At full thrust a jet engine 30 m away can exceed 150 dB, louder than a 30-06 rifle beside the shooter and well beyond the 130 dB threshold of pain. At the same distance military jets taking off from a carrier with afterburners reach 130 dB, while a turbofan aircraft only 200 ft overhead records 118 dB. From farther away these levels scale down: 100 m from a runway a turbojet delivers 110-140 dB, and at one nautical mile a Boeing 707 on approach registers 106 dB, comparable to a riveting machine. Smaller airliners are only slightly quieter - a Boeing 737 approaching from the same distance produces 97 dB, roughly the 88 dB of a propeller plane flying overhead at 1000 ft but amplified by size and power. Routine jet traffic at 1000 ft registers 103 dB.
How many decibels does a plane engine produce?
The decibels produced by a plane engine vary with type. A turbo-fan aircraft at takeoff power at 200 ft (60.96 m) is 118 dB, while at one nautical mile (1.852 km) before landing the Boeing 707 or DC-8 aircraft is 106 dB and the Boeing 737 or DC-9 aircraft is 97 dB. A propeller plane flyover at 1000 ft (304.8 m) produces 88 dB, and AOPA notes that a typical piston-powered single-engine airplane in flight generates around 65 dB. Commercial aircraft average 79-84 dB, and cabin noise inside an Airbus A321 during taxi is 65 dB(A). At cruising altitude the noise level is typically 80-85 dB, and SEL value for aircraft flyovers is typically about 10 dBA higher than the maximum noise level.
How many decibels is a jet engine?
A jet engine can generate noise levels of around 140 dB at a distance of 100 feet (30.48 m). At 30 m (98.4 ft), jet engine noise approaches 150 dB. During takeoff, a jet engine at 100 meters (328.084 feet) hovers around 130 dB. Fighter jets at takeoff can reach 140+ dB. Military jet aircraft take-off from an aircraft carrier with afterburner at 50 ft (15.24 m) is 130 dB. Afterburner increases the jet noise levels by 5 to 10 dB above military power. Eliminating the afterburner during takeoff will provide a noise reduction benefit.
How does the motor of a single engine airplane sound?
A single engine airplane motor has a grinding or growling sound. Propeller noise levels are high and occur in the frequency range 500 Hz to 4000 Hz, a range to which the ear is sensitive. Primary noise from a propeller originates from aerodynamic lift forces on the blades, which generate a more impulsive sound, and from blade thickness, which produces a whistling sound. The grinding sound is distinctly very loud on the ground, yet engines do not sound very loud inside the cabin because fuselage walls limit transmission of engine noise.
Expert behind this article
Jim Goodrich
Jim Goodrich is a pilot, aviation expert and founder of Tsunami Air.
