Cracks found in RCAF Cyclone
 

CBC News is reporting that serious cracks have been found in the Cyclone helicopters stationed in Shearwater.
https://www.cbc.ca/news/canada/nova-...acks-1.6273953

CBC has updated the story and are now reporting 19 helicopters that have been grounded due to cracks. https://www.cbc.ca/news/canada/nova-...acks-1.6273953

Luv how they are listing various S-92 / cyclone incidents to add drama and alarm to the story. NOT.

This Canada's national broadcaster at its finest

Cracks in tails of RCAF Cyclone helicopters
 

That ain’t good.

https://www.cbc.ca/news/canada/nova-...pert-1.6274439

Instead of listening to Michael Byers, a professor and defence policy analyst at the University of British Columbia, why not listen to someone who understands the aircraft and why it may be cracking? I love the way they keep drawing parallels with the S-92. My company contracts a fleet of S-92s some of which are 15 years old, we don't have any tail cracking problems. The CH148 has a higher MTOM, folding blades and a folding tail. The S-92 tail is a hostile enough area without adding the complexity of tail folding.

I like the other expert's explanations!

Me too, remember, “ expert” ex, has been, spurt, small drip of water under pressure.

Why is nobody happy they found the cracks before someone got hurt ?
Just replace the parts and be happy , maintenance is always cheaper than an accident .

Might not have been expected in Aircraft that are still brand spanking new. Replacing cracked tails can be quite expensive. Moreover: How to ensure that in 5 years from now you don't have the same mess, next time possibly even with an accident?
I can somehow understand irritation in this case.

They had problems with cracks on the Cormorant too, both the windscreens and the TR hub ISTR.

Additional S-92 Modifications required to meet Canadian Requirements
 

There are a few modifications to the S-92 that had to be incorporated in the CH-148 to accommodate Canadian requirements. Blade and pylon fold are just a few. In addition, the CH-148 required an increase in main rotor diameter. Unless the actual airframe was increased in length, this would have reduced the clearance between the main and tail rotor arcs. This could be a contributing factor to tail vibration signatures with resulting cracking.

The only one calling the cracks “Serious” is the so called “Expert”.

Albatross Given that they grounded 19 out of 23 aircraft with 2 already out of service for maintenance. How would you catalogue the situation if not Serious, Normal wear and tear ?

The military tend to take a very conservative approach until they have the full picture.
Example Navy Gazelle found with a broken rear undercarriage crosstube. Alll aircraft inspected and any with signs of internal corrosion are grounded. Result 80% plus non operational until repaired or a war breaks out.

I do not argue that having nearly all the aircraft out of service is a cause for concern.
However having the cracks defined as serious is another matter. I see no mention of the military defining the cracks as serious. They did not say if the cracks are affecting the structural integrity of the airframe.

I am surprised and concerned that these cracks were not discovered long before they developed in so many airframes.

MSN now reporting that the Cyclone has software issues which showed up from the crash last year. 'Scope' and cost of software fix to naval helicopters expected in spring 2022 (msn.com)

The early years of ANY aircraft is riddled with teething issues - some serious, some not so serious and sadly, some continually. But the one thing any OEM can’t do is tell the future for all operators - who all operate with different envelopes, equipment, enviroment, methods, weather and particular situations. One size does not fit all.
The maintenance systems you use have worked and they have raised the issue of cracks in the same areas - pooh happens! A repair will soon be formulated and some of your aircraft will be back on your Lines soon enough. Wait till your told you can fly again and stop wingeing….sit in the Sims for a while and dream of being a winged god another time.

Sikorsky has issued a service letter to the S92 civil fleet, that these cracks found on the Cyclones have not or are not common on the Civil fleet. The cracks are reported as minor at STA 599 of the aft transition area and does not affect the primary structure of the Aft transition area. They go on to say due to Unique aspects of the CH-148 airframe alter load path reason for this cracking.
Repairs are covered by the SRM ( Structural Repair Manual). If you see the photos will see the cracks are very small maybe one inch or two and require a small doubler angle to be installed. No changes to the existing inspection schedule are expected , follow the existing 1500 hour inspections schedule.
Please don't ask I cannot post the photos.

Cracks in airframes are something engineers have to deal with continuously. Remember a tarmac hand pointing out a large crack in the fin of a 212 to the crew as they were loading on a turn around. Rebuilding 205 and 212 tail booms kept engineers in gainful employment.

Question:
Are the new, more powerfull engines installed to provide better OEI power or do they provide higher torque limits for normal twin engine operations? Have torque limits on the transmission been raised vs the S-92?

Update, RCAF now saying cracks caused by heavy equipment
 

Two news agencies now reporting that cracks were caused by equipment installed in the tails.

https://ottawacitizen.com/news/natio...-been-repaired

https://www.ctvnews.ca/politics/tail...-dnd-1.5761819