Paul and Colleen broadcast from Dayton, Ohio, for Aviation Maintenance Technician Day, and together with Mike, do their best to help owners suffering with engine problems, mysterious cold air leaks, improper fuel indications, and more. Send your questions to podcasts@aopa.org for a chance to be on the show.
Full notes below:
Jim has a heavily modified Twin Comanche that blows cold air on the back of his neck, and he can’t find the source. He suspects it’s from the rear tailcone, but he can’t figure out how to stop it. Paul suggests it could be the rear bulkhead or from the wing roots. Despite his attempts, it’s actually gotten worse and is now blowing air on his legs that varies based on attitude, whether the heater is on, and maybe even heading. Mike suggests a camera and tufts of yarn in the tailcone to see where the airflow is coming from. Paul suggests that the airflow from the heater might be blocked, causing problems. They said if you pull out seats and floor panels on a test flight with a mechanic he might be able to find the culprit.
Sam asks about dynamically balancing a propeller. When is it necessary? Who does it? The hosts agree it’s a good service to do when you change something, although the prop should be balanced from the shop.
Arnold has a Bonanza that improperly shows the fuel level on the right tank, but only after it’s burned a few gallons. This is using Ceis fuel senders on a Garmin display. After many attempted fixes, it’s still reading low. Paul said they have to forget what they think has been eliminated and instead go and try to recreate the problem on the ground. Mike suggests putting a small vacuum on the tank to see if they can do just that.
Keith has a turbonormalized Bonanza and wants to make sure he treats it well. He’s been surprised at how contentious the turbo versus non-turbo debate is. Mike said he thinks it’s a geographic problem where people on the East Coast think it’s useless and everyone out West thinks it’s a great tool. Although a turbocharged airplane is easier to abuse, the mechanisms themselves don’t have any inherent downfalls. So long as you treat it well and know that turbochargers are wear items, you should be fine.
Ben has a Bonanza and he wants to know if he can remove the rear seats and remain legal by doing the weight and balance math based on station and equipment info from the manual. He also wants to exchange the fasteners to make it faster and easier. Colleen said a new weight and balance from an A&P is required once in order to be legal, and the hosts agree that fasteners approved for a later model Bonanza should be easy to get approved for his airplane.
Kyle has a problem on both of his airplanes. His Cessna 182 with a bit more than 1,800 hours had a bent push rod and a bit of his lifter body had cracked as well. He is wondering if he should overhaul now since the case has to be opened anyway. Mike said the answer is always based on what happens after the case is split. If everything measures well then an IRAN is a good way to go, but an overhaul might be warranted too. It all depends on the inspection. The Continental C85 in Kyle's Luscombe has a stumble around 1,800 or 1,900 rpms. He thinks it might be a lean mixture issue because a bit of carb heat helps. Paul suggests he borrow a carb from a friend to see what happens. Even though Kyle has already overhauled his carb, Paul said he’s seen numerous times where even a supposedly overhauled carb won’t perform any better because they can’t duplicate the issue on the bench. A different carb would help to isolate the problem.