India’s aviation authority, the Directorate General of Civil Aviation (DGCA), has issued a significant advisory to airlines operating Boeing 737s aircraft in the country. This advisory addresses a potential flaw in the rudder system, which, under specific conditions, could jam, posing risks to aircraft safety. The issue was discovered following an incident involving a United Airlines Boeing 737, where a rudder pedal malfunctioned after landing at Newark Liberty International Airport.

Advisory for Indian Airlines

In response to a recent safety recommendation from the U.S. National Transportation Safety Board (NTSB), the DGCA has directed Indian airlines to take preventive actions concerning the rudder system of certain Boeing 737 models. The concern centers on Collins Aerospace’s SVO-730 Rudder Rollout Guidance Actuators, installed in some older Boeing 737 Next Generation (NG) and MAX variants.

The DGCA’s advisory affects three Indian airlines currently operating the Boeing 737: SpiceJet, Air India Express, and Akasa Air. Five aircraft from Air India Express have been directly impacted, and the airline has already initiated compliance measures in accordance with regulatory guidelines. In contrast, SpiceJet has confirmed that none of its aircraft are affected, while Akasa Air has yet to issue a statement.

The DGCA emphasizes that airlines must communicate this issue to their flight crews, providing clear guidance on how to recognize and address a rudder system malfunction. “Appropriate mitigations must be communicated to help crews identify and handle such a situation,” the advisory states.

What’s Behind the Issue?

The faulty rudder system came to light earlier this year when a United Airlines Boeing 737 MAX 8 experienced a stuck rudder pedal upon landing at Newark Airport. Following months of investigation, the NTSB determined that the malfunction was tied to the rudder actuator.

Collins Aerospace, the manufacturer of the actuator, discovered that moisture could accumulate inside the actuator housing and freeze at high altitudes, potentially jamming the rudder system. RTX, Collins Aerospace’s parent company, has since issued a statement confirming that it is collaborating closely with both the NTSB and Boeing to resolve the problem.

The root cause of the malfunction has been traced back to a bearing incorrectly assembled during the production process. This assembly defect allows moisture to infiltrate the component, which can then freeze during high-altitude, low-temperature flights. It is estimated that since February 2017, over 353 of these faulty actuators have been delivered to Boeing.

Global Impact of the Problem

While the DGCA’s advisory focuses on Indian carriers, this issue extends far beyond India’s borders. The NTSB has revealed that 16 U.S. carriers and more than 40 international airlines may have aircraft affected by the faulty rudder actuator.

United Airlines, which experienced the initial rudder issue, confirmed that nine of its Boeing 737 aircraft had the problematic actuators, and these have since been replaced. The issue predominantly affects aircraft equipped with an optional autoland system, meaning that the majority of Boeing 737s in operation today are unaffected.

Regulatory Response in India

In light of these concerns, the DGCA has imposed additional operational restrictions on Boeing 737 aircraft in India. The authority has temporarily prohibited Boeing 737s from conducting Category III B approaches, which are critical for landing in low visibility conditions. This ban will remain in place until further notice.

Additionally, the DGCA has mandated that discussions on potential rudder control system issues must be included in recurrent training programs and proficiency checks for flight crews. These discussions are to be held during pre-simulator briefings, ensuring that flight crews are fully aware of how to manage potential rudder malfunctions.

With Northern India’s fog season just around the corner, the DGCA is hoping that these measures will ensure continued safe operations until a permanent solution to the rudder actuator issue is implemented.