prflyer Posted February 27, 2018 Report Share Posted February 27, 2018 Question for the group: My new partner noticed that our attitude indicator is not aligned with the sides of the indicator. It seems to operate normally and responds appropriately, but the interior part of the indicator is always above the indicator on the side. See the picture below as it is easier to see than explain. I wonder if when the panel was redone the tilt in the panel was not quite right. I looked back through pictures taken during the past year, and the attitude indicator shows this indication back then. The airplane was flown IFR regularly during this period. IMG_1853 copy.tiff In any event, do you think it is ok to fly with this instrument? If it is off tilt, how can this be corrected? Thanks. Fernando Quote Link to comment Share on other sites More sharing options...
prflyer Posted February 27, 2018 Author Report Share Posted February 27, 2018 Let me try this again, here is the picture: Quote Link to comment Share on other sites More sharing options...
takair Posted February 27, 2018 Report Share Posted February 27, 2018 That seems to be off a little...7 or 8 degrees. Does it get even worse at higher speeds? The gyros have an erection mechanism that would tend to fight this. Would check your panel tilt. I don’t know that it is unsafe, but it may not be optimal for IFR and perhaps gyro life. At high cruise I see perhaps a couple of degrees on mine. 1 Quote Link to comment Share on other sites More sharing options...
jetdriven Posted February 27, 2018 Report Share Posted February 27, 2018 It looks like a 5 degree tilt gyro installed at zero tilt. 1 Quote Link to comment Share on other sites More sharing options...
prflyer Posted February 27, 2018 Author Report Share Posted February 27, 2018 24 minutes ago, jetdriven said: It looks like a 5 degree tilt gyro installed at zero tilt. Byron, if that is the case, what is the fix? Some type of install bracket that gets you the right tilt? Quote Link to comment Share on other sites More sharing options...
0TreeLemur Posted February 27, 2018 Report Share Posted February 27, 2018 What really matters is the relative position of the little airplane wings and the center of the AH. The outer ring could be painted black an not affect the pitch reading of the instrument. Proof of the arbitrary nature of the position of the the little airplane and the moving part of the AH is the fact that the pilot has great freedom to adjust the position depending on pilot height, angle of attack required to maintain level flight, etc. The outer ring markings are necessary for determining roll angle, but the effect of this apparent parallax error in pitch will be slight, something like the cosine of the pitch error (0.99 at 5 degr.). Quote Link to comment Share on other sites More sharing options...
Piloto Posted February 27, 2018 Report Share Posted February 27, 2018 Check for the panel shock mounts at the corners. The panel may tilt when they break. http://www.aircraftspruce.com/catalog/inpages/shockmounts3.php?clickkey=3069201 José Quote Link to comment Share on other sites More sharing options...
jetdriven Posted February 27, 2018 Report Share Posted February 27, 2018 18 minutes ago, prflyer said: Byron, if that is the case, what is the fix? Some type of install bracket that gets you the right tilt? As far as I know the only thing that can change the panel tilt angle is an instrument shop. 2 Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted February 27, 2018 Report Share Posted February 27, 2018 You have to readjust the indicator to the gyro capsule and rebalance it so it doesn't precess in one axis when you move it in another axis. This takes a precision motion table. So as jet driven says, you need to take it to an instrument shop. There is no harm running it the way it is. It's accuracy and longevity is not affected. It is just off by a few degrees. Quote Link to comment Share on other sites More sharing options...
MIm20c Posted February 27, 2018 Report Share Posted February 27, 2018 Looks like you went from the old panel that had a V down the middle to a flat panel attached to the original mounts? I know the new electronic AI can be calibrated in the plane but I’m not sure about the gyro driven ones. Quote Link to comment Share on other sites More sharing options...
jaylw314 Posted February 27, 2018 Report Share Posted February 27, 2018 3 hours ago, Fred_2O said: The outer ring markings are necessary for determining roll angle, but the effect of this apparent parallax error in pitch will be slight, something like the cosine of the pitch error (0.99 at 5 degr.). There shouldn't be any parallax error if you're looking at the arrow and outer tick marks at the top of the AI (as opposed to looking at where the horizon on the gyro meets the tick marks). Assuming I actually understood what you were saying Quote Link to comment Share on other sites More sharing options...
prflyer Posted February 27, 2018 Author Report Share Posted February 27, 2018 Thanks everyone for their suggestions. We will keep exploring and see what we find. Fernando Quote Link to comment Share on other sites More sharing options...
carusoam Posted November 27, 2018 Report Share Posted November 27, 2018 Old Mooney IPs were flat for the top row, the lower instruments were tilted... All modern Mooney instrument panels are not tilted... Pull that instrument out, to see where they printed a code for the 8° panel tilt... it is most likely written on the outside of the can. If you descend with an 8° attitude, does everything line up nicely? For some reason 8° became a standard for panel tilt... why 8°? How did that ever help? MooneySpace somewhere has explained this situation before... somebody said, leave it as is... another person mentioned why it may wear at a faster rate... Either way, an instrument shop would be the best solution to adjust the tilt out of it... If VFR only, not a big deal... the back-up is looking out the window. If flying in IMC, you want to have a good back up instrument that is better than a worn out TC... Christmas is coming, the Mooney could use a good Xmas gift... G5 or other? PP thoughts only, not an instrumentarian... Best regards, -a- 1 Quote Link to comment Share on other sites More sharing options...
thinwing Posted November 27, 2018 Report Share Posted November 27, 2018 I've got a low time sigma tec 0 tilt that would fix your problem 1 Quote Link to comment Share on other sites More sharing options...
Jerry 5TJ Posted November 27, 2018 Report Share Posted November 27, 2018 I hope you are not flying in IMC when your only attitude gyro is acting odd. It is time to fix the first one and perhaps a good opportunity to add a second AI. 3 Quote Link to comment Share on other sites More sharing options...
David Lloyd Posted November 27, 2018 Report Share Posted November 27, 2018 (edited) It isn't acting odd. It is just an indicator built for a 8 degree tilt installed in a 0 degree tilt panel. Look at the way the mid-sixties panel are made with the bend in between the top and bottom row of instruments--8 degrees. That bend is what makes 0 degree where the AI mounts. Mooney must have got a deal on a ton of 0 degree tilt military surplus gyros when they were making decisions on their panels. The right side panel appears to be 8 degree tilt. Anyone that modifies their old Mooney with a one piece panel (ala Bob Bellville), the entire panel will be 8 degree. Most instruments can be rebuilt for either. Will work fine in the meanwhile, just looks odd. Edited November 27, 2018 by David Lloyd 2 Quote Link to comment Share on other sites More sharing options...
Jerry 5TJ Posted November 27, 2018 Report Share Posted November 27, 2018 I admit it: I am “inclined” towards gyroscopic caution: I have 3 AI in my panel. Four including the AHRS displayed on the iPad. Quote Link to comment Share on other sites More sharing options...
David Lloyd Posted November 27, 2018 Report Share Posted November 27, 2018 Ach! "inclined." Gyro humor. Quote Link to comment Share on other sites More sharing options...
Shadrach Posted November 27, 2018 Report Share Posted November 27, 2018 Color me surprised that there are two airplanes in this thread with incorrectly calibrated instruments installed. I'd be interested to see the logs regarding the install. I would not think an A&P would do something like this. Quote Link to comment Share on other sites More sharing options...
LANCECASPER Posted November 27, 2018 Report Share Posted November 27, 2018 2 hours ago, Shadrach said: Color me surprised that there are two airplanes in this thread with incorrectly calibrated instruments installed. I'd be interested to see the logs regarding the install. I would not think an A&P would do something like this. I think a friendly, helpful A & P might do it at the owner's request without doing all of the necessary research, but I don't think a competent Avionics shop would. Quote Link to comment Share on other sites More sharing options...
Marauder Posted November 27, 2018 Report Share Posted November 27, 2018 I admit it: I am “inclined” towards gyroscopic caution: I have 3 AI in my panel. Four including the AHRS displayed on the iPad. I’m not a JetProp guy so I have only 3. But I got to think something doesn’t look right the way my shop installed them. Sent from my iPhone using Tapatalk Pro 1 Quote Link to comment Share on other sites More sharing options...
Shadrach Posted November 27, 2018 Report Share Posted November 27, 2018 (edited) 16 minutes ago, LANCECASPER said: I think a friendly, helpful A & P might do it at the owner's request without doing all of the necessary research, but I don't think a competent Avionics shop would. I’ve a number of good relationships with A&Ps. All of them want to look over new parts and installations. None of them would want their name on this. I don’t think it’s dangerous, but in the event of an upset from spatial disorientation, I can see how it might complicate matters a bit. I think a clear and accurate pitch indicator is not something to take for granted. Edited November 27, 2018 by Shadrach 1 Quote Link to comment Share on other sites More sharing options...
Shadrach Posted November 27, 2018 Report Share Posted November 27, 2018 6 minutes ago, Marauder said: I’m not a JetProp guy so I have only 3. But I got to think something doesn’t look right the way my shop installed them. Sent from my iPhone using Tapatalk Pro Three AI’s and you still can’t keep it upright... 3 Quote Link to comment Share on other sites More sharing options...
carusoam Posted November 27, 2018 Report Share Posted November 27, 2018 The Marauder panel... Tilted, inverted, and mirror imaged...? That AP looks a bit out of place with its TC hiding on the edge... I sense a new (mechanical gyro free) panel layout coming in the new year...? 2 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.