What Happens If Heat Exceeds An Aircraft’s Certification?
The certification (or recertification) of an aircraft is a complex process, in which many aspects are regulated to…
The certification (or recertification) of an aircraft is a complex process, in which many aspects are regulated to ensure that the plane in question can operate safely. Heat is one area in which careful attention is paid, as overheating can prove catastrophic under particular circumstances. But what happens if a plane does overheat? Let’s take a look.
Aircraft certifications are designed to minimize the risk of overheating as much as possible. For example, EASA regulations deem that, as part of an aircraft being certified, “overheat or failures leading to damage to Engine Control System components, must not result in a Hazardous Engine Effect due to Engine Control System Failures or malfunctions.”
As part of the testing process, the EASA (European Union Aviation Safety Agency) requires aircraft to be pushed to extreme parameters that cause overheating. This verifies to regulators that “the electrical/electronic portions of the Engine Control System, when subjected to an overheat condition leading to Failure, will not cause a hazardous Engine effect.”
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Despite the aforementioned regulatory framework, overheating can happen. As such, it is important that aircraft have preventative mechanisms in place to minimize risk to them and their occupants. So what exactly happens in the event of overheating?
Modern aircraft are equipped with sensors to monitor temperatures in crucial areas. According to Skybrary, for example, “overheat detectors are installed in the vicinity of bleed air ducts, and the bleed system is designed so it can be partially or totally isolated if required.” Skybrary also adds that this will generate a warning for the pilots in the cockpit.
Professional Pilot Magazine adds that “Saab’s Overheat Detection System consists of a fiber optic sensing line placed near the engines and bleed air ducts, and includes optical integrators and processing hardware and software for collecting data and control.”
As such, we can see that, in a sense, aircraft take care of themselves when overheating thanks to these systems. Aircraft Systems Tech explains further that the detectors function as part of a circuit. This means that, if an area overheats, the sensor will detect this and cause the circuit to be broken, allowing the component(s) in question to be safely isolated.
How did Concorde prevent overheating?
Aérospatiale and BAC’s legendary Concorde airliner made the dream of supersonic a reality for the select few who could afford it. The world is yet to see another airliner quite like it (although Boom Supersonic hopes to change this by the end of the decade).
With it being an airliner like no other, its overheating prevention was also different. Flying at supersonic speeds up to twice as fast as the speed of sound generated significant heat. As such, it was painted with a special brand of highly reflective white paint.
This reduced its temperature by 6 to 11 °C (11 to 20 °F), and allowed it to sustain supersonic flight without compromising its safety. This was also the reason why Air France’s blue Pepsi-liveried Concorde was not able to cruise at such speeds. Indeed, the lack of protection provided by this paint scheme limited Mach 2 flight to periods of 20 minutes.
Did you know about the various mechanisms that are in place to protect aircraft in the event of overheating? Let us know your thoughts in the comments.