Turn Coordinator or second attitude indicator?

FloridaMan · July 1, 2011

carusoam, I don't remember the DG doing much of anything. It also took about 5 minutes from the time the low vac light came on until I lost the attitude indicator. I was on the horn with ATC and first thought it was just an indicator failure. The controllers were real excited; they kept asking if it was an emergency and were giving me "no gyro" headings and all that. It was clear daytime VFR and I could see where I was going.

**jetdriven** · October 5, 2011

here are some ASRS reports from pilots who lost their primary attitude indicator while in IFR. What is surprising is the amount of them that completely lost control of their aircraft, some even striking trees or coming out of the clouds looking at corn. Of course, these are the pilots who didnt crash. We did Oshkosh and put 25 hours on the airplane. We also flew it about 4 hours IFR. One thing I noticed was in anything other than light turbulence the T/C isn't particularly reliable, it dances around a lot. Any yaw fools it into thinking you are in a turn. We are installing a Castleberry attitude indicator to replace our T/C this month.

enjoy reading these. Some are outright shocking.

*****Then I lost control of aircraft totally and became totally disoriented. Sheer panic for a couple of mins. Aircraft would not seem to ascend. Bank indicator and attitude gyros disagreed? Aircraft shook (probably close to stall). *****

deviated from the instrument approach procedure due to gyro instrument failure (vacuum) which caused some disorientation on my part. While on a flight from ZZZ1 to ZZZ, I chose to make a localizer approach into runway 34 at drake field. I was on localizer, a little below the GS about 1 mi from the touchdown zone. My wife (passenger) was looking out the windows to see ground (we were in the clouds). My wife hollered 'trees.' I was watching the aircraft instruments. Upon her exclamation, I gave full throttle and pulled back on the yoke. I heard the noise of scraping tree tops on the aircraft. I looked back at my instruments and the aircraft attitude indicator had tumbled and my directional gyro was spinning to the right and taking the aircraft with it.

http://www.37000feet.com/report/547636/M20-pilot-strikes-tree-tops-on-lda-DME-approach-and-experiences-primary

Bennett · October 6, 2011

The Castleberry is a nice looking unit, but I chose the MidCentury "LifeSaver" becasue of its built in back-up battery. With loss of the elctrical bus, just pressing the correct buton gives you about and hour and a half of AI. Very steady display, and the "ball" is well damped.

Cruiser · October 6, 2011

I have flown partial panel many times. Just put a cover over the AI. Try it in bumpy air. As mentioned above, the TC indicator will bounce all over the place BUT you can get it and the plane in wings level attitude with some concentration. One of the first things taught in IFR training is a proper steady scan. I hear/read these stories about instrument failures and near loss of control that baffles me. Why, please explain why the pilot in the above message didn't know he was BELOW the MDA? and by a considerable distance if he was scraping the belly on the treetops. This pilot was not prepared to be flying an approach in IMC. The altimeter is calibrated and independant of the vacuum system. He should have never allowed the descent to continue that far, instrument, vacuum failure or not.

mulro767 · December 4, 2011

Considering the RCA 2600-3 as a replacement for my turn coordinator. Anyone have one in their Mooney?

I agree with all who replace the TC with the 2nd AI as a backup. Personally, I think I will get a warm fuzzy feeling knowing my attitude is redundant while flying IMC.

wishboneash · June 2, 2012

My TC is dead. The flag disappears when powered up but no sound from the unit. I have the Century IIB autopilot and from what I read, the TC doesn't feed that. I have backup vacuum for the primary AI. I am thinking of replacing the TC with the Castleberry AI as a backup electric AI. Good idea? What is the difference between the 14V Gyro or the one with the 8deg tilt? Thanks for any information.

Sriram

'78 M20J

**jetdriven** · June 2, 2012

Sriram:

I installed the Castleberry because its lighted, has 20 degrees of pitch (labeled), and gets good reviews on BT. Further, theres an article were they opened up it and an RCAllen, and thr Castleberry was determined to be built better. Anyways, we put it in the top center and put the vacuum AI in the hole left by the turn coordinator. Check my photos. Correct, the C-IIB only gets inputs from the vacuum atitude and the DG. Your need the 14v zero tilt gyro for your application.

M20F-1968 · June 2, 2012

I have an STEC-60-2 which requires the turn coordinator. I mounted it blindly behind the panel, and have a Garmin 600, a 3" vacuum AI with off flag and a 2" Mid-continent electric AI with inclinometer. I did not use the back-up battery for the Mid-continent since I have enough redundance and have a RAT (air driven alternator) in the airplkane as well. The vacuum AI is the only vacuum instrument I have left. The reason for it is that in unusual attitudes (which you hope you do not get to) the vacuum instrument is more reliable and rights itself quicker. I would rebuild you vacuum AI, and replace the turn coordinator with a 2" electric AI with inclinometer. You can take a look at my panel pictures in my gallery.

John Breda

**jetdriven** · June 2, 2012

I will add to John's post that the vacuum AI rights itself and is erect in about ten seconds after start. The Castleberry requires begin caged and is reliable in two minutes. Performance in flight is within +/- 1 degree of roll and pitch. The Castleberry also has a gyro flag as well. If they disagree, use the compass to break the tie. If you have a good scan and crosscheck, you will notice a disagreement before it becomes a big deal.

wishboneash · June 2, 2012

Quote: M20F-1968

I have an STEC-60-2 which requires the turn coordinator. I mounted it blindly behind the panel, and have a Garmin 600, a 3" vacuum AI with off flag and a 2" Mid-continent electric AI with inclinometer. I did not use the back-up battery for the Mid-continent since I have enough redundance and have a RAT (air driven alternator) in the airplkane as well. The vacuum AI is the only vacuum instrument I have left. The reason for it is that in unusual attitudes (which you hope you do not get to) the vacuum instrument is more reliable and rights itself quicker. I would rebuild you vacuum AI, and replace the turn coordinator with a 2" electric AI with inclinometer. You can take a look at my panel pictures in my gallery.

John Breda

**jetdriven** · June 2, 2012

I would also add we bought our Castleberry used for 1K. Overhaul is also 1K, but so far we are doing OK. But it is a mechanical instrument. The RCAllen digital attitude is 2500$, which is 200$ more than the Castleberry but it is digital. It was all lout of our price range, but if I was committed to spending that much, I would give the RCAllen digital a good look. No maintnenace ever.

Bennett · June 2, 2012

My Mid-continent "Life Saver' (with inclinometer and back-up battery) starts caged, but one press of the button and the unit is then fully erect and usable. So far it tracks perefectly with my vacuum AI (which also has a back-up - an electrictic vacuum pump in the tailcone). This is an expensive solution. but brings a good deal of redundancy to the panel.

FAST FLIGHT OPTIONS LLC · June 2, 2012

The current version of the RC Allen 2600-3 looks pretty good and at $2,600 would seem reasonable if I were flying through the clouds with a failed primary AI. Could apply that money to an Aspen though.....

**Lionudakis** · September 21, 2012

I just installed an RC Allen2600-3 an old aircraft as primary, as it is an all electric system. I wasn't impressed at all with the display quality of the unit, the screen was very jittery, for a high tech 2500 piece of equipment. My pirep without even flying behind it. I was stoked about getting one as standby till seeing it in action.

wishboneash · February 5, 2013

I bought an iPad/iPod app called Pocket Horizon and with the GDL-39 WAAS GPS connection I have a decent backup AI solution. The attitude updates at 10Hz so it is pretty responsive. The total cost was $9 for the app and $120 for an used iPod (8Gb Gen 4). Currently attached on top of my Stormscope :-)

A picture of the setup below.

http://www.flickr.com/photos/59522027@N08/8449095584/

Marauder · February 6, 2013

I put a second AI in my Mooney, and kept the TC. If you have two gyros, which do you believe if they disagree? With three sources of roll information, you can determine which device has failed more quickly.

I'm in BIG trouble! I now have 4 sources of roll indication (Aspen PFD, Aspen MFD in reversion, AI and TC connected to the STEC). Who do I believe when there is 4?!

Marauder · February 6, 2013

I bought an iPad/iPod app called Pocket Horizon and with the GDL-39 WAAS GPS connection I have a decent backup AI solution. The attitude updates at 10Hz so it is pretty responsive. The total cost was $9 for the app and $120 for an used iPod (8Gb Gen 4). Currently attached on top of my Stormscope :-)

A picture of the setup below.

http://www.flickr.com/photos/59522027@N08/8449095584/

Holy crap! I forgot about these! I have 6 sources of roll! I forgot about the Garmin Pilot on the Nexus 7 and the Garmin Pilot on the iPad 2!

randypugh · February 6, 2013

G500 will solve it all

**jetdriven** · February 6, 2013

I'm in BIG trouble! I now have 4 sources of roll indication (Aspen PFD, Aspen MFD in reversion, AI and TC connected to the STEC). Who do I believe when there is 4?!

Best 3 out of 4 win. All else fails, use the whiskey compass to break the tie.

**jetdriven** · February 6, 2013

Holy crap! I forgot about these! I have 6 sources of roll! I forgot about the Garmin Pilot on the Nexus 7 and the Garmin Pilot on the iPad 2!

The Garmin pilot indirectly uses ground track as a source of "heading". It wont keep you out of the ground, but is a nice novelty.

wishboneash · February 6, 2013

I'm not sure how I had missed this, but this was the first that I had heard of this app. I just downloaded it just to play with it, as I already have all of the required hardware, and it only costs 8 bucks. The company states on their website that a big upgrade is in the works that will require a later version of iOS than is currently required. I bet that it is gps-based altitude and groundspeed tapes like the new Dynon D1. How much longer can it be before they add Synthetic Vision? It'll be interesting to see how well it works, but the reports that I have read so far on the Internet are very positive. These new iOS-based technologies really amaze me.

And yes, I know that these things aren't for use in IMC and are just a novelty, but if they work as advertised within the limits of their technology, how cool is that?

Jim

There were some issues with iOS 6.0 (wouldn't support external GPSs), but that has been resolved in iOS 6.1. I am working with the developer to see if the GDL-39 is wholly compatible and accurate with this app. It works well with the Dual XGPS-150 but the developer had concerns with the ADS-B type receivers with GPS out. I will keep the group updated. I have no financial interest in this company, just trying to get my set up as good as it can get without having to use multiple GPSs!

fantom · February 7, 2013

More is not always better, IMHO :rolleyes:

FloridaMan · February 7, 2013

I bought an iPad/iPod app called Pocket Horizon and with the GDL-39 WAAS GPS connection I have a decent backup AI solution. The attitude updates at 10Hz so it is pretty responsive. The total cost was $9 for the app and $120 for an used iPod (8Gb Gen 4). Currently attached on top of my Stormscope :-)

A picture of the setup below.

http://www.flickr.com/photos/59522027@N08/8449095584/

From what I've been seeing of these sorts of things, I would not trust any of them. I'm having misgivings about the Dynon D1 as well. I've been in contact with their support about an issue that I've been having.

wishboneash · February 7, 2013

Well, it is a cheap back up compared to the Dynon D1 ($9 if you had an iPhone/iPod already). I plan to do a flight test this weekend and would like to record it and compare the output between the AI and this backup AI under different conditions.

AndrewR · February 7, 2013

If going with an iPad or iPod/iPhone as a backup is an option, I'd go down the Xavion route. Getting hoop guidance to an airport is a definite bonus. Pushing higher accuracy AHRS/GPS data to the app is the next step, but iLevil should have a good battery powered unit for ~$1200 out soon (with FIS/TIS/ADS-. Complete electrical & engine failure IMC or night is now managable.

https://itunes.apple.com/us/app/xavion/id574203838?mt=8

http://www.aviation.levil.com/iLevil.htm

I haven't purchased the app yet, but am seriously considering doing so. My only reservation now is that the iPad is mounted to the RH yoke, so the internal 'gyros' would be useless. Panel mounting the iPad is not really an option in the old '63 M20C. Maybe I can work out something for my old iPhone...

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