Mark89114 Posted October 22, 2015 Report Posted October 22, 2015 My Mooney Ovation is new to me and learning all of the quirks. I certainly understand the concept of a trimmable stabilizer. However my thoughts would be that if the plane is trimmed and in C.G. the elevator should be aligned with the movable stabilizer, right? That is the point of having it movable? It stays aligned and minimizes drag. As you can maybe tell from this picture the elevator is up, as evidenced by the counterweight being below the stabilizer. The AP is flying and when I turn it off there is no weird pitch deviations. I have noticed that the engine does appear to point "down" from axis of the plane. The MSC prebuy said nothing to worry about and my reading on MS also implies not an issue. The AP does hunt nose up and down a bit, imperceptible altitude change, but visually it goes up and down. Flies fine otherwise. What do I need to look at check, etc. I am looking for speed and efficiency and if this is costing 20 knots I want to know about it. Joke people. Thanks, Mark Quote
carusoam Posted October 22, 2015 Report Posted October 22, 2015 (edited) Mark, There is a thread around here regarding the same issues from different Mooneys. Right or wrong, they seem to all be doing the same thing. I think what happens when you move the tail in trim, it also moves the elevator some. This was more noticeable on the ground with My C. On The O, while ground bound, the elevator just hangs down. Fuzzy old memory seems to remember... the more the tail trims up, the more the elevator hangs down. What happens if you put some weight in the back to lessen the need for tail trim? Best regards, -a- Edited October 22, 2015 by carusoam Quote
M20S Driver Posted October 22, 2015 Report Posted October 22, 2015 (edited) On 10/22/2015 at 9:19 PM, Mark89114 said: My Mooney Ovation is new to me and learning all of the quirks. I certainly understand the concept of a trimmable stabilizer. However my thoughts would be that if the plane is trimmed and in C.G. the elevator should be aligned with the movable stabilizer, right? That is the point of having it movable? It stays aligned and minimizes drag. As you can maybe tell from this picture the elevator is up, as evidenced by the counterweight being below the stabilizer. The AP is flying and when I turn it off there is no weird pitch deviations. I have noticed that the engine does appear to point "down" from axis of the plane. The MSC prebuy said nothing to worry about and my reading on MS also implies not an issue. The AP does hunt nose up and down a bit, imperceptible altitude change, but visually it goes up and down. Flies fine otherwise. What do I need to look at check, etc. I am looking for speed and efficiency and if this is costing 20 knots I want to know about it. Joke people. Thanks, Mark My Mooney Eagle looks identical to this.. Edited October 22, 2015 by M20S Driver Quote
Flymu2 Posted October 22, 2015 Report Posted October 22, 2015 On 10/22/2015 at 11:05 PM, M20S Driver said: My Mooney Eagle looks identical to this.. Mine too 1 Quote
jetdriven Posted October 22, 2015 Report Posted October 22, 2015 the 201 is opposite of that, but still its quite a deflection. Quote
gsengle Posted October 23, 2015 Report Posted October 23, 2015 My ovation looks the same Sent from my iPhone using Tapatalk Quote
ArtVandelay Posted October 23, 2015 Report Posted October 23, 2015 On 10/22/2015 at 11:45 PM, jetdriven said: the 201 is opposite of that, but still its quite a deflection. Ditto, but that is just with me, has anybody check when they have passengers? Quote
cliffy Posted October 23, 2015 Report Posted October 23, 2015 A couple of things come to mind. How much equipment has been added/subtracted from the airplane since the last time it was weighed? You might want to reweigh it and figure a new CG Has the elevator/stabilizer trim/operation angles ever been checked and confirmed including the elevator trim assist cable tension as shown in the TCDS? I would start there.Your A&P needs a cable tensiometer to do the trim assist unit correctly. And he needs travel boards for all the other angles. Don't forget to check the aileron and flap angles with travel boards also at the same time. They can have an effect on it also. You have to make sure everything is correct as per the TCDS before you can start to work on something "wrong". "If" it's wrong it's either a CG issue or a control setting issue. Quote
N231BN Posted October 23, 2015 Report Posted October 23, 2015 Void of some outside force the elevators will always trail with the incoming wind. The stabilizer needs to produce some amount of downforce so it will always have some angle of attack. Some airplanes have trim bungees and some have a variable down spring so there usually is some influence in the elevators. Assuming the horizontal is an asymmetrical airfoil, the only time the elevators can be lined up is if the aircraft center of gravity is the same as the center of pressure. In this case the tail is producing no downforce. The airplane will be quite unstable in this condition. 1 Quote
Hank Posted October 23, 2015 Report Posted October 23, 2015 Found it! A nice thread with lots of discussion and inflight tail pictures. On the ground, Vintage elevators are straight while long body's all droop. Seems like Ks droop, too, but I'm not sure. Seems like there was no consensus regarding in flight position. But generally, as CG moves aft, less trim is required, so the tail creates less downforce, meaning less induced drag and more speed. Seems like my elevator is slightly down when traveling lightly, with about half the thickness of the counterweight visible if I twist around and look. Are you saying that your elevator is UP, with the counterweight hanging down? Quote
Mark89114 Posted October 23, 2015 Author Report Posted October 23, 2015 Well thanks for all of the replies, it appears all is normal. Quote
turbotrk Posted October 23, 2015 Report Posted October 23, 2015 I have the same problem on myne, it's due to too fwd CG, when flying with peaple and baggage at the back it becomes alligned. If you look to my recent topic about needed fixed ballast on the tail you may realize your plane and many others are out manufacturer's limit on empty weight and require charlie weights installation. My plane needs maximum weight (19lbs) according to the graph and none is installed at the moment. Trying to order them from mooney dealer, not easy to find tough. Anyway you are right that condition produces significant drag, so much that I cruise faster with peaple on the back even if heavier. Check your CG on empy weight, if possible get the aircraft weighted (manufacturer's computed weight and balance often doesn't seem to match with real world figures) if the CG is out of prescribed limits mooney requires charlie weights according to the following graph. You may disregard this and put ballast in the bagage compartment but it would require three times more weight due to shorter arm and according to mooney out of certification limits anyway. 1 Quote
N201MKTurbo Posted October 23, 2015 Report Posted October 23, 2015 I did some experiments a few years ago about that. With my plane I found that the in trail position was not the fastest. I found the factory setting was so close to the fastest that I didn't bother adjusting the bungees to optimize it. Quote
turbotrk Posted October 23, 2015 Report Posted October 23, 2015 I guess you are right, as long as you comply with manufacturer's instructions and avoid the CG being too forward, with 4 peaple on board on my a/c I had it slightly pointing downwards. That should be the best setting. Quote
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