This Knee Defender Diverts UA Flight 1462

Flying in economy is no longer fun due to the tight seat pitch and my constant awareness to defend my knees from being hurt because of an inconsiderate passenger in the seat in front reclining without warning or getting caught by a metal galley trolley when in an isle seat. But, thanks to a fascinating story I have read today of United Airlines flight UA1462 from New York (Newark) to Denver being diverted to Chicago O'Hare Airport  I have been introduced to the knee defender!

According to United Airlines, it seems two passengers in Premium Plus (with an extra 4 inch seat pitch) more than regular economy got into a ding-dong of an argument over this neat little gadget. 

The guy in his seat wanted to use a laptop so moved to put in place the knee defender gadgets on the seat in front occupied by a female customer. Cabin staff told the guy the device was not permitted by the airline. He ignored the flight attendant. The two passengers argued over use of the gadget. The woman threw a cup of water over the man. Both ignored the cabin crew's calls for restraint and were considered unruly. The captain was informed and the flight diverted to Chicago.

Ironically, under US Transport Safety regulations no crime was committed by the two passengers. To me the key point of this story is that this was a B737 aircraft where space is already tight enough.

The question now is, do I run the gauntlet of a crew when I next take a 3hr+ flight and go on board armed with a knee defender?  I will wish to use the computer or read without my space being restricted. Hopefully as with many charter/scheduled flights to and from Crete the seats are in a fixed position and won't need the gadget. But just in case, I need to be prepared. The smaller the aircraft, the more I am aware of not hurting my knees.