N201MKTurbo Posted April 2, 2020 Report Share Posted April 2, 2020 I think I read once that the Mooney test pilot flew a Mooney with the trim screw disconnected. I've never heard about one failing. It is hard to imagine that they ever would. Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted April 2, 2020 Report Share Posted April 2, 2020 Just now, Bob Weber said: Nope, but both airframes deal with a jack screw, as well as just about every other airframe out there. Wear happens, those that have learned to recognize and react are who I want to be around. The big difference is that you can fly a Mooney at any attitude and any power setting at any trim setting. Some combinations take a lot of strength and I wouldn't want to do it for very long. You can't say that about airliners.... Quote Link to comment Share on other sites More sharing options...
Hank Posted April 2, 2020 Report Share Posted April 2, 2020 2 hours ago, mike20papa said: My old A model trims beautifully...just light pressure on the trim wheel does the trick in cruise. I still say the Mooney, because of it's laminar flow wing, is a trim sensitive AC. Always roll it back to the stop for landing and set appropriate for take off. A beast for flying touch & goes. In my Stearman, you can touch the trim wheel once in the spring - and forget about it. But it has a lifting tail. Most of my landing, with Takeoff Flaps on downwind and adjusted as needed on final per my Owner's Manual, the trim setting is pretty close to the Takeoff setting when I reach the ramp. And no, I don't adjust trim on the ground, except just before Takeoff. Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted April 2, 2020 Report Share Posted April 2, 2020 I was hanging out at the Continental maintenance hangar in Denver back in '84. The guy I was hanging out with (B.J. Blackerby) took me over to show me this plane. The captain reported this ship was using too much fuel. They found that 3 of the 4 pins that hold the elevator assembly to the vertical stab were corroded through and had failed. the remaining pin was about to go. the horizontal stab was leaning about 2 degrees to the side. That would have been a hard one to deal with! Quote Link to comment Share on other sites More sharing options...
cliffy Posted April 2, 2020 Report Share Posted April 2, 2020 12 minutes ago, N201MKTurbo said: I was hanging out at the Continental maintenance hangar in Denver back in '84. The guy I was hanging out with (B.J. Blackerby) took me over to show me this plane. The captain reported this ship was using too much fuel. They found that 3 of the 4 pins that hold the elevator assembly to the vertical stab were corroded through and had failed. the remaining pin was about to go. the horizontal stab was leaning about 2 degrees to the side. That would have been a hard one to deal with! Interesting notation there. I started as a green A&P in 67 with Continental at LAX. I'd be interested to know what type of airplane it was. There is some document from Mooney that I have read (it might be the tail hinge AD that came out a few years ago) that signifies that the hinge itself is the secondary load path for the jack screw. The 2 close tolerance bolts at the hinge line then the jack screw and the hinge. I don't think there has ever been a Mooney lost because of the jack screw. They do get worn quite a bit, the bolts and hinge cap. Its all because of lack of lubrication. If they were better lubed they wouldn't get worn so bad. The one item that really doesn't get service are the ball bearings inside the jack screw. There are a few threads here on MS with pictures on how to disassemble them and relube the bearings. Quote Link to comment Share on other sites More sharing options...
Mooneymite Posted April 2, 2020 Report Share Posted April 2, 2020 I do think that "touchy trim" should be investigated at the empenage first. Nothing in the trim wheel is going to kill you. Sometimes serious problems have subtle clues. Here's hoping it's a minor issue, or even a perception, not something serious. 1 Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted April 2, 2020 Report Share Posted April 2, 2020 10 minutes ago, cliffy said: Interesting notation there. I started as a green A&P in 67 with Continental at LAX. I'd be interested to know what type of airplane it was. There is some document from Mooney that I have read (it might be the tail hinge AD that came out a few years ago) that signifies that the hinge itself is the secondary load path for the jack screw. The 2 close tolerance bolts at the hinge line then the jack screw and the hinge. I don't think there has ever been a Mooney lost because of the jack screw. They do get worn quite a bit, the bolts and hinge cap. Its all because of lack of lubrication. If they were better lubed they wouldn't get worn so bad. The one item that really doesn't get service are the ball bearings inside the jack screw. There are a few threads here on MS with pictures on how to disassemble them and relube the bearings. It was a B727. I thought you were talking about the screw link bolts. You are correct the pivot bolts should be in good shape. Most of the time the vertical slop in the tail is caused by trim screw slop. If it is caused by the pivot bolts, you have a serious problem! Quote Link to comment Share on other sites More sharing options...
Bob Weber Posted April 2, 2020 Report Share Posted April 2, 2020 Just now, N201MKTurbo said: The big difference is that you can fly a Mooney at any attitude and any power setting at any trim setting. Some combinations take a lot of strength and I wouldn't want to do it for very long. You can't say that about airliners.... My autopilots have been a passion for 40 years, learning the different airframes and idiosyncrasies of them, though a challenge, I developed an understanding of the balance that must be achieved between an airframe, an autopilot design, and the pilot. The balance between the autopilot and the airframe has become the greater challenge lately due to age. During my racing days(the reason they will not let me anywhere near an aircraft engine), I preached blueprinting. Put it back the way the engineers designed it, as I'm still saying today. You are flying a 40 year old aircraft, with your family, in the bumpy soup. I Love old things, we just have to understand and respect them. I started flying models in my front yard at the age of 7, my first lesson was flying out of Glenwood Springs CO in 1975 and spent the rest of the time flying broken aircraft for troubleshooting and about a million cert. flights beginning with KN 74's. I still learn with every experience, anyone steeped in this stuff knows this as a life... Your really going to be mad when I bring up the wiring harness, the central nervous system. 2 Quote Link to comment Share on other sites More sharing options...
carusoam Posted April 2, 2020 Report Share Posted April 2, 2020 52 minutes ago, N201MKTurbo said: The big difference is that you can fly a Mooney at any attitude and any power setting at any trim setting. Some combinations take a lot of strength and I wouldn't want to do it for very long. You can't say that about airliners.... We could probably write a Mooney pamphlet on this topic... Would make a great hand-out for every new Mooney pilot... A great annual reminder for existing Mooney pilots... A great shelf space saver next to all the other important stuff... We have one MSer that survived a runaway/stuck trim.... with their SIC. The plane didn’t fare so well... lots of strength required to hold back the forces... but, there are things that can be done to better mitigate those forces... These were discussed in primary flight training for the C152... at the CPC schools... Worn tail bolts were simulated by Bill Wheat back in the day... by swapping in a smaller diameter bolt where appropriate... that experiment probably resulted in how much motion is acceptable at the tail when raised during the pre-flight... PP thoughts and fuzzy memories only, not a CFI... or Mooney historian... Best regards, -a- 1 Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted April 2, 2020 Report Share Posted April 2, 2020 Just now, Bob Weber said: My autopilots have been a passion for 40 years, learning the different airframes and idiosyncrasies of them, though a challenge, I developed an understanding of the balance that must be achieved between an airframe, an autopilot design, and the pilot. The balance between the autopilot and the airframe has become the greater challenge lately due to age. During my racing days(the reason they will not let me anywhere near an aircraft engine), I preached blueprinting. Put it back the way the engineers designed it, as I'm still saying today. You are flying a 40 year old aircraft, with your family, in the bumpy soup. I Love old things, we just have to understand and respect them. I started flying models in my front yard at the age of 7, my first lesson was flying out of Glenwood Springs CO in 1975 and spent the rest of the time flying broken aircraft for troubleshooting and about a million cert. flights beginning with KN 74's. I still learn with every experience, anyone steeped in this stuff knows this as a life... Your really going to be mad when I bring up the wiring harness, the central nervous system. Glenwood Springs, that's wild. I've landed there about 30 times mostly back in the 80s. Learning at a short high altitude airport in a canyon makes everything else look easy! I do like skiing Sunlight. Ski in Ski out condos for $100/night! Quote Link to comment Share on other sites More sharing options...
Bob Weber Posted April 2, 2020 Report Share Posted April 2, 2020 2 minutes ago, N201MKTurbo said: Glenwood Springs, that's wild. I've landed there about 30 times mostly back in the 80s. Learning at a short high altitude airport in a canyon makes everything else look easy! I do like skiing Sunlight. Ski in Ski out condos for $100/night! 110 polo road, Graduated 1977. Jim Andre was my instructor. The "big D" was where I began to explore RC and became brutally aware of density altitude. My first research was at around 700' msl. A very close friend was well on his way to 80 days at sunlight this year until they closed it, that place and Aspen pretty much destroyed my wrists! Look up Skinny ridge Grand Junction, yet another source of chronic pain.. Far happier lookin at the lake than the mountain... Quote Link to comment Share on other sites More sharing options...
Bob Weber Posted April 2, 2020 Report Share Posted April 2, 2020 17 minutes ago, carusoam said: We could probably write a Mooney pamphlet on this topic... Would make a great hand-out for every new Mooney pilot... A great annual reminder for existing Mooney pilots... A great shelf space saver next to all the other important stuff... We have one MSer that survived a runaway/stuck trim.... with their SIC. The plane didn’t fare so well... lots of strength required to hold back the forces... but, there are things that can be done to better mitigate those forces... These were discussed in primary flight training for the C152... at the CPC schools... PP thoughts only, not a CFI... Best regards, -a- Perhaps when we look a bit deeper into what caused this incident, we may have expanded insight on the problems we are facing today. Quote Link to comment Share on other sites More sharing options...
carusoam Posted April 2, 2020 Report Share Posted April 2, 2020 8 minutes ago, Bob Weber said: Perhaps when we look a bit deeper into what caused this incident, we may have expanded insight on the problems we are facing today. That and the recent M20S accident... not much known about this accident yet... trim setting is highly suspected to be part of the challenge, by many... Fortunately, the M20K / stuck trim accident pilot and SIC are still with us... an accomplished pilot, and phenomenal writer, and veteran MSer... find @ Amelia... I believe she detailed what happened, around here somewhere... find Marvin K Mooney (The plane had a name)... PP thoughts only, not an accident investigator... Best regards, -a- 1 Quote Link to comment Share on other sites More sharing options...
Bob Weber Posted April 2, 2020 Report Share Posted April 2, 2020 (edited) Back a few decades I suppose now, I read an FAA report of a Mooney crash. It was observed that the trim was at the stop, don't recall which one, but the determination was that it happened during the crash as the airframe exploded. Later theories were floated about runaway trim as the original cause. This was around the time an acquaintance/fellow Pilot died in a Seneca out in Utah running checks for the banks if memory serves, CIII runaway trim. The left wing and empennage departed the aircraft before it hit the ground. Much thought was put into continuing with these bleeping autopilots and having so many souls to feel responsible for when I received this news. I was not involved with the repairs or maintenance of the aircraft at the time, but had nightmares about what the guy that did must have been going thru. I chose to persevere with the notion of education, the more I can educate people, about the how and why, as well the why not, the safer we all will be. Fly Safe and Healthy Bob Weber webairconsulting.com Edited April 2, 2020 by Bob Weber 1 Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted April 2, 2020 Report Share Posted April 2, 2020 1 hour ago, Bob Weber said: 110 polo road, Graduated 1977. Jim Andre was my instructor. The "big D" was where I began to explore RC and became brutally aware of density altitude. My first research was at around 700' msl. A very close friend was well on his way to 80 days at sunlight this year until they closed it, that place and Aspen pretty much destroyed my wrists! Look up Skinny ridge Grand Junction, yet another source of chronic pain.. Far happier lookin at the lake than the mountain... When I was a kid, my grandparents had a place on Freemont lake, near you. I spent many summers there. 1 Quote Link to comment Share on other sites More sharing options...
Bob Weber Posted April 2, 2020 Report Share Posted April 2, 2020 Marie is well known in Freemont, Gerber was huge there. Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted April 2, 2020 Report Share Posted April 2, 2020 6 minutes ago, Bob Weber said: Marie is well known in Freemont, Gerber was huge there. My mon used to tell me that you could tell what Gerber was making by the color of the lake! That was I the late 1930s. 1 Quote Link to comment Share on other sites More sharing options...
cliffy Posted April 2, 2020 Report Share Posted April 2, 2020 3 hours ago, N201MKTurbo said: It was a B727. I thought you were talking about the screw link bolts. You are correct the pivot bolts should be in good shape. Most of the time the vertical slop in the tail is caused by trim screw slop. If it is caused by the pivot bolts, you have a serious problem! I've seen one Mooney that used plain old AN bolts in the hinge holes and the stabilizer wobbled 1/2 " above and below center and went fore and aft almost as much and they flew it that way for years. No one caught the slop in any annual but then of course the airplane had been bellied in 3 times by the owner and it turned out he did most of the maintenance (Not an A&P) BTW it had the wrong gear actuator in it also. Gear wouldn't go up all the way and it just came out of an annual the month previous. Mooneys are tough! The screw link bolts will also wear but the link wears more. Its ALL lack of lube. I've found several frozen rod ends on flight surfaces when doing flight line checks for fun. They do break and leave the flight surface without a means to actuate. In fact there is a picture somewhere around here of a broken one. Hence our AD for lubrication and gear swing every 100 hrs (that some do not do). If the plane sits outside it needs lube more than every 100 hrs or 1 year. 1 Quote Link to comment Share on other sites More sharing options...
Bob Weber Posted April 2, 2020 Report Share Posted April 2, 2020 12 minutes ago, N201MKTurbo said: My mon used to tell me that you could tell what Gerber was making by the color of the lake! That was I the late 1930s. I kept my boat in Holland right next to Heinz vinegar plant for a few years, you could smell it. The long time residents talked of pickles floating everywhere. Becoming aware and assertive in the early 1970's, I followed as the waterways were reported and then mitigated.. The Ohio river on fire was a pivotal sight. Today we get to celebrate the amazing reclamation of our waterways, just in our area alone, Muskegon Lake is being transformed from heavy industry to tourism and entertainment. These changes are having an enormously positive effect on all of our lakes as well as communities. After all we do have more shoreline than many.. We are really chomping at the bit, our launch and slip is 1/4 of a mile from us but can't touch.. Soon. "to internal combustion and wind in the face" 2 Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted April 2, 2020 Report Share Posted April 2, 2020 1 minute ago, cliffy said: I've seen one Mooney that used plain old AN bolts in the hinge holes and the stabilizer wobbled 1/2 " above and below center and went fore and aft almost as much and they flew it that way for years. No one caught the slop in any annual but then of course the airplane had been bellied in 3 times by the owner and it turned out he did most of the maintenance (Not an A&P) BTW it had the wrong gear actuator in it also. Gear wouldn't go up all the way and it just came out of an annual the month previous. Mooneys are tough! The screw link bolts will also wear but the link wears more. Its ALL lack of lube. I've found several frozen rod ends on flight surfaces when doing flight line checks for fun. They do break and leave the flight surface without a means to actuate. In fact there is a picture somewhere around here of a broken one. Hence our AD for lubrication and gear swing every 100 hrs (that some do not do). If the plane sits outside it needs lube more than every 100 hrs or 1 year. No joke, I've lubed Mooneys and found many rod ends and bearings that hadn't been lubed sense it left the factory! I think the 100 hours is a little overkill, but must be done at annual. Heck, If they would get lubed every 10 years, they probably wouldn't break! A greasy Mooney is a happy Mooney! 2 Quote Link to comment Share on other sites More sharing options...
Bob Weber Posted April 2, 2020 Report Share Posted April 2, 2020 6 minutes ago, N201MKTurbo said: No joke, I've lubed Mooneys and found many rod ends and bearings that hadn't been lubed sense it left the factory! I think the 100 hours is a little overkill, but must be done at annual. Heck, If they would get lubed every 10 years, they probably wouldn't break! A greasy Mooney is a happy Mooney! We need to be replacing the loose rod ends and be very sparingly on the dripping lube, it gathers dirt and grit that tends to accelerate wear. My biggest desire here is to get folks thinking about, and addressing, many issues we are now finding in older aircraft. I just spoke earlier today with a long time Colleague that found another elevator cable failing in a single Cessna. frayed and cut.. Waiting on pics, trying to determine the cause. Fly Safe and Healthy Bob Weber webairconsulting.com Quote Link to comment Share on other sites More sharing options...
skykrawler Posted April 2, 2020 Report Share Posted April 2, 2020 I felt the stab trim in my airplane was stiff and needed attention. I read a number of forum postings and went after it during an annual. There is very little in the maintenance manual about removing the jack screw assembly bolted in at the aft bulkhead of the tail cone. For the '82 J the most difficult part is to get the separation of the square sectioned link that attaches to the jack screw shaft in the tail cone. Its like the system is designed so that if all the bolts fell out it still wouldn't come apart and would still work. I finally go it out and cleaned the screw thoroughly and opened the bearing box expecting slag and it was perfectly clean light oil and perfect bearings. Put it all back together - probably spent 6 or 8 hours on the job and the trim still feells stiff. But at least I know. Quote Link to comment Share on other sites More sharing options...
cliffy Posted April 2, 2020 Report Share Posted April 2, 2020 1 hour ago, Bob Weber said: We need to be replacing the loose rod ends and be very sparingly on the dripping lube, it gathers dirt and grit that tends to accelerate wear. Use 100% silicone spry on the exposed rod ends and no dirt or grit will adhere. Triflow or other similar silicone carrying lube for everything enclosed in the airframe. You can lube every month with 100% silicone with no harm. Mooney also approves of silicone spray. Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted April 2, 2020 Report Share Posted April 2, 2020 49 minutes ago, skykrawler said: I felt the stab trim in my airplane was stiff and needed attention. I read a number of forum postings and went after it during an annual. There is very little in the maintenance manual about removing the jack screw assembly bolted in at the aft bulkhead of the tail cone. For the '82 J the most difficult part is to get the separation of the square sectioned link that attaches to the jack screw shaft in the tail cone. Its like the system is designed so that if all the bolts fell out it still wouldn't come apart and would still work. I finally go it out and cleaned the screw thoroughly and opened the bearing box expecting slag and it was perfectly clean light oil and perfect bearings. Put it all back together - probably spent 6 or 8 hours on the job and the trim still feells stiff. But at least I know. If you take the clevis pins out of any of the u joints in the trim shaft, and loosen the electric trim chain, you can slide the square coupling right off by just sliding the shaft forward. 1 Quote Link to comment Share on other sites More sharing options...
Bob Weber Posted April 3, 2020 Report Share Posted April 3, 2020 1 hour ago, skykrawler said: I felt the stab trim in my airplane was stiff and needed attention. I read a number of forum postings and went after it during an annual. There is very little in the maintenance manual about removing the jack screw assembly bolted in at the aft bulkhead of the tail cone. For the '82 J the most difficult part is to get the separation of the square sectioned link that attaches to the jack screw shaft in the tail cone. Its like the system is designed so that if all the bolts fell out it still wouldn't come apart and would still work. I finally go it out and cleaned the screw thoroughly and opened the bearing box expecting slag and it was perfectly clean light oil and perfect bearings. Put it all back together - probably spent 6 or 8 hours on the job and the trim still feells stiff. But at least I know. Any anomaly in an aircraft needs to be attended to, quickly and correctly. Many of them are worthy of AOG until they are resolved. It is amazing the effect of seeing just how small of pieces an aircraft shreds into when it hits the ground after you have lived in and around them most of your life.. Especially multiple times, when there was an acquaintance, Friend, or work mate, lost. Fly Safe and Healthy Bob Weber webairconsulting.com Quote Link to comment Share on other sites More sharing options...
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