We never expect airplanes to get so close to one another, but the only time they really get within inches is usually military planes or private planes doing formation flying. A spectacular things to witness and behold is the aerial refueling of an airplane. It takes immense skill and concentration to get metal tubes flying through the air at hundreds of miles an hour close enough together so that one can refuel the other.
This is common among military aircraft as it enables them to fly longer missions and be in the air for greater amounts of time which would be lost of they had to fly all the way back to a military base, refuel, and takeoff again to get back to where they need to go. The concept of aerial refueling planes is amazing and if you make one wrong move two planes might go down.
That’s almost what happened here with an aerial refueling plane and an E-3 AWACS that almost collided probably due to an inexperienced pilot. The basic rundown here is that the E-3 AWACS was coming in to be refueled but as it was setting up for refueling it violently pitched nose up almost hitting the rear stabilizer of the refueling plane then did a sharp nose down to abort from the other plane.
So what happened? A redditor has the perfect first-hand experience to tell us all about it:
This starts as a new refueling pilot error that is actually quite common. The initial problem is his closure rate on the tanker is too great, he makes contact with the tanker but had too much forward velocity which is why the boomer retracts the pod. The following events I’ve seen and actually done myself when learning, the closure is still happening so the “copilot” pushes over very slightly to create a small amount of separation. Unfortunately, this small separation often appears greater than it is to new refuelers because the angle they are looking at the tanker drastically changes. This results in the aggressive pitch up you see next by the AWACS. The instructor pilot in the AWACS was at fault here for not being ready for this common over-correction. However, while dangerous, this was corrected by the IP and proper break-away procedures were then executed by the AWACS.
Thanks to /u/mfrogue13 for the in depth explanation.