Depends on the Model Year
Airstream likes to monkey with the "Length" to differentiate model years.
Our 2007 Classic Limited 30' actually measures 31' bumper to ball.
In other years, the same trailer is called a "Classic Limited 31"
Our 2000 Safari 27 was was closer to 28 feet and in some years it is called a Safari 28.
Hope this helps.
P.S. The true length should be measured from bumper to ball.
2007 Classic Limited 30 (Sold)
2007Chevy Silverado 2500 HD Duramax/Allison
Four Corners Unit WBCCI #8654, Affiliate NM Unit