Kingfisher Airlines, once one of India's largest airlines, failed due to excessive debt, unprofitable routes, high costs, and delays. It accumulated over $1 billion in losses and $7 billion in debt. Reasons for its failure included expanding too quickly, taking on many unprofitable routes, high employee costs, aging aircraft fleet, and shifting operations to more expensive terminals. Competitors like Indigo were more profitable by focusing on efficient operations with standardized, new aircraft and profitable routes only. Kingfisher's diverse fleet led to higher maintenance costs and more complex scheduling.