Root Cause Analysis of Air France Flight 4590

On the morning of July 25, 2000, Air France Flight 4590 was meant to be the beginning of the end for Concordes. Just after liftoff, the supersonic jet crashed into a hotel in Gonesse, France, killing all 109 people aboard and an additional four people on the ground (Bureau d’Enquêtes et d’Analyses pour la Sécurité de l’Aviation Civile, 2002).

Five minutes before Flight 4590 took to the runway, a Continental flight headed to Newark, using the same runway, lost a titanium alloy strip. Normal protocol for a Concorde flight includes a full runway inspection before takeoff; on this July afternoon, the planned inspection was canceled due to a routine fire drill (Forsgren, 2019).

During Flight 4590’s takeoff, a piece of this debris from the Continental flight, cut and ruptured one of the Concorde’s left tires. As the aircraft accelerated down runway 26R, this tire disintegrated, and a piece of it struck the underside of the wing, where fuel tank five was located. A pressure wave inside the tank caused it to rupture forward of the tire strike. (Bureau d’Enquêtes et d’Analyses pour la Sécurité de l’Aviation Civile, 2002).

Root Cause Analysis – Intro

According to PMI (2017), there are seven basic quality tools used to solve quality-related problems. One of the most common tools is the cause-and-effect diagram, which is also known as the fishbone or Ishikawa diagram. The causes are found by looking at the problem statement and asking “why” until the actionable root cause has been identified or until the reasonable possibilities on each fishbone have been exhausted.

Root Cause Analysis – 5-Whys for the Concorde Accident

To get a better idea of what caused the crash of the AF4590’s Concorde, we built our very own Ishikawa diagram. For the sake of brevity, in the current article, and as presented by Wilson (2020), only five levels of “why” will be discussed.

Fishbone Diagram for AF4590, Karachalios (2020)

By using this technique in the root cause analysis, and based on BEA’s (2002) final accident report, it is found that:

Why #1. The aircraft was unable to climb and finally crashed because of the loss of the two engines on the left side of the aircraft.

Why #2. Engines were lost because of fire caused by fuel that was leaking out of one of the fuel cells.

Why #3. The fuel cell ruptured from a piece of tire that hit the underside of the aircraft.

Why #4. A piece of debris on the runway caused one of the left side tires to disintegrate and explode.

Why #5. A loose titanium engine strip had fallen off a DC-10, which took off 5 minutes earlier from the Concorde.

Conclusion

The 5-why technique is a baseline, to assist someone in reaching the root cause. However, for the AF 4590, one might need even more Whys to reach to the latent failures that lead to this horrific accident. Even though both British Airways and Air France improved several safety aspects to ensure the quality of fuel tanks and tires, the “9/11 effect” was the tombstone for the Concorde’s (Forsgren, 2019).

Let’s hope that the supersonic commercial flights will resume soon again…

References

Bureau d’Enquêtes et d’Analyses pour la Sécurité de l’Aviation Civile. (2002, January 16). Accident on July 25 2000 at La Patte d’Oie in Gonesse (95) to the Concorde registered F-BTSC operated by Air France (REPORT translation f-sc000725a). Retrieved from BEA.

Forsgren, R. (2019, February). APPEL NASA: The Concorde Accident: A Case Study. Retrieved from APPEL NASA.

Project Management Institution. (2017). A guide to Project Management Body Of Knowledge (PMBOK) (5th ed.). Pennsylvania.

Wilson, N. (2020, June 16). AVIT 590 – Week 5 – Quality and User Acceptance_V2. Introductory lecture on Quality Management, Quality Escapes, Root Cause Analysis and impact to End-Customer. Grand Forks, North Dakota, North Dakota: University of North Dakota.