During the display at the Zeltweg airshow in Austria, the Belgian Air Force F-16 suffered a compressor stall that caused a loud bang and an impressive backfire.
On Sept. 3, during its display at the AIRPOWER 2016 airshow in Zeltweg, the “Viper” of the Belgian Air Force F-16 Solo Display Team suffered an apparent compressor stall that forced the pilot to perform a precautionary landing.
Take a look at the footage below. If you jump to 03:20 you will see the aircraft’s engine emanating flames (generating a loud bang you can’t hear) in what seems to be the typical behaviour of a compressor stall.
Compressor stalls (sometimes referred to as afterburner stalls in aircraft with reheat) are not too rare among military aircraft. They can be caused by several factors, including birdstrikes, FOD (Foreign Object Damage), ingestion of turbulent or hot airflow into the air intake etc.
A compressor stall is a local disruption of the airflow in the compressor whose severity may vary from a momentary power drop to a complete loss of compression.
A particular kind of compressor stall is the compression surge that occurs when the hot vapour generated by the aircraft carrier’s catapult is ingested by the aircraft air intake thus creating a breakdown in compression resulting in a the compressor’s inability to absorb the momentary disturbance and to continue pushing the air against the already-compressed air behind it. As a consequence, there’s a momentary reversal of air flow and a violent expulsion of previously compressed air out through the engine intake producing some loud bangs from the engine and “back fires”.
You can find several images of aircraft suffering compressor surges while taking off from airbases or being launched from the flight deck of an aircraft carrier.
As already explained on The Aviationist in the past, in most of the cases even after suffering a “surge” the compressor will usually recover to normal flow once the engine pressure ratio reduces to a level at which the compressor is capable of sustaining stable airflow.
Some engines have automatic recover functions even if pilots experiencing the surge can be compelled to act on the throttle or, in some cases, relight the engine.
Image Credit: Flight Video & Photo. H/T our friends at From The Skies for sending this over to us.
