Garuda Indonesia is set to become the first airline to officially cancel an order for the Boeing 737 Max 8 after two crashes involving the plane.

The flag-carrier has 49 of the aircraft on order from the American manufacturer, in a deal worth around US$5 billion.

However, following the crashes of 737 Max 8 planes operated by both Ethiopian Airlines and Lion Air, questions have been raised over the safety of the plane.

Blaming passengers’ loss of trust in the aircraft, Garuda Indonesia spokesman, Ikhsan Rosan, said: “We have sent a letter to Boeing requesting that the order be cancelled.”

Around 400 of the planes have been delivered to airlines around the world – but the fleet is currently grounded while investigators examine the two crashes.

With nearly 5,000 more 737 Max planes on order, Boeing has promised a software update to alleviate concerns by the end of the month.

Rosan added: “The reason is that Garuda passengers in Indonesia have lost trust and no longer have the confidence in the plane.”

The airline is currently awaiting a response from Boeing, he said.

Garuda has already received one of the 737 MAX 8 planes, part of a 50-plane order worth $4.9 billion at list prices when it was announced in 2014.