Yes, I have flown Rio in a sherpa as an adult. She is 16.5 inches at the withers. Adults need to be comfortable laying down in the sherpa because they won't have room to stand. I have only used it for short flights, Sacramento to Los Angeles and back. When I was researching how to fly with her in the cabin, I got great advice from another basenji breeder who has flown her adult basenjis to Eukanuba in sherpa bags.
I have not flow with a b, but I will say, if you're flying with your dog, do not get a window seat. The window seats have less under-the-seat room.
I try to get the middle seat. I don't like the aisle seat because of the amount traffic going by the seat and people not realizing there is a live animal in the bag.
How do you get through security? Does the dog get x-rayed? Do you take them out and just walk through with them, while the bag gets x-rayed?
You take them out of the bag and carry them through security. They can not wear their collar through the metal detector.
For those who have wondered about an adult basenji fitting into at sherpa, I have taken some pics of Rio and her sherpa.
Rio checking out the sherpa with her mom and sister
Rio looking for her "crate" treat
Rio getting in the sherpa
All in and zipped up
Don't wake me, I'm napping
Really, I think I'll just chill awhile in here
Thanks for posting those pics…I was curious about how she fit. 
Yes, I have flown Rio in a sherpa as an adult. She is 16.5 inches at the withers. Adults need to be comfortable laying down in the sherpa because they won't have room to stand. I have only used it for short flights, Sacramento to Los Angeles and back. When I was researching how to fly with her in the cabin, I got great advice from another basenji breeder who has flown her adult basenjis to Eukanuba in sherpa bags.
I want to point out that I tried to do this a few years ago with Bella. She was perfect in the Sherpa, but she was WAY over the twenty pound weight limit. And, yes, they had me put the bag on the scale (dog+bag 20# limit). They also pointed out that she couldn't stand up, and turn around, as is their requirement. So, it can be kind of hit and miss with an adult dog…always have a back up plan. She ended up riding under the plane in her crate that I was bringing along anyhow. But I was a nervous WRECK!! She was fine 
Things might be a little easier to deal with now that you can check in online...if the only place that anyone will check out the dog is security, they won't care how big your dog is (within reason!)...but the airline folks have to follow the rules if they see a violation.
This was on Northwest.
I want to point out that I tried to do this a few years ago with Bella. She was perfect in the Sherpa, but she was WAY over the twenty pound weight limit. And, yes, they had me put the bag on the scale (dog+bag 20# limit). They also pointed out that she couldn't stand up, and turn around, as is their requirement. So, it can be kind of hit and miss with an adult dog…always have a back up plan. She ended up riding under the plane in her crate that I was bringing along anyhow. But I was a nervous WRECK!! She was fine
Things might be a little easier to deal with now that you can check in online...if the only place that anyone will check out the dog is security, they won't care how big your dog is (within reason!)...but the airline folks have to follow the rules if they see a violation.
This was on Northwest.
Exactly Andrea.. this happened to a friend of mine that was flying to the PNW to get her bitch bred…. and while she was just fine in the bag... they would not let her on the plane cause she couldn't stand up... (like you would want them to?).... and she too had to fly in a crate, but they had to buy one... from the airline... and that was not cheap. So it can be hit or miss depending on the airline and who is at the ticket counter.
NOTE:... this was again for an adult, not a 10wk old puppy...
It definitely varies from airline to airline and even airport to airport. I have flown Rio on United. They did not require the bag be weighed and I never allow them to see Rio outside of her bag and they have never looked real close at her in the bag. Since she is calm in her bag, they haven't really made a big deal about it.
Also, I'm curious about when lvoss was flying. i think things have changed a bit. I don't think you can use the computer check in if you're flying with a dog. I took a papillon to my mom a few years ago and had to go up to the counter to check in. OTOH, they didn't even look at the dog/bag or weigh it. So yes, I agree that things are kind of hit and miss.
I flew last with Rio 3 years ago and my mom flew with Dean in a sherpa just this past February on United. You have to check in at the airport, you cannot check in online.
It has been quite a number of years, right before 9/11, since I flew with Arnie but I did train him to go in and out of the large Sherpa bag. I only flew Delta and he probably flew about 5 roundtrips, from Houston to OH/KY/IN. He flew up until he was almost 9 months old but he probably weighed over 20 lbs. Luckily I was a frequent flyer and the first time I flew with him I acted like I knew what I was doing and Delta never weighed him. His first flight was a noisy prop plane with 30 seats from Houston to Dallas and I was sure he was going to make noise but he was great even during the thunderstorm. The Dallas airport closed and cancelled all flights for hours and I knew he had to go to bathroom as he was only 4-5 months old and he went in the rain in the parking lot. After that he only flew first class as I was able to get upgrades. He brought me good luck with the upgrades. No one even knew I had a dog with me not even when they served food as he made no noise. You must tell the airline when you make your reservation that you will be flying with a dog onboard as they only allow a limited number, I believe three, but it depends on the size of the plane. I used to make my reservation online and then immediately call and let them know I would be traveling with a dog.
I have flown Continental with a puppy a couple of times… you can book carrying a dog right on line with your flight... and they are great.. at least the times I used them.
I just had to post this - I'm actually at Denver airport right now… just got off a Southwest Airlines flight. Two women came off the plane - each had a sherpa bag. They opened the bags and out jumped these two iggies! They are both about the size of Tayda! I asked them about flying w/ them and they said they just sit down without a problem. They can stand and turn, but the bag is soft sided and will stretch if they want to stretch. They also said they have flown with them on Southwest a lot and have never had a problem. Never been weighed or tested to see if they can stand and turn as the rule states. They said they each weigh about 16-17 lbs. Tayda weighs 17!
They are way bigger than I thought would fit in the bag and under the seat - I actually asked if i could take a pic of them! Makes me wonder if i could have brought Tayda with me.
Depends on the airline or sometimes even the attendants….. I know of one person with a Border Terrier that went from Washington to NY with her Border in a Sherpa.... same airline but on the way back, they refused to let her on....
They would have to be in the largest Sherpa Bag available. I was wondering if anyone has flown with a B on SW Airlines. I am considering flying to Houston and was thinking of taking my smallest B, a female who has Fanconi, and weighs about 16-18 lbs. She is not long legged.
I think the hardest part is going through security and taking the dog out of the bag, walking through the metal detector carrying the dog, and putting the dog back in the bag. This area is usually congested with a lot of people.
I would think a Border Terrier would have no problems fitting into and standing up in a large Sherpa bag.
Jennifer
I have read such horror stories about dogs who fly in the below cabin because they are too big to go under the seat - my smallest weighs 20.8 pounds, and would never settle for one of those Sherpa bags - they look very useful for smaller dogs though. If the time comes I have a long way to travel, we will drive it.
