Coffin corner in aviation is a dangerous aerodynamic phenomenon that occurs when an aircraft is flying at high altitude, close to its maximum altitude and speed limits, and in a region where the margin between stall speed and critical Mach number is very small. In this situation, any increase in speed or decrease in altitude can cause the aircraft to exceed its critical Mach number and enter an unrecoverable stall, resulting in a loss of control and potentially catastrophic consequences.
The term “coffin corner” refers to the small region on a flight envelope diagram where the altitude and airspeed limits intersect, creating a tight space that is difficult to navigate safely. Pilots must carefully manage the aircraft’s speed and altitude to avoid entering this region, and they must be trained to recognize and respond to the warning signs of an impending stall.
Why’s it risky?
Flying in the coffin corner is like balancing on a tightrope blindfolded. A slight change in speed or altitude can trigger a stall (loss of lift) or overspeed, both potentially catastrophic.
There have been several high-profile incidents and accidents involving coffin corner in aviation history, including the crash of a B-47 bomber in 1956 and the loss of an Air France Concorde in 2000. In both cases, the aircraft entered a stall at high altitude, resulting in a catastrophic loss of control.
To prevent these incidents, aircraft manufacturers have developed advanced aerodynamic technologies and flight control systems that help pilots to maintain safe flight conditions. Additionally, pilots receive extensive training in aerodynamics and flight physiology to help them manage the complex demands of high-altitude flight.
References: and Further Reading:
- Federal Aviation Administration (FAA). (2019). Risk Management Handbook. Retrieved from https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/risk_management_handbook/
- National Aeronautics and Space Administration (NASA). (2015). Aerodynamics: High-Speed Flight. Retrieved from https://www.grc.nasa.gov/www/k-12/airplane/highs.html
- Smith, C. (2017). Coffin Corner: What it is and How to Avoid It. Boldmethod. Retrieved from https://www.boldmethod.com/learn-to-fly/aerodynamics/coffin-corner-what-it-is-and-how-to-avoid-it/
Coffin corner image source: By https://de.wikipedia.org/wiki/User:RosarioVanTulpe – File:CoffinCorner.png, Public Domain, https://commons.wikimedia.org/w/index.php?curid=87376786