AMERICAN BONANZA SOCIETY NEWSLETIER

Page 217 January 29, 1972COMMENTS AND CORRESPONDENCEFAULTY FUEL LINE VENTING COLLAPSES FUEL CELLSA collapsed fuel cell can give a false fuel quantityreading and can also lead to punctures in the neoprene cell.James Q. Hotness, ABS 82995, on page 193 of the Sept. 1971Newsletter, discusses punctures in the cells of his 5-35.Dr. !. Kantrowitz, ABS #3377, confirms similar troubles onhis p-35 as does Jack Coyle, ABS 82067, on his V-35ATC.Plugged fuel line vents, bent vent tubes, located belowthe wing, or improperly sealed fuel caps are all possiblecauses as Norm Colvin of Beech tells us in his letter.We would again~to recommend that anyone who anticipatesthe possibility of flying in icing conditions considerinstalling the V-35 type recessed vents if your planehas 2 fuel cells or the Baron type recessed vent if yourplane has 4 fuel cells. These eliminate the possibility ofplugging vents due to icing. They are not available as amodification kit but can be purchased from a Beech dealeras a part. The V-35 part numbers are scoop, left-hand,#414-920022-5, scoop, right hand, 8414--920022- 3 ~~d retailfor $14.60 each. The Baron part number is 414-920022-1 andsells for $23.75 with no left or right-hand rlifferentiarion.These recessed vents are then installed as extra vents andteed into the existing fuel vent lines with rubber tubingam! clamps.Dear Ralph:I am having a potentially serious problem with myV-35ATC Bonanza. Several times I note~ that the fuel gage,on the starboard Side, would not show any change, even afterI 1/2 hours of flying on that cell. Recently, upon removingthe filler cap, the rubber fuel cell was all bunched uparound the fuel quantity tab. There was no suction at thetime the cap was opened, indicating that there is a vacuumin that particular cell during flight. Both the overflowand the air vent are clear.At the last inspection, my mechanic could find no flaw,although problem has continued . To prevent damage to thecell, we removed the filler cap assembly and put a dishshapedprotector on the end of the tab (see sketch). Wealso determined that the fuel cell was properly clipped inplace.Subsequent flights have shown that the rubber cellstill sucks up around the tab, but there is no apparentchafing of the rubber where it contacts the tab.Have you had any experience with this problem?Jack Coyle, ABS #2067560 West 25thGentlemen: San Bernardino, CA 92405The problem of puncturing the fuel cell in the S-35Bonanza, described by Mr. James D. Hoiness, is a repeat performanceof problems which plagued me for about three monthsseveral years ago.I own and fly a P- 35 Bonanza in which we have put closeto 1500 hours. One summer morning we came to get into theairplane to spend a pleasant weekend at Martha's Vineyardwhen during the ground check I noticed green dye indicatinga leak on the undersurface of the right wing. Inspectionof the right fuel cell disclosed a leak in the neoprenecell. The injury to the neoprene app~ared to be a semi-circulartear about an inch in length. The fuel cell was removedand replaced.A few weeks later, the same green dye, on the undersurfaceof the wing indicated another leak. The injury wasprecisely in the same spot. I complained to the FBO, whograciously paid for the second repair to the fuel cell, andthen proceeded to cut the nozzles off all of the fuelingtrucks to prevent presumed injury because the fuel nozzlehad been placed too far into the tank and ruptured it.The third occaSion, several weeks later, again in theright hand tank, had to make all of uS suspicious becausethe linemen had been particularly careful with our Bonanza.Closer examination clearly indicated the same problem thatMr. Hoiness described, that the bottom of the fuel cell hadobviously been rubbing against the bottom of the flange andhad worn a hole alwavs pre~isely in the same spot. Verycareful examination of the underside of the wing revealedthe 45° angle cutoff on the vent tube beneath the wingshould be facing forward to scoop air into the fuel cell andthus hold it distended. Under the left wing on my Bonanza.the vent tube was facing forward as it properly Should,whereas, the vent tube on the right wing was facing rearward,tending to suck air out of the fuel cell and collapsingit. The problem was corrected by merely turning thevent tube around to face the front and thus pump air intothe fuel cell during flight .I will still be interested in whether or not Mr. Hoiness'vent tube is facing the wrong way (toward the rear).Adrian Kantrowitz, M.D. ABS #3377Dept. of Surgery, Sinai Hospital of Detroit6767 W. Outer Drive, Detroit, HI 48235Dear Mr. Haesloop:Thank yo u for your letter of October 7 in which youasked for information on the fuel tank vent system as usedon the BEECHCRAFT Bonanza.The vent system on the Bonanza is a simple one. Airmust enter from the vent tube below the wing and if fuelwere used from the tank while the airplane is on the ground,air would enter the vent tube and flow into the tank, replacingby volume the fuel used. In flight, there is avariation in air movement around the end of the vent sothe vent tube must be bent slightly forward so that ram airwill flow into the system. The vent tube is chamfered at45 degrees which aids air entry into the vent lines.In order to reach the air stream, the vent line extendsbelow the wing 1 3/4 inches and is bent forward 10 degrees.The vent line can be bent by mechanics as they jack the airplane.Because the jack handle is on the right Side, chancesare that the right-hand fuel vent would be bent more frequentlythan the left-hand vent.The tube may be bent aft, so that in flight, insteadof the vent line being pressurized, suction is applied andthis causes the fuel cell bottom to lift. Lifting of thecell bottom can cause contact with the tab indicator andcause the fuel level transmitter arm t o lift giving anerroneous fuel level reading.Sometimes ice or a mud dobber will plug the vent line;however, a small vent hole which is drilled in the aft sideof the vent tube near the bottom wing skin will allow acertain amount of air to enter in this event.Starting with Bonanza Serial D-6875 and after, a flushfuel vent was added t o the vent system and ties into the extendedvent line. This vent is indented into the wing sothat it still will receive ram air but will be free of foreignmaterial.A poorly sealed fuel cap can also cause fuel cells toact up. The fuel cap is located in a high suction area soif the seal is bad, it too may cause some suction on thefuel cell. Usually poor seal of the cap will be noted fromfuel being drawn from the tank in flight so a poor cap sealis usually noted and repaired.We trust the above information willhow the Bonanza fuel vent system works.opportunity to be of service.help t o clarifyThank you for theJ.N. Colvin, Project Service Engr.Beech Aircraft Corp.AMPERAGK DRAIN J ELECTRIC PR1MERS J AND PRESSURE CARBURETORSGentlemen:The follOWing is furnished in reference to my modelD-35 with an E-225-8 engine.1. I found a way to cut the amperage drain on thebattery while taxiing at night at low RPM when the 50 ampgenerator has not reached cut in speed. I replaced the LHlanding lite bulb GE 14522 (250W-290,OOOCP) with GE #4537(100W-200,OOOCP). PhYSical dimensions of the bulb are identicaland ,difference of brightness seems to be negligible,but you can readily see that the power drain is only 40%,yet delivering 66% of the illumination.2. I installed an electric primer, but had a difficulttime finding a primer solenoid. The regular sources wereout of stock and the price was out of this world. I substituteda primer (24V solenoid valve item # 9SV256, $2.50ea.) obtained from Graban Supply Co., Inc., 9300 Southcontinued on next page

January 29, 1972Page 218COMMENTS AND CORRESPONDENCEcontinued from previous pageDrexel, Chicago. Ill. 60619. This valve looks to be identicalto the ODe found on local Bonanzas. Some minor modificationsof the electrical connector were involved, alongwith adapting the female tube connector fittings with "0"rings. ~he 24V label doesn't hinder the excellent operationon the Bonanza 12V system.Shortly after installation of the above system I experiencedengine roughness at low power settings and tracedit to the primer valve- leaking. This might be a reminderto those with primer systems to consider the possibility offoreign matter on the seat of this valve when baving problemswith richness at low or idle power during the wintersesson when the primer is used.I have the Bendix PS-5C pressure carburetor and havehad extreae difficulty in starting as well as initial runningof this engine since the day I purchased it. It wouldquit many times and, after start·ing, the RPM would surgefrom 300 to 600, gradually getting into the range of 700~100 while. Lapp.lied alte.rQAte~ -elosed_th.e-c.owl.-_flaps, pumped the throttle and the wobble pump feverishly,and generally had fits of temper. Over the summer I methodicallywent over the plugs, harness, magnetoes and inductionsystem, but when the temp dropped to 40 0this fall, Ifound the same old problems plaguing me again. I reset theidle mixture and installed the electric primer system, onlyto find that it would now run on the primer, but I had totickle the primer for up to 5 minutes before it showed anysigns of carrying on by itself . During all this troublementioned above, once the engine was warm, it purred like akitten and never showed any signs that, as soon as it cooledoff, it was going to give me the very same fits .A careful study of ~he problem showed that even if Ienriched the idle mixture to its max, the idle was only100 RPM rich once it warmed up and there was j ust inadequatefuel flowing during start and initial warm-up. I spoke toLew Smith, the Bonanza mechanic at Central Bucks CountyAirport, here in Doylestown, Pa. , and had him inquire whatthe cost and time involved would be to have this ~arburetorchecked on the bench and repaired. I had already priced anexchange carburetor and found the price to be near $300.He was able to inform me that the solution to tpis wassimple and involved no labor or materials , just a simpleprocedure for the pilot to place the mixture control in thecockpit midway between full rich and idle cutoff a fewminutes after stopping the engine, particularly when theaircraft is not to be used for extended periods of time andin cold weather. This procedure prevents the very delicatespring (this spring is mechanically compressed by a cam onthe carburetor engaged by the mixture control when placedt o idle cutoff) in air chamber "A" of t he reguiator , whichholds the poppet valve open for idle f uel pressur e duringlow power operation when the air regulator sect ions are notoperating effectively, . from taking a "set" towards .itherexcessive richness or leaness when initial start-up takesplace. He informed me that if I went to t h~s procedure ,it would cure the problem. In fact, a service bulletin in1959 concerned this very problem and covered many differentpressure carburetors.I believe this procedure to be of vit al interest touther owners, particularly for cold start ing . I have alwaysbeen baffled by the fact that some days I could get fuel t oflow freely from the scoop drain by pumping the wobble pumpwith rich mixture and open throttle prior to starting. butother days I couldn't get a drop. I used t o occasionallyput the mixture control in rich after shut- down because theknob was in the way of entry and exit from t he cockpit andthese were the times I got fuel to flow during the nextstart. Of course. as many owners point out. I pump fuelinto the manifold and pull the prop thru by hand over 2revolutions to get that fuel-air mixture into the cylinder sprior to engaging the starter.Hy sincere appreciation for the wealth of info in theNewsletter and hope I have contributed a bit also.Cy Hehling, ABS #2893R.D. 12. Ridgeview Dr.Doylestown, PA 18901SAFETY TIP CORNERRecently your Editor was down in Allentown , Penna.to take some recurrent IFR training from Bill Guinther,ABS 11354 R.D. 12, Kutztown, Penna. Bill is an excellentinstructo~ (he'll be teaching "Making IFR Easier" at ourMilwaukee Convention, July 12-16. 1972) and always amazesme with the extra bits of plane- lore he has stored away.As I was preflighting the Bonanza. he stood by watchingthe procedure. When I reported that I had emptied ateaspoonful of water out of the left fuel cell quickdrain,he said. "Wait a minute while I try something.'" With thathe ~igorously pushed the left wing near the wing tip, rockingit back and forth. Then he bent under the left wing.carefully centering his back under the main spar, and rockedthe wing up and down. 10 and beholdl More water I In fact,we took out close to a cupful more. Apparently water canlie on the bottom of the f uel cell but doesn't necessarilyall run into the quickdrain. Rocking the wing shakes itloose and it runs into the quickdrain where it can bedrained oue-.Should you get water from a fuel cell, use this procedureand see if you really did have it all drained out .1972 ADS MEMBERSHIP CARDS AND DUES BILLING PROCEDURESAll 1972 membership cards are enclosed with this Newsletter.However, to clarify ABS billing procedures, annualdues are paid on an anniversary date basis, not a calendaryear basis. Hence, receipt of your 1972 card does notnecessarily mean your dues are paid for the year.LANDING GEAR SWITCH HAY CAUSE GEAR-DOWN PROBLEMSDear Mr. Haesloop:In each issue of the ABS NeWSletter, fellow membersfurnish useful information and, in many cases, the answerto my questions and problems. Perhaps my experience withmy B-35 Bonanza may help some fellow member who is experiencinga similar problem. A brief preview and the historyof the trouble follows.About 12 months ago. while enroute to Alaska. the landinggear circuit breaker (CB) would pop out when the gearwas put down. This happened on three different occasions .A retract test was made each ' time and, after much testingand checking, the trouble disappeared. After returninghome I discussed this with Beech , who suggested the troublewas in the gear motor. The gear motor was then changed andhad no more trouble for several months. Then it happenedagain. This time I was at my home airport and was able tohave the service department immediately put the aircraft onjacks for a retract test. Just like the previous trouble,the CB popped out as the gear came full down, but this timew1th a differ ent twist. The landing gear reversing switchwas operated to t he down position and left in that positioD'.The gear came to the full down position, opening the downlimit switch, and then the gear motor electrically reversedand started the up cycle. As the down limit switch wasclosed, the gear motor electrically reversed and startedthe down cycle again. This cycling of gear down. gear up,continued until the CB popped out. If I had not seen it. Iwould not have believed it. But just as on previous occasionsduring the retract test, t he trouble disappeared. Ianalyzed the circuit and was convinced that the trouble hadto be in the landing gear reversing switch. The gear switchwas replaced. I carefully took the old switch flpart andthere was the trouble. Wear on the rocker type armature oft he up-down switch permitted contact to be made, at times,on bot h the down and the up contacts at the same time.The gear motor on the down rotation was sufficient toovercome the up-field of the motor and, thereby. continuedown until the down limit switch contacts opened. whichallowed ~he up- field to reverse the motor for the up cycle.The up rotation continued only until the down limit switchclosed the down- field of the motor and reversed its rotation.The worse psrt of this trouble was the uncertainty ofthe gear in its down posit ion. After this experience Isure know how to use the emergency gear down crank!J. E. Hoffmire, ABS #126241 Burlington RoadClifton. NJ 07012

Page 219 January 29, 1972COMMENTS AND CORRESPONDENCELATEST INFORMATION ON NEW AVGAS--80/87 TO stAY?Gentlemen:As a new member I look forward to receiving the ~onthlyNewsletter snd usually review it thoroughly. I also expectto avail myself of the various offers being extended.Of late, I have been very distressed by the actions ofseveral of the oil companies in their efforts to remove80/87 gasoline from the field. Yesterday. I read an AD notefrom the FAA' relative to the changes to be made in our enginesin order to receive this gasoline.In the phasing-out of this grade of gasoline, I feelthat we are being led dawn the primrose path by the governmentin the fact that they are not protecting the rights ofthe aviation consumers. My plane is a comparatively newone. If the plan of the oil companies goes through, I, andmany other plane owners will be subjected to needless expensein converting our engines to accept this gasoline withsafety.What about thetimes the amount of"100" gasoline.pollution factor? I believe that eightlead will be expelled in the uae of theI would like to hear the comments from Beechthe Beech Aircraft Company, the Continental Motorfurther information from the Federal Government.like to have the ABS take up the cudgel, since itto grind except for the interests of its members.Sydney P. Wiener, D.M.D.,1789 Hacienda PlaceEl Cajon, CA 92020owners,Co., andI wouldhas no axABS #3653Dear Ralph:In response to your request and the letter from memberDr. Sydney Wiener, I have been in touch with Norman Colvinof Beech and Ken Gardner of Continental and I have the followingreport.Mr. Colvin felt sure that all Bonanza engines couldtolerate the higher octanes--withstand more lead contentwithout valve damage, but that perhaps platinum plugs wouldbe advisable. He felt that the oil companies would not proceedwith the announced plans to do away with 80/87 octanefor some time.Mr. Gardner clarified things even more, saying thatplans now are not to do away with 80/87, but that if, achange should be made in the future, the fuel would then becompatible and suitable. He explained that 80/87 has 4 cclead/gal., where the new 100 octane has only 2 cc lead/gal.,so it actually has lower lead and pollution problems--thatthe higher octane is a result of blending butanes and propanes.The main difference in the higher octane is slowerburning than 80/87 and that a pilot would not notice theSlightly higher cylinder head temperature and slightly lowerpower if using higher octane as an alternate fuel. He saidthat lead fouling would not be the problem and, while a timingchange had not been tested, it might be a possibility.Also, he indicated that since the higher octane was aromatic,it required the use of neoprene hoses, but that surelyall fuel hoses, by now, were of neoprene.Mr. Gardner made the additional observation tbat hehad received requests to explain why low-lead automobilegasoline could not be used in aircraft engines. He emphasizedthat the fuels are completely different and tbat autogas should not be used. The fuel vapor pressures for autogas are in the 9-14 psi range and the highest limit for avgasis 7psi.Mr. Colvin requested more members to drop him cardsabout service clinics. He said he had about 125 inquiriesand that they were scheduling clinics for Indianapolis inFebruary and Oakland in March, and more requests would helpto line up more. I understand United Beech, here in Wichita,was so pleased with their clinic that they plan another nextyear.Frank G. Ross, ABS #386P.O. Box 2696, Wichita, KS 67201Editors Note: Free Beech Service Clinics should be encouraged.Please send a card to J. Norman Colvin, BeechAircraft Corp., Wichita, KS requesting a cl~n yourarea.RECENT BEECHCRAFT SERVICE INSTRUCTIONSWe have received three new Beechcraft Service InstructionLetters, all too lengthy to reprint in our Newsletter.They are:1. No. 0254-156. Rev. III, ATA Code 27-10Sub1ect: Control wheel. clock and map light, replacingthe control wheel adapter.Synopsis of Changes ·in Revision III: Add. an improvedadapter with a second weld around the adapter shaft toensure weld penetration through thickness of adapterplate2. No. 0021-248. -249. Rev. I, ATA Code 61-10Subject: Propeller--2-bladed and 3-bladed--Revision93-3 to McCauley Service Bulletin No. 93, Counterweightatt3chment improvement.Reason: To comply with Revision 93-3 to McCauley ServiceBulletin No. 93. (Note: work cannot be done byan A & P mechanic but must be done by a FAA approvedpropeller repair station.)3. No. 0439-242. Class II, ATA Code 71-10Subject: Power plant-cowling-Part I, installation ofurethane adhesive rub strips on cowl doors and nosecowl bulkhead flange; Part II, increase of flange widthat forward end of engine compartment side panel longerons.Effectivity: Part I. Beechcraft Bonanzas F33 and G33,serials CD-123S through CD-1255; Bonanza F33A. serialsCE-290 through CE-345; Bonanza F33C, serials CJ-26through CJ-30; Bonanza V3SB and V35B-TC. serial D-9069through D-9278; and Bonanza A36, serials E-l$5 throughE-272 .Part II: Beechcraft Bonanzas F33 and G33, serialsCD-1235 through CD-1263, except CD-1255j Bonanza F33A,serials CE-290 through CE-353; Bonanza F33C, serialsCJ-26 through CJ-30; Bonanzas V35B and V35B-TC, serialsD-9069 through 0-9297; and Bonanza A36, serials E-18Sthrough E-294.Reason: Part 1. The abrasive resistant urethane adhesivewill provide highly durable rub strips at theedges of the cowl doors and on the nose cowl bulkheadflange to retard cowl door wear.Part II: The longeron flange width increase at thelower forward edge of each cowl door will furnish addedsupport for the doors in these areas and thus reducewear.Compliance:At the owner's discretion.HIGH OIL CONSUMPTION AND PERFECT CIRCLE PISTON RINGSGentlemen:I am not normally prone to systematic letter writing,but feel I must write regarding your November "Bonanza ofthe Month" editorial, taking to task several points mentionedby the author. Both of those points concern high oil consumptionexperienced with Continental engines.1. It is an established, well known fact, one thatengine manufacturers have extolled for sometime, that certainadditives found in detergent oils possess a qualitythat prevents surface to surface bearing ''wear in" duringthe critical 100/150 hour breakin period, ergo, the requireduse of nondetergent oils during this period.2. High oil consumption experienced on re~ently toppedor majored Continental engines can be traced to the impropertype of oil control ring being used, due to an incrediblefoul-up by Perfect Circle Piston Ring Company, a vendor forContinental Hotors. It appears that P.C. redesigned theface profile of the control ring without notifying Continental.the ring was totally unsatisfactory, but Continental,not knowing of the change, was supplying the ring to alltheir outlets with a subsequent high incidence of servicecallbacks and customer complaints.Richard J. Lang, ABS #3766940 E. Old Willow RoadWheeling, IL 60090