Thank you saving the fox! It was a thoughtful thing to do.
Don't know if this comes under your requirement for lightweight (30"L x 14.5"W x 14"D | Capacity: 98L | Weight: 8.3 lbs) but I have the 22" version of this bag and really like it. Eddie Bauer Expedition Duffel. It is semi rigid with the part near the handle being rigid and the top being fabric. It is very sturdy and I haven't had any problems with the durability. I've had it for about a year and taken several trips with no problems. Haven't had it on a small plane yet but planning on taking it to Alaska this year.
https://www.eddiebauer.com/p/82300255/expedition-30-duffel-2.0?sp=1&color=True%20Blue&size=ONE%20SIZE&sizeType=Let us know what you decide.
Suzanne
Really beautiful - who knew?
Beautifully done - as always!