A scary incident occurred on July 6, 2023, when an Air Algerie Airbus A330-200 had several of its tires burst during a series of runway tests at Algiers Houari Boumediene Airport in Algeria. The aircraft was performing touch-and-go and aborted takeoff maneuvers on the newly renovated runway 09/27 when sparks and flames were seen coming from the right main landing gear. The pilots managed to stop the aircraft safely and return to the apron without any injuries. Here's what happened and why.
What are runway tests?
Runway tests are a common practice in aviation, especially when a new or renovated runway is opened for operation. They are designed to check the performance and safety of the runway, as well as the compatibility and suitability of different types of aircraft. Runway tests usually involve a series of maneuvers, such as:
- Touch-and-go: The aircraft lands on the runway and immediately takes off again without stopping.
- Aborted takeoff: The aircraft accelerates to a high speed on the runway and then aborts the takeoff by applying maximum braking and reverse thrust.
- Rejected landing: The aircraft approaches the runway as if to land, but then aborts the landing by applying full power and climbing away.
These maneuvers are intended to simulate various scenarios that could occur during normal operations, such as emergency situations, bad weather conditions, or technical issues. They also help to evaluate the runway's surface, markings, lighting, drainage, friction, and slope. Runway tests are usually conducted by specially trained pilots and engineers, who monitor and record various parameters, such as speed, altitude, distance, temperature, pressure, and vibration. The data collected during the tests are then analyzed and used to validate or improve the runway's design and construction.
What caused the tire bursts?
According to preliminary reports ¹, the Air Algerie Airbus A330-200 with registration 7T-VJY was carrying out a series of runway tests on the newly renovated Algier’s runway on 09/27. During one of the tests, the aircraft’s main landing gear began to overheat. The air traffic control reported to the cockpit that they could see visible sparks and flames from the right main landing gear. The pilots aborted the takeoff at high speed and the aircraft returned to the apron on its own.
The cause of the sparks and flames is still under investigation, but it is likely that they were caused by excessive friction between the tires and the runway surface. This friction could have been due to several factors, such as:
- High speed: The aircraft was accelerating to speeds of over 300 km/h during the tests, which generates a lot of heat in the tires.
- High pressure: The aircraft's tires were inflated to about 13 bar (190 psi), which is much higher than car tires (about 2 bar or 30 psi). This increases the stress and strain on the tires.
- High temperature: The ambient temperature at Algiers was about 30°C (86°F) on that day, which adds to the heat generated by friction.
- Low profile: The aircraft's tires have a low profile (the ratio of height to width), which means they have less cushioning and more contact area with the runway surface.
- Repeated maneuvers: The aircraft was performing multiple touch-and-go and aborted takeoff maneuvers, which means it was repeatedly applying high forces on the tires without giving them enough time to cool down.
All these factors could have contributed to weakening or damaging the tires' structure or integrity, leading to their failure or rupture. When a tire bursts, it releases a lot of air pressure and energy, which can cause sparks and flames. It can also damage other parts of the landing gear or wing.
How did the pilots handle the situation?
The pilots of the Air Algerie Airbus A330-200 reacted quickly and professionally to the situation. They followed their standard operating procedures and aborted the takeoff as soon as they were alerted by the air traffic control. They also used their brakes and reverse thrust to slow down and stop the aircraft safely on the runway. They then taxied back to the apron without any assistance from emergency services. The pilots also communicated clearly and calmly with the air traffic control and their maintenance crew throughout the incident. They reported their status and intentions, requested information and instructions, and confirmed their actions. They also checked their instruments and systems for any anomalies or warnings. The pilots managed to avoid any injuries or further damage to themselves, their aircraft, or other people or property.