PT20J

I had the left mag replaced with a SureFly using the STC and the installer filed the 337. Later, I had the SureFly removed and the mag reinstalled and the IA said that we didn’t need a 337 for that. I always wondered why. At least the Bowers opinion explains that: “Regardless of the type of STC, the approved design change does not become part of the specifications ofa particular aircraft, aircraft engine, or propeller until the particular aircraft, aircraft engine, or propeller has been altered in accordance with the STC.”

Yeah, that’s actually what drove me to LEDs. You would think they would be designed to be changed by removing the lens and extracting them from the front. But it’s a Mooney and the basic design philosophy seems to be “we hate maintainers.”

How long has the new 200 hr engine been sitting? If it hasn’t flown for many years and wasn’t pickled, it may have corrosion issues, also. After making sure the airframe is in good shape, I would suggest moving on to next checking the engine condition.

Which, of course, is the problem with trying to get a consistent answer because the FAA delegates so much decision authority to the FSDOs and they don’t all agree. What one region allows, another may prohibit.

I read the interpretation and I see why you said "suggests". The opinion states that "an STC is design approval for a major change". Then it goes on to state the legal definition of major and minor changes. Then it says if you use an STC to make a major change, you need to file a 337. It never explicitly says that if you use an STC to make a minor change that you do not need to file a 337. It might be implied, but it doesn't explicitly state that. What it actually implies to me is that a STC should not be used to approve minor changes. But it has long been the policy of some regions to do so. Really what the FAA should do is create something like an STC for minor alterations that gives approval basis for installation without any ambiguity about a 337. Skip Bowers_2016_Legal_Interpretation.pdf

In my experience, you absolutely, positively cannot understand the FARs without also reading the legal opinions because there are sometimes opinions that directly contradict the wording of the law. And, you cannot understand how the FAA works without reading its various Order documents that provide guidance to FAA personnel. And, what normal person can keep up with all that? "Why?" questions frequently don't have satisfying answers when dealing with the FAA or Microsoft. It's easier to go with the flow and just go with it. As Don Maxwell once said, "It's only a piece of paper."

That’s because that latch handle engages the emergency gear extension drive and jams the motor. If the handle is only partially raised and the motor can turn it can chew up the brass clutch in the gear actuator.

I believe the FAAs logic is that the part has to somehow be approved for installation an a certificated aircraft. Standard parts like nuts and bolt made to an industry standard are approved. Parts made or specified by the airplane manufacturer are approved. The FAA sometimes approves parts that have the same form, fit and function with just a PMA (for instance GLAP windshields). But something like a generic light dimmer usually gets approved through the STC process. And by definition, since it is a supplement to the type certificate, the FAA considers it a major alteration requiring a 337.

Fixing the Mooney dimmer depends on what’s wrong with it. Your symptoms sound like worn potentiometers. I don’t believe there is a TSO for dimmers. Seaton has an STC for the MaxDim, so your IA would fill out a 337.

I looked at a couple of schematics for later models and the diode goes from the terminal with the field wire to ground, so I think my schematic is wrong. Diodes are cheap and it couldn’t hurt to give it a try. Skip

Interesting idea about the diode. My schematic shows a diode on the alternator, but it doesn’t make sense to me since it is on the grounded field terminal. It might be a mistake and should be on the other terminal. I’ll have to look next time I have the cowling off.

I always liked the Aerostar ever since watching Jimmy Franklin's Zar routine. And the really cool thing is that as soon as you slip into the left seat, you instantly look like Tom Cruise in American Made. But, you need the Randolph Engineering sunglasses (randolphusa.com)

Not sure what you mean by that. If the alternator field circuit breaker pops due to a fault, it will cause a low voltage indication. Different voltage regulators handle an over voltage differently. Some have a relay that removes field excitation. Others have a crowbar circuit that shorts out the field circuit which will cause the field circuit breaker to pop thus removing field excitation. Skip

I would definitely call LASAR. I exchanged emails with Brett Stokes (LASAR owner) inquiring about whether they still were reconditioning landing gear trusses and rebuilding landing gear actuators. He replied: "As far as nose gear truss landing gear actuator rebuilds go, the answer is 100% yes!" He also said that they were investing heavily in the parts side of the business and plan to remain the largest parts supplier for the Mooney fleet. Skip

If you are thinking of this one, it's no longer available. Corrine told me before she left that they used to have these made by a local machinist in Lakeport and he retired. They decided not to look for another machinist because these weren't a big seller -- most people opted for the rebuilt factory horns because they were (wait for it) ... cheaper.

I got lost somewhere: Does G100UL work in my barbeque?

Well, that's a new one: I've never seen a bulb holder like that one, or heard of a 336 bulb. Reminds me of my 1978 M20J. Soon after I bought it the flap/trim position indicator bulb burned out. It wasn't replaceable from the front of the console like the later models. To get to it, I had to drill out pop rivets to remove the side panel. Then an aileron push-pull tube was in the way. Disconnecting the rod end still didn't get it far enough out of the way, so I had to go underneath and remove a belly skin and disconnect the other end. Then I could get to the bulb which I removed and took to the avionics shop on the field. It was some kind of weird bulb (maybe a 336?) that they didn't have and had to order, so I had to put the whole thing back together to fly it and then repeat to install the bulb when it arrived. That's when I learned something about the way Mooneys are built. Skip

George Braly (GAMI) has stated that most engine monitors %power indications are pretty inaccurate. He developed a proprietary algorithm for Cirrus for the Avidyne system that Cirrus shared with Garmin. I think that’s what is in my G3X as it seems pretty reasonable. Without giving away too much detail, George described it to me thus: The algorithm does a basic check to figure out from MP/RPM/OAT/FF if the engine is ROP or LOP and then calculates the HP accordingly.

If raw speed is the need, and piston power is a requirement for insurance and/or operating cost, you will not beat a big-engine Mooney. That is its niche.

The important thing is to arrive at the flare point in the desired configuration, at the proper speed and attitude, aligned with the centerline with no side drift. How you get there is a matter of technique of which there are many.

Gives new meaning to "shower of sparks."

The early units had a long reboot time so when doing mag checks with Bendix mag switches that momentarily turn off both mags when switching between positions the SureFly would shut down long enough to cause a backfire. I believe that they fixed that at the same time that they fixed the 28V voltage spike shutdown problem. The problem is that that they never recalled these so you have to somehow make sure when you order one that you are not getting one that is old stock. Since the older units only had the voltage spike shutdown problem on 28V systems, it seems for a while at least that they were shipping the old stock to all the 14V orders. Skip

Must have been at night They really should light that ramp.

Hey James, @OSUAV8TER, not to confuse things, but what's the projected certification timeframe for the PAR46 dual mode landing/taxi lamp and is it G3 technology? Skip

I just figured something out. There must me a lot of old marker beacon antennas around that have been removed. It looks like this one protected part of the belly on this airplane. So if we mounted four (two forward and two aft) on the belly as skids, maybe it would reduce repair costs if the no-back spring breaks?