It was earlier this year on February 7th when an Icelandair Boeing 757-200 flying from Berlin Tegel (Germany) to Keflavik (Iceland) had its right main landing gear collapse upon arrival at Keflavik International Airport. Passengers reported that the aircraft bounced as it landed. The collapse is said to have occurred on the second touchdown. Authorities have completed their investigation and have made some interesting findings. Their report on the incident was released today.

Airplane TF-FIA resting on its Right Engine at the accident site. Photo: RNSA

Findings from the investigation

When searching the scene of the incident, investigators found that the swivel nut and an associated washer were missing from the immediate scene. These components were located near the aircraft’s touchdown point. A locking bolt for the nut was also found to have sheared off.

Side Strut Swivel – Missing the Nut and the splined Washer. Photo: RNSA

According to FlightGlobal, examination of the 757 revealed that the side strut of the landing gear had detached from the shock strut. The side strut is connected to the shock strut by a swivel.

The RNSA (Rannsóknarnefnd samgönguslysa), the Icelandic Transportation Safety Board, reports that threads in the swivel underwent "undersizing" twice during maintenance work in 2008 and 2019. Reducing the diameter of the swivel threads was allowed, on the condition that a special undersized nut be manufactured for a secure fit. However, RNSA investigators’ initial measurements, revealed that the nut from the landing-gear was “too large” for the undersized swivel threads.

As a result, Icelandic investigation authority RNSA has recommended specific safety checks on four aircraft that were serviced by Florida-based company Landing Gear Technologies. This is being ordered to ensure that other aircraft with parts that have also undergone this type of undersizing continue to function properly.

Right Main Landing Gear - Side Strut Swivel disconnected from the Shock Strut. Photo: RNSA

Investigating other aspects of the flight, the RNSA said that cockpit-voice recordings show the crew was “not aware of any problems” before the landing. Furthermore, flight-data recorder information revealed no abnormal loading during touchdown.

More about Landing Gear Technologies

As described on the 'About' section of their website,

"Landing Gear Technologies is proud to be an independently owned company specializing in the repair and overhaul of landing gear systems and a variety of other aircraft components."

The company goes on to say that its motto is “Fine workmanship and attention to detail” and that their work is backed by the "best warranty in the industry".

Looking at its listing on Indeed.com, the company has some mixed reviews from employees and/or former employees. While four out of eight reviews were glowing, five-star reviews, the rest were mixed. Three reviewers gave three stars and one cited "Lack of training [and] unsafe conditions to work" as negatives.

Icelandair will soon replace its aging Boeing 757s. Image: Wallpaper Flare

Conclusion

The investigation is ongoing as full analysis work on the swivel and nut has yet to take place. In fact, it has been delayed by US travel restrictions imposed as a result of the current travel situation.

However, RNSA has made interim safety recommendations to Icelandair and its associate operator Cabo Verde Airlines regarding landing-gear checks.

For those interested in reading the full RNSA report, it can be found on their website.

Simple Flying reached out to both Icelandair and Landing Gear Technologies to get a statement or comment on the report. However, no response was received at the time of publication.