I mean a guitar or small keyboard similar size in soft bag,
Is it a big risk to try to take without asking and see how it goes?
What is the worse case scenario?  

I've never carried on an instrument.
I checked my Alembic in the 80's once. Fear and dread come to mind when I actually say the handler pitch it into the cargo hold. I had loosened the strings before I checked it. Suffice it to say, after that, nothing was wrong with the bass (the player, yes, but not the bass).

One of my friend tours quite a bit in Canada and frequently takes one of his guitars as his hand luggage (soft case) and assured me he never had any issues bringing it onboard w/ him.

I don't know how things are in the US and it depends on the company I guess. 

As I mentioned in that other thread, on our flight from NY to Vegas, Virgin actually offered me to check in my 2 guitars (hard cases) so that they wouldn't end up in the cargo. They said that it's what they usually do for musical instruments.  The good thing is that they also bring them back to you right after you land, instead of just sending them on the rails at baggage claim w/ the rest of the stuff that's in the cargo.

They even offered to re-imburse us because we had paid for them as regular luggages.

Make sure you loosen the strings. Hope for the best - because pressure isn't a good thing for yor instrument. That one friend I mentioned above had the great displeasure to find the neck of his precious Godin had not stood the pressure on a trip to the UK recently. But that's the only such negative experience he's had.

It's SOP that all accordians and bagpipes get thrown out the back once the plane is above 30,000 feet.

Actually, back on topic, the best place for your guitar is in the storage near first class.  I've never heard of anyone having a issue with this.  You don't want it in the general storage area if possible.

I take my Johnson travel guitar as carry-on each time i go long haul to China, and also on local flights there.

It has a stndard neck but small body and has a soft bag. No problems. I always release the string tension.

Also have taken my fender as cabin baggage with Air France. And checked it in as fragile hold baggage. They looked after it perfectly.

Cheers,
Jerry

A Steinberger "Broom" is the easiest to travel with.

A few years ago, I was asked to bring my guitar with me to Argentina. 

I inquired with the airlines and what I discovered was a bit disheartening. I opted to leave my guitar home and asked instead that someone from Argentina look into having a guitar for me on the other end of the planet. 

I was told I could buy a seat ticket for the guitar. And that would be the safest way to travel with it. 

I could consider it as one of my carry on bags and if it did not fit in the overhead bins....luggage was given priority, perhaps the flight crew could find a place for it in the flight crew storage bin..... but no guarantees there. There is also the option to allow the ramp loading crew to place it in the cargo hold from the plane's passenger loading ramp.

I could check it and hope it arrived safely. 

As it turned out.... the guitars provided to me by folks in Argentina were quite nice. 

I've never had a guitar damaged when checked on a plan...   Just get an industrial flight case...


I'd prefer not to check guitars but...  A.  Some airlines got real tough after 9/11.  B.  Its just a room thing... "where do you put it on a plane nowadays."

Unless you can fly first, or have your own jet..

I take my air guitar on every flight without any problem.  My backup usually ends up being stored in the overhead 'cause whoever sits next to me tends to get tired of holding it for me.

Some say my Alembic is a "hot air" guitar.