You should crashed down the airplane behind Lara, so that you can climb up and reach the treasure.
Burn this canvas and wooden beam, in order to…
…crash the right wing of the plane down.
Go to the tail end of the airplane and …
Shoot that lantern with your bow and start a fire.
Jump onto the crane holding back the burning debris.
This will in turn burn another support of the airplane.
Next, go onto the left engine of the plane and shoot another lantern.
Afterwards, jump down and climb onto the platform. You want to push that burning corpse onto the plane.
Once you push it it will move the plane even further.
Next, go all the way onto a platform behind the right wing of the airplane. There are burning lanterns there you can pick up
You can aim the lanterns and throw them at the last support beam.
Airplane will split in half and there is some burnable debris in on of the halves. Pick up another lantern and aim it at the debris.
This will clear the way to climb the airplane’s tail and reach the house/shrine on the top.