1/18 During the firefighting season of 2018, the @IrishAirCorps dropped thousands of tons of water on fires throughout Ireland. Each drop involved lifting over 1000kg out of a water source, flying at very low level in turbulence and smoke, often in mountainous areas. @kevpipps

2/18 Power demands on the engine and transmission would vary almost instantly between ‘all of it’ and ‘almost none’ as the aircraft pulled water from confined areas in the hover, accelerated as quickly as possible to a safe airspeed, manoeuvred to the drop and released its load.

3/18 On each lift, the crewman who would be lying on the deck of the aircraft cabin for the best view of the Bambi bucket, could feel the floor move away from him as the aircraft tried to lift a lake. @koceallaigh @PaulFry88778073 @RACO_DF @ARCOIreland @tchukstr @SeanFionn

4/18 This is a good example of how to increase the fatigue life on the structure of an aircraft beyond its’ years or flying hours. Metal bends, but bend it often enough and cracks will start to appear. @CllrPioSmith @nealerichmond @BrianLeddin @MattShanahanTD @GCraughwell @donlav

5/18 Arriving in @IrishAirCorps service in 2006, the oldest of the AW139 fleet is now around a 15 years old. Originally bought for Army support and Aid to Civil Power (ACP) tasks in the then benign security environment, it was expected that they would last for up to 30 years.

6/18 Experience gained through operational and maintenance experience, and actual usage versus that which was forecasted, means that a life time closer to 20 years will be more accurate. @Edward__Burke @McNamara_Eoin @kourousis_k @MattGONeill @patinVRAI

7/18 Beyond that time, maintaining a fleet as small as six aircraft as a viable means of delivering required capabilities will prove increasingly unlikely, as major unscheduled maintenance tasks becomes more probable. @IRLDeptDefence @IRLDeptPER @slandail_nssi @IRLCoDF

8/18 As per the example above, the aircraft have been put through the mill compared to some of the more benign types of civilian flying that other AW139s with higher hours might endure. @JohnMinihan @BerryCathal @GCraughwell

9/18 This article contends that, with the timelines involved in aircraft replacement being as long as they are, the time to start looking at the eventual replacement for the primary operational helicopter fleet is now. @Rotorblur @SpotterIrish @TonyKB777

10/18 Although the focus of recent years has been on ATCA (Aid to Civil Authority) tasks such as HEMS (Helicopter Emergency Medical Service) in the form of Emergency Aeromedical Service (EAS), it is quite likely that...

11/18 ...a return to more normal, purely military tasks, may well occur in the near future. You don’t simply buy a new helicopter ‘just because’. @kforfitz_Wayne @NoelO832597 @mupper2 @ConorHogarty

12/18 You buy one because you have identified a specific capability that the state needs to have available, either on an ongoing basis or as an insurance policy. In determining these military needs for an Air Corps helicopter, you will need to...

13/18 ...look at both the domestic and international situation. The domestic situation will largely result from the reaction of the various armed groups in Northern Ireland to the effects of the eventual resolution of Brexit negotiations at the end of this year. @MccrumJacqui

14/18 The overseas situation is in view for the first time in an Air Corps aircraft replacement competition, as the previous restriction on using Air Corps aircraft overseas was deleted from the last white paper. In addition, international actors may also act to... @roryireland

15/18 ...destabilise either the EU, UK or Ireland directly if they find value in doing so and, in addition, international actors may also act to destabilise either the EU, UK or Ireland directly if they find value in doing so and this too must be borne in consideration.

16/18 In a world where liminal warfare has become a threat in Europe and elsewhere, there would be concern that such international actors would view the post-Brexit situation in Northern Ireland very much as an open goal to be exploited. @CharlieFlanagan @wrafter_colin @dsmooney

17/18 This forms the basis of the security related considerations of this assessment. As air power in general will be a major focus of the @IRLCoDF, future threads will look at... @LauraMcGonigle @Aiden_Corkery @CormacJOKeeffe @conormlally @joseph_aidan

18/18 ...where the land, air and maritime components respective doctrines all overlap: helicopters, specifically the main operational fleet of the Air Corps, the AW139. (with thanks to @declan275 for content). @GaryGannonTD @garypgar @lawlessj @