A64Pilot
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Everything posted by A64Pilot
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Based on the G100UL fuel leak thread what's your position?
A64Pilot replied to gabez's topic in General Mooney Talk
ADI wise. Failure is or could be easily made to be extraordinarily unlikely, the injection plate is just that, no moving parts with several injection holes. Then there are two pumps and surely both are tested on run-up, Separate electrical systems is as easy as a battery back-up like several current instruments. Have a pressure switch like one that runs many hobbs meters will tell you it’s on via a light, and or a failure light is dead easy, heck add a horn if you think it necessary, if the electronics fail it fails to the on position, or you have a switch that merely turns the power on, it’s not modulated it’s just on or off. Real easy to make it orders of magnitude more reliable than our engine, When I Certified the MVP-50T in the S2R-H80, it’s first installation in a Certified airplane. I spoke with Rob Roberts EI’s owner a little concerned about what if it quits, because if it does you lose everything, ALL engine instrumentation, fuel flow, fuel quantity, even voltage and amps, prop RPM, everything. I forget the number but he had to prove to the FAA that the likelihood of failure was if memory is correct over a million to one. How do you prove that I have no idea, but the FAA required it. So he can make electronics stupid reliable and he’s set to build the electronics for ADI. Using Unlimited’s as an example is a little silly, it’s like comparing a normal car to Top Fuel. If ADI fails in truth most likely nothing will happen but you will have time to either turn on the manual switch or reduce power. I know people that run our motors on 93 Octane pump gas and IO-540’s too, Experimentals do as they please, some run one tank 100LL for T/O and some don’t. I’m not abdicating running car gas or 94 UL, just know some that foolishly do. You think we have hot start issues, you ought to see how bad it is with car gas, that stuff vapor locks the moment you turn it off, you can hear it frying. Methanol mix handles freezing concerns, a tiny bit of oil handles corrosion concerns, but what do you think is going to corrode? I imagine a Rotomolded plastic tank, the pump can handle water, use an RV water pump if you think it’s necessary, the hose is rubber and the injection tube could be stainless. Windshield washer fluid is 30% to 50% Methanol, ADI wants %40 https://carfluidguide.com/how-much-methanol-is-in-windshield-washer-fluid/ Methanol Content: Windshield washer fluid typically contains 30-50% methanol, critical for preventing freezing and enhancing cleaning effectiveness Leaves the engine, Methanol is going to exist in it for milliseconds so I can’t see Corrosion there. But finally there is decades of actual experience with ADI from the Military, Airlines back in the day and hot rodders, they often use windshield washer fluid which is apparently Methanol and water, and I’ve never heard of corrosion from windshield washer fluid and I’m sure it doesn’t contain any oil. No need to modulate it, it’s only on at high power and the amount your spraying is way in excess to what’s needed as until you start spraying a stupid amount excess isn’t harmful. I assume size of the injector will likely be based on HP of the engine? If we accept that lead is a health concern and has to go (I don’t myself) but that only leaves a few options (Magic fuel) that has eluded smart people for decades? A new engine that I can assure you all in is over $100K, or scrap our aircraft, add maybe a low compression motor STC, maybe possibly low compression pistons and or cylinders and live with the power loss with our existing engines? Or ADI and 94UL Now to be clear, I do NOT want ADI, I want to keep 100 LL, but if forces beyond my control take it away from me I don’t see anything viable but ADI. Do you? -
The sad thing is a Bonanza is a very easy airplane to fly, especially to land, reduce power and they come down right away, no float. They have short wings and pretty big flaps I think that has a lot to do with their popularity, the ease of flying, especially landing. If I could get past the nauseating tail wagging in light turbulence I might have bought one, a few years ago when I was looking you could get a V tail for about the same money as a J, because I think the average V tail is twenty years older.
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I think GA accident rates follow the hours flown, so unless the rate is factored against hour flown as in x number of accidents per xxxx hours flown I don’t think it’s necessarily accurate. I’ve seen rates that factor in hours flown, but usually it’s just a number per year.
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Based on the G100UL fuel leak thread what's your position?
A64Pilot replied to gabez's topic in General Mooney Talk
Yes, that’s what I’m thinking too, 94UL is of course a “fit for purpose” Aviation fuel, refined etc under I think an ASTM spec etc. should I think not have any vapor loc issues etc that car gas does, 94UL won’t “eat” composites or nitrile, fuel tank sealer, paint etc. It would let you burn car gas too, but car gas has its own problems with different formulations existing and changing seasonally etc. So it might be difficult, not saying you couldn’t make it work, just it may require even more airframe mods and tomorrows car gas likely won’t be what we test and Certify today. Without being any kind of expert from what little I know is ADI would allow unleaded fuel tomorrow without any problems and my bet is the engine and airframe manufacturers would test and sign off on 94UL if they haven’t already. In my opinion it’s very important for the manufacturers to approve any alternate, to require a product they don’t test and approve is at a min irresponsible. Only the high compression and turbo motors would need ADI, the majority of GA would be fine just switching over to 94UL. There is a solution for those that think we need one, we don’t need a Magic fuel mixed from Lord only knows what with unknown health consequences etc. -
Based on the G100UL fuel leak thread what's your position?
A64Pilot replied to gabez's topic in General Mooney Talk
I doubt it, but assume if they said they were going to it was both possible and Lycoming was OK with it. My SWAG is liability from saying you can burn Mogas, mostly including me think that means Auto pump gas, but does it really? Does Mogas even exist anymore? By that I meant the fuel that was Certified to burn in the Peterson and EAA STC’s in the 80’s isn’t what is at the pumps nowdays. Plus I think the target market fir the airplane is Part 121. Would that matter for Auto fuel? I don’t know not having personal experience with Part 121, but finally Auto fuel just isn’t available at airports I don't think Lycoming is the stick in the mud most seem to think as they allow and of course Certified a 540 for Embraer to burn pure Ethanol for Brazil. So I think Lycoming will allow ADI, by allow I mean not deny Warranty etc. Its astonishing when you think about it that the FAA allows a fuel that no manufacturer tested, or none that I know of, both airframe and engine. It would seem to me that puts the FAA into a liability problem, Cirrus says don’t use it, FAA says it’s fine, your million dollar aircraft becomes unairworthy, who is paying? -
Based on the G100UL fuel leak thread what's your position?
A64Pilot replied to gabez's topic in General Mooney Talk
Our Grandfathers would dribble it into the carburetor of a running engine at high idle and gunning it every so often. This was back in the day when pulling the head and de-carburizing an engine was recommended. If there is sufficient water it will clean, but I don’t know if ADI is of sufficient quantity. From this Avweb article Tecnam is going to build an aircraft with ADI. Will they? I don’t know but think there is a market, but maybe mostly in Europe? Haven’t seen many Tecnam’s around here. I believe the T means turbo, never seen one but seems to be the engine we have been crying for? IE electronic controlled, variable timing etc. https://www.avweb.com/features/the-return-of-anti-detonation-water-injection-adi/ “Air Plains isn't the only company exploring ADI. At least one European manufacturer, Tecnam, will reportedly use ADI in a new twin called the P2012. Powered by Lycoming's new TEO-540-A1A, Tecnam says the airplane will be operable on mogas. Another Lycoming-powered aircraft, Grumman's pilot-optional Firebird drone, will also have ADI, presumably to operate in theaters where 100LL isn't available but mogas is.” -
Based on the G100UL fuel leak thread what's your position?
A64Pilot replied to gabez's topic in General Mooney Talk
There is 109 Octane unleaded race gas https://racefuel.boostane.com/products/109-octane-fuel Oxygenated is good for power production, back in around 1980 when I was drag racing turbo bikes when we set a record, on the way back to the starting line they would take a turkey baster sample of fuel to make sure the fuel was legal, must not have been a difficult test. I think it may have just been specific gravity like you test antifreeze maybe? Has anyone actually tested the Gami fuel for octane? Does it claim to be 100 Octane? Is the requirement to be 100 Octane or just pass detonation testing? -
Making Sense of Best Glide and Glide Ratio
A64Pilot replied to Max Clark's topic in Modern Mooney Discussion
Or just don’t trim full, personally my trim ends up where it is at takeoff, and you should plan on electric trim not working, because it’s some kind of rule, when you need anything the most is when it won’t be available, even when trimmed for takeoff, it takes quite a lot of pressure and trim when I raise flaps -
Making Sense of Best Glide and Glide Ratio
A64Pilot replied to Max Clark's topic in Modern Mooney Discussion
I try to tell this whenever it comes up, but try going rapidly to full power on short final with the trim full up, if you have the strength and are comfortable with the excess pressure required to keep from stalling, fine. Maybe it should be done at altitude. If nothing else I think it should be done so pilots see just how much pressure is required, if you don’t expect it, it could catch you off guard. Ray Maule used to teach an approach in a Maule trimmed full nose up, I did a go around once and that was the last time I landed trimmed full up, it took both hands to hold the nose down, obviously I didn’t die, Mooney especially a 4 cyl one ought to be more forgiving -
IF it were rebalanced when the servo was installed it should be a little nose heavy, which is conservative for flutter
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O&N icing mast installation, low fuel indication
A64Pilot replied to Mobius708's topic in Vintage Mooneys (pre-J models)
Mine does anyway, always thought if it faced backwards that the icing mast wouldn’t be needed -
O&N icing mast installation, low fuel indication
A64Pilot replied to Mobius708's topic in Vintage Mooneys (pre-J models)
Blocking a vent should not change level indication, unless and this would be an extreme event but unless it was blocked and over time the pump pumping fuel out pulled such a vacuum that it collapsed the bladders. I have seen a metal fuel tank crushed from a blocked vent though so it can happen. -
Yeah all of our dealers kept trying to say that what they could sell was a 400 gl airplane, thinking of course 20% less capacity = 20% less cost. But that wasn’t the case the money saved in fiberglass in the hopper was trivial, money difference between a -15 (680 HP) Pratt and a -34 (750 HP) wasn’t much, a Hartzell three blade is a Hartzell 3 blade cost wise, batteries, Starter / Generator, airframe, wings, landing gear etc are the same, there just isn’t any real savings. But you could get a Factory overhauled Walter 750 HP for about half the cost of a Pratt, the Avia prop was less, the Starter / Generator came with the engine etc. Now the Walter wasn’t as powerful as a Pratt, but I was going to derate it to 680 HP as it could make that, leave the airconditioner off as well as lights etc and a 400 gl airplane became viable, then GE bought Walter and killed that plan, but GE was building a “New” Walter making much more power, no hot end insp, no fuel nozzles to clean and several other things and they were wanting to get this new engine in new aircraft of course so we became their launch customer. I think GE General Aviation died on the vine, nobody else jumped on the engine, they designed and built a new engine with 3D printed parts and 21st Century GE aero technology etc for the Cessna Denali. But where is the Denali? Pratt also began giving sweet heart deals to manufacturers to block GE too, but our current owner was too arrogant and stupid to listen. Point I’m making is I don’t see the price point changing. I believe the street price of a Pratt -34 is about $500,000, OEM was about $350,000 back then, but then you buy prop, prop governor, starter / generator, even engine mounts are thousands, so an OEM ends up with half a mil in the engine, so I’d guess you would need a million five to turn a profit for a non pressurized four place? You know I wouldn’t be surprised if a Turboprop isn’t as expensive as a Williams Turbofan, and who wouldn’t want a Jet over a Turboprop? Transition wise a Turboprop is much easier than a piston to manage, especially a Turbo, if FADEC there really isn’t anything to manage. You have to be stupid to hurt a Pratt, they start so easily you have to be stupid to hot start one. But yeah, money is the problem, and a 680 HP Pratt airplane just isn’t much cheaper than a larger higher HP one, Everything is the same, same Avionics etc, just bigger airframe. A TBM is likely about as small as a Turbine makes sense, and a Bonanza is about as big as a single engine piston makes sense. Now if a 500 SHP turbine cost half as much as a 1,000 SHP one did, then you could do it.
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Usually VNE is pretty easy to increase, especially if it’s flutter. The Thrush S2R was an R-1340 aircraft, it got a turbine conversion via an STC, when Fred Ayres bought the plant, he bought the STC and the the first factory built turbine Ag aircraft was born. It kept the same gross weight and speeds of course, but Ag pilots fill the hopper until they just barely make the trees at the end of the strip, they don’t care about weight so they sold like hot cakes. Overseas though they very often hold applicators to the POH and as there were a great many overseas sales, they needed higher limits Years later Fred thought he was going to get rich building a purpose built Cargo aircraft for Fed-ex, overextended himself and went broke, we bought the plant and after a couple of years I went about increasing gross weight and Airspeeds. It took a couple of years to establish ourselves, clean things up and get a good “book of business” etc. , until then we just didn’t have the funds for Certification projects On the S2R-H80 my first real “new” aircraft that was of course really just a modified S2R using the same airframe, landing gear etc I increased gross weight from 6,000 lbs to 10,500 and airspeed VNE from 160 mph to 196 and flap speed to higher than the original VNE. Other than testing and analysis to prove the margins were there there was not all that much actual structural redesign required, only thing needed to increase VNE other than testing of course was tightening up the balance limits some. Aircraft are very often Certified not to their actual limits, but to realistic and safe limits that the aircraft is capable of in its current form. For example I have no idea what the actual flight CG limits are on the S2R-H80, the forward limit we tested to about as nose heavy as we thought safe to prevent a nose over on a tail wheel aircraft and the aft was the amount of lead we could stuff into the weight box that was mounted as far aft as possible. Neither limit could possibly be approached under any loading condition possible in the aircraft as it is. So very often when you make big changes to an aircraft there is a lot of room in increasing limits and often it’s not much actual work required to do so, what the gotcha is being able to afford all the DER’s etc to jump through all the FAA hoops to get there, the aircraft mods are the cheap and easy part, they may take only 90 days, but Certification can take two years after you finish the aircraft. So what I’m saying is that I bet fuel, VNE and gross weight may be within the possibilities of increasing on a Mooney, all it takes is Money Maybe Although a Certified four pax turbine already exists, it was built and Certified over 50 years ago, just was never built. It would in my opinion be a better aircraft, but it is not an inexpensive aircraft to build. All it would take is Money https://www.aopa.org/news-and-media/all-news/2019/november/01/will-the-interceptor-400-only-live-twice
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Guidance for return to service after engine fire.
A64Pilot replied to Shadrach's topic in General Mooney Talk
@PT20J I got you beat on the car story. It was a 1973 Ford F-250, during the first gas shortage My Father had saddle bag fuel tanks put on it because we were building a beach house in Fl and you could buy gas only on odd or even days based on your tag number and we couldn’t get home without the extra tanks, it had a fuel selector valve. Well he would run it out of course, switch tanks and grind the starter until it started, second starter I put on it I put a Holley electric fuel pump on it connected to the ignition, told him turn the key on and when the pump quit rattling, crank it, which worked fine, no more burning up the starter. A few years later the truck got older and became a Farm truck, it wasn’t maintained very well and I guess the oil bath air filter must have gotten dirty because one of the men had removed it who knows when. One day it backfired, carb caught fire, but I knew we were in trouble when I heard the pump start rattling and instantly we had a BIG fire, pump kept running until there wasn’t much left of the truck. I think it quit when the battery melted. Bad thing was it was parked real close to the house but I was able to drag it away with the tractor before it caught the house on fire. -
Guidance for return to service after engine fire.
A64Pilot replied to Shadrach's topic in General Mooney Talk
I’ve had one and seen the results of another. ‘I set my C-85 on fire from overpriming, some C-85’s inject fuel into the cylinders, mine does into the throat of the carb. Anyway once I figured out I was on fire, full throttle and motor the starter in the idea of sucking the fire in. Line guy came and squirted it with dry chemical. There was some charring if the paint on the cowling but mostly smoked up, and of course the air filter was toast. Threw filter away after inspecting for damage, got in a cranked it up and flew it home. Second was was a Fuel injected Maule on floats at Jack Browns, as starting a float plane often has a greater sense of urgency because yiu could be being blown into trees or drifting down stream etc. They were showing the owner the flooded start procedure, intentionally flooding it. Well he burnt the Maule down to not much but a steel frame with floats. I think it depends on severity, if the airplane burns up and the engine gets so hot seals etc are melted then I believe they are considered toast, but are the renuildable or which if any parts can be re-used. ‘I’d call Lycomings help desk, but think unless they have criteria it’s going to be at the discretion of the A&P -
Flush the system well, I mean really well. 5606 turns to syrup when it gets old in Summer temps and this Syrup turns to grease in cold weather, grease won’t pump well, pulling a Vacuum is likely the springy feel you have, and it will suck in air too. Consider changing to 83282 (Aeroshell 31) but there are other brands, it won’t turn to syrup when it gets old. It just a new synthetic replacement and it’s 100% miscible with 5606 with no issues. It’s been around for a long time so if it were going to be a problem we would have known decades ago
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Making Sense of Best Glide and Glide Ratio
A64Pilot replied to Max Clark's topic in Modern Mooney Discussion
It’s called “Attitude flying” something I learned in helicopters and it works for everything. Basically it’s learning what attitude correlates for what airspeed. If your example you learn the 90 kt attitude and if the engine quits you adjust to that attitude the aircraft will end up at 90 kts allowing you to do other things like looking out for a place to land as opposed to chasing airspeed. It is also more efficient as in you will lose less altitude pitching to the correct angle of attack and staying there than if you pull the nose up to slow to 90 kts then drop the nose to stay there. We had “bucket” airspeeds on the helicopter and I’m sure we do too on an airplane. basically if you graph the lift vs drag on a chart it will be bucket shaped and not a perfect one lowest point, on the helicopter 64 kts was lowest rate of descent in an autorotation and 94 kts gave max range in autorotation. Get slow though and you don’t have the extra energy speed gives you to swap for a low rate of descent for touchdown, and you won’t have the altitude to recover the speed, so don’t get slow until your sure you have the landing area made, it takes discipline to maintain that 90 kts, when the ground is coming up, but you need to. Long way of saying I guess that it’s better to be a little fast than a little slow -
That’s what it ended up being on mine, but mine was intermittent, often just delayed coming down by several seconds and sometimes recycling the switch was it. My advice if you have the solenoids that look like starter solenoids as they are cheap and readily available, just go ahead and replace them and the switch that’s also cheap and inexpensive. Mine were 40 years old, why not start out with new stuff, reset that clock as it’s only an hour or two work and less than $100 to do so. Limit switches I don’t know how available they are, but if they are I probably ought to replace them too, nothing lasts forever.
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Unlikely The system I’m speaking of is completely different than Googles, Goggles are of course on your head and use both eyes, the PNVS and TADS are those things on the nose of the Apache and are your eyes at night, but only your right eye. They don’t move as fast as your head, 60 degrees a sec if memory serves for TADS, faster for PNVS, but I’m sure that’s what the poster earlier was saying about clearing your tail, you spin your head around but the picture is still slewing when you stop because the system is slower, that can be disorienting and even make you sick to your stomach, you learn to not move your head faster than the system can skew. I’m better than 90% sure they weren’t on Googles, probably had them on their helmet but not using them, I’m pretty sure there is a currency requirement here so they had them to fulfill that currency requirement for the Staff Aviator, but Googles in an environment filled with bright lights just aren’t the best thing to have, bright lights, especially red ones bloom them out and shut them down both. I think they were there to check a currency block. I used to fly Staff Aviators from savannah Ga to Daytona at night so they could get their minimums and check the NVS currency block. Understand that in time of War the Staff is not part of a combat crew, will never fly a mission, truth is they will be working long hard hours doing their Staff job, planning getting you beans and bullets etc. Their jobs are important and critical, just it’s not being a Pilot. Need to understand that for the Female getting the Checkride, that flying wasn’t her Job, her Job was, well whatever she did in Politics etc. but as a Military Aviator she had minimums she had to fly in order to stay on flight status and receive flight pay as I assume a FAC 2 Aviator, line Pilots are FAC1, FAC 2 has lower minimums, and frankly much lower expectations for a Checkride etc. Then and this is going to tick someone off I’m sure but the truth is that the best pilots don’t get these kind of assignments. I’m speaking to the Warrant Officer here, the ones that do are the ones a unit Commander can afford to send and frankly the “Real” pilots don’t want to go, there is no real tactical flying, it’s just Ferrying VIP’s around, no yanking and banking down in the trees etc.
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Many Experimental’s use Model airplane Servos for Autopilot and or trim
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Based on the G100UL fuel leak thread what's your position?
A64Pilot replied to gabez's topic in General Mooney Talk
Maybe I do not know your compression ratio, and the bigger the cylinder the more likely detonation is, so my example should be conservative. Motorcycles can run very high compression ratios largely from modern combustion chambers but also because they have tiny cylinders compared to our motors An R-1340 is allowed to pull I believe 36” of boost from its Supercharger. It has again from memory a 6 to 1 compression ratio and it can do this on 87 Octane car gas. Now car gas and Aviation fuel Octane ratings are different, 100LL I believe if rated as car gas would be more than 100 Octane, likely the reason why we don’t just switch to 100 Octane unleaded race gas. It’s been around for years and I believe even higher than 100 Octane exists https://www.sunocoracefuels.com/fuels/fuel/ss-100 apparently as high as 109 https://racefuel.boostane.com/products/109-octane-fuel I do not know what your limit will be but am sure the actual limit will be higher than 25”. Then we are assuming 25” for 94UL, the 25” is very conservative and was I’m sure picked more for it being a number people can live with as most Big bore Continental bush pilots won’t cruise higher than 25 squared, but the ADI original STC’s were also established for Auto fuel, which I’d bet are lower Octane and more likely to detonate than 94UL. Will they find the actual limits and Certify for them? I doubt it because it raises the probability of failure and would cost time and money but doesn’t get them anything. Everything at this point is speculation -
Based on the G100UL fuel leak thread what's your position?
A64Pilot replied to gabez's topic in General Mooney Talk
This says 6 GPH, if you carry 11 gls so you have just less than 2 hours, half that for the small tank https://www.avweb.com/features/the-return-of-anti-detonation-water-injection-adi/ But I’m sure of a few things 1. ADI flow rate surely is HP specific, meaning that I doubt a 300 HP and a 200 HP motor need the same. I think the flow rate they have is based on 300 HP as my C-210 was rated at 300 HP for 5 min and the STC back in the day was for bigger motored Cessna’s often in Alaska etc where 100LL is hard to get and stupid expensive, so car gas and ADI. So maybe it would be lower for lower HP motors or maybe they want to field a one size fits all kit? I think probably the latter at first. Original ADI STC was back in the 80’s when Auto fuel STC’s were common and cheap. Peterson used to charge $1 per HP of the motor for his Auto fuel STC 2. That 25MP and 400F is very conservative as there is no harm if it’s not needed and engine damage if it’s not on when needed so lean towards super conservative 3. All engines are not the same, some are much more likely to detonate than others, so the only way to come up with blanket numbers is to test the worst case engine and use it’s limits, that’s the mose conservative and as the fluids cost is minuscule the best idea I think. ‘I think taking off in my case a sea level that I would need it for 5 or 6 Min as at 1000 FPM it takes 5 min to get to 5000ft where you only have 25 MP, but let’s use 10 min as a nice round number and for extra safety. 10 min consumes 1 gl even, I like whole numbers. That means I can get 11 takeoffs before I run out, so let’s use 10, if using the big tank, cut it down to 5 if using the small tank. I would use the small tank I don’t know about you but in my World 10 takeoffs is plenty even if the fluid isn’t available at FBO’s because at first I don’t think it will be. -
Based on the G100UL fuel leak thread what's your position?
A64Pilot replied to gabez's topic in General Mooney Talk
I’m pretty sure that a “True” turbo has a much lower compression ratio than a Turbo normalized engine does as the purpose of a “True” turbo is to increase power not just maintain it like a normalized Turbo. So if I’m correct then your MP limit will be higher than 25” while a Turbo normalized engine might be 25”. Sorry but I have to beat this dead horse, that’s where ADI comes in, it will maintain your current MP limit as long as you don’t mind the ADI running, but one assumes that you wont cruise with it on, so your cruise limit ADI off might be lower than your now allowed. Running LOP will complicate things of course, but I wouldn’t expect it to be addressed in an ADI STC unless your POH allows LOP and has a procedure, then it might. The LOP is speculation on my part, whether or not ADI will allow full boost isn’t. -
Based on the G100UL fuel leak thread what's your position?
A64Pilot replied to gabez's topic in General Mooney Talk
The list of fuels is also on the TCDS of course look under S2R-T34 I’d cut n past it but can’t a .pdf? If your curious also look under note 13 on the TCDS the aircraft was only Certified to 6,000 lbs but I believe CAM 8 allows a 31% overload if flight tested and it has the performance to do so, note 13 allows operation in the Restricted Category increase from 6,000 lbs to 8,500 lbs. The S2R-T34 is also the only dual Category Ag plane Certified in both the Normal and Restricted Category. Story is some wealthy person that lived in an Airpark in Colorado I believe bought one as a toy, well his neighbors got their nose bent on there being an Ag plane on their exclusive Airpark and the Home Owner Association ruled that only Normal Category aircraft were allowed, so the guy paid Fred to have it Certified in the Normal Category. There are two sections in the POH, one for Restricted and a separate for Normal. It can’t be Certified in Utility because No Thrush has ever been officially spin tested, for an aircraft that’s mission is that close to the ground there is no point, and apparently the FAA agreed. I’ve been told that they recover from a spin better than most though, I suspicion it’s because of the huge rudder, but I have never spun one myself. They don’t roll well though, you would think they would as they have a very high initial roll rate, but after about 90 degrees roll dampening kicks in a the roll rate past about that does not accelerate so they roll slow. People have a hard time understanding this but they are not an aerobatic aircraft, it’s best to think of them as heavily loaded trucks. What other aircraft has a useful load exceeding its empty weight?