Southern Airways Express LLC, doing business as Mokulele Airlines, began grounding a portion of its fleet to inspect and address findings of a routine maintenance check on Saturday — a day after the U.S. Department of Transportation awarded it roughly $4 million per year for two years in federal subsidies to provide essential air service to Lanai.

Mokulele notified the state Department of Transportation of the groundings Saturday and told the agency that it expected to resume normal operations Wednesday.

Louis Saint-Cyr, president of Hawaii operations, Mokulele Airlines, said Monday in a statement: “The Mokulele team has been working diligently to safely and efficiently return our fleet back to service through these maintenance checks. Through we are not yet at full capacity, we are close to having all flights running on their regular schedules.

“We have successfully reaccommodated the vast majority of our passengers, and we greatly appreciate the continued flexibility and understanding from the Hawaii community.”

Saint-Cyr sent a letter to customers Saturday explaining that the airline during routine maintenance procedures had identified potential discrepancies in the documentation of a recent landing gear servicing on one of our aircraft.

“As a precautionary step to uphold our rigorous safety standards, we’ve decided to temporarily ground affected aircraft in Hawaii while we conduct thorough inspections,” he said.

The disruption follows Mokulele’s selection Friday by the U.S. Department of Transportation to provide federally subsidized essential air serv­ice at Lanai Airport. Pacific Air Charters also vied for the role in a highly competitive request for proposals process.

The order, which covers Sept. 1 through Aug. 31, 2026, said Mokulele would provide Lanai with 63 weekly round trips consisting of 21 weekly round trips to Kahului Airport and 42 weekly round trips to Daniel K. Inouye International Airport, using nine-seat Cessna Caravan aircraft, at an annual subsidy of $3,970,286 for the first year and $4,069,543 for the second.

The order was the first essential air service subsidy for Lanai since it qualified over 40 years ago.

Mokulele took over unsubsidized EAS on Lanai on Oct. 23, 2020, after ‘Ohana by Hawaiian, operated by Empire Airlines, sought an exemption to allow Mokulele to provide subsidy-free EAS at Lanai. But on Dec. 8, 2023, Mokulele gave the U.S. Department of Transportation a 90-day notice of intent to suspend unsubsidized EAS on Lanai, saying that “rising costs and stagnant market demand have caused unsubsidized air service on the island to remain perpetually unprofitable.”

The order from the U.S. Department of Transportation said that during the selection process “the majority of elected officials who have corresponded with the Department have expressed support for Mokulele.”

However, the department noted in its order, “Notwithstanding support from the community for the selection of Mokulele, the Department has heard from many users of EAS, through formal comments, telephone conversations, and emails, that Mokulele often delays flights and ‘reschedules’ flights with little notice, negatively impacting Hawaiian residents that travel to Oahu for medical appointments and those connecting to other airlines at HNL and OGG. Given that residents on neighbor islands like Lanai do not have road access to their doctors and health facilities as residents do on the larger Hawaiian Islands, it is critical that flights be reasonably on-time with understandable occasional operation cancellations due to unforeseen circumstances. When flights are cancelled, residents may miss medical appointments that are difficult to schedule, and they may have to spend unplanned nights in hotels as a result of flight cancellations and delays.”

The U.S. DOT said it viewed the complaints as a “serious matter and believes that additional accountability factors are warranted to monitor the air carrier’s operation for this two-year period.”

As such, it imposed an additional accountability measure directing Mokulele to file on-time performance statistics monthly to the department’s Bureau of Transportation Statistics.

Mokulele operates at nine airports across the state, including Daniel K. Inouye International Airport, Kahului Airport, Kapalua Airport, Hana Airport, Ellison Onizuka Kona International Airport at Keahole, Waimea-Kohala Airport, Molokai Airport, Kalaupapa Airport and Lanai Airport.

During the groundings, Mokulele is operating limited flights between Maui, Molokai, Honolulu and Lanai, and will use other airlines to reduce disruption to its passengers. Saint-Cyr said in a letter to customers that the airline was “prioritizing available seats for passengers traveling for medical care or connecting to flights in the mainland.”

Mokulele’s most disruptive groundings occurred Sunday when it operated at half capacity, offering three flights with 24 seats into Molokai and 12 seats departing from Molokai per flight. It added additional flights Monday to begin working toward supporting normal loads.

Mokulele gave customers who chose not to travel or could not be reaccommodated credit for their canceled tickets, and a voucher for future round-trip travel.