The Mosquito Research and Control Unit (MRCU) has returned its only serviceable aircraft to flight after a mandatory 100-hour inspection that kept Cayman without aerial mosquito control for roughly two weeks at the height of the season.

The Unit confirmed on 20 October that the aircraft had "successfully completed its mandatory 100-hour inspection and is once again available for mosquito control operations across the Cayman Islands". Aerial treatments can now resume alongside the truck fogging, larviciding and ground-based control work that carried the load in the interim.

MRCU said mosquito numbers "have improved considerably compared with two weeks ago", but acknowledged that activity "remains at unacceptable levels in several communities" and that some residents "continue to experience significant biting". It continues to monitor populations through traps, field inspections and resident reports.

A fleet of two, both registered in 2006

The Civil Aviation Authority of the Cayman Islands' active aircraft register, updated in May, lists two aircraft under Cayman Islands Government MRCU, VP-CKE and VP-CKF. Both are Thrush Aircraft S2RHG-T65 agricultural sprayers, a turboprop variant of the Georgia-built Thrush line powered by a Pratt & Whitney Canada PT6A engine. VP-CKF was registered on 20 February 2006 and VP-CKE on 15 June 2006, making both aircraft 20 years old this year.

A 100-hour inspection is a scheduled check that falls due each time the airframe accumulates 100 hours of flying. MRCU said in late September that it typically takes about two weeks.

The Unit's second aircraft remains grounded. In a statement on 29 September, MRCU said the aircraft was "currently grounded following a mechanical issue" and would stay out of service until the problem was resolved and the aircraft cleared to fly. By 8 October the Unit said it was awaiting a replacement part that was not readily available. The 20 October statement did not give a return date.

MRCU did not say which registration completed the inspection. The photograph released with the 20 October statement shows VP-CKF.

Ten extra hours, then a fortnight on the ground

The sequence that left Cayman without a spray aircraft began in the last week of September. With one aircraft already grounded, the remaining machine had reached its 100-hour interval and was granted an additional ten flight hours before it had to be withdrawn. MRCU said it would use those hours where surveillance showed the greatest need, and warned that the gap in aerial capability "is expected to affect MRCU's ability to rapidly reduce adult mosquito populations".

The timing coincided with seasonal rains and high tides that flooded wetland breeding grounds. MRCU reported that light-trap counts on Grand Cayman fell from about 41,000 mosquitoes on 3 October to about 10,000 on 7 October, a drop of roughly 75 per cent achieved without aerial spraying.

Replacements funded, procurement under way

Government has approved replacing both aircraft. In a statement to Parliament on 1 October, Minister for Health, Environment and Sustainability Katherine Ebanks-Wilks MP said the 2026-2027 budget had already provided for one new aircraft and that Cabinet had approved a further CI$1.8 million, funded by an equivalent reduction in the Infrastructure Development Fund, so that both could be replaced together.

Buying two at once, she said, would bring "measurable financial benefits" through procurement efficiencies and streamlined maintenance, and replacing the fleet was "prudent and necessary". The aircraft remain airworthy, the Minister said, but the number of days they spend out of service for maintenance and repairs "continues to increase", and parts are becoming harder to source.

In a second statement the following day, the Minister said Cabinet had approved CI$1.89 million for additional larvicide, on top of MRCU's roughly CI$10 million operating budget for the year, after stocks ran down faster than usual. The Unit has about 15,000 acres to treat at roughly eight pounds of product per acre.

MRCU said in late September that the procurement process for the new aircraft was under way. According to the Government's summary of the 1 October sitting, the purchase is intended to replace both ageing aircraft by early 2027.