philiplane

Half of that loss is due to forward CG alone. The three blade prop has more drag than a two blade, but worse, it's heavier. And that extra weight is all the way upfront, causing more load on the tail. Figure out how to get your CG further back. Push your seat back in cruise, add weight to the baggage, etc. Mooney, like all other manufacturers, got the book speeds with the plane loaded to gross weight, but also with the most favorable CG. But most pilots fly at or near the forward limit, which adds a lot of drag, slowing the plane down. Cooling drag is the next big item to tackle. If the engine baffles aren't perfect, a lot of air goes through the cowl, but in the wrong manner. You end up with higher CHT's, and can lose 2-4 knots depending on how bad the leaks are. External things like antennas and gear door rigging, and flight control rigging, are the smallest contributors to your problem.

oil starvation due to main bearing shift, or other blockage of the oil system. I personally know of two dozen ventilated Continental cases over the past 25 years. But zero Lycomings, even though I've seen more large Lycomings over the same span. Lycoming failures tend to come from broken exhaust valves, and that doesn't trash the whole engine. Also, since Continental camshafts are at the bottom of the case, all that extra oil just falls into the pan. The top mounted cam in a Lycoming spills its overflow oil onto the crankshaft.

It's yet another big Continental with a hole in the case. It seems to always be #2 or #6.

Surefly has timing advance based on MP and RPM. The Electroair only uses MP, and only advances below 25" MP.

A Surefly is even better than an impulse coupling, because it has full voltage available the moment the engine turns. It doesn't even need a half turn or more like an impulse coupling or shower of sparks. I had impulse coupled mags, and no starting issues hot or cold, but with the Surefly, the starts are exceptionally fast. As soon as the prop turns, it's running.

It has no effect. Any Continental engine, large or small, in any airframe, suffers the same short cylinder life.

I personally fly a pair of 540 Lycomings in my Aztec. Best engines ever built. Strong, reliable, low maintenance. Continentals have a reputation for weak cylinders. The folks on the Beech and Cirrus forums list cylinders as their biggest problem. And it is a design problem. There's nothing you can do but spend extra money to head off problems that do not occur in Lycomings. Sodium filled exhaust valve stems have been a solution that extends the life of any engine. Ford used them in their industrial and heavy truck gas engines starting in the 1960's. It's a proven technology. Continental would be wise to adopt this simple tech to help extend the life of their cylinders. The associated problem is harder to fix. Continental put the cam below the crank, which also means the pushrods are at the bottom of the cylinders. But the cooling oil that travels through those pushrods does not defy gravity, and flow freely upwards onto the valve stems. This is where the Lycoming design, with the cam above the crankshaft, is superior. All that cooling oil flows downward over the valve stems in a Lycoming. Much more cooling oil flows down and over the valves, than is splashed upward on a Continental. So Lycoming has a cooler exhaust valve, due to the sodium filled stem, and more oil to carry that heat away. Continental has neither. Continental relies only upon a rotocoil to rotate the exhaust valve, to help distribute the heat evenly. The low expectations of Continental cylinder life are something that people live with in return for a slightly more efficient engine. But the gas money you might save, is given back many times over, in maintenance costs and shorter service life. So why do some OEM's use Continentals instead of Lycomings? Years back, it was a combination of price per HP, and fuel efficiency. Longevity is not a concern for an airframe manufacturer, because weak cylinders and other problems don't come up until well after the airframe warranty has expired. One great example of change is the Cirrus SR20. Introduced with six cylinder a Continental IO-360-ES in 1999. But when flight schools demanded better, Cirrus switched to the four cylinder Lycoming IO-390 in 2017. Because it's a better engine, with greater longevity and lower maintenance costs.

I change at least 80 rotocoils each year as preventative maintenance on 550 Continentals. And do exhaust valve lapping. Otherwise, these engines will not make TBO without cylinder replacement, turbo or non-turbo. The Lycoming engine does not suffer from this problem. Nor does it have starter adapter failures. I would choose a Bravo over an Acclaim if you are concerned about reliability, or choose the Acclaim if you really need the last few knots it will give over the Bravo. But remember that the Acclaim needs to be faster while in flight, because it will spend more time in the shop. There's no getting around that. Continental has a weak cylinder design, with the rocker arms at the bottom of the cylinder where they don't get much oil onto the valves. And lacking the sodium-filled exhaust valve stems that Lycoming has, the Acclaim exhaust valves will NEVER last as long. I'm drawing on tens of thousands of hours of customer's airplanes flights over the past three decades. It is extremely rare for a Continental engine, let alone a turbo Continental, to make TBO without cylinder changes. And there is also the bearing shift problem after cylinder maintenance. There are hundreds of Continental engines that have thrown rods through the case with no prior warning. Lycomings can do the same, but it is extremely rare.

there is a GNS480 owners group: https://gns480-users.groups.io/g/main

Here's a fresh data point to consider. Cirrus has adopted the Earth-X battery in the 2024 models. I have a client with a six-month old SR22, and his Earth-X battery just failed. Probably due to my main complaint, which is the small reserve time compared to conventional batteries. The newer Cirrus have an app just like newer cars do. (Cirrus IQ)You can check the status of the plane from your phone. The problem is, planes usually reside in hangars, where there may be limited or no cell network. The plane's IQ unit tries to connect with the network, and will continue until the battery is dead. Like any cell phone will do under the same conditions. But with half the reserve capacity of a conventional battery, well, you get the idea. Dead battery, quickly. It also appears that the Earth-X battery does not come back quickly after using ground power to charge, and then start, the plane. They tried, and had to ferry the plane over to a Service Center to sort out the cascade of failures resulting from the dead battery. I think they'll be replacing it with a good old Concorde RG24-11M. Unfortunately, Cirrus changed the battery tray when adopting the Earth-X. So if your lithium battery dies on the road, you are stuck until a new one can be delivered. Like anything new, getting replacement parts can add to the downtime.

Borescope the cylinders, and pull the pushrods & tubes out on one side, to remove lifters and inspect the camshaft. This would only take half a day to do. And it will reveal any possible corrosion that could shorten the life of the engine. In the event you find any minor pitting on the lifters, they can be replaced easily. So long as the camshaft itself passes Continental's Service Bulletin specs.

The contract towers in Florida seem to work better than FAA staffed towers. The worst tower is at Fort Lauderdale Executive. It's not only an FAA tower, it's s training tower to boot. Super inefficient.

Do you know that the engines come preserved from the factory, with desiccant bags and desiccant plugs in the cylinders? And they have air conditioned parts storage...Wow, who would have thought that a shop in Florida might have air conditioned parts storage?

If you need an IO-550 you can likely get one from Certified Engines Unlimited, next week. They are one of the largest stocking engine shops in the US. https://ceu.aero/

That's odd because Lycoming has been shipping ahead of schedule on many engines. Previous 10-12 month wait times have been reduced. The last IO-360-M1A engine I ordered was quoted at 11 months, revised to 8 months shortly after, and was delivered in 6 months. And a turbo Aztec engine (close relative of the Bravo engine) came in 8 months rather than the 15 months first quoted.

Having dealt with six different FDSO and two different ACO offices, I can tell tell you that the problem is definitely a government issue. They all use the same book of rules, but no two will "interpret" them the same. Even though they go to classes specifically designed to identify and prohibit "inspector's personal preferences". And over the past decade, it's increasingly difficult to get any inspector to sign off on anything new. Want a Field Approval? No, spend $$$$ and get a DER to draw up an 8110 instead. And check rides for an initial CFI was the sole province of the FSDO. Now, they're being done by DPE's. They're getting paid more and more, and putting out less than ever. Doling out what used to be FSDO core functions, to designees. I sympathize with the employees though, they waste huge amounts of time on non-productive bureaucratic chores that Washington thinks are needed. Oklahoma City has no say in the matter. This has led to FSDO shopping, which the FAA is trying to stamp out. There are a few FSDO's that are still operating like they were 30 years ago. That will change as the oldest inspectors retire.

Therein lies the problem. Why is moving a shop from one FSDO to another such a difficulty? The FAA exists to ensure that safety is assured. But it often results in completely unreasonable costs and delays, without ensuring or improving safety. This has to change.

Ovations are nice planes overall. To keep it running well, replace the exhaust valve rotocoils every 800 hours. And use oil analysis to track nickel trends, which will tell you well in advance if an exhaust valve guide is wearing. In combination, these items can help extend the cylinder life dramatically.

3AA standard steel cylinders have no life limit 3HT lightweight steel cylinders have a 24 year life limit Composite cylinders usually have a 15 year life limit.

Since you're at 800 hours, you should change all six exhaust rotocoils right now.

Not total crap. But not 100 percent accurate either. All turbo airplanes are a few knots slower (on the same power & fuel flow) below 8000 feet for a simple reason. The engines are heavier, and nearly all that extra weight is up front. The weight difference on a Cirrus turbo vs non-turbo is as much as 180 pounds. Because turbos will come with oxygen, de-ice, and other equipment that add weight and drag, in addition to the heavier engine. The turbo Cirrus will be faster above 8000 feet, up to its' max cruise of 214 KTAS at FL250 on 18 GPH. I can get a little more speed if I can move some weight aft.

A DA50 is not remotely comparable to a Mooney anything. It's a 1.5 million dollar pig with the power-to-weight ratio of an old Cessna 172, and a questionable engine. All of the DA50's produced so far are under a SB to analyze the oil every 50 hours, due to a manufacturing defect that can result in a failed crankshaft.

Continentals do not have sodium filled exhaust valves, or good oil cooling of the valves, like Lycomings have. It's really hard to overcome that basic difference in design. No matter how carefully you operate a Continental, it will not last as long as a comparable Lycoming. And Lycomings don't suffer from the occasional main bearing shift that results in thrown connecting rods. You can extend Continental cylinder life by changing out the exhaust valve rotocoils after 800 hours. They tend to wear out around that time, and once the valves stop rotating, they will burn shortly thereafter.

The biggest con with the Acclaim is the Continental engine. It eats money. Cylinders, starter adapters, leaks, etc.

ATR-72's are susceptible to loss of control in severe icing conditions, like any other plane. Take that, add a young crew to the mix, and you've got serious potential for an unrecoverable stall. Not a tail plane stall, because the nose hasn't dropped in the video shown. Those are recovered with back pressure on the elevator, the opposite of a normal stall. A heavily contaminated wing no longer wants to fly. NASA has done extensive research on airframe icing, mostly using their Twin Otter. An associate of mine has been aboard for those tests. He provides the ice measuring devices, and ones that measure the content and type of water in the air. He also uses this equipment while documenting the icing certification tests for all the major GA airframe, and engine, OEM's. His company is one of the most experienced in aircraft icing certification and our discussion was fairly short. The inexperienced crew flew into severe icing, lost control, and were unable to recover the plane. It's rare, but until aircraft are equipped with actual ice-sensing and crew-alerting equipment, it will happen again. The equipment exists, and has for years.