A key safety change which would help the air force find its staff after crashes has yet to happen even though it was recommended by an investigation into the fatal Anzac Day helicopter accident two years ago.

The air force says a plan is under way to equip its staff with upgraded personal locator beacons which carry a GPS function, meaning missing air crew can be found when the devices are activated.

The upgraded beacons - which cost about $500 each - were one of the recommendations made by the air force's court of inquiry into the April 2010 accident, which killed three servicemen and seriously injured Sergeant Stevin Creeggan.

Minister of Defence Jonathan Coleman has ordered an inquiry into the progress of the court's 27 safety recommendations. The air force has signed off four urgent improvements which were carried out in May 2010. Others are expected to be signed off as completed this month.

The upgrade of the beacons would mean survivors such as Sergeant Creeggan would be found more quickly, with GPS constantly signalling their location. Existing beacons relay a location only occasionally.

Sergeant Creeggan was found by Flight Sergeant Darren Smith, who was awarded the Distinguished Service Decoration after a 2km dash uphill to find the crashed Iroquois.

His search on foot began about 80 minutes after the crash and about the same time rescuers finally pinned down one survival beacon signal from the downed helicopter.

The court of inquiry found two beacons had actually been turned on after the crash but a signal was received from only one of those.

Investigators found Sergeant Creeggan had activated the beacon attached to Ben Carson, who was killed, as he crawled from the wreck.

Sergeant Creeggan also removed his own locator beacon from the life preserver vest before turning it on. The removal meant he had to fix a new antenna to allow it to broadcast.

When found, Sergeant Creeggan's beacon was trapped under him with its antenna incorrectly connected and running on low power.

The single signal picked up from the crash site was later found to have come from Corporal Carson's beacon.

It was picked up about 20 minutes after the crash at 6.09am although it initially broadcast its location off the coast. It did not report the correct crash location until 7.05am.

An air force spokesman yesterday said the plan to upgrade the beacons was "under action" and had been "marked as complete". The beacons had not yet been fitted with GPS.

He said the air force found the beacon showing low battery had done so because it was not "correctly deployed". No procedures had changed since, even though Sergeant Creeggan was seriously injured when he tried to fit the antenna.

Safety inquiry

Why is air force safety an issue?

The crash which killed three RNZAF crew and seriously injured another on Anzac Day 2010 was avoidable. The inquiry into it found safety failures, internal confusion over standing orders and potential air force-wide issues.

Were there safety changes made?

There were safety changes ordered. The Court of Inquiry made 27 of its own recommendations and endorsed 51 other changes recommended as part of the investigation. They range from locator beacon upgrades to ground proximity warning systems through to studying wider air force issues.

What has happened since?

Four of the main recommendations have been signed off after being completed with urgency in 2010. Another nine (or 27) are scheduled to be signed off this month.
Who checks the progress on the safety improvements?
Defence Minister Jonathan Coleman has ordered an external review to check on the air force's progress.

What have external inquiries found?

There has been no external inquiry. The former Department of Labour should have done one but didn't realise it was meant to. There is also an inquiry into that.

By David Fisher @@DFisherJourno Email David