Jetstar workers at Sydney airport were in danger of being crushed or “ingested” by operational aircraft or colliding with moving planes and engine fans, according to a SafeWork NSW inspection.

Jetstar has been issued two official notices by SafeWork, after an inspection on Thursday at the airline’s domestic terminal at Sydney airport.

In one case, it was found that ground staff were are at risk from the “frequent malfunctions” of a power unit used to push the planes back from the gate.

The notices came the day before Jetstar baggage handlers and ground crews began industrial action to ask for a pay rise and safer working conditions.

Ground crew, represented by the Transport Workers Union, are taking two two-hour work stoppages on Friday. Pilots, represented by a separate union, are also taking action on Saturday and Sunday.

On Friday, the TWU announced that ground crew would strike again next Thursday after negotiations broke down.

“Again we apologise to the travelling public for the disruption,” said TWU’s national secretary, Michael Kaine. “We want to emphasis that this is the only course that Jetstar has left workers to take.”

The SafeWork inspector said he “reasonably believes” that Jetstar had contravened sections 19 and 21 of the Work Health and Safety Act 2011, and clauses 39 and 213 of the Work Health and Safety Regulation 2017.

“Workers (ground crews) are at risk to health and safety from serious injury such as being crushed, ingested or other, when working around operational aircraft,” the notice said.

It said “inadequate workplace safety procedures” meant some crews were not specifically allocated to individual aircraft, and did not complete all their necessary tasks before being allocated to new planes.

Another notice, also from Thursday, said workers may be at risk of “collision with moving aircraft and rotating engine compressor fans during aircraft pushbacks due to the frequent and inadvertent malfunctions and breakdowns of the Schopf Power Push Unit”.

The power push unit is a remotely controlled wheeled machine that attaches to a plane’s landing gear and pushes it back from the gate. One unit, the inspector wrote, “frequently malfunctions and ceases operation”.

The airline was given until 20 December to fix the power unit and until the end of the year to rectify other issues.

In response to the SafeWork findings, a Jetstar spokesman said on Friday that the airline had high safety standards that had been regularly reviewed and approved by the Civil Aviation Safety Authority.

“We would never put the safety of our people or passengers at risk,” the spokesman said. “The TWU has a history of playing the safety card when it suits them, and this is another example of that.

“We have robust safety management systems in place which are regularly reviewed and audited by a range of regulators, including CASA. Our resourcing practices are consistent with global aviation standards and in line with other airlines.”

Kaine said ground staff had already suffered a range of injuries.

“In just a few months workers have reported a broken hand, detached bicep, concussion and shoulder, back and neck injuries that have required surgery,” he said.

“SafeWork NSW’s investigation of Jetstar confirms what workers have been telling us for months: that staffing levels at the airline are dangerously low.”

The TWU is asking for a 4% pay increase, more rest breaks and a guaranteed 12-hour break between shifts.

“Workers are expected to do the same back-breaking work – lifting thousands of kilos of baggage and operating heavy machinery – but with half the staff,” Kaine said.

“Jetstar also schedule fewer staff to work on multiple aircraft. It is leading to chronic fatigue and burnout.”