CHC AW 189s
 

Hearing a rumour that the CHC AW189s have been grounded in Karratha, Australia due to being inadvertently operated 200kg over weight? Anyone know anymore detail?

Excuse my ignorance...but grounding an R22 for being operated 200kg over weight I could understand, but a AW189, seriously?

Overweight is overweight! What would you expect? That'll be fine, mate ... crack on? Or an inspection to make sure you havent damaged something which is going to show it in 50 hours time?
Good grief!
:rolleyes:

In all of my years in this business I've never heard of grounding an aircraft for an over weight inspection...

Hence why if it did get off the ground some sort of inspection would be due...as for an 8 ton helicopter, I wouldn't have thought 200 kg over would cause much of a whimper from the airworthiness maintenance aspect.

How long might it have been routinely operated overweight? How much much stress might have all the different components been subjected to after an unknown number of cycles of perf class 1 & 2 takeoffs, helideck landings etc? If it was overweight, was it also way outside C of G?
Of course these questions have to be considered before you can release an aircraft back to service after it has exceeded its design limitations. What if it crashed tomorrow? Do you think the management staff would be justified in saying, "Well, we were only a bit illegal, as its a big aircraft, so we thought we would just ignore it and keep our fingers crossed".
Have you ever heard of a safety culture?

Apparently they did fine if no one noticed.
Bring the MGW to 8800 Kg then!

Just what might such an inspection begin to look for that would manifest itself visually?

This brochure shows an approved 300 KG upgrade in Max Gross Weight if I read it correctly.

https://www.leonardocompany.com/docu...89Offshore.pdf

I would be less worried about the "over weight" than" how and why" it happened!

But that 300kg upgrade will require additional equipment/modifications and/or adjustments to the performance graphs - that is what happened with the 139.

If the standard aircraft was fit for the additional weight increase then it would have been certified as such in the first place.

As Non- PC plod says - overweight is overweight and at the very least you need to assess how much and for how long and then carry out inspections and perhaps calculate time penalties for critical components.

What would happen if you crashed during a PC1 departure because you were outside the WAT graphs? What would your insurance company say and how long would your licence last - remember ass, tin, ticket SAS?

The 8600 Kg is already on.

Bit quick to jump into the Weeds are you Crab?

You assume of course the Pilots knowingly operated the aircraft 2.5% over the 8300 kg weight limit.

Perhaps they did not know....thus why would their "Ticket" be in jeopardy?

Now if like in the "Iron 41" S-61 Crash.....had the Operator provided the Pilot's bogus Weight and Balance and WAT Data....it would be the Operator and not the Pilots that were in violation.

As the weight was upped by 300 kgs....perhaps not as much damage was done as might be assumed.

Again....I am more concerned how such a thing happened and let the chips lay where they fall following the inquiry.

The Carson culprits wound up in the Gray Bar Hotel over their falsifying FAA and USFS documentation.

By the way....I lost a friend in that crash so I do fully grasp the significance of such issues.

As Crab says, they dont normally just "up" the weight without, for example, beefing up the landing gear. I have no idea what a post- overweight ops inspection might include, but it may not be purely visual. Maybe they would re-examine HUMS data, do some NDT on particular components etc.
SAS - I agree completely that there is something even more worrying in the SOPs if the aircraft are dispatched overweight, but for the airframe, you cant just treat it as if nothing has happened.

Operational Control weakness is what Malabo is referring too. The 139 overweight issue was directly due to the fact that they screwed up their W&B and never caught it. He isn't saying the 139 has weak controls.

They flew the 139's overweight for a number of weeks before the "anomaly" with the weight and balance was found and the aircraft were grounded pending Leonardo prescribing inspections for returning the aircraft to service.

I imagine the percentage over max gross would be the number they'd look at it for any penalties

It was quite a while ago now. I believe I was still a Crew Chief at CHC Global when it happened but can't be 100%sure. Might have been just after I left. It was certainly before the 7000kg upgrade came out. I either heard about it through SQID reports or company email. Just not sure which company :)

And yes, as a Licenced Aircraft Maintenance Engineer I am very familiar with weight and balance and I also know that when you had a crap load of loose equipment/survival equipment to the aircraft, it needs to be recorded.

If you sign for the aircraft and spank it in following a performance chart that the mass of the aircraft exceeds - whether it is an engineering snafu or just not checking the C of G and Mass properly - it's still going to be the pilots fault.

Fortunately - and it seems so in this case, the error was noticed (sometime later) and the only red faces are the engineers who got their sums wrong. I have challenged weight and balance sheets before when thing didn't look quite right as I am sure many here have.

Perhaps the pilots may have noticed if it was outside cg? Like, unable to control the attitude on pickup, rapidly put it down again?

This issue (overweight CHC 139's) was discovered about 6 years ago. It wasn't the whole CHC 139 fleet in Australia as someone has suggested, but just 2 aircraft in Karratha (the only ones on contract) in the offshore role. Weight and balance was calculated in good faith before each flight, with operations planned within PC1 limits, and the aircraft were never knowingly operated overweight. This went on for nearly 2 years from memory. Two new aircraft then arrived on contract and the RFM empty weight of both was around 200 kg heavier than each of the "old" aircraft, for no apparent reason. The original aircraft were then re-weighed, and subsequently found to be approx. 200kg heavier than the aircraft empty weight recorded in their respective RFM's. Nothing to do with incorrect sums or equipment not being counted, so no matter how diligent you might be in checking your paperwork before flight you would not have detected the error. I don't recall exactly how the original incorrect empty weights in the W & B section of the RFM occurred, but I believe they were there when CHC Oz took delivery.

Crab stated this......


Mark Six told us this.....


Crab also told us he has challenged "questionable" W and B Data in the past.


So, Crab young Lad, please do explain exactly why you would "blame" a pilot for a 200 kg error in the W&B data used when it comes directly from the RFM for that particular aircraft he is flying that day and had done what Mark Six points out?

We are talking about a two and a half percent error....that is not very much.

The only two aircraft on the Operation had similar errors and similar weights per their RFM's.

You really think it was the Pilot's fault do you?

Explain please....just how was a Pilot on that Operation supposed to determine there was a problem?

Please do not try to tell me they should have known from the performance (or lack of.....) felt each time they flew the machines....as that Dog won't hunt!

Sas - you are like the proverbial dog - not a hunting one but one with a bone:)

My only point was that an investigation into an accident that was caused by operating overweight would inevitably focus on the pilot who would then need a very staunch defence to prove it was manufacturers/weighing/role equipment discrepancies et al to blame.

Fundamentally you sign for it you are saying you checked it.

My point is simple....you do your job properly....and carry out the preflight planning and related procedures and you cannot be found at fault.

The Pilot has to rely upon the data he is provided being accurate re Weight and Balance and Engineering actions that lead to the Aircraft being presented as "Serviceable" and safe for flight.

Absolutely the Pilot's actions will be examined but it would be an absolute defense against civil, criminal, or administrative action if he can demonstrate he took the proper actions.

Likewise....as in this case.....it is the Engineers who signed on the dotted line that would wind up carrying the bucket (or should).

As part of the Certificate of Airworthiness....the aircraft should have been inventoried, weighed, and a CG calculated per the Authority's Regulations.

Once that is done....that data is entered into the Aircraft Documentation.

The Pilot's calculation should have confirmed the Mission Equipment and other items were accounted for when he did his own W and B calculations prior to flight.

I cannot remember ANY time a Line Pilot has queried the basic weight and balance data for the RFM/Aircraft Records as part of his daily preflight preparation.

I have as you have said....challenged a weight and balance report AFTER discovering unlisted items on the Inventory (four sets of Speakers in the cabin overhead behind the sound proofing and some other items)....and was very dismayed by the Company's reaction.

But then.....knowing the Company in question that really did not surprise me.

When one finds a tail rotor pitch change link dangling loose after a Tail Rotor change....and the Logbook signed off as Test Flown and Released for Service.....and neither the Engineer or Pilot involved got reprimanded....what's a bit of extra kit on the aircraft and not on the W and B Documents.

Sas - you do need to get out more - you are spending so much time arguing every point on these threads you might be turning into he who must not be named on pprune:):ok:

If you start arguing about numbers of engines then I'll know you have lost it:)

Not so long back I was tasked with checking the details of a used helicopter for a potential buyer. When it came to checking the empty weight of the aircraft I studied the factory weight and balance schedule (in the individual RFM) to calculate a few typical mission profiles. Whatever calculation I did, the C of G was well outside the envelope. Even the zero fuel figure, with one pilot up front, was 4" outside the fore/aft limit. I asked for the aircraft to be re-weighed and this showed that the original factory figures were nonsensical and were nowhere near reality. I used the new W & B schedule for my original calculations and found the aircraft fore/aft C of G to be as close to neutral as any could be.

Two worrying things:
1) The factory figures should have been absolutely correct in the first place and whoever did the weighing should have noticed what must have been large discrepancies from normal figures on that type of aircraft.
2) I was probably the first person to ever carry out a mission W & B calculation on that aircraft. If the original figures had been correct, it had been inadvertently operated for almost four years with a C of G approximately four inches outside limits!

Air Navigation Order Section 2-43 pertains to Weight and Balance.

The Air Navigation Order 2016

"Must be weighed", "Must be documented", and "Must be provided to the Pilot" stand out along with a requirement to retain the old W and B Document for a period of Six Months following a re-weigh.

SAS, I don't know who your post was aimed at - but the aircraft I refer to was on the N reg...

The old schedule was retained for posterity and amazement.

The post was generic.....not directed to any individual.

As this is a somewhat UK Centric Forum....I was trying to use the UK ANO as a reference.

I can add the FAA Regulation if you wish.

The basic premise is the aircraft has to have an equipment inventory done, be weighed, and a CG determined based upon that data.....and that be the starting point for the Crew to determine the Weight and Balance of the aircraft when prepared for their particular flight.

If the data provided to the Crew is in error then naturally their calculations are based upon a false premise but due to no error of their own.

You were sharp enough to smell a Rat when your calculations kept coming up out of tolerances and then do a followup to determine what that cause was.

I would assume if the prospective buyer went through with the purchase he had the aircraft properly weighed and its correct CG determined.

That discrepancy would have raised some other Red Flags I should think.


FAA Information....

https://www.faa.gov/documentLibrary/.../AC120-27E.pdf

Yes, I did write that it was done .. ;)

Back to the AW189s, I heard from one of the drivers at CHC that the issue was an incorrect weight from the factory. The machines were grounded on the Friday, inspected over the weekend and back in service Monday. No biggy.