[schwarze-man]

Hi Everyone,

I am posting some information here that is very generously available by member Charles Bavarois. You can view the five pages of RLM orders about aircraft and engine lives on his member page, in his album.
Thank you Charles!
The pages are documents from 1942 and there is a single page 257/42 that describes the administration of the declared life and the extension policy.
This is supported by four page document 487/42 that usefully lists the approved life of aircraft and engines. It is interesting that the later document in late '42 did not include original figures for the DB 605 A/B/C, these have been added as amendments. Also, the DB 605 amendments obviously cover very early engine build standards, with specific references to fuel injection timing and "old-type" pistons, with engine life varying between 50, 75 and 100 hours.
The documents should be read with careful understanding of the Partial and Full overhaul definitions, Teilüberholung and Grundüberholung.
As I have described earlier, the work for the engine servicing is listed in the engine handbook, the overhaul work is listed in the Instandsetzungsvorscriften and the details are further covered in the Reparatur Anleitung DB 605 A-B.
I have translated some of the guidance about engine life from the document 257/42, and this is it:

"Teilüberholungszeiten können im normalen Betreib für Zelle und Motor bis zu 20% überschritten Werden. Für die aufgeführten Flugmotorenmuster können unter Berücksichtigung der Betreibsickerheit und wenn der Einsatz es erfordert, die Richtwerte jeder Teilüberholung bis zu 50 v. H. überschritten werden.
Die Grundüberholungszeit, z B, bie BMW 132 A Richwert = 200/3 kann im Höchstfalle (200 + 50 v. H.) x 3 = 900 Stunden erreichen.
Ist die Summe der jeweils errichten TEILÜBERHOLNSZEITEN kleiner als der untere Richtwerte der Grundüberholungszeit, (BMW132A 200 x 3 = 600 stunden ) so kann wenn es der Motorbefund gestattet, ein weiterer Teilüberholungsabschnitt angehängt werden."
Translated:
"Partial overhaul times can be exceeded by up to 20% in normal operation for the cell and engine. For the aircraft engine types listed, the guide values of each partial overhaul may be exceeded by up to 50 %, taking into account the operating inertia and where the use so requires.
The basic overhaul time, e.g. with BMW 132 A benchmark = 200/3, can reach a maximum of (200 + 50 %) x 3 = 900 hours.
If the sum of the respective established PARTIAL OVERHAUL TIMES is less than the lower guideline values of the basic overhaul time, (BMW132A 200 x 3 = 600 hours), a further partial overhaul section can be added if the engine findings allow."

Now, the precise application of these orders seems complicated. Also, the later orders for the DB 605 life and overhaul will likely have been revised in later RLM orders. However, this is great information and I must thank Charles Bavarois again for putting this information on his album.

Cheers

SM