Question about travel on Lufthansa in-cabin

I'm moving to Europe and taking my cat. Lufthansa has been recommended to me as a good airline when traveling with pets, but I can't get a straight answer from them about whether I can use my Sherpa carrier for my cat. I know I can have him in cabin, know all about the vet certificate, microchip, vaccination records, etc. But after 4 phone calls, all I can get them to tell me about the rules for carriers is that it can't be bigger than 22"x16"x8". This is the same size rule for carry-on baggage. I've asked them: Is this only for hard-sided carriers, and soft-sided carriers just need to fit under the seat, right? Not one agent could tell me.

So, has anyone used soft-sided carriers for taking pets on board Lufthansa flights?
I brought my cat to the US in a hard-sided carrier, but he's so much less anxious since using his Sherpa that I'd really like to use it for this long trip. So if anyone has personal experience taking pets on board Lufthansa, I'd greatly appreciate hearing about it. Thanks so much.

I cannot speak for that airline, but the rules are the same for United, which is what I flew home Penny in. I used a Samsonite soft-sided carrier that is rated for air travel and had no problems.

If a cat is traveling in cabin, it MUST go under the seat, and hard-sided will not fit.

I had an almost flat hard-sided carrier to fit under the seat. Don't have it any more, cause I felt the cat was more of a sandwich - could not stand up in it - only good for kittens about 4-5 months old.

But if the soft-sided carrier fits the measurment requirements, then use it. I've always used the soft-sided one - fits nice under the seats and no problems/questions.

I have a friend who took her cat back to Germany, and they wouldn't allow her to use the hard carrier. I don't know which airline it was, but I'm pretty sure it wasn't Luftansa out of this airport. It turned out to be quite a scramble, because her husband had to rush down to Petsmart to get a soft carrier that was approved for travel.

(As a side note, thanks to that little rule, I now have a very good, sturdy hard carrier of a quality that I haven't been able to find anywhere else. )