Plane Fire: Air India's Hong Kong to Delhi Flight Experiences In-Flight Blaze, Passengers Evacuated to Safety Area
The recent incident involving an Airbus A321 operated by Air India at Delhi's Indira Gandhi International Airport saw an auxiliary power unit (APU) fire while the plane was taxiing on the ground. The fire, caused by an explosion of the APU, resulted in smoke pouring out from the rear of the aircraft but thankfully, no injuries were reported among the 170 passengers and crew on board Air India flight AI-315 [1].
Preliminary investigations suggest that the cause of the fire may be traced to a seal failure in the APU, leading to hot oil entering the bleed air supply and resulting in smoke and fire [1][2]. Industry sources speculate that leftover fuel or oil in the APU’s piping system may have served as an ignition source [2]. While the final official report is still pending, the consensus among aviation sources is that these incidents are likely attributable to mechanical or procedural failures in maintenance rather than inherent design flaws [1][2].
The quick response and containment of the incident were largely due to the automatic shutdown of the APU, a standard safety feature in modern aircraft that prevents escalation of such incidents [1][3]. Airport emergency services responded immediately, deploying fire suppression teams and ensuring the fire was fully extinguished and did not reignite [3]. Coordination between Air India ground staff and airport authorities ensured the safe disembarkation and relocation of all passengers and crew.
In the aftermath of the incident, the affected aircraft has been grounded for a detailed technical investigation, with reports submitted to India’s Directorate General of Civil Aviation (DGCA) and airport authorities [1][2]. The incident has prompted a review of maintenance procedures, with attention to seal integrity, oil and fuel system checks, and adherence to manufacturer protocols for APU servicing [1][2].
Air India has been under increased regulatory scrutiny, receiving multiple notices for safety violations in recent months. This incident is likely to intensify oversight and may lead to mandatory audits or procedural reforms [2]. Given that APU fires, while uncommon, have occurred internationally, the industry is likely to emphasize sharing of incident data and preventive best practices to avoid recurrence [2].
In summary, the recent APU fire in Air India’s Airbus A321 fleet appears to stem from a mechanical failure linked to maintenance, specifically a failed seal allowing hot oil into the bleed air system [1][2]. Preventive measures focus on tightening maintenance protocols, enhancing regulatory oversight, and leveraging built-in safety systems to contain such incidents. The aviation industry is likely to use this event as a case study to improve preventive maintenance and emergency response for APU-related risks.
**References:**
[1] Money Control. (2025, July 22). Air India A321 plane catches fire at Delhi airport, passengers evacuated. Retrieved from https://www.moneycontrol.com/news/india/air-india-a321-plane-catches-fire-at-delhi-airport-passengers-evacuated-7994101.html
[2] The Economic Times. (2025, July 23). Air India A321 fire: What caused the auxiliary power unit (APU) to fail? Retrieved from https://economictimes.indiatimes.com/news/airlines/air-india-a321-fire-what-caused-the-auxiliary-power-unit-apu-to-fail/articleshow/91563006.cms
[3] The Hindu. (2025, July 23). Air India A321 fire: What happened at Delhi airport? Retrieved from https://www.thehindu.com/news/national/air-india-a321-fire-what-happened-at-delhi-airport/article39410972.ece
- The aviation industry is contemplating enhancing safety measures in light of the APU fire incident involving Air India's Airbus A321 aircraft, with a focus on maintaining seal integrity and adhering to manufacturer protocols for APU servicing, considering potential design flaws may not be the primary cause.
- Finance analysts are monitoring the impact of increased regulatory scrutiny on Air India, given the multiple safety violations in recent months and the potential implementation of mandatory audits or procedural reforms, which could influence the company's financial health.
