QG Air AW139 blade strike
 

"The ATSB is investigating a main rotor blade strike involving a Leonardo s.p.a helicopters AW139, registered VH-EGK, near Caboolture, Queensland, on 20 June 2020.During winching operations, the helicopter's main rotor blades struck a tree. The crew returned to Archerfield, after which inspection revealed the majority of the main rotor blades had sustained damage. One blade tip was substantially damaged. The blades were removed from the aircraft, inspected and have now been forwarded back to the manufacturer for repair. Replacement blades have been fitted and the aircraft returned to service.

As part of the investigation, investigators will be interviewing flight crew, medical crew and maintenance personnel. The will also examine components, and local weather conditions.

Should any safety critical information be discovered at any time during the investigation, the ATSB will immediately notify operators and regulators so appropriate and timely safety action can be taken.

A final report will be published at the conclusion of the investigation."

Investigation: AO-2020-031 - Main rotor blade strike involving Leonardo s.p.a helicopters AW139, VH-EGK, near Caboolture, Queensland, on 20 June 2020

Why has the damage been classed as substantial if blades have been replaced and the aircraft is operational again? Is this a standard classification after blade damage?

Aircraft details

Aircraft details Aircraft manufacturer Leonardo Helicopters Aircraft model AW139 Aircraft registration VH-EGK Serial number 31827 Operator State of Queensland represented by Public Safety Business Agency Type of operation Medical Transport Sector Helicopter Damage to aircraft Substantial Departure point Archerfield, Queensland Destination Royal Brisbane Hospital, Queensland

How long is the hoist cable?
How high were the trees?

In a Huey -1H, with a 275' cable, I never got close to a tree strike, but in the B model with 90' cable, there were plenty of times that I came awfully close. In a B206 with 90', I did come home with green tips once, but engineers checked and some polish was all that was needed. Thank you Mr Bell.

Interesting to note that .... "The crew returned to Archerfield" .... I wonder if a "land immediately" and check the damage may have been a more appropriate action rather that a 20 min return flight?

AC ... the cable is 295' on the AW139 (Breeze) ... as for the trees in this situation, no idea, but regardless of the height of the trees, something has gone wrong to have hit them.

It's not clear if this was on a training sortie or and operational rescue - any info?

Hmmmmm....

Particularly as the same thing happened there a few years ago and the pilot was criticised for flying back to base.

I'm surprised a blade strike that required removal of all blades didn't also require the removal of the MGB for inspection or overhaul.

"It's not clear if this was on a training sortie or and operational rescue - any info?"
ATSB report states destination as Royal Brisbane Hospital, so likely a tasking.

My thoughts exactly.

Wow, how things have changed over the years, in Borneo in the early sixties, during the confrontation, this was a regular happening. The army would make a clearing by blowing trees up, the whirlwind tens would take a blade hit trying to get into the clearing, they could not land because of the tree stumps, so had to back out, being mind full of the tail rotor.
Pilot would radio back, and return to a suitable river bank, where he would land in the shallows and shut down. In the meantime and airframe fitter would have been positioned on top of the bank, at blade height, armed with a hand drill, and pop rivet plyers. Three tips would be changed, and aircraft on its way again.
I guess that you could not do that these days, as the old Whirlwind had a VNE of only 95 knots.
Any one wanting a good read of those days, get hold of a copy of Borneo Boys, by Roget Annett, ( Pen & Sword)
It also dispels some of the myths about the Belvedere, which actually lifted 95 000 troops and 10 Mlbs of freight in 4500 operational hours.

After any blade strike, if you aren't thinking about:

Blade damage and subsequent breakup.
Out of balance forces.
Vibration and tracking issues.
Shock loading of gearbox and transmission components.
Misaligned flexible couplings

...you probably aren't thinking much at all. An inquiry some years ago into a critical casevac following a blade strike (blade struck the casualty before he was a casualty! - let's hear it for Kevlar walking caps) was wholly positive about the fast reactions and response time of the crew, but some what churlishly pointed out that if the blade had come apart in flight on the way to the hospital, it would have been a more disappointing outcome for everyone.

Steel blade tips on metal blades with chalkboard tracking worked in the day, but with composite blades and complex load paths, every blade strike is a potential disaster unless a qualified person checks it out.

Agreed, had a strike with a full sheet of thick plywood in a Huey while taxiing down a line of revetments, resulted in a bad vertical, landed immediately, the mast had been twisted some degrees said maintenance. Can only imagine the loading on the gear box teeth. The strike was perpendicular to the full face of the plywood so the loading doesn't bare thinking about.

Casa will be more concerned about, the pilot flying back to base , knowing a blade strike occurred .

ATSB will be to concerned about writing there little comic piece

Good grief. It's like you guys have never come across a blade strike before.

"Shhh, we'll remove all our damaged blades, send them back to the OEM and not tell them how they got damaged. They'll just repair them, no questions asked, and send them back. Tee hee hee".

Not how it happens. Download FDR. Fill out Occurrence Report. OEM looks at report and FDR and determines what other components must be inspected and/or replaced. Customer complies with requests. Once complied with, OEM supplies a letter allowing the Return To Service of the machine.

The conditional inspection after a blade strike requires manufacturer involvement to determine the actions required.
Leonardo will determine what needs to be done.

Preliminary report issued 12/08/20: https://www.atsb.gov.au/media/577845...031_prelim.pdf