# SAIB ACE-99-05: - Type: Special airworthiness information bulletin (advisory, not mandatory) - Status: Current - Revision: 0 - Issued: November 17, 1998 - Products: Cessna 310, 310A, 310B, 310C, 310D, 310E, 310F, 310G, 310H, 310I, 310J, 310J-1 and 37 more - Product type: Aircraft, Small Airplane - PDF: https://openairdocs.org/files/sha256/e2/cc/e2cc3fa8fa7804558c7a58f081f97a14bb6eee87921427cda0b403fab168aa31 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/707E4080A23FA9158625721F0052ED1A.0001 - DRS record last changed: September 23, 2011 - Page: https://openairdocs.org/saib/ACE-99-05 ## Text **SPECIAL** **AIRWORTHINESS** **INFORMATION** **BULLETIN** **AIRCRAFT CERTIFICATION SERVICE 800 INDEPENDENCE AVENUE, S.W.** **WASHINGTON, DC 20591** U.S. Department of Transportation Federal Aviation Administration No. ACE-99-05 November 17, 1998 Published by: FAA, AFS-610, P.O. Box 26460, Oklahoma City, OK 73125 This is issued for informational purposes only and any recommendation for corrective action is not mandatory. Introduction: The purpose of this Special Airworthiness Information Bulletin (SAIB) is to advise registered owners of certain Cessna twin engine models of the need to determine if there is adequate alternate crankcase breather provisions. This SAIB is being sent to registered owners of: Cessna 300 and 400 Series Model airplanes except for the 303, 336 and 337 series airplanes. Background: The Federal Aviation Administration (FAA) has r eceived service difficulty reports concerning oil loss on certain Cessna twin engine airplanes. This oil loss was due to the forward crankcase oil seal being dislodged by abnormally high crankcase breather pressure. The abnormally high crankcase breather pressure was caused by icing of the crankcas e breather vents. These airplanes either did not have, or had inadequate alternate crankcase venting provisions which are intended to ventilate the crankcase in the case of the ici ng of the primary vent. This condition may have occurred due to inadequacies in the original design or the unintentional deletion of the alternate venting provisions by field repair and/or modification. The original ve nting provisions were in many cases the installation of a hose section in the breather line that had a elongated hole in it. Even though Cessna has released service informa tion concerning this problem, the FAA has not concurred with the Cessna provisions as alleviating the condition. The FAA has not mandated this m odification but is strongly recommending that owners/operators of the affected airplanes examine the crankcase venting provisions installed on their airplanes for the existence of adequate alternate venting provi sions, which should be a slit or hole (at least approximately one inch by .25 inches) in the breather line within a minimum of six inches inside the cowling. If these provisions do not exist, is it recommended that alternate crankcase venting provisions be incorporated per the below figure. NOTE: The FAA is considering several options , including rulemaking action, to mandate these recommendations. **2 ACE-99-05** Drill 5/16” and elongate as shown lengthwise only Diameter of hose 3 inches Breather vent tube Air flow Cowl skin, (reference) AN737 hose clamps or equivalent 6 to 9 inches Breather outlet (reference) 1 ½” 3/8” typical For Further Information Contact: Federal Aviation Administration, Wichita Aircraft Certification Office, Attention: Mr. Paul Pendleton, 1801 Airport Road, Mid-Continent Airport, Wichita, KS 67209; or, Federal Aviation Administration, Project Support Office, ACE-112, Attn: Mr. Karl Schletzbaum, 1201 Walnut; Suite 900, Kansas City, Missouri 64106, telephone (816) 426-6932, fax (816) 426-2169. ## Registered aircraft it may concern (OpenAirDocs) Registry models matched by make and model, the same way as ADs, most registered aircraft first. - [Cessna 340A](https://openairdocs.org/model/cessna-340a): 543 registered aircraft (airframe model) - [Cessna 421C](https://openairdocs.org/model/cessna-421c): 496 registered aircraft (airframe model) - [Cessna 414A](https://openairdocs.org/model/cessna-414a): 363 registered aircraft (airframe model) - [Cessna 310R](https://openairdocs.org/model/cessna-310r): 361 registered aircraft (airframe model) - [Cessna 310Q](https://openairdocs.org/model/cessna-310q): 277 registered aircraft (airframe model) - [Cessna 414](https://openairdocs.org/model/cessna-414): 242 registered aircraft (airframe model) - [Cessna 421B](https://openairdocs.org/model/cessna-421b): 225 registered aircraft (airframe model) - [Cessna 441](https://openairdocs.org/model/cessna-441): 172 registered aircraft (airframe model) - [Cessna 340](https://openairdocs.org/model/cessna-340): 164 registered aircraft (airframe model) - [Cessna 425](https://openairdocs.org/model/cessna-425): 161 registered aircraft (airframe model) - [Cessna 402C](https://openairdocs.org/model/cessna-402c): 115 registered aircraft (airframe model) - [Cessna 310](https://openairdocs.org/model/cessna-310): 103 registered aircraft (airframe model) - [Cessna 310K](https://openairdocs.org/model/cessna-310k): 78 registered aircraft (airframe model) - [Cessna 310L](https://openairdocs.org/model/cessna-310l): 62 registered aircraft (airframe model) - [Cessna 310P](https://openairdocs.org/model/cessna-310p): 61 registered aircraft (airframe model) - [Cessna 310I](https://openairdocs.org/model/cessna-310i): 60 registered aircraft (airframe model) - [Cessna 310J](https://openairdocs.org/model/cessna-310j): 59 registered aircraft (airframe model) - [Cessna 310C](https://openairdocs.org/model/cessna-310c): 58 registered aircraft (airframe model) - [Cessna 310D](https://openairdocs.org/model/cessna-310d): 56 registered aircraft (airframe model) - [Cessna 310N](https://openairdocs.org/model/cessna-310n): 55 registered aircraft (airframe model) - [Cessna 402B](https://openairdocs.org/model/cessna-402b): 49 registered aircraft (airframe model) - [Cessna 310B](https://openairdocs.org/model/cessna-310b): 45 registered aircraft (airframe model) - [Cessna 310F](https://openairdocs.org/model/cessna-310f): 41 registered aircraft (airframe model) - [Cessna 310G](https://openairdocs.org/model/cessna-310g): 41 registered aircraft (airframe model) - [Cessna 310H](https://openairdocs.org/model/cessna-310h): 33 registered aircraft (airframe model) - [Cessna 320D](https://openairdocs.org/model/cessna-320d): 30 registered aircraft (airframe model) - [Cessna 421](https://openairdocs.org/model/cessna-421): 28 registered aircraft (airframe model) - [Cessna 320E](https://openairdocs.org/model/cessna-320e): 27 registered aircraft (airframe model) - [Cessna 335](https://openairdocs.org/model/cessna-335): 26 registered aircraft (airframe model) - [Cessna 404](https://openairdocs.org/model/cessna-404): 26 registered aircraft (airframe model) - [Cessna 320C](https://openairdocs.org/model/cessna-320c): 23 registered aircraft (airframe model) - [Cessna 320B](https://openairdocs.org/model/cessna-320b): 21 registered aircraft (airframe model) - [Cessna 401](https://openairdocs.org/model/cessna-401): 21 registered aircraft (airframe model) - [Cessna 421A](https://openairdocs.org/model/cessna-421a): 20 registered aircraft (airframe model) - [Cessna 320](https://openairdocs.org/model/cessna-320): 17 registered aircraft (airframe model) - [Cessna 401A](https://openairdocs.org/model/cessna-401a): 15 registered aircraft (airframe model) - [Cessna 401B](https://openairdocs.org/model/cessna-401b): 15 registered aircraft (airframe model) - [Cessna 310A](https://openairdocs.org/model/cessna-310a): 14 registered aircraft (airframe model) - [Cessna 320F](https://openairdocs.org/model/cessna-320f): 12 registered aircraft (airframe model) - [Cessna 402](https://openairdocs.org/model/cessna-402): 7 registered aircraft (airframe model) - [Cessna 310E](https://openairdocs.org/model/cessna-310e): 6 registered aircraft (airframe model) - [Cessna 320A](https://openairdocs.org/model/cessna-320a): 6 registered aircraft (airframe model) - [Cessna 411](https://openairdocs.org/model/cessna-411): 6 registered aircraft (airframe model) - [Cessna 411A](https://openairdocs.org/model/cessna-411a): 4 registered aircraft (airframe model) - [Cessna 402A](https://openairdocs.org/model/cessna-402a): 3 registered aircraft (airframe model) - [Cessna 320-1](https://openairdocs.org/model/cessna-320-1): 1 registered aircraft (airframe model) - [Cessna 310-J1](https://openairdocs.org/model/cessna-310-j1): 0 registered aircraft (airframe model) - [Cessna 321](https://openairdocs.org/model/cessna-321): 0 registered aircraft (airframe model) - [Cessna 406](https://openairdocs.org/model/cessna-406): 0 registered aircraft (airframe model) --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.