SERVICE BULLETIN SB02-3A.

This Owner Advisory is to inform you that Service Bulletin SEB02-3 has been issued to provide replacement time requirements for engine driven dry vacuum pumps,vacuum pump drive couplings and electric standby vacuum pumps. SEB02-3 requires replacement of vacuum system components as follows: A.    Replace engine driven dry vacuum pumps not equipped with a wear indicator every 500 hours of operation, or replace according to the vacuum pump manufacturer's recommended inspection and replacement interval, whichever occurs first. B.    Replace electric standby vacuum pumps not equipped with a wear indicator every 500 hours of operation or 10 years, or replace according to the vacuum pump manufacturer's recommended inspection and replacement interval, whichever occurs first. C.    Replace engine driven vacuum pump drive couplings at vacuum pump replacement or every 6 calendar years, whichever occurs first.         NOTE: For a vacuum pump equipped with a wear indicator, replace pump according to the vacuum pump manufacturer's recommended inspection and replacement intervals.         NOTE: If the manufacturer of the vacuum pump or the vacuum pump drive coupling has a shorter/more restrictive replacement interval, then that interval shall be used as the pump and/or drive coupling replacement interval.         NOTE: When installing new dry vacuum pumps, use only S3346-1 or Cessna approved equivalent gaskets. Cork type gaskets and other gaskets are not approved. Compliance is mandatory; components shall be replaced as stated in the Accomplishment Instructions of Service Bulletin SEB02-3. An initial inspection to determine total time in service of installed applicable vacuum pumps and drive couplings shall be accomplished within the next 100 hours of operation or 12 months, whichever occurs first. The information contained in the referenced Cessna Service Bulletin shall be considered an amendment to the Cessna Manufacturer's Service/Maintenance Manual or Instructions for continued airworthness, and must be accomplished for ongoing airworthness compliance as required per 14 CFR Part (FAR) 43.13.

CPA’s TAKE ON THIS SERVICE BULLETIN:   Failure of a vacuum pump in IFR conditions, with the resultant loss of attitude instrument indications, can and has lead to tragic accidents. For this reason if your aircraft is used for ANY IFR at all it would be wise to comply with this bulletin. John Frank also warns about not trusting a brand new pump installation, infant mortality has occurred with some frequency. If you are going to have a pump failure it will be within the first 20 hours of pump operation or after at least 500 hours of pump operation. If your aircraft ALWAYS and ONLY flies VFR, pump failure is only a minor inconvenience and not something that could cause an accident. In this situation you might as well get as long a life out of the pump as it will give. Fly it till it fails or engine overhaul. Just as important as replacing the pump to reduce the possibility of pump failure is knowing how to handle a pump failure IFR. Partial panel is a difficult skill that requires constant practice to remain competent at. Rather than relying on this mentally straining procedure, if one flies IFR you should have some form of backup system. This backup could be a second engine driven vacuum pump, a tee into the intake manifold as a source of vacuum (normally aspirated engines only), an electrically driven standby system, an electric horizon to back up the vacuum horizon or a autopilot that is totally electric (All STECs and some others). You must know what your back up is and how to use it.
John Frank mailto:john.frank@cessna.org

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