On first glance this seems to be a great case for a small sewing machine for air travel but I looked at customer reviews on LLBean to see what some of the reviews were. If you read the 1 and 2 star comments the biggest complaint was that it did not fit under the seat of the average 'economy' seat. Some comments said that the type of aircraft and also if the underseat space was an aisle/window vs center seat were all factors. The case seems to be too long to fit in the given underseat space and many travellers had to put their bag either in overhead storage or give it up to be put in cargo.
If I travel with my precious featherweight as a carry-on and the case does not fit then I have to consider whether I want to risk it being hefted up in overhead storage and perhaps falling out and hitting someone on the head or being damaged in cargo.
The type of case really should be researched and investigated completely. When you are quickly taking your seat on a plane, you want to be sure that your machine will be ok during your flight.