston engines but with a greater range than jet engines.
The original plan for the TU-95 was for it to be able to fly 5,000 mi (8,000 km) without needing to refuel and carry a total weight of 24,000 lb (11,000 kg), a distance far enough to carry nuclear weapons to targeted points in the United States.
The TU-95 is considered one of the loudest airplanes in production, with its propeller blade tips rotating faster than the speed of sound, creating shock waves and consequently generating sonic booms.
The turbulent airflow created between the two contra-rotating propellers creates a deep buzzing sound that’s so loud it can be heard by a submarine crew with the vessel submerged.
In November 1952, the first Tupolev (TU-95/I), which was fitted with two TV-2F engines experienced a propeller gearbox malfunction and crushed, just six months into its test flights, killing the test pilot. The second version (TU-95/II) fitted the current NK-12 turboprop engines.
The TU-95 is still in production today and is expected to serve the Russian military till at least the year 2040, with some of its variants converted to civilian airliners.
Due to the lack of adequate intelligence, the United States Department of Defense has had varying information about the TU-95, having previously evaluated it to have a top speed of 400 mph (640 km/h) and a range of 7,800 mi (12,500 km). Still, these figures keep on being revised upwards.
3. Avro Vulcan
The Avro Vulcan was a strategic bomber aircraft produced in the United Kingdom between 1956 and 1984 for use by the Royal Air Force. It was loved by the public because of its distinctive howling noise during airshows.
Although there was a demand for high-speed aircraft, little information was available about high-speed flight at the time. Experiments and research were done, and this led to the design of the delta wing, which made the plane easier to control at high speeds.
Fitted with jet-powered engines, the Vulcan was the first combat aircraft in the world to use delta-shaped wings.
Despite being produced for combat and designed to carry nuclear weapons, the Vulcan had no defense weapons fitted. It depended on its capability for high-altitude flight and high speeds to evade enemy interceptions.
Over the years, the engines were upgraded several times, but the manufacturer settled on Bristol Olympus twin-spool turbojet engines, with each of the four engines producing a thrust of 11,000 lb (49kW).
When the engines of the Vulcan were running, about 220 lb (100 kg) of air would be sucked into the aircraft’s intake per second and rush through the engine’s reducing pathway. This produced a loud howling sound, similar to the effect of a person blowing over the neck of a glass bottle.
This noise, coupled with the shock waves produced during flight, brings this aircraft to the list of the loudest airplanes.
4. General Dynamics F-16 Fighting Falcon
The F-16 is a very popular multirole fighter aircraft, with over 4,600 units produced since its approval in 1976 to date. It serves the United States Air Force and has gone ahead to be put into service in 25 other countries for military purposes, earning it the title of being the most numerous fixed-winged airplane in the world in military use.
Preferred for its versatility and high maneuverability, the F-16 is a loud, single-engine airplane capable of achieving speeds twice the speed of sound. This supersonic flight generates very strong shockwaves and loud sonic booms.
The F-16 also utilizes the vortex lift phenomenon to increase lift at high angles of attack. These vortices create high negative pressure on the wing’s surface and non-linear flow of air, further increasing airflow friction and the subsequent noise.
The F-16 was the first aircraft designed to be able to pull off 9-g maneuvers. This high maneuverability meant it had to be made more unstable, making it the first fighter aircraft in production to be intentionally made aerodynamically unstable (relaxed static stability). With this in mind, the constant aerodynamic changes distort linear airflow and increase aircraft noise.
About THE AUTHOR
After spending years watching every video I could find about flying, I finally scratched the itch and got my pilots license. Now I fly every chance I get, and share the information I learn, here.Read More About Joe Haygood