The Airport Police Fire Service (APFS) was formed by Aer Rianta in 1936 and was a civilian security force headquartered at Dublin Airport that derived its "authorised officer" powers from the Air Navigation and Transport Act, 1950 to 1998. Under the 1950 Act, Aer Rianta was given statutory responsibility for the Dublin (DUB) Airport. On 1 April 1969, Aer Rianta management was extended to include the Cork (ORK) and Shannon (SNN) Airports. The Aer Rianta Airport Police Fire Service operated at all three of these Airports.

With the 1998 Act the Airport Police Officers became warranted officers but as of the 1950 Act, the Airport Police had the power to stop and search any person or vehicle on airport grounds. They could demand that a person give their name and address and state their purpose for being in the airport. Anyone who refused to account for themselves or their baggage could be removed or arrested without warrant [before the 1998 Act]. In the event of an arrest, the Airport Police delivered the individual into the custody of the Garda Síochána to be dealt with in accordance with the law. The small Gardai airport station was a sub-station of Santry, where most prisoners were transferred for questioning, as there was no holding cell at the airport. The Airport Police had very similar powers to the Garda but, technically, their jurisdiction ended at the airport boundary. Over the years, the airport boundary was a cause of difficulties between the Airport Police and Garda who also policed these same airports.

The key objective for the Airport Police Fire Service of Aer Rianta was to ensure the safety of all people using the airports under their authority in conjunction with the security and protection of all installations, buildings and aircraft. They multi-tasked, performing traffic control, security searches, fire and ambulance duties as well as customer assistance and normal policing duties. The security force rotated duties regularly including fire and crash rescue duties. They also held regular operational and strategic meetings with the Gardai. None of the Airport Police were armed.

In the middle of the 1980s, security at the three airports was divided between Aer Rianta, the army and the Special Branch of the Gardai. The army regularly patrolled the perimeters and carried out surveys of the airports as security risks - as they did with other major installations deemed potential terrorist targets. The Gardai operated from an operations room in the airport terminal complex. They were plainclothes armed detectives of the 'D-Branch' security and intelligence section of the Gardai. The Gardai carried out a number of specific duties at the airport including security checks on prospective staff.

In 1986, 350 staff, male and female, worked as Airport Police operatives across the three Aer Rianta Airports with £6.5 million spent on security. The budget was spent on payroll, patrol vehicles, the airport dog unit, radio, video and other security equipment. Anthony Keane was the Chief Fire and Security Officer in 1986. Although the leadership role over both fire and police was combined in Mr Keane, a few years earlier in 1971, a separate Chief Fire and Rescue Officer was advertised for, as a proposed position to be based at Dublin Airport.

Divisions of the Airport Police included a fire unit, crime prevention and lost property. A new search unit was introduced before 11 September 2001 and was based in the 'frisk' area of departures, where passengers put their baggage through x-ray machines. It focused on inspection and screening of passengers, staff and baggage to international standards as defined by ICAO and ECAC. The Airport Police achieved these standards through passenger and staff screening and searching, x-ray examination of baggage, physical search of baggage and securing a sterile area. Advertising for applicants for the new unit noted the under representation of female officers, welcoming applicants.

The Airport Police dressed in blue uniforms and high-visibility jackets that resembled Garda uniforms. They were engaged in shift work, for which extra muneration was payable. Shift times were from 7am to 3pm, 3pm to 11pm and 11pm to 7am. Entry into the profession required a leaving certificate, driving licence and was subject to a medical. Applicants were preferably between 19 and 30 years of age. Starting salaries ranged from £9757.28 to £11,310.52 per year in 1986 to £22,500 per year in 2001. The Airport Police trained their own staff. Airport Police who underwent a 13-week training course at an Aer Rianta base on airport grounds could be promoted to Inspector grade. The command structure also included the ranks of 'Officer' and 'Sergeant'.

The rifts between the Airport Police and the Garda began when Gardai mounted checkpoints on the approach roads to Dublin Airport. Unhappy with the traffic delays these were causing, Aer Rianta instructed Airport Police to deal with the problem. Some personality clashes ensued and, by some accounts, all-out war was declared. Tensions reached a new high when the Airport Police enjoyed their Christmas party at a club on the airport grounds to find the local Gardai setup to proceed to breathalyse the party-goers upon exiting. Airport Police had their revenge the following year by challenging Gardai who arrived to enter restricted areas, including sending them back to their station to get a letter of endorsement to prove, even when in uniform, they were a real Garda.

Members of the Airport Police Fire Service performed charitable work at both a Service and individual level and participated in various events. Mr Paddy Hughes, a member of the Airport Police, was the overall winner of the first ever Police Dog Trials held at Dublin Airport. Charitable work included the Airport Police raising money to transport aid to Romanian children. Along with their Dublin Airport colleagues, who later joined the campaign, they funded dozens of trips with "Drivers for Romania" over several years after the crisis of the country's orphanages first made headlines. A special lorry was purchased for the missions with "AerRianta - Dublin Airport Police Fire Service Drivers for Romania" and the Force badge emblazoned on the side. In 1997, Airport Police Fireman, Eamonn Linnane continued the charitable tradition by taking part in a 1,000km charity cycle from Calgary to Vancouver in aid of the National Council for the Blind (NCBI).

Among the more tense moments for the Aer Rianta Airport Police Fire Service included the two bomb blasts at Dublin Airport on 29 November 1975, that killed one and injured seven people and brought an emergency security clampdown at airports. In 1970, hundreds of placard-carrying supporters of the anti-apartheid movement mustered at Dublin Airport for the arrival of the South African rugby team on 7 January 1970. Airport Police were involved in controlling the demonstrators and clearing crash barriers they dragged on to the road. Passengers inborn to the airport could also bring trouble as was the case in February in 1962 when Airport Police drove out to meet a plane after the pilot radioed the control tower at Dublin Airport about a party of troublesome passengers pushing each other around in a disagreement that escalated while in-flight. The Airport Police also backed up the Gardai during a wildcat protest by up to 300 craftworkers in January 1987 at Dublin Airport. Tensions also rose the following year at Dublin Airport for the funerals of three IRA members shot dead in Gibraltar. Massive security operations swung into action that included Airport Police manning extra checkpoints. Also making headlines was the Airport Police search for £3,600 in cash that was thrown into a dustbin by mistake at Dublin Airport in 1966. It was not found and believed to have been emptied into the incinerators along with other refuse.

Some standout memories through the years at Dublin Airport involving the Airport Police were the visit of Pope John Paul II in 1979 and the return of the Irish Football team after they were beaten by Italy in the World Cup Quarter Final in 1990. The Pope's visit was a large security operation as he was in and out of the building several times.

The Airport Police Officers or APOS, as they were also known, had their share of activity at Shannon Airport as well. In the 1980's the Government was anxious to place military and anti-terrorist units at Shannon Airport but this was resisted by Aer Rianta. Aer Rianta was instead very successful with security measures operated by the Airport Police. There was a very high security arrangement at Shannon with one airport room used exclusively for TV monitoring of the whole airport complex, especially at the area of check-in. However, shortly after US air raids on Iraq, massive security measures were put in place at airports around the world, including Shannon, to counteract the growing threat of pro-Iraqi terrorist attacks. Security patrols, involving Airport Police and Special Branch Detectives were stepped up in Shannon. This security cordon at Shannon, at the centre of the controversy over landings by US planes en route to the Gulf, was one of the tightest ever mounted in peace-time. Among other less threatening disturbances at the Shannon Airport were cleaners on strike in 1986 who picketed at the check-in entrance, refusing to move when ordered outside the boundary by Airport Police. In 1987, the Airport Police captured and detained a passenger from an aircraft of the Soviet airline, Aeroflot, who jumped his flight and fled from the terminal building as he tried to make his way out of the area. Political asylum seekers were not a rarity at the airport. A man was arrested and removed from an Airbus A-330 jet in 2000 by Airport Police for an air rage incident. Shannon Airport's reputation for security was tarnished in 2002 when a man committed a major security breach by managing to scale the perimeter fence at Shannon Airport and daub slogans on a US Hercules plane.

Other occasions involving the Airport Police at Shannon ranged from the sombre to the celebratory including providing a guard of honour to the airport boundary for the Dunhill British Masters winner Christy O'Connor Jnr when he arrived. A mournful memory was the Airport Police and Fire Officers lining the apron at Shannon Airport with an honour guard of Timoney fire tenders in November 1991 to pay their last respects to Professor Seamus Timoney, the inventor of the full independent suspension fire tender which was in use at all Irish airports including four at Dublin, three at Shannon, with a fourth on order at the time, and two in use at Cork Airport.

The Airport Police and Fire crews were a key group of airport workers. This was a fact they would use to their advantage by interrupting airport operations several times during their history as their positions and responsibilities were put under threat by the changing time. This was especially true in the 1980's and 1990's when the introduction of new security units and the lack of pay parity across the Force and with the Gardai were high profile issues. In March 1998, in support of Ryanair staff, the Airport Police even closed the airport, the only time this had occurred in over 60 years of operation. 1996 brought job loss fears for the Airport Police arising from plans to introduce outside security firms. A strike was threatened that would shut down the three airports but this was avoided as talks eventually progressed and a ballot of the 350 Airport Police across the airports took place when talks were completed successfully. A few short years later in 1999, the Airport Police balloted for an industrial action in a row over setting up a new safety unit. In 2001, they undertook an industrial action that would have had maximum action on Dublin, Cork and Shannon airports at one of their busiest periods - the bank holiday weekend in August. The 270 employees were seeking enhanced pensions as part of a redesignation of jobs which provided them with a 15% pay rise on top of the Programme for Prosperity and Fairness. In return for the agreement by management to the increase, the Airport Police agreed to the establishment of a new grade of hand-baggage checkers known as 'friskems' - x-ray machines which scanned for potentially dangerous items. The pay deal linked Airport Police to fire brigade and Garda pay scales and improved relations between the Airport Police and Gardai.

Further unrest arose in 1989 over desparity in night duty pay within the Force with the 100 members of the Airport Police at Shannon Airport threatening to take industrial action following the rejection of their claim for an increase in night duty allowances that were set at £6.05 at the time. The members of the Force in Shannon wanted parity with their colleagues in Dublin. Shannon Airport Police also protested in 1989 when Pan Am staff were found to be checking hold luggage following the Lockerbie disaster. The Airport Police argued it was illogical to have a highly trained security force in the airport who did not have responsibility for all security checks. The Shannon Force also walked out over a weekend in 2002 over the disciplining of two union representatives, leaving managers to search suspect passengers and man fire engines in their place. Though a serious situation, the Gardai were not called in to cover for the striking policemen. Job security was again at risk for the Airport Police in 2001 when Shannon Airport management raised the prospect of outsourcing the security aspect of the Airport Police Fire Service, at the time, planning to bring in a private security company to carry out the duties of the Airport Police, while maintaining the fire rescue element of the operation.

Re-organisation of the Aer Rianta Airport Police Fire Service came about in 2004 as a result of the legislature of Ireland passing the State Airports Act, 2004. The Act was designed to separate out the three state airports, each having its own separate board for management, setting them to operate as independent and competing entities but all three initially under the control and ownership of a single newly created Dublin Airport Authority (DAA). By the Act, the DAA was given authority to appoint authorised officers for Dublin Airport and the Cork Airport Authority and the Shannon Airport Authority were granted the same responsibility over their airports that would take effect when they eventually take over management of their respective airports. The Act also extended the authority of the authorised officers previously appointed by Aer Rianta until the appointed day on which the DAA assumed responsibility of the three airports in 2004. The officers of the Aer Rianta Airport Police Fire Service had the opportunity to transfer to the Airport Police Service (APS), or Póilíní an Aerfoirt, as operated under the new DAA.