SUBJECT: Auto Reignition Control Box Assem blyP/N 6877139 - 206A
& B HelicoptersP/N 6891969 - 206L Helicopter
250-C18, A, B, C, CSL-84250-C20, -C20B CSL-1053
COMMERCIAL SERVICE LETTERDetroit Diesel Allison
p Indianapolis, Indiana 46206 June 30, 1976Page 1 of 2
Recent improvements have been incorporated in the Auto
Reignition ControlAssem blies. These improvements resulted in a
letter change following thepart number.A significant improvement to
the unit has been a new transducer incorpora-ting silastic coating
on the wire bonds and unpassivated contact areas ofthe pressure
sensor element to make the transducer less susceptible
tocorrosion.Change letter H following the 6877139 part number s
ignifies incorporationof the improved transducer.All part number
6891969 units incorporate this improvement.Serial number
effectivity for the above is as follows:
P/N 6877139 ?I - S /N RD 12773 and up.P/N 6891969 - Not App
licable - All conform.
In addition to the above, all units are now vibrated during
check out and areidentified as follows:P/N 6877139 J - S/N RD 13230
and up.P/N 6891969 A - S/N RD 13510 and up.
Rolls-Royce Proprietary Data Uncontrolled Printed Copy
7/29/2019 Csl 1053
2/2
250-C18, A, B, C CSL-84250-C20, -C20B CSL-1053Page 2COMMERCIAL
SERVICE LETTER
All units, both 6877139 and 6891969 being returned for repair
have the afore-mentioned improvements incorporated during repair.
As the auto reignitioncontrols are a Condition part, no overhaul
schedule is established.Naturally, serial numbers below the up
numbers will incorporate these improve-ments at time of repair, so
knowledge of the change letter is necessary andshould be included
in any reference to a control.Raven Industries, manufacturers of
the auto reignition control, offers a 120day-warranty on their
repaired units conform ing to the 6877139 T-I or Jconfiguration for
the 206A and B helicopters. This also applies to the P/N 6891969and
A configuration units for the 206L helicopters.In order to provide
a rapid turnaround of repairedunits, Raven has establisheda pool of
serviceable units which are available via your respective DDA
Dis-tributor.Troubleshooting the auto reignition control consists
of transferring the suspectunit to another helicopter if possible,
thus confirming the unit is actually thecause of the
discrepancy.
Service ManagerGas Turbine EnginesRNB:aw
Rolls-Royce Proprietary Data Uncontrolled Printed Copy
