Can pilots and truck drivers shorten their prayers?

Travel for work is still travel

The permission to shorten is for anyone on a journey, whatever the reason, as long as the trip itself isn't for something sinful. The Quran even mentions people travelling to earn a living, in the same breath as those who are ill:

The Prophet ﷺ called shortening a charity that Allah has given us, and told us to accept His charity (Sahih Muslim 686). Doing it every week doesn't make the gift smaller. See What is qasr prayer?

Where the scholars differ

• The majority (Hanafi, Maliki, Shafi'i): a professional driver or pilot shortens whenever the trip is long enough, even if they're on the road most days.
• Hanbali view: someone who lives on their vehicle with their family and has no other home, like a sailor whose family lives aboard the ship, does not shorten, because the vehicle is effectively their home. A trucker with a home and family in a town, who comes back between runs, shortens on the road.

Some contemporary scholars add that if your route is local, like a city bus or a delivery driver who never leaves the metro area, you are not a traveler and pray in full.

Layovers and hotels

Crew who stay a night or two in a hotel abroad are still travelers. The four-day rule of the majority (15 days for Hanafis) only matters if a stay is longer than that. In your home base, pray in full, even between flights.

Practical tips on the job

• Truck drivers: plan prayer stops at rest areas, and combine Dhuhr with Asr or Maghrib with Isha to save time. Never pray while driving. See How do I pray on a road trip?
• Pilots and cabin crew: pray during rest breaks in the crew area or galley if possible. If you can't stand or face the qibla, pray as well as you can. See Can I pray on a plane?
• Wudu: wiping over socks lasts three days for a traveler, a big help on long shifts.