From flight cancellations to baggage failures, there's a lot that can go wrong with your airline when travelling. To help you out before you book the Air Travel Consumer Report by The US Department of Transportation has ranked US domestic airlines from best to worst. The report reveals the worst airlines based on four categories: flight cancellations, mishandled baggage, overbooked flights and complaints. Read on to find out which airlines are flying high and those that aren't.

One of the worst feelings when travelling is looking up at the departures board and seeing the word "cancelled" next to your flight. Part one of the report looks at the number of flight cancellations for each airline during July 2019 starting with the airlines that cancelled the least flights to the worst offenders. 

It's great news if you're flying with Hawaiian Airlines, only 0.1% of its 7,334 flights during July (when this study was completed) were cancelled. That makes it America's most reliable in this category – although do bear in mind it only operates at 19 airports, the least of all the airlines on this list. However, we still think Hawaiian's excellent track record is just another reason to book that break to Honolulu.

Next best is Allegiant Air, who less well for cancellations last year with 1.6% of their flights staying on the ground. Things have improved hugely for the budget airline this year however, as just 0.3% of their 11,786 July services were cancelled.

Delta was not far behind Allegiant Air, but it's worth noting the carrier has far more scheduled flights with 90,812 in July 2019 alone. Only 0.4% of their services were cancelled. 

In all categories this year things are looking brighter for the airline which completed a merger with Virgin America in 2018. Only 0.6% (139 of its 24,593 flights) were cancelled, an improvement on last year's 0.8%.

With more than double Alaska Airlines’s number of cancellations, United takes the next spot with 1.3% of its 56,106 flights cancelled.

Southwest, the world’s largest low-cost airline, saw just 1.4% of its whopping 119,342 flights cancelled in July. That's 1,614 services that didn't get off the ground.

SkyWest Airlines is next to make the list, with 1.4% of its 73,742 flights in July cancelled. That's a significant rise on the tiny 0.9% the airline reported in 2018. It's worth noting that SkyWest operates at 246 airports nationwide, the largest number on this list.

JetBlue has also improved in the rankings with just 1.6% of its flights cancelled this July, compared to 2.4% in 2018.

Spirit, who operate flights in the US, Caribbean and Latin America, had 2.2% of their 18,845 scheduled flights cancelled in July. That's a big jump from the 1% it saw during the same period in 2018.

Frontier Airlines is next with 2.3% of their 12,535 flights cancelled – although that's considerably better than last July where 3.8% of its flights failed to make it off the ground.

American Airlines, the world’s largest airline by revenue and number of passengers, takes seventh place in our list of the worst for cancellations. American had 3.1% of their 81,801 flights fail to depart.

If you're travelling through Phoenix, Dallas Fort Worth or Louisville airports you'll know Mesa as American Eagle, while the airline operates as the United Express brand at Washington Dulles and Houston. It saw 3.2% of its 20,122 flights scheduled in July stay on the runway, up on the 1.9% from last year. 

With headquarters in Dayton, Ohio, PSA is a brand owned by American Airlines flying as American Eagle. It saw 3.4% of services cancelled in July, with passengers on 846 flights facing the misery of rebooking. 

A subsidiary of Delta Air Lines, you might know them as Delta Connection, flying around the country from hubs at Atlanta, Detroit, Minneapolis, and New York. Endeavor comes in fourth on our list of the worst cancellation offenders, also with 3.4% of their 22,312 flights staying on the tarmac.

Envoy Air, another airline flying as American Eagle, made it to the top three of the worst, a small improvement from the second-place spot it held last year. A hefty 4.4% (0.3% more than 2018) of their total 29,565 flights were cancelled in July.

Republic Airways, another partner of United Express, Delta Connection and American Eagle that broadly speaking operates in the east of the country, comes in second in the air travel consumer report with 4.4% of their 28,158 flights never taking off.

Scooping an accolade no airline really wants is ExpressJet, which also operates as United Express. It saw a whopping 5.1% of its 11,182 scheduled flights cancelled in July 2019, making it the worst domestic airline for cancellations overall.

After a tiring flight, there's nothing worse than arriving to find that your luggage has been damaged or lost. Part two looks at the number of mishandled baggage reports, which includes bags that have been delayed, damaged, stolen or lost per carrier from US airports in July 2019. The report rate is calculated per 1,000 bags handled by the airline.

Those flying with Allegiant Air not only saw low cancellations, but also a low number of bags being mishandles. For every 1,000 bags they handled just two bags went astray.

Frontier Airlines has the second lowest baggage complaints, with 4,563 mishandled bags out of the 1.1 million it took care of in July 2019. Frontier's average total is 3.91 mishandled bags in every 1,000.

Hawaiian have the second lowest number of complaints when it comes to luggage. A total of 2,513 bags were mishandled meaning it saw 4.18 bags per 1,000 lost, damaged, delayed or pilfered.

For every 1,000 bags onboard Alaska Airlines's flights, 4.32 had issues that were reported. It's worth noting that Alaska Airlines got 2.1 million items of luggage onto its planes in July 2019 alone.

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Southwest saw 53,660 mishandled baggage reports, slightly higher than the 49,484 in 2018. That means 4.69 bags had issues for every 1,000 handled by the carrier. However, do note the airline dealt with the biggest number of luggage items of any on the list – a staggering 11.4 million bags.

Next on the list, Endeavor Air (Delta Connection) ups the reports per 1,000 bags to 5.10, with a total of 4,925 mishandled bags in July 2019.

Delta Air Lines itself is the eleventh worst airline, with a dramatic increase in bag reports since last year, they had over double the reports from 20,760 to 41,390. It's report rate per 1,000 bags for July 2019 was 5.36.

Spirit is in the top ten worst offenders for baggage rates, with a total of 6,708 luggage mishandles reported at a rate of 5.53 per 1,000 customers.

SkyWest Airlines saw a 6.08 report rate per 1,000 bags, with a total of 17,743 mishandled bags, up on the 11,569 for the same period last year.

The eighth worst is JetBlue, with a report rate of 6.36 per 1,000 customers and a total of 7,871 luggage mishandles.

ExpressJet (operating as United) saw 6.44 bags in every 1,000 get misplaced or pilfered this year – that's a total of 2,417 reported baggage issues.

United Airlines took care of 4.8 million bags and it saw 35,542 complaints. Its report rate for every 1,000 items of luggage was 7.37.

PSA (flying on behalf of American Airlines as American Eagle) is the fifth worst with 8.31 bags mishandled in every 1,000. It had a total number of 9,814 lost or stolen items in July 2019.

Mesa Airlines (flying on behalf of American Eagle or United Express) takes the rate slightly higher with 8.71 per 1,000 bags mishandled, translating to 8,067 mishandled items in July 2019.

American Airlines makes the top three of the baggage baddies, with a report rate of 9.71 per 1,000 bags and a total of 64,014 mishandled bags reported. American was the airline with the overall highest number of individual reports.

Republic Airways, partnered with American, Delta and United, takes the second spot with 9.94 complaints per 1,000 bags and a total of 8,321 mishandled bags.

Envoy, part of American Airlines, takes first place. It saw 10.11 complaints per 1,000 bags and a total of 10,611 mishandled bags.

Having a ticket doesn't always guarantee a plane seat as airlines sometimes overbook flights with the hope of no shows. Part three looks at the total number of involuntary denied boardings (being bumped from a flight when you don't want to be) for domestic and international flights that start from the US from January 2019 to June 2019. The number of involuntary denied boardings data is calculated per 10,000 passengers. Once again we've ranked these from best to worst.

Trusty Hawaiian Airlines is first on the list with the lowest rate of people denied boarding. It saw 0.00 involuntary denied boardings per 10,000 passengers, with nobody turned away. And they handled 5.3 million (presumably happy) customers. 

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Endeavor Air (flying as Delta Connection) comes in next, also with none of its 6.8 million customers from January to July 2019 bumped from flights.

In 2018 only 22 people were denied boarding with Delta, but during the same period this year the company has beaten its excellent track record in this area – there was only one person who couldn't board with the airline from January to July 2019.

ExpressJet (flying as United Express) takes the next spot with a slightly higher 0.01 involuntary denied boardings rate per 10,000 customers. There were just two involuntary denied boardings in total.

United also has a good record here holding its rate of 0.01 denied boardings per 10,000 passengers from 2018. Just 45 people found they couldn't fly with the airline between January to June 2019.

JetBlue saw just 30 passengers turned away at a rate of 0.02 per 10,000 passengers. That's up on last year though, when the airline failed to board just 16 people in the same period.

Spirit saw a rate of 0.12 involuntary denied boardings per 10,000 passengers and 195 involuntary denied boardings in January to July 2019.

Alaska Airlines is the 10th worst for involuntary denied boardings, with a rate of 0.19 per 10,000 passengers. In total, from January to July 2019, 313 customers were told they couldn't travel on the flight they'd originally booked.

In 9th place is SkyWest with a 0.23 involuntary denied boarding rate per 10,000 passengers. It was responsible for 446 involuntary denied boardings, higher than the 0.17 rate and 294 denied in the same period in 2018.

Although Republic (partner of American, Delta and United) had a smaller number of involuntary denied boardings overall than SkyWest at 242, the rate per 10,000 customers is higher at 0.26, making it the eighth worst.

Southwest Airlines takes the seventh spot with a 0.32 involuntary denied boardings per 10,000 customers, seeing 2,525 passengers unable to take to the skies. Do note that the airline's results were partly caused by the grounding of the Boeing 737 MAX planes, after two flights crashed in October 2018 and March 2019. And Southwest Airlines also handled 79.5 million passengers from January to June 2019, the most of all the airlines in this section of the report. 

Frontier is next with a slightly bigger rate of customers refused entry per 10,000 at 0.34 and a total of 352 involuntary denied boardings.

Although American didn’t have the highest involuntary denied boarding rate at 0.73 per 10,000 customers, they did turn away 5,022 people, the highest number of all the airlines listed here. However, like Southwest Airlines, it too was affected by the grounding of the Boeing 737 MAX planes which has negatively impacted the results here.

Allegiant saw a slightly higher involuntary denied boarding rate of 0.83 per 10,000 customers, with 633 people unable to fly through no fault of their own.

Now to the top three. PSA (flying on behalf of American Airlines as American Eagle) ups the involuntary denied boardings to 1.03 passengers per 10,000 with 754 unable to fly in the first six months of the year.

In the second spot is Mesa Airlines (American Eagle or United Express) with 1.16 passengers in every 10,000 turned away – that means 799 involuntary denied boardings in real terms.

Once again it's not good news for Envoy Air. It ranked the worst for overbookings with a 1.49 involuntary denied boardings rate per 10,000 passengers, translating to 1,027 involuntary denied boardings in the first six months of the year.

The fourth and final part covers customer complaints from US major airlines during July 2019. This includes grievances via email, on the phone and in-person. The US's major airlines had 1,279 complaints in July, an increase on last year's 962. That's also compared to the 522 recorded against foreign airlines during July 2019.

Southwest had just 44 complaints in July 2019, that's 0.30 moans per 100,000 passengers, making it the lowest on the list. Do take into consideration that they welcomed a mammoth 14.6 million customers too. And it's also a reduction on the 0.51 they had at the same time last year too. Well done Southwest.

Alaska is next with the second-lowest, only 17 formally logged complaints in total, with 0.50 grievances per 100,000 passengers. Alaska has also seen a slight drop in their complaints from 2018, when they had 24 complaints in total and a rate of 0.70 per 100,000 passengers.

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Endeavor Air (Delta Connection) takes the third lowest spot with only a slightly higher 0.51 complaints rate per 100,000 passengers and just seven logged complaints.

SkyWest is 14th with a total of 23 complaints, with 19 of those being due to flight problems. Its complaints rate was 0.59 per 100,000 passengers.

Delta was still one of the best performers despite 102 gripes. Of these 23 were baggage complaints and 33 were flight issues, with a complaint rate of 0.65 per 100,000 passengers.

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PSA (flying for American Airlines as American Eagle) is next with only 10 formal complaints in total, nine for flight issues and one for customer service. Its rate of complaints was 0.76 for every 100,000 passengers, so still excellent.

Hawaiian Airlines dealt with eight complaints overall, four being about flight problems. The flag carrier also had a 0.76 complaint rate per 100,000 passengers overall.

Republic Airways (partner of American, Delta and United) has seen an increase in the rate of complaints, 0.78 per 100,000 passengers in July 2019, higher than the 0.60 figure from 2018. But in reality Republic only had 13 complaints, 12 of them were flight-related.

Allegiant saw 1.30 passengers in every 100,000 complain. That's a slight decrease from 1.70 passengers in every 100,000 with a moan last year. The airline had a total of 23 complaints in July 2019 about issues ranging from flight complaints to baggage.

Mesa (you might know them as American Eagle or United Express) is the eighth worst performer with a 1.37 complaint rate per 100,000 passengers. It was on the receiving end of 19 formal complaints in total in July 2019, the majority (16) were flight issues.

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JetBlue is the seventh worst with a complaint rate of 1.46 per 100,000 passengers and a total of 58 complaints. Seven of those (12%) were disability-related too.

Nine complaints overall doesn't sound like much for this airline that flies under the United Express brand. But ExpressJet's passenger numbers of 534,029 – the lowest of any airline listed here – means their complaint rate is 1.69 per 100,000 passengers.

United Airlines is next with 239 complaints in total: 46 of those recorded were baggage, 24 about boarding or ticketing and 15 were disability-related in addition to the 90 people encountering flight problems. Its complaint rate was 2.12 per 100,000 passengers leaving it fifth in this category.

Envoy Air (part of American Airlines) takes the fourth spot with a complaint rate of 2.42 per 100,000 passengers. It generated 34 complaints, 28 being flight-related and 2 being about over-sales.

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American comes in third with the highest number of actual complaints of all the airlines with 358 in total during July 2019, and a complaint rate of 2.49 per 100,000 passengers. Nearly 200 of the complaints were flight-related (194), 24 were disability-related and 34 were about customer service.

Although Frontier’s complaint rate dropped massively since last year from 5.77 to 3.32, it still comes in second for the most complaints per 100,000 customers, with 70 in total.

This year Spirit has leapfrogged Frontier to claim the dubious crown of the airline with the highest complaints rate, 3.64 per 100,000 passengers in July 2019. That's a slight increase from the 3.55 in 2018. Spirit saw 117 complaints overall with 20 about boarding issues and 56 over flight problems.

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