A UPS Boeing 747-400F found itself in an awkward position at Seoul Incheon Airport on Wednesday. The aircraft suffered an issue with its main landing gear, causing the entire plane to tip backward and the nose to lift off the ground. Thankfully, no one was hurt in the incident, but the aircraft will require extensive repairs before flying again.

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Hit the ground

According to JACDEC, the incident occurred while the 747 was parked at Seoul Incheon Airport after its arrival from Dubai. There was no loading or unloading taking place at the time of the incident notably. However, due to unknown issues currently, the rear main landing gear suffered a failure and collapsed/retracted.

The collapse caused the aircraft to tip back and sent the nose of the aircraft in the air. It's not clear if the belly of the 747 comes into contact with the ground, but that could be another source of repairs for the jet. An image of the aircraft can be found below.

It's unknown what caused the main landing gear (MLG) to retract or collapse while the aircraft was parked. It is also rare to see a failure of the MLG, with the nose gear being more prone to facing issues. While there have been several recent cases of aircraft hitting the ground due to nose gear issues, there have been far fewer with the MLG.

The 747

The aircraft involved in this week's incident was a Boeing 747-400, registered N572UP. The plane was delivered new to UPS in November 2007 and has been in active use ever since, according to Planespotters.net. Packed with four GE CF6 engines, the 744F is one of the most reliable cargo jets in the world. However, it's not the only thing that the 747 has four of.

The Boeing 747 is also one of the only aircraft to feature four main landing gears. While most modern planes only have two or three sets of MLGs, engineers for the 747 were concerned that the aircraft's weight could pose issues while landing. To ensure a stable landing, they added four gears, each with four wheels and two axels.

Boeing 747-8 Landing Gear
The A380 also features four MLGs for similar reasons of weight distribution and stability. Photo: Olivier Cleynen via Wikimedia Commons

While the 747 could land on just two landing gears as well, this would put a heavy strain on the MLG and also prove risky over thousands of landings. Instead, all 747s now use this intricate landing gear. It's unclear which MLGs failed during Wednesday's incident, with an investigation likely to tell us more in the coming months.

Every freighter counts

Considering the global demand for cargo, UPS has been using its freighters on overtime. The absence of one of its 13 747-400s will mean rerouting operations and recruiting other stored planes to take over some flights. For now, UPS will be working hard to get N572UP back in the air and find out what caused it to go nose up in Seoul.

What do you think about UPS' 747 fleet? Let us know in the comments!