2175301 wrote:

No; but many companies - including MRO's bring in contractors to do work that they do not have the technical abilities to do. A MRO can easily hire them.

No they cannot, little issue called the FAA. Performing structural modifications on aircraft requires FAA accreditation by the people performing the work.

2175301 wrote:

2/3 of the NDE companies I have worked with in the nuclear world also do aircraft and aircraft part NDE inspections at various aircraft service centers, airports, and in some cases at part manufacturing facilities.

And to perform those tasks on aircraft parts the organization, the people, and the equipment used have to be FAA accredited. Every aspect f the process has to be traceable.

2175301 wrote:

I'd estimate that this cost could drop to as low as $5000 per hole if a company trained their own people and had the right equipment on hand once the rail and drive head system exists.

Thanks for a good laugh, if only you knew how far $5000 doesn't get you in aircraft maintenance.

fcogafa wrote:

The article is behind a paywall and I can't read it. I used to be able to get a few free articles from Flight Global, but now I can't even log in without subscribing. Can anyone post a short summary?

From FG....

Tom Crabtree, then a regional director for business strategy at Boeing Commercial Airplanes, casually gave the secret away in a presentation to journalists inside the company's sprawling factory complex in Everett, Washington.

Buried in the blueprints of the all-composite fuselage of the new widebody are the provisions to quickly transform the 787 from an airliner into a pure freighter, Crabtree said.

"We worked with the initial design five years ago during the initial sizing of the airplane," said Crabtree. "We have routed the systems such that the area where the main deck door would go are clear of any reroutings, say, [of] electrical or hydraulic lines."

"Long term, we have designed provisions into the [787] when the market demands it to allow that aircraft to become a freighter," Crabtree said.

Good Boeing had the foresight to have the 'designed provisions' approved BM (before MAX) when airworthiness authority approvals were easier and softer.

zeke wrote:

iamlucky13 wrote:

I would not use asbestos as an example for comparison either of the hazards or of the mitigation. It's a different material used in different ways.

The use is irrelevant, carbon fibres once in the lung cannot be removed by the body like abestos. There have been significant changes in occupational heath over the years, even dry cutting solids containing silica wasn’t considered a hazard until recently.

I'm just going to simplify this and tell you from a position of experience that cutting carbon fiber is not a fundamental problem for a 787 freighter variant. Vacuum capture, respirators, and cleaning procedures all are demonstrated methods of controlling the risk of fiber inhalation, usually as a combination of those practices.

My current job and my last job both have been in business that produce carbon fiber products. We're actually using water jets less and mechanical machining (usually, but not always with coolant) more due to better tolerances and the range of operations possible. Manual trimming (usually with vacuuming, but without coolant) is also used to a limited degree in our normal production for cutting not feasible to do in our milling machines, as well as outside normal production such as when rework is necessary or during destructive evaluations.

I would not rate the safety culture of the previous job as remarkable, but at my current job, we have the most proactive safety culture I've seen anywhere, and very routinely create internal policies that exceed OSHA standards, where as most businesses focus on just meeting the minimum.

I have not had reason to look up all the documentation our safety team has that was used to set our airborne fiber protection practices, but from what I have seen at my current employer, I have very high confidence we have the risks very well controlled.

Therefore, I likewise have very high confidence if Boeing wants to design a 787 freighter, they can control those risks without having to deal with onerous safety challenges.

zeke wrote:

iamlucky13 wrote:

The simple fact is that mechanical trimming of composites and controlling respiratory risks from fibers liberated as a result has been done for decades now. There are precautions involved that need to be planned for when developing a production system, but they are not onerous.

Nothing to the scale of a cargo door installation in place on an aircraft. Again you are confirming my point, there are significant occupational health issues that have to be prevented. Same could be said for painting, some states eg California simply elect to ban the risk of some chemicals used in aircraft painting.

Yes, to larger scales than cargo door installations. You can continue doubting me on this, as I'm not going to publicly state my background to explain why I am so certain about this, but I am asserting it is demonstrated practice that trimming carbon fiber on parts the size of cargo doors is viable and can be done safely.

I'm not going to make as strong of assertions about frames versus relying on lap joints, as I wouldn't know what either Boeing or Airbus has in mind for cargo doors in composite fuselages, but I strongly suspect that in a few years when we hopefully get to see pictures from inside the A350F, we'll see a frame very similar to what gets installed for aluminum fuselages.

DenverTed wrote:

9Patch wrote:

Scott Scott Hamilton and Bjorn Fehrm at Leeham News and Analysis have a new post up about the proposed A350F. It details the specifications of new plane and how it stacks up against the Boeing 777F and future Boeing freighter offerings. One paragraph that jumped out at me:

The 787 doesn’t lend itself well to a freighter. Boeing has a challenge with doing a cargo door in a barrel composite airplane. Airbus chose the panel approach for the A350. Was Airbus thinking about a cargo version of the airplane, or did it just happen to work out that way?
https://leehamnews.com/2021/11/11/airbu ... more-37783

This is the first time I've ever heard this. I thought Boeing designed the 787 with a freighter version in mind. Are they talking about P2F conversions only, or new build freighters?

Yes, new build or conversion form passenger to freight?

The article didn't specify whether they were talking about a new build or a conversion.
Nor did it identify any specific challenges they might encounter doing a cargo door in a barrel composite airplane.
Not their best effort, IMO.

zeke wrote:

2175301 wrote:

I can name one contractor off the top of my head that could do the job including controlling and cleaning up the fiber release to 1mm accuracy without breaking a sweat and in full compliance with all safety regulations (they can do more accurate tolerances if you spend the money for a more ridged track and more tight tolerance cutting head).

Are they a MRO ?

One doesn't need to be an MRO to work on an aircraft, if you do so under the control of an MRO or an airline.

Weatherwatcher1 wrote:

zeke wrote:

Polot wrote:

Everything obviously depends on where the cargo door is (forward or aft of the wing) and the variant. For the 788 things might get tight but possibly doable with cargo door far forward but with the 789 it looks like there may be room behind the wing. For 788 avoiding barrel join behind wing might be difficult due to clearance concerns with wing. For new builds all of this assumes, of course, that a freighter has to have the same length barrels as the passenger variant though.

Industry best practice these days is to have the main deck cargo door behind the wing so the aircraft does not get tail heavy loading or unloading.

Industry best practice is to put the door behind the wing if there is enough space. 777s, 747s and A350s have aft cargo doors since there is enough clearance between the wing and stabilizer. A330s, 767s, 737s, 757s, A321s etc all have the cargo door in front of the wing.

You're talking belly cargo, zeke was talking main deck.

zeke wrote:

2175301 wrote:

No; but many companies - including MRO's bring in contractors to do work that they do not have the technical abilities to do. A MRO can easily hire them.

No they cannot, little issue called the FAA. Performing structural modifications on aircraft requires FAA accreditation by the people performing the work.

2175301 wrote:

2/3 of the NDE companies I have worked with in the nuclear world also do aircraft and aircraft part NDE inspections at various aircraft service centers, airports, and in some cases at part manufacturing facilities.

And to perform those tasks on aircraft parts the organization, the people, and the equipment used have to be FAA accredited. Every aspect f the process has to be traceable.

2175301 wrote:

I'd estimate that this cost could drop to as low as $5000 per hole if a company trained their own people and had the right equipment on hand once the rail and drive head system exists.

Thanks for a good laugh, if only you knew how far $5000 doesn't get you in aircraft maintenance.

All work in nuclear plants have to have appropriate accreditation to nuclear work standards as well and at least 1/3 of the NDE contractors I hired and supervised in the nuclear world have both the appropriate aviation and nuclear accreditations.

You seem to think that no one in the Aviation world hires contractors to do work. Of course they do... NDE is the most common; but their are other contractors for other things.

I doubt that Aviation work is any less expensive than nuclear work. The NDE contractors tell me that their billing rates are the same for both. One mechanical contractor told me the same. In fact, its likely less in the aviation world as the people do not have to go through a security clearance and radiation protocols. It often takes 3 days to get an experienced person from reporting to onsite to inside the plant and at least a week for someone who has not had nuclear facility access in the last year. In nuclear we have to pay them for that and all per-diem cost. Aviation does not have that.

That $5000 was for labor cost only if a company has all the equipment and processes set up; and all they have to do is assemble and and plan the specific job, execute, cleanup, closeout, with all QA as well. I admit that it cost a lot to set the processes up and building the frame and drive head would not be cheap as well.

WayexTDI wrote:

Weatherwatcher1 wrote:

zeke wrote:

Industry best practice these days is to have the main deck cargo door behind the wing so the aircraft does not get tail heavy loading or unloading.

Industry best practice is to put the door behind the wing if there is enough space. 777s, 747s and A350s have aft cargo doors since there is enough clearance between the wing and stabilizer. A330s, 767s, 737s, 757s, A321s etc all have the cargo door in front of the wing.

You're talking belly cargo, zeke was talking main deck.

No I wasn’t. I was referring to the main deck door.

zeke wrote:

fcogafa wrote:

From FG....

Does the same article also say

"On the other hand, there are no guarantees
that the 787 will find other roles, and some analysts
wonder if the aircraft’s design philosophy
will prevent its success in other markets.

“One problem is that the 787 is designed
with minimal margin tolerances, while older
jets were designed before [computer-aided design/
computer-aided manufacturing] became
an extremely precise tool,” says Richard
Aboulafia, vice-president of analysis at the
Teal Group."

"“The 787 freighter concept is extremely
premature. Cargo planes in this class tend to be
conversions, which are useful for maintaining
asset values but typically only kick in
after 15–20 years of airline service, at least,”
Aboulafia says.

Boeing’s 20-year market forecast shows that
it expects the market for a 787-sized freighter to
shrink in the future. In 2009, freighters with between
a 40-tonne and 80-tonne payload capacity
represented 36% of the market, according
to Boeing’s latest World Air Cargo Forecast
2011. In 2029, the same market is projected to
account for 27% of all freighters."

That market analysis would count for pretty much nothing now. It's a whole new world compared to 2009, you just need to look at how many 767's and 330's are too be and have been converted and they fit squarely in that payload size. Add in the 777's that are to be converted and the fact that MD-11's have been brought out of storage, MD-10's are still flying and even 747-200's have been brought back from the dead, just shows how much that market size analysis can be discarded.