Australian airlines reviewing flight deck security as Air New Zealand moved to ensure two crew members remain in the cockpit at all times.

The security flaw was raised after the co-pilot of Germanwings flight 4U 9525, Andreas Lubitz was said to have barricaded himself inside the cockpit of an Airbus A320 and directed the plane to descend at a steady pace into tall mountains in the French Alps.

The crash killed 150 people and given the 700km/h velocity of the A320, left it in small pieces.

• Who was Germanwings copilot Andreas Lubitz?
• Germanwings copilot crashed deliberately: prosecutor

Increased flight deck security was introduced to block unauthorised entry after the hijackings of September 11, 2001, which ended in two planes flying into the World Trade Centre in New York on September 11, 2001, and one into the Pentagon building outside Washington DC. Another other plane crashed into a Pennsylvania field.

But it appears the rules in this case have made the co-pilot impervious and the passengers doomed.

Qantas is analysing information from the French investigation. Photo: AAP

Qantas has said it will hold off from making changes for now.

“We are monitoring the information coming out of the French investigation and considering if any changes to our existing safeguards are needed. This includes discussions with regulators.”

As questions arose about the mental health of Lubitz, Qantas said it annually evaluates pilots under 40 with aeromedical testing, and every six months in older pilots.

“Pilots have access to confidential counselling services and safety reporting channels,” a spokeswoman said.

The New Daily is aware that the Department of Infrastructure are all reviewing their responses to the flight deck security issue.

Virgin Australia provided the following statement when asked about its response to the Germanwings disaster:

“Safety is the number one priority for Virgin Australia. The Virgin Australia Group continuously undertakes detailed risk reviews, including consultation with the relevant regulatory and industry bodies.

“Any updates regarding changes to our processes will be provided where appropriate.”

A spokesperson for Virgin said the airline already required pilots to undertake regular aeromedical exams, include mental health assessments, while many other safety provisions remain confidential for security purposes.

“The risk of making any changes to in-flight procedures must always be properly assessed to ensure the highest possible safety standards are maintained and that any changes do not open other potential vulnerabilities,” the spokesperson added.

Tiger Airways has also been approached for a comment.

Air New Zealand joined Air Canada, Norwegian Air Shuttle, Lufthansa, Air Berlin, Easyjet and other charter airlines who have all changed their procedures to ensure two crew members are on deck at all times.

The United States based Air Line Pilots Association said the two-crew policy was already in place for American, and some Canadian, airlines.