It’s been fifty years since regular passenger flights have made a stop in Cuba. Unfortunately, just six months since flights have been allowed to the estranged country, two U.S. airlines are turning their backs on the country already.

Both Silver Airway and Frontier say that they will soon drop their routes to the country. Silver says that by April 22 all nine of its routes to Cube will have ceased, and Frontier will have dropped its Miami-Havanan route as soon as June 4^th.

The initial reason? Both airlines say that the cost just seems to be too much. The two small regional carriers agree that the overcapacity on the freshly renewed service between the two nations is also a large cause in their backing out.

Frontier spokesperson, Jim Faulkner made a statement to a source saying that the initial cost of operations in Havana “exceeded our initial assumptions.” Frontier added that the seating capacity from Florida to Cuba made it a bit complicated for its Miami-Havana route to perform as well as expected.

Yet Frontier isn’t the only carrier making the trip. Seven other airlines make a daily route out of South Florida’s two largest airports in Miami and Fort Lauderdale to Cuba. That’s not even counting the flights from Southwest and JetBlue that are taking off to Cuba from other parts of Florida.

It was just a year ago that flights to Cuba opened up to the United States. The route to the island had been capped and in order to fly in and out, U.S. carriers had to apply for the rights to do so with Cuba’s international airports. Once the gates were open and the rights secure, nearly all the major U.S. carriers flooded in bringing their requests for flights to Cuba. The main sight of trajectory was Havana.

Yet even though many executives were excited at the new prospect of flying to Cuba, others had to wonder if it would pay off in the end.

In the last fifty years that there had been very little air service to the island. That meant that there was little to no new data that many of the carriers need in order to assess any and all potential flight demands for new destinations.

Another issue comes with the fact that most carriers that fly in and out of Cuba are doing so with medium or full-sized jets. For airlines like Silver who are flying routes from Fort Lauderdale to Cuba with jets like the 34-seat Saab 340B Plus. Silver also doesn’t do flights to Havana like other carriers. It flies to other destinations across the island, around eight to be exact and has said that it will announce a ninth destination later on in the year.

Misty Pinson, a spokesperson for Silver says that since flights were open to Cuba it has kept up its travels to “smaller Cuba markets-which are similar to its successful network and fleet strategy in Florida and the Bahamas.”

That wasn’t Silver’s only issue with its flights to Cuba. The airline says that in the past selling its flights to the island through online travel sights never really proved to be too customer friendly. Pinson commented that since the start of service to Cuba last autumn “distribution through online travel agencies and codeshare agreements have been unavailable.”

While Silver might not bother with a return to Cuba, it and Frontier aren’t the only ones who are a tad hesitant when it comes to flight service to and from the island. American and JetBue have since lowered their capacity to the island.

Although American didn’t stop flight altogether it did, however, say that it would be cutting down on the number of flight its jets made to Cuba. JetBlue said something along similar lines and didn’t drop any of its regular routes to the island but did say that it would begin using smaller planes for the flights to specific destinations.

Americans problems with Cuba costs started back in October making note of the issue during quarterly earnings. The senior vice president Don Casey made a comment to a source saying, “I think everyone is struggling a little bit in the terms of selling in Cuba. There are a lot of restrictions that are still in place that has made it difficult to sell.”

Many other airlines are feeling sales struggle as well. That and that fierce competition to secure route to the island through the Transportation Department. However, larger carriers aren’t letting that bother them. They claim to be waiting for the market to develop a bit more.

CEO of Southwest, Gary Kelly made a statement to investors saying that it would take about a year to say for sure what type of performance would be yielded by Cuba, and in that time he would be comparing results. There’s no way that Southwest, Silver, Frontier or any other airliner could have expectations on the market for Cuban flights. Even Kelly said, “I don’t know how you would know because there hasn’t been air service to Cuba in 50 years.”