There are two ways to hit an iron out of a fairway bunker: picking it cleanly or hitting it like a normal shot. If you’re not worried about hitting a great shot and just want to get the ball out of the bunker, try to half-blade the ball. By taking stock of where the buttons of your shirt are at address, you can make sure that you’re not getting lower through impact and therefore not taking up any sand.
The natural momentum of your swing and your club will slightly stretch your arms, but by ensuring a tall swing using your arms, you’ll pick the ball out of the bunker and get some height on it as well.