FCBS for DC10-30

[manuelo]

Hello:
I need to know about the fatigue critical baseline structure for the DC10-30 airplanes. It is about the Operator Implementation Plan that the company where I work is requiring to perform, and after send it for FAA MPI approval. I know that this list can be obtained from myboeingfleet portal, previous payment for getting access. But I would like to know if there are another source where I can obtain this FCBS list, as the fleet in the company where I work, is very small and Boeing apply very high charges for this list, including the compliance document and repair guidelines.
I hope someone can help me to answer this questions.
Thank you in advance.
Manuelo

 

[rb1957]

i feel your pain, brother ...

if getting the official FCBS definition from Boeing costs too much, here are a couple of thoughts ...

1) can you show that the strcuture you're modifying is obviously not primary structure ? maybe clearly not loaded by fatigue ?? if so then you've got an argument for saying that it isn't FCBS.

2) is the structure included in the madnatory inspection program ? if so then it could be considered as FCBS.

3) you could assume it's FCBS, derive some fatgiue loads for baseline operations (that may be nil), then derive fatigue loads for your installation (may be not nil !) and develop an inspection program. you could base an inspetion program on "nominals" (1/4 life repeat ??) but i think FAA don't like that approach (i think it helped create the monster that is Part 26 !)

btw, i did part 26 for my company

 

[737eng]

Not only is there a cost associated with the FCBS list but there is also going to be a cost associated with the Compliance Document/Repair Evaluation Guideline. I am not saying that you need this data to put your OIP together, but it would sure make it easier.

If your fleet is small enough, perhaps just generate your OIP to state that any major repair affects FCBS and requires a DTA, the same would go for your survey, any repairs/mods found during your survey that are classified as major would require a DTA. I think your PMI would possibly by that, since it is a very conservative approach. Don't forget about routables, you don't want to purchase an overhauled part from a vendor and later find out that it contained FCBS and needed surveyed, etc...

If you are able to hold out long enough (several years) enough of the operators may push Boeing into placing the FCBS lists into the SRMs which then would be readily available.

Since I work for an operator who also has STCs, I was able to enjoy (sarcastic) heading up the Part 26 compliance and now am in the process of helping generate the OIPs. The part 26 compliance was easier than this OIP, so you can come to your own conclusion about what I think of the OIP.

 

[KirbyWan]

Manuelo,

I don't know if this is current but here it is. Can't remember where I got it from and I make no claim to it accuracy.

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[der8110]

If you are an operator then I would question why you would need the FCBS, that was intended for STC holders to determine if their modifications affected such structure. Maintaining the basic airframe IAW the current documents should keep you in compliance for DT requirements. What you are probably looking for is the DTI documents from each of the STC holders for modifications.

You could possibly be concerned about non-SRM repairs by third parties, in that case, you would be very interested in the FCBS if your task is to clean up their messes.

 

[KirbyWan]

I know in our case we rarely work on primary structure (nacell systems) but everytime I submit an EO for a non-standard repair, the DER wants proof via the FCBS that the structure/repair does not need to consider damage tolerance requirements.

I'll throw this out here because it might be a useful discussion but I think my DER (and I) are confused about when the requirements for DT come into plan and what documents should be used for showing that something does not need DT consideration. Generally I think if it is non-primary structure than no DT is needed. If it is primary structure (as some inlet cowls are)...?

Still learning as an engineer.

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[manuelo]

Thanks all for your responses.
1) In accordance with the AC 120-93, I am following the instructions for the DTI assessment process (appendix 6) where in the first step: Airplane repair survey."A survey will will be used to identify repairs and repair configurations on FCBS". Also in the chapter 4, 403.Repairs:"Repairs affecting FCBS need to be evaluated to determine if DT-based inspections are needed to ensure continued airworthiness".
2) In this AC, it is also referred about the compliance document and repair guidelines. It will be necessary buy this documentation?

 

[rb1957]

assuming you're an STC holder (as opposed to an operator),
the OEMs are obliged to make the FCBS definition available but they can charge for it. if you don't want to buy it (and maybe pass the cost down to your STC clients), i think you can define your own FCBS with concurrence of the FAA (your local office or HQ). two easy outs ...
1) clearly this mod doesn't affect prinary structure, therefore it won't affect FCBS; or
2) we'll assume that it does affect FCBS and develop a DT based inspection program.

 

[USACompositeGuy]

If your company owns an aircraft or if your client owns an aircraft they will need to purchase this document, however the rumor is that the next revision of the SRM (due in march) will have this included.

Are you putting together a plan for compliance or just repairing a component?

 

[manuelo]

I am preparing the operator implementation plan in accordance AC120-93, but I got to be confused with the documents we need to use,
1.- since it refers at the beginning that we need FCBS, to determine what repairs or alterations that we need to evaluate, and it refers that we need to get from Boeing.
2.- Then the compliance document and repair guidelines, I am not sure, if they are obligatory to buy, since for example we have the repair guidelines for repair assessment program, but I think may be this guide is only for RAP and not for this case.
3.- and the compliance document, may be has another directions that we do not know.
On the other hand , I have another question that I need to clarify:
a.- at december 20, 2010; operator need to have an approved maintenance program with all the DT requirements? or
b.- this program will be obtained at the time we are accomplishing the Plan, that may be extended, several years, depending of the surveys (in heavy C or D inspections) we could have planned?
Just I need to convince my boss that it is the option b.

 

[rb1957]

sorry but can we clear up one point ... are you an operator or a manufacturer ? do you operate the planes, so preparing the OIP is your way of complying with the OEM instructions; or, or a manufacturer, is the OIP your instructions to the operator ??

if an operator, then why do you need the FCBS ? you have the OEM instructions (inspection program) ?? then plan the inspections. repair guidelines ? ... do you do your own repairs ? are the people qualified by the OEMs ??

but i do feel your pain, it is a most confusing rule !

 

[manuelo]

Yes, the company where I work is an operator.

 

[rb1957]

then i think the wording of the rule has confused you, hardly surprising !

i think you don't Need the definition of FCBS, but you do need OEM inspection programs for STCs incoprorated onto your planes. The OEMs shuold be providing this data to you, and you need to show your local authority how you comply with the requirements.

at least that's the way i see it ! maybe talk with your local FAA inspector ?

 

[737eng]

As an operator you need to know what structure is FCBS. Yes, the DAHs will provide you with a mtc program that will cover the damage tolerance requirements of the original OEM and/or STC structure. However, you also have to determine if existing/future repairs/mods require further supplemental inspections based on a DTA. For a newer fleet of aircraft of for an operator that sends everything to the OEM for approval, then this should be an easy task. However, for an older fleet, especially a pre-amdt 45 fleet, or a fleet that defined DT requirements as only for PSE's and not FCS, then this could be more difficult and the FCBS list may need to be required.

I commonly hear the Part 26 and Part 121 requirements used interchangably, especially at my place of work. I think it is very important to seperate these and to not use them interchangably. An operator is concerned with the 121.1109 requirements only, the DAH is concerened with the Part 26 requirements only. The DAH data produced for compliance to Part 26 is a valid method for an opertor to show compliance to 121.1109, however, it is not the only method.

Another issue is that I see 8110-3s only coming back with the Part 26 compliance and not 25.571, however, as an opertor, I am not concerned with Part 26 compliance, I am concerned with 25.571 (appropriate amdt level) compliance. Showing compliance to Part 26 does not show that the repair/mod has returned the aircraft back to the TC basis which only contains Part 25 requirement. Part 26 compliance only shows that the DAH met there requirements.

Sorry for going off on the little tangent at the end, just gettting a little frustrated with this bandade. If the FAA would of ensured compliance to Part 25.571 appropriate amdt level all along, and with the SSID AD's, we wouldn't have this problem today.

 

[rb1957]

"If the FAA would of ensured compliance to Part 25.571 appropriate amdt level all along, and with the SSID AD's, we wouldn't have this problem today." ... amen to that.

 

[FlyDCJets]

Good post, 737eng.

An operator must have an FCBS / FCAS to screen future repairs and determine which will require DTE. If, as an operator, all of your non-SRM repairs will go through Boeing, you can make a case that you don't need the list of fatigue critical structure as Boeing will screen it as part of their quote. Note that a major repair that is not on FCS (defined by FCBS / FCAS / DAH (STC) data) will not require a Damage Tolerance Evaluation. Nor would it be required for FCBS structure classified as Note 2 (existing maintenance program sufficient for DTI) or Note 3, composite repair on composite structure.

The OIP is basically the operator's method for dispositioning past alterations / past repairs / future alterations / future repairs for damage tolerance considerations. Part 26 forced the OEM's to generate an ACO-approved means of addressing the effects of repairs/alterations on FCS that could be used by a Part 121/129 operator as a basis for the OIP. As 737eng states, the relavent Part 26 and Part 121/129 rules are seperate (though related).

I attended the Boeing seminar on this subject and can highly recommend it. The AC is very confusing. It was written prior to the final completion of the Part 26 OEM documents, so the AC and the OEM documents do not always agree.

Note that in 121.1109, the "means" used by the operator must be approved by the FAA Oversight Office. This means the ACO. Your PMI signs your OIP, but if you use a "means" different than developed by the OEM (in Boeing's case, the ACO-approved CD/REG) that must be approved by the ACO. Boeing states that the Seattle ACO has advised they have no manpower to review/approve other "means" by December 20, 2010. Such alternate means would include, in my opinion, the AC.

The RAP is a means of compliance with 121.1109 in the area that it covers, but the FCBS includes other structure.

The CD/REG can be used to determine the deadlines for surveying existing repairs to FCS. The suggestion is that if your fleet is many years away from survey implementation, you may not have to develop the survey process (cards) by Dec 20 -- just a plan to develop it in plenty of time before the deadline. This is subject, of course, to approval by your PMI. But there should be a recognition that it doesn't make sense to produce cards for a survey that is 10, 20 or more years away. You may not have that aircraft by then!