In DC-10 SBs what does Group I thru IV indicate?

[KirbyWan]

Howdy all,

I'm going through some DC-10 Service Bulletins (SBs) and in these SBs it referes to Group I, II, III and IV aircraft, but nowhere does it indicated what these groups are. Are they DC-10-10, -30, -40 and KC-10? Could someone point me to a reference where I can read it and say "Aha! that's what they mean." Specifically I'm revewing SB's that effect the upper forward rudder, 55-11, 55-15, and 55-21.

Thanks,

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[kontiki99]

Usually the groups in a SB identify portions of the work applicable for specific aircraft. You may be missing pages if that's not apparent.

 

[KirbyWan]

So it can be different for each SB? It has pages listing the effectivity by aircraft, but we are usually working on spares and it is less clear which section our spare will apply to. I was thinking it was common between all SBs for DC-10s.

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[ERAU82]

Boeing (ex-Douglas) S/B's list the affected aircraft in Groups, usually due the changes in a/c configuration. The modification steps are then listed by Group. S/B's are for aircraft modifications, usually for spares there is a paragraph in the S/B that denotes what needs to be accomplished or what group instructions need to be followed.

With LRU's, the S/B may reference a Component Manual Manual (CMM) to follow for the modification as the S/B will state for example to remove a -1 component and install a modified -2.

 

[JetinTX]

Kirby,
I'm working the same issue with S/B 55-21. However, after identifying the effectivity, now the question is the intent of the S/B group I vs. group II. Particularly for this S/B, is the intent to first remove the upper rudder or not? Changing the weights with rudder installed seems risky and the S/B does not clearly state on or off. Do you have experience with this?

 

[KirbyWan]

I never work with the parts "on wing" (or tail in this case). These weights are heavy and dangerous. In flipping a weight over to measure the underside I dropped one edge on my finger from about an inch and it hurt like the dickens, but was luckily not broken. There are threaded holes in the top and bottom to attach a mounting jig to, which if attached to a hoist would be relativly safe to use while the parts are still on the wing, but follow the recomendatiosn of the AMM.

By the way I tried following the progression of parts through the three service bulletins (55-11, 55-15 and 55-21) and got confused. Were you able to make sense of the SB's P/N changes? I'm still not sure if I want the Tungsten weight with the aluminum shield because the previous weight had the aluminum shield as it reccomends in the SB or just got for the Tungsten weight without the shield since the tungsten doesn't need it like the DU weight did.

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[JetinTX]

From what I see there are the DU part numbers; the main weight and an underlying weight and then the new weights for replacement have new numbers and old numbers, shielded and unshielded (See pg. 43). As for the shielding, see pg. 15. DAC offers both. Also see pg. 45, (3), 6/, this apparently comes only in unshielded.
It appears to be your choice (shielded or unshielded) except for the parts listed on pg. 45.
The grouping for 55-21 is confusing. I find A/C effectivity, man hours, and two methods.
• Group I: upper, mid-span
• Group II: both upper and mid-span
• Group I man hours
• Group II man hours
Hope this helps.