Instead of buying random planes, use route planning tools (many are available online or in the game's Discord community). Calculating the maximum profit per seat on specific routes is the fastest way to grow your cash flow legitimately.
The game is praised for its realism. However, the "Money" resource is critical. Without enough cash, you cannot expand your fleet, open new routes, or survive economic downturns in the game. Airline Manager 4 Mod Apk -unlimited Money-