This Boeing 747 has just made a water dropping procedure at very high altitude. This can be considered as a first procedure of the emergency landing, because with the water inside, the plane would be just heavy for normal landing, and it would cause the plane to take a hard hit on the landing.
This way, when the water is dropped, the Boeing 747, will be much lighter and it will make a much smoother landing, more comfortable for the people that are traveling with it. This procedure cannot be seen in more situations, and how the video was taken we don’t know, but we are sure that there was one more plane to assist the landing, and the video was taken from the plane that was flying close to the Boeing 747.
Not many people get the chance to see how it looks when water is dropped at such high altitude, this is a one-time experience all we are all thankful that this video was shared, so that we can see how it looks like, when a Boeing 747 will drop the water, to make itself more lighter, for much better landing.
This is a special jumbo made for firefighting, the Evergreen 747 Supertanker. That is just normal water and no other plane will ever carry this amount of water, nor will drop waste water. The waste water ist carried in tanks and is dumped on ground into trucks that will dispose it correctly. However in serious emergencies planes are able to dump fuel, if they have to land immediately because of imminent danger, but that is very rare.
Thanks a lot for the wide explanation Daniel. Amazing machines.