Introduction
On October 4, 2025, a dramatic event unfolded aboard Air India flight AI117, flying from Amritsar, India to Birmingham, UK: the Ram Air Turbine (RAT) unexpectedly deployed during final approach, raising alarm and speculation. As a backup emergency system, the RAT is intended to engage only under extreme conditions—such as complete engine failure or hydraulic/electrical system collapse. However, in this instance, Air India quickly issued a statement saying the deployment was “neither due to a system fault nor pilot action,” calling it an “uncommanded deployment.”
This incident has reignited concerns about the safety of Air India’s Boeing 787 Dreamliner fleet, especially following a tragic June 2025 crash of another Dreamliner (AI171) soon after takeoff from Ahmedabad. In this article, we examine the facts as presented, analyze the airline’s clarification, explore possible explanations, and consider reactions from regulators, pilots’ unions, and aviation observers.
Basic Information (Quick Reference)
| Item | Details |
|---|---|
| Flight / Incident | Air India AI117, Amritsar → Birmingham |
| Date | October 4, 2025 |
| Aircraft Type | Boeing 787-8 Dreamliner |
| Event | Unexpected Ram Air Turbine (RAT) deployment during final approach |
| Outcome | Safe landing in Birmingham; aircraft grounded for inspection |
| Air India’s Claim | Deployment was “uncommanded,” and not due to system fault or pilot error |
| Regulator Notified | Directorate General of Civil Aviation (DGCA) |
| Union / Pilots’ Reaction | Federation of Indian Pilots (FIP) demands inspection of 787 fleet |
| Related Incident | June 2025: AI171 crash in Ahmedabad after engine failure, RAT activation |
What Is a Ram Air Turbine (RAT)?
To understand the significance of this event, it’s helpful to understand what a RAT is and when it is supposed to deploy. A Ram Air Turbine is a small, fold-out propeller device designed to generate emergency hydraulic and electrical power using the airflow at high speeds. In normal operations, it remains stowed and is only deployed in dire emergencies—typically in response to a dual-engine failure, electrical system collapse, or severe hydraulic failure.
Once deployed, the RAT provides minimal—but crucial—power to essential flight control and instrumentation systems, enabling the aircraft to maintain control during a catastrophic loss of its primary systems. Its deployment is automatic or commanded by integrated system logic when sensors detect critical failure thresholds. Under ordinary circumstances, it is not supposed to deploy unless the main systems have failed.
Thus, having the RAT deploy during final approach—when the aircraft was apparently in stable descent and under control—raises obvious questions about how and why it happened in this case.
Air India’s Clarification
In response to widespread media coverage and public concern, Air India released a statement asserting the following:
- Preliminary investigations show that the RAT deployment was neither due to a system fault nor pilot action—in other words, there was no failure in electrical or hydraulic systems, and the pilots did not intentionally trigger it.
- All key system parameters—including electrical and hydraulic—were found to be within normal limits at all times.
- The deployment was described as “uncommanded,” meaning it happened without human input. Air India also noted that similar uncommanded RAT deployments have occurred in other airlines’ aircraft historically, though rarely.
- The aircraft was grounded immediately for inspection, and the airline has submitted its preliminary report to the DGCA as required under regulatory norms.
- Following checks, the aircraft was cleared to resume service and operated onward from Birmingham to Delhi on October 5.
In short, Air India’s position is that while the RAT deployment was anomalous, no explicit fault or pilot error could be established in the preliminary findings.
Possible Explanations & Expert Thoughts
Given Air India’s claim that systems were normal and no errors were made, what are the plausible explanations?
1. Software / Logic Glitch / False Sensor Trigger
One possibility is a false sensor reading or software logic malfunction causing the RAT to deploy when the system misinterprets certain parameters. Such “spurious activation” has been reported rarely in the aviation industry. If sensor thresholds are miscalibrated or circuitry malfunctions subtly, the system logic might mistakenly assess a critical failure when none exists.
2. Transient Electrical Anomaly
Even if systems were normal by the time engineers checked, there could have been a transient glitch—such as a brief undervoltage or a spike—that triggered the deployment. By the time maintenance teams measured system logs, the anomaly may have subsided, making detection harder.
3. Fault in Backup Control Logic / Interlock
The RAT system is controlled by redundant logic and interlocks. A failure in backup wiring, a short circuit, or unintended cross-signal might cause automatic deployment. Even without primary system failure, a fault in the RAT control system itself could misfire it.
4. Mechanical / Hydraulic Trigger Issue
Although unlikely given the airline’s statements, mechanical or hydraulic pressure fluctuations near threshold values could potentially cause RAT activation under certain edge conditions.
5. Rare Design / Manufacturing Anomaly
Given Boeing’s involvement in past RAT behavior studies, there may be undiscovered corner-case scenarios where 787 aircraft electronics or control buses behave unexpectedly under flight dynamics or environmental influences.
6. Concealed System Stress
Sometimes, stress in electrical buses, electromagnetic interference, or circuitry aging might create scenarios where the emergency logic “sees” a fault, even though instrumentation appears normal later.
Experts suggest a comprehensive flight data and maintenance log audit is needed—checking spools of sensor data, voltage/current waveforms, interlock system behavior—and a long, forensic examination of cockpit voice and flight data recorders.
Reactions: Pilots, Unions & Regulators
The incident drew immediate reaction from the Federation of Indian Pilots (FIP), which demanded a full inspection of all Boeing 787 Dreamliners in India. They called for:
- A grounding of Air India’s 787 fleet until safety is assured
- Thorough checks of electrical systems on all 787s
- A DGCA special audit of Air India’s maintenance practices, especially for Dreamliners
Some pilots and aviation analysts have expressed alarm, citing that RAT deployment without a fault is virtually unheard of. One pilot stated that he had “never heard of the RAT being deployed automatically without power, hydraulics, or electrical failure.”
The DGCA is expected to examine Air India’s submitted report and coordinate independent checks, possibly in collaboration with Boeing and international safety bodies.
Questions have also been raised in light of the June crash of AI171, where RAT deployment followed what is believed to have been engine fuel cutoff and total power loss. Some observers worry that repeated RAT anomalies may point to systemic issues in the Indian 787 fleet or aircraft operation, even though Air India has denied any design or fleet-wide fault so far.
The timing is sensitive: the public, media, and safety regulators are already on edge following the June disaster, and the new RAT deployment adds pressure. Boeing may come under scrutiny, particularly if internal design or control logic is implicated.
How This Compares to the June 2025 Ahmedabad Crash
The earlier AI171 crash is a tragic benchmark. That accident occurred shortly after liftoff from Ahmedabad, and investigators found that both engines lost thrust following a seemingly automatic switch from “RUN” to “CUTOFF” in the fuel control system—causing power loss and RAT deployment in emergency mode.
While that crash was catastrophic, this Amritsar–Birmingham incident appears to be a far gentler version: RAT deployment during landing, no casualties, and safe landing. However, the parallels raise concerns: both involve the 787, involve RAT activation, and now call into question the robustness of failure handling in that aircraft class.
Some analysts caution against conflating the two, since the crash appears to have involved actual engine failure, while this RAT deployment is claimed to be uncommanded and without fault. Still, public confidence and regulatory pressure are likely to treat them as part of a pattern needing urgent review.
What Comes Next / What to Watch
- DGCA’s Independent Review
The Directorate General of Civil Aviation will likely order an independent check of the investigator’s findings, possibly bringing external audits or involving international safety bodies. - Boeing’s Response & Investigation
Boeing may be asked to provide internal data, software logs, design documents, and historical instances of RAT deployments. If anomalies in 787 logic are found, this could lead to software updates or design changes. - Fleet Inspections / Grounding Requests
The FIP has already demanded grounding of all 787s. While full grounding is unlikely immediately, focused inspections—especially of electrical and control systems—are expected. - Expanded Data Forensics
Comprehensive review of flight data recorder (FDR) / cockpit voice recorder (CVR) logs, power bus waveforms, interlock behavior, sensor anomalies, and maintenance logs will be critical. - Public & Media Scrutiny
Media attention is intense. The public will demand transparency, especially given the June crash. Air India and regulators will need clear communication to maintain trust. - Policy & Regulatory Outcome
Depending on findings, mandates may be updated for more rigorous safety checks, regulatory oversight of emergency backup systems, or even manufacturer accountability.
Conclusion
The RAT deployment on the Amritsar–Birmingham flight struck fear among aviation observers—but Air India’s emphatic claim that it was not caused by system fault or pilot error shifts the narrative from mechanical blame to technical mystery. The “uncommanded” activation challenges the assumed logic of aircraft safety systems and demands close scrutiny.
Given the historical backdrop of the June Dreamliner crash, this occurrence is more than just an isolated anomaly. It raises systemic questions about how backup systems like the RAT are controlled and protected, how sensor thresholds and logic safeguards are validated, and how maintenance and design protocols evolve under stress.
As investigations unfold and regulators demand accountability, stakeholders from Boeing to pilot unions to airline management will be on high alert. Until final findings emerge, the incident will remain a cautionary reminder: even cutting-edge aviation systems can surprise us—and when they do, safety protocols, transparency, and rigorous analysis are the only way forward.
