Boeing 737 Rudder System Under Scrutiny: Safety Concerns and Investigations

Boeing 737 Rudder System Under Scrutiny: Safety Concerns and Investigations

Sub: Sci

Sec: Msc

Why in News

Certain variants of Boeing 737 aircraft, fitted with a rollout guidance actuator, have come under scrutiny due to concerns about a potentially defective rudder control system. This issue surfaced following an incident involving a United Airlines Boeing 737-8 MAX flight on February 6, 2024, and has prompted safety alerts by the United States National Transportation Safety Board (NTSB). In response, India’s Directorate General of Civil Aviation (DGCA) has issued directives to Indian operators of Boeing 737 aircraft.

Boeing 737 aircraft:

The Boeing 737 is a popular narrow-body aircraft, widely used by airlines for short- to medium-haul flights. It has undergone several updates since its introduction in the 1960s, with models ranging from the 737 Classic to the more advanced 737 MAX. The aircraft is known for its efficiency, reliability, and versatility

About Rollout Guidance Actuator:

The rollout guidance actuator is a specialized component found in some variants of the Boeing 737, particularly those equipped for advanced landing procedures. It plays a crucial role in controlling the aircraft’s rudder during specific types of landings known as Category III Instrument Landing System (ILS) approaches, more specifically in CAT IIIB Autoland operations.

About Category (CAT) in Aviation:

CAT, or Category, in aviation refers to specific Instrument Landing System (ILS) approach categories defined by the level of precision and the visibility conditions under which an aircraft can land.

These categories range from CAT I to CAT III, with CAT III having subcategories (A, B, and C) that allow for landing in progressively lower visibility conditions. These systems guide aircraft to land safely using a combination of radio signals and, at times, ground-based lighting systems, especially when pilots have limited or no visibility.

CAT III is the most advanced ILS category, used in very poor visibility conditions such as dense fog or heavy rain. The autoland system and rollout guidance actuators are critical in these operations, as they allow aircraft to land and maintain directional control on the runway, even when pilots have little to no visual cues.