IF IN DOUBT- REPORT

The Occurrence Reporting System is one of aviation’s strongest safety tools used by flight crews, maintenance teams, and air traffic controllers alike. Its purpose is not to assign blame, but to identify root causes and prevent recurrence. Every event that endangers or could endanger flight safety must be reported within 72 hours, even if it doesn’t fit standard categories. The Southwest Airlines incidents highlight why reporting matters failing to report delayed vital safety actions across multiple aircraft types. In aviation, the rule is simple: “If in doubt REPORT.” Reporting protects lives and drives continuous safety improvement.

T his article is written to emphasize the importance of Occurence Reporting. One of the most important mechanisms for enhancing safety in civil aviation is the Occurrence Reporting System.

Occurrence Reporting is not solely the responsibility of the flight crew. In addition to the flight crew, all units that may affect flight safety, such as Aircraft Maintenance and Air Traffic Control, are required to report significant events.

Subsequently, most incidents that led to changes in the Flight Operations Manual (FOM), Quick Reference Handbook (QRH), or the issuance of Airworthiness Directives were reported to the competent authorities using Occurence Reporting.

For the Occurence Reporting System to be used effectively and to ensure that reporting is carried out, the rationale behind the system must be explained to employees and adopted by them. The Occurence Reporting System requires that events that endanger or could endanger flight safety be reported to the competent authority within 72 hours at the latest when they are identified.

The purpose of reporting is not to punish the person who caused the significant event. The purpose is to find the root cause of the occurence and prevent its recurrence by implementing preventive measures.

To facilitate the review of Occurence Reports and enable classification for statistical purposes, the competent authorities provide examples of Significant Events in their manuals. If the occurence you wish to report falls under one of these headings, you should reference that heading when submitting your Occurence Report.

However, if the occurence you wish to report is not listed under any of the main headings, this does not mean you should not file an Occurrence Report. In this case, you should select the OTHER heading to file the Occurence Report.

In 2023, two similar incidents occurred on two different B737-8 MAX aircraft belonging to the US airline Southwest Airlines. In the first incident, the aircraft returned after taking off from Havana, the capital of Cuba, due to a sharp-smelling white smoke filling the cabin. Cuba launched an “Accident-Significant Event Investigation” in relation to this incident.



In the second incident, another B737-8 MAX aircraft took off from New Orleans, USA, and returned due to a sharp-smelling white smoke filling the cockpit, raising suspicion of an engine fire. The pilots followed the engine fire procedure by cutting the engine’s fuel supply, silencing the engine. Since the air intake from the engine into the cockpit was cut off, the white smoke also stopped. The aircraft landed on one engine. After landing, it was determined that there was no fire in the engine. A mechanical system called LRD (Low-Rise Damper) had engaged to separate the load after bird feathers entering the engine during takeoff caused damage.

During the separation process, oil inside the engine was exposed and turned into white vapor due to heat, and this white vapor entered the cockpit through the ventilation system.

outhwest Airlines did not report to the NTSB after the incident in which the aircraft was forced to land at the airport with only one engine.

Southwest Airlines’ failure to report indicated that the incident was not included in the Significant Event Report Headings.

Failing to report to the NTSB an incident involving dense smoke in the cockpit obscuring flight instruments, the need to shut down one engine in flight, and landing at the airport with only one engine indicates that the airline did not understand the logic of this system.



The incident was reported to the NTSB by some other source, and the NTSB determined that the load separator system, known as LRD, was also present in other LEAP engines manufactured by CFM.

Consequently, the NTSB issued warnings to the relevant civil aviation authorities not only for the Boeing B737-8 MAX but also for the Airbus A320 NEO family and the Chinese COMAC C919 aircraft.

Therefore, we say “IF IN DOUBT- REPORT,” meaning if you are unsure whether to report or not, REPORT.

Let the institution you report to evaluate your report.