The U.S. Coast Guard is searching for three passengers of a fixed-wing medical transport aircraft that went down in the Maui Channel. 

The Coast Guard's Hawaii and Pacific district said in a series of early morning tweets that small boat Station Maui and multiple aircraft had responded to a report of the aircraft, later adding that the Fast Response Cutter William Hart joined in the search.

"A patrol boat from Station Maui, a MH-65 Dolphin Helicopter, and a C-130 from Air Station Barbers Point also continue in the search," it said. 

"Global Medical Response can confirm that one of our Hawaii Life Flight emergency fixed wing airplanes based in Maui, went off radar while en route to pick up a patient in Waimea Big Island," a spokesperson for Hawaii Life Flight told Fox News in an emailed statement on Friday morning. 

There was no patient on board, but the company noted that it was in the process of reaching out to the families of the crew members.

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The incident occurred at 9:27 p.m. local time on Thursday. 

The Coast Guard on Friday said one of its aircraft saw a sheen in the search area, and a patrol boat recovered debris from the area. It could not be confirmed if the debris is from the aircraft. 

U.S. Coast Guard helicopter flying

A U.S. Coast Guard helicopter  (U.S. Coast Guard)

Hawaii Life Flight said that it was working with the Coast Guard and rescue teams to provide all information, including the last-known coordinates of the flight.

"Our immediate focus is helping the search and rescue teams. Please keep our team members in your thoughts," it said. "Out of respect for our team members and their families, we ask for your patience. We will provide updates as soon as we have them."

Hawaii Life Flight said that – as standard procedure – it had temporarily paused Hawaii Light Flight transports. 

Hawaii News Now reported, citing the Coast Guard, that the Honolulu Control Facility reported losing radar contact with the plane approximately 15 nautical miles offshore south of Hana, Maui. 

The station said that the flight had departed from Kahului and was headed to the Waimea-Kohala airport.

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A U.S. Coast Guard ship off the coast of Honolulu, Hawaii

A US Coast Guard ship sits docked just off shore in front the Hilton Hawaiian Village hotel along Waikiki beach on Nov. 12, 2011 in Honolulu, Hawaii.  ((Photo credit should read ROBYN BECK/AFP via Getty Images))

The Coast Guard also told Hawaii News Now that a Coast Guard plane that was flying across the Alenuihaha Channel to search for the crew has flown back to Oahu due to difficulty seeing anything in the dark and that a sheen was seen in the search area and that a patrol boat had recovered some aircraft debris

It was not known if it belongs to the missing aircraft.

Hawaii Life Flight operates medical aircraft capable of transporting one stretcher patient, two medical attendants, one pilot and one family member. 

Focused on serving rural communities, its fixed-wing aircraft is the Beechcraft King Air C90B.

A U.S. Coast Guard boat patrols Honolulu Harbor

HONOLULU, HI - JUNE 13: A U.S. Coast Guard boat patrols Honolulu Harbor June 13, 2002.  ( (Photo by Phil Mislinski/Getty Images).)

All aircraft are operated by AMRG Inc. and function 24 hours a day and seven days a week.

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Hawaii Light Flight said its pilots are credentialed for all weather and night conditions.

According to its website, the company has been operating in Hawaii since 2010.