Boeing 787 jets keep deploying their emergency turbines mid-air, inquiry finds pattern across 31 aircraft

DGCA launches detailed probe after Air India’s emergency turbine deployed mid-landing in Birmingham; 31 similar cases reported worldwide

India’s aviation regulator has launched a detailed investigation into an unusual in-flight event involving an Air India Boeing 787-8 aircraft, after its emergency power system deployed unexpectedly while landing in Birmingham on October 4. The Directorate General of Civil Aviation (DGCA) has also requested a comprehensive report from Boeing on preventive measures, as similar incidents have been reported worldwide, according to Hindustan Times.

The Birmingham incident: turbine deploys mid-landing

The Air India Dreamliner, operating as Flight AI-117 from Amritsar to Birmingham, was on its final descent when its emergency power turbine, known as the Ram Air Turbine (RAT), unexpectedly extended from its fuselage at around 1,600 feet.

The RAT is a small, fold-out turbine designed to generate backup power if both engines or main electrical systems fail. Air India confirmed to the DGCA that none of the conditions that normally trigger the RAT were present, and the aircraft landed safely. After ground checks, it returned to Delhi the next day.

Boeing admits 31 similar cases globally

People aware of the matter told Hindustan Times that Boeing informed Indian regulators about 31 similar incidents worldwide involving its 787 fleet. Most of these cases, 29 to be exact, occurred on aircraft that had not been fitted with a modified component designed to prevent such malfunctions.

Moneycontrol could not independently verify the news.

Boeing’s internal assessment traced the cause to a faulty locking mechanism. When technicians stow the RAT while hydraulic pressure is still high, the toggle assembly may fail to lock properly. Vibrations during landing or gear operation can then dislodge it, causing the turbine to deploy unexpectedly.

Design flaw, not pilot error

According to Boeing’s briefing, the problem often surfaces within six months of RAT maintenance, when the turbine is manually stowed. Air India’s affected aircraft, registered as VT-ANO, had undergone such maintenance in July.

Boeing introduced an improved shuttle valve in 2014 to regulate hydraulic pressure and ensure proper locking—but neither Boeing nor parts supplier Collins Aerospace has made the upgrade mandatory through a service bulletin.

That means airlines are not required to retrofit their fleets. Out of India’s 32 Boeing 787s, 19 still lack the improved component.

DGCA orders inspections, seeks Boeing report

Following the Birmingham event, Air India rechecked 16 aircraft that had undergone RAT maintenance in the past six months. The airline re-stowed the turbines on 14 planes and scheduled the remaining two for routine inspection.

The DGCA has since directed Air India to reinspect all aircraft that recently replaced their Power Conditioning Module (PCM)—a key electrical system that distributes power across onboard equipment.

“Air India has been advised to reinspect the RAT for stowage on all the aircraft whose PCM module was replaced recently,” a senior DGCA official told Hindustan Times. Boeing has been asked to provide detailed data on similar uncommanded RAT deployments worldwide, as well as any service difficulty reports filed after PCM module changes.

A second 787 incident and calls for grounding

The probe comes amid two back-to-back technical events involving Air India’s Dreamliners. On October 9, another Boeing 787 operating AI-154 from Vienna to Delhi had to divert to Dubai after a failure of its autopilot system triggered multiple technical malfunctions.

The Federation of Indian Pilots (FIP) has written to the Civil Aviation Minister urging the government to ground the entire B787 fleet and conduct a special audit of Air India. In its letter, the group said the pilots faced failures across critical systems, including flight directors, instrument landing systems, and degraded flight controls that forced them to fly manually at night.

Air India, however, denied any electrical failure, describing it instead as a 'technical issue.'