Bird strikes have emerged as a growing problem for aircraft operating in Ireland with almost 1,400 incidents reported in the past two years.
According to the Irish Aviation Authority's annual safety performance review for 2021, bird strikes were the second most common type of safety incident reported to the aviation safety authority during the period of the pandemic after system and component malfunctions in aircraft.
Bird strikes had only been the 5th most frequent type of safety event in the period 2017-2019.
A total of 1,379 bird strikes were recorded between 2020 and 2021, while a further 1,823 were logged over the previous three years.
The IAA said bird strikes were "one of the emerging risks" identified in its assessment of safety issues during the Covid-19 pandemic period due to the "increased presence of wildlife on aerodromes".
"As the level of aircraft movements reduced dramatically during the pandemic, there was a statistically significant increase in the rate of bird strikes experienced," the IAA said.
It said the increase which was "statistically significant" supported the general assessment across the EU that reduced aircraft operations had led to increased activity by birds and other wildlife around airports.
However, official figures show that the overwhelming majority of bird strikes are classified as low risk incidents.
They also reveal that bird strikes have only been responsible for one serious incident over the past five years.
IAA said the impact of Covid-19 on aviation also affected safety risks such as bird strikes, the storage of aircraft and the degradation of skills and knowledge of aviation personnel caused by their reduced flying.
"Due to its pervasive nature, it has the potential to act as a contributing factor in all the safety areas and safety issues identified and discussed," the IAA said.
Bird strikes are considered a serious issue in global air travel as one was responsible for one of the most famous incidents in aviation history when it forced a US Airways flight to crash land in the Hudson River in New York in January 2009.
All 155 passengers and crew on the aircraft survived in a rescue which was dramatised in the 2016 movie, Sully, featuring Tom Hanks in the lead role of the chief pilot, Chesley Sullenburger.
The IAA report shows a total of five non-fatal accidents involving Irish-registered commercial aircraft were recorded last year - the highest annual total since the same figure in 2017.
In addition, there were five serious incidents reported during 2021, which was the second lowest annual total over the same period.
The IAA said three non-fatal accidents and one serious incident which were reported last year related to passengers suffering an injury while disembarking from an aircraft.
Another non-fatal accident involved a cabin crew member and a passenger being injured during turbulence on a flight.
The last non-fatal accident was categorised as a ground collision.
The four other serious incidents were classified as a "significant component failure".
Over the past five years, the most common reporting event has been a system or component failure or some type of malfunction of which 11 have been recorded.
Since 2017, there have also been five incidents of runway incursions and five incidents of loss of separation or near mid-air collisions, none of which were recorded last year.
The IAA said the chances of being on a flight operated by an Irish registered aircraft that experienced a safety occurrence remains very low.
It noted that just 4,036 mandatory occurrence reports were filed last year out of over 550,000 flights - an annual increase of 27% in aircraft movements over 2020 but down 51% on 2019 levels.
"Over 99% of these flights passed off without any safety occurrence that required reporting to the IAA," it observed.
It claimed the vast majority of occurrence reports submitted to the IAA are classified as "low risk".
However, it added: "It remains important to monitor these events to ensure they remain under control."
The latest report shows there were 216 incidents of unruly passengers on aircraft in the past two years, which the IAA said was a heightened risk because of the pandemic, although all were categorised as low risk.
A total of 171 passengers suffered a medical emergency and 57 cabin crew became incapacitated.
There were also 175 incidents of interference by lasers, with about one-fifth of such events classified as a moderate risk.
During 2020 and 2012, pilots also reported 47 incidents of aircraft being struck by lightning.
The IAA also noted the unique fire hazard characteristics of lithium-ion batteries which are commonly used in many electronic devices such as mobile phones and laptops.
It claimed they posed "a significant safety risk that must be effectively mitigated and managed".
The aviation regulator, Diarmuid Ó Conghaile, said accidents and serious incidents in commercial aviation in Ireland last year showed reducing trends in many areas.
As the aviation industry endeavoured to rebuild after two years of the pandemic, Mr Ó Conghaile said it was regrettable that other disruptors had appeared on the horizon including the Russian invasion of Ukraine, rising fuel costs, disrupted supply chains, climate change concerns and cyber security threats.
"The intensive risk management skills gained over the past two pandemic years will be required in the monitoring of hazards and mitigation of risks in a fragile recovering industry over the coming year," said Mr Ó Conghaile.
The regulator said a healthy safety occurrence reporting culture was also required to gain the most accurate indication of how the sector was performing.
"The IAA encourages and welcomes the active participation of all involved in any aspect of civil aviation to report safety concerns to their organisation or to the IAA so that lessons can be learnt and safety levels continuously improved," he added.
The IAA revealed that 138 of the 660 commercial aircraft listed on the Irish aircraft register were in storage at the end of 2021 - the highest number ever recorded.
