February 2007 - American Bonanza Society

300 lb. decrease in useful load, and a300' increase in takeoff roU). [s there,indeed, a substantial change in performancepost '87?A: There was no change to the basicstructure of the airplane with introductionof the [0-550 beginning with the1984 model. The claimed speedincrease isn't borne out in my experience,but the reduced useful load andtakeoff performance at maximum grossweight are. The spar web material usedis about 50% thicker in post-1 987 airplanes,which the FAA feel s was sufficientas a terminating action; so the sparweb AD does not apply to those airframes.-TTStandby generator& landing gearJoe McMurrayGilroy. CaliforniaQ: The alternator on my G36 wentout the other week. Luckily it happenedwhile I was still close to my home airpon.I turned right around and got intothe pattern. I hesitated in activating thestandby generator because I was at 1700rpm and 'fl ying by the numbers' as youhad taught me. The gear came down, butrather sluggishly, and I verified the threegreen lights. The JPI showed the batterylosing voltage (pretty quiCkly, I mightadd!) and after I had landed the JPIshowed only 18 volts. The standby generatorrequires 2300 rpm for output.Does that mean I have to operate it at2300 rpm for it to work? And how doesthat go we ll when I have to reducepower for landing? Will it stop working?A: The standby generator requires2300 rpm to develop its full ratedpower. It may be capable of producingsome power below 2300 rpm, but notenough to reach its already-limitedcapacity to power selected aircraftequipment. It does not harm anything toturn the standby generator on at lowerengine speeds, and any power developmentat all from the standby will reducethe rate at which the battery depletesalthoughthe standby does not rechargethe battery.You mentioned the gear comingdown sluggishl y. Remember, the landinggear requires full operating voltageto be assured it locks down. The gearactuator's dynamic brake cuts off thegear motor when the landing gear isalmost, but not quite, at full extension.If the gear motor is operating on fullsystem voltage (28v in your case), itwill coast the rest of the way into thedown-and-Iocked position.If system voltage is reduced, thegear motor will cut off at the same physicalpoint in the extension process, butthe gear may not have enough inenia tocompletely lock down. However, it maybe far enough out to give you the "threegreen" lights in the cockpit, and to disablethe landing gear warning horn andannunciator when you reduce throttle.Hence I recommend that, if youhave to extend the landing gear on anythingother than full electrical power(28v in your case), you back up the partial-electricextension with the manuallanding gear extension procedure tomake cenain the landing gear is indeedlocked down. Manually cranking to thestop is the only way to tell for cenain.From my accident reviews, I'vefound a high correlation between alternatorfailures and landing gear collapseaccide nts in ai rplanes (like yourBonanza) that have electrical landinggear systems. I'm glad that didn't happento you. - TTExcessive tire wearDavid BarnesShelbyville, TennesseeQ: The left main gear tire on myC33A wears twice as fast as the othertwo tires. I have had the bushings andthe wheel bearings replaced and madeother minor adjustments. My mechanicnow attributes this problem to excess P­factor resulting from the fact that theaircraft has a 300-hp conversion, athree-blade prop and other mods, andrequires considerable rudder on groundroll. What is causing this wear problem?A: I doubt that the problem is excessiveP-factor. Check its wheel alignment.Pull the airplane forward ontogreased plates (two for each wheel withgrease between each set of plates). Letthe wheel assume the position it wantsrelative to the direction of travel. Thenmeasure to the wheel flange fore and aftfrom a chalk-line snapped to the floorfrom points on the fore and aft ax is ofthe airplane. Use shims on the scissorsto change the alignment.-NPNOTE: ABS board member Bill Stovalladds: "Everybody lVears the left mainquicker because lVe all prefer left tumsif there is an option, since lVe havebetter visibility filming left. I startedmaking as many right films as possiblealld thal really helps. Seriously!"Aluminum aileron skinsGary PeitzmeieJDayton, OhioQ: I'm interested in fi nding how topurchase aluminum ailerons for my J35 .Corrosion is beginning to form in theinboard edges (nearest the flaps). I haveheard magnesium can be replaced byaluminum but don't know the specifics.A: Aluminum ailerons and flaps canbe legally installed. Try Glen Biggs (405-258-2965), Hampton (479-394-5290) orStebbins (800-852-8155). -NPSkin thickness testRocky Harbourlevelland, TexasQ: I need to get the ski n on my A35checked for thickness. Is there an easyway to do the caliper checks or is theresomeone I can call to do the sonic test tomeet SB-27-3358?A: The caliper/depth gauge andmicrometer are legal methods to checkthe skin thickness. Ultrasound by a testinglab is also possible. Testing labs inTexas are AADFW in Euless (8 17-540-