The seven categories and rankings that went into the overall ranking:
On-time arrivals
1. Delta
2. Alaska
3. Spirit
4. Southwest
5. United
6. American
7. JetBlue
8. Frontier
Tarmac Delays
1. Southwest
2. Alaska
3. Frontier
4. Spirit
5. Delta
6. JetBlue
7. United
8. American
Involuntary Bumps
1. Delta
2. JetBlue
3. United
4. American
5. Southwest
6. Alaska
7. Spirit
8. Frontier
Extreme Delays
1. Alaska
2. Delta
3. Southwest
4. Spirit
5. American
6. United
7. JetBlue
8. Frontier
Cancelled flights
1. Delta
2. Spirit
3. Alaska
4. Southwest
5. United
6. Frontier
7. JetBlue
8. American
Mishandled bags
1. Spirit
2. JetBlue
3. Delta
4. United
5. Alaska
6. Frontier
7. Southwest
8. American
Formal DOT complaints
1. Southwest
2. Alaska
3. Delta
4. JetBlue
5. United
6. American
7. Spirit
8. Frontier