Regarding a camera malfunction ? I very much doubt it. You have a Nikon D3100 which must be pretty well new as I see that your previous pictures were taken with an older Panasonic. There is unlikely to be any issues with a new camera.
The picture was shot at 220mm so I assume you have a lens something like a 70 - 300 zoom ? The aperture was f8 and shutter speed 1/320 which means you have exceeded the rule of thumb of having the shutter speed at least eaqual the focal length so I can only think that your problem lies with your panning. I would however suggest that you increase the aperture to f9 - f10 to ensure that you get the depth of field needed at longer ranges. I would also suggest that you change the metering mode to centre weighted from the current spot mode but that is not involved in this blurry issue.
When panning, Make sure you are set to continuous focus. Take a breath fully in and then slowly let half of that breath out and hold it. Pick up the aircraft in the viewfinder early before you intend to take the picture and focus with the half pressure on the shutter button. Lock your arms to your body if you can and pan from the hips (this is why you hold your breath, if you breathe now the camera will move up/down). Centre the viewfinder on the middle of the aircraft and aim to keep it there throughout the pan. Start to shoot as the aircraft comes into the area that you want shooting to commence. Fire off 5 or 6 shots as the aircraft passes, stop shooting BUT KEEP THE PANNING FOLLOWED THROUGH. Get into this habit and you won't fall foul of the common error of pausing your movement during shooting.
By the way.....you can breathe again now !!
There is an easy way to practice this at home. Find a main road with moderately fast traffic and step back 100 yards. Two reasons for this. 1. You'll be simulating the kind of movements you use at the airport and 2. You'll be too far back for any drivers to get annoyed at you photographing them !!
Heavy goods vehicles are a good choice of subject as their length simulates that of an aircraft. The sketch below illustrates what I am trying to say...