Neither the Naval Service nor the Air Corps can continue to function for much longer without replacement of key equipment at a total cost of £235 million over a 10-year period, the Price Water house review says.
In the case of the Air Corps, it recommends a package costing £40 million, with the gross price of £77 million being offset by £37 million in savings.
It also recommends reducing staff numbers by 10 per cent to 930, mainly in the technical area of engineering and maintenance.
The recommended equipment package includes purchase of four medium-lift helicopters over the next four years - the Air Corps has no such craft at all - and the replacement of the existing helicopter fleet of 15 Dauphin and Alouette craft with eight Squirrel-type helicopters.
It also recommends replacement of the six Cessna 172 aircraft with a minimum of two Defender-type aircraft.
The 13 Fougas and Marchettis should be replaced with eight light strike/trainer aircraft, and a substitute should be found for the Kingair.
The two Casa fishery protection planes and the Gulf Stream IV government jet should remain in service, it says.
The Casas are not due for replacement until 2024, by which time the "whole scenario in relation to fishery protection may have changed", the review notes.
Figures for both Naval Service and Air Corps re-equipment are based on costs to the State and assume no EU funding. The EU is currently underwriting 65 per cent of the cost of the new £20 million naval patrol vessel on order from Britain.
Purchase of four medium-lift helicopters would allow the Air Corps to bid for the State's search-and-rescue service when the contract on the west coast comes up for renewal.
The new contract for the east coast, provided by Bond Helicopters to the Department of the Marine, is due to come into service next week.
The overall cost of this service is £4.5 million a year, with no assets transferring to State ownership.
However, if the new helicopters were purchased, the Air Corps would have to operate a search-and-rescue service to Department of Marine and Natural Resource standards, and on the basis of a "formalised service level agreement", the review warns.
The consultants note that the Air Corps currently cannot provide the required level of back-up to the Garda Siochana when there is downtime, or when excess demand cannot be met by the force's own air wing of Squirrel and Defender aircraft.
Alternatively, the Garda Siochana could obtain additional aircraft or contract services, possibly from the British police authorities, it says.
Identifying changes required in current practices to make the Air Corps more businesslike, the review focuses on various elements including flying hours for crew and aircraft, crewing factors, downtime of aircraft, maintenance regimes and customer relationships.
The degree of change required to give value for money will require a "massive culture and operational shift" for both the Air Corps and Naval Service, it says.
Contracting basic flight training in the Air Corps should also be considered in the context of the military capability requirement, the review says.
Nor is there any "compelling" rationale for the Air Corps having its own air traffic control function.
It does say that a detailed career plan for flying officers needs to be developed, and recommends relocating the Army Support Squadron from Gormanston Air Station in Co Meath.
