Southwest Airlines 737 MAX Descends Below Minimum Safe Height on Approach to Tampa

Tampa, FL – On July 14th, 2024, a Southwest Airlines Boeing 737-8 MAX, registration N8841L, encountered a potentially serious situation while on final approach to Tampa International Airport. The aircraft, operating as flight WN-425 from Columbus, Ohio, descended below the minimum safe height during its approach to runway 10, prompting air traffic control to issue a low altitude alert and eventually instruct the crew to go around.

Incident Overview

The flight had been holding en route due to adverse weather conditions in the Tampa area before being cleared to continue its approach. As the aircraft neared the final stages of its approach, the Tampa Tower informed the crew that the ambient pressure was 30.14 in/Hg and advised them of a headwind gain of about 10 knots at lower altitudes, along with a “bumpy ride” to be expected.

Despite these warnings, the aircraft descended to approximately 370 feet above ground level (AGL), which was significantly below the minimum safe height for that segment of the approach, and still about 4.2 nautical miles from the runway threshold. Recognizing the danger, air traffic control issued a low altitude alert to the flight crew, who promptly leveled off. About 50 seconds later, the tower queried the crew about their intentions, to which the crew responded that they would go around. The tower then canceled the approach clearance and instructed the aircraft to initiate the go-around, which it did safely.

After climbing out of the low altitude, the crew diverted the aircraft to Fort Lauderdale, where it landed without incident approximately 40 minutes later. After spending about an hour on the ground, the aircraft continued its journey to Tampa, landing without further issues.

ADS-B and Weather Analysis

Data from ADS-B showed that the aircraft descended to around 370 feet AGL/MSL, with standard pressure measurements indicating it was about 150 feet higher than this due to the ambient pressure of 30.14 in/Hg. The descent occurred approximately 4.2 nautical miles from the runway, a significant distance from the threshold, underscoring the severity of the altitude deviation.

Weather conditions at the time included scattered thunderstorms in the vicinity, light rain, and broken clouds at various altitudes, contributing to challenging landing conditions. The turbulence and shifting winds reported by air traffic control further complicated the approach, likely playing a role in the aircraft’s unintended descent below the minimum safe height.

Safety and Operational Implications

This incident highlights the critical importance of adherence to minimum safe altitude protocols, particularly during final approach phases in adverse weather conditions. Descending below the minimum safe height can lead to controlled flight into terrain (CFIT), one of the most dangerous types of aviation accidents.

The prompt intervention by air traffic control, issuing a low altitude alert, and the crew’s subsequent decision to go around, were crucial in averting a potential disaster. The diversion to Fort Lauderdale was a prudent decision, allowing the crew to reassess the situation and approach Tampa under more controlled conditions.

This incident also serves as a reminder of the importance of maintaining situational awareness, particularly in challenging weather conditions where distractions and turbulence can lead to deviations from planned flight paths.

Conclusion

The Southwest Airlines flight WN-425 incident on July 14th, 2024, serves as a critical example of how quickly routine operations can escalate into potential emergencies, particularly when weather and other environmental factors come into play. The swift actions by both the air traffic controllers and the flight crew ensured a safe outcome, but the incident underscores the need for constant vigilance and adherence to safety protocols in aviation.

As with all such incidents, it is likely that both Southwest Airlines and aviation regulators will review the circumstances to identify any potential improvements in procedures or training that could prevent a recurrence of such an event.