Aspen EFD 1000 RSM Fail

Deelee

Deelee

Pattern Altitude
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Deelee
I am going to get this looked at by an avionics shop/Aspen installer, but wanted to see if anyone with the Aspen EFDs has ever seen this.

Short story - Every once in a while, we'll get the double X on the EFIS - Attitude Fail and Direction Indicator Fail. This has happened to me once on the ground and to my partner in the air - each time, the EFIS went back to normal pretty quickly.

Pic of double Xs:

IMG_8948.JPG

Today, I had the issue on the ground as I was doing a run-up. I decided to stay in the run-up box and try to reset the EFD. Powered it off, then back on. This time, when it came back up, I got an error on the startup/initialization screen on the RSM status line - RSM fail [4] check link.

Pic of init error:
IMG_8951 2.JPG

Couldn't get that to clear. Reset the EFD and this time it passed the initialization stage, but went to double X mode (as described above) right away. I did a lap in the pattern to see if this would clear, but it didn't. Landed, taxied back and shut down. Reset a few more times then decided to check the RSM itself (since the init failure mentioned the RSM).

That is when I noticed there is a little metallic sticker that seems to be peeling away from a small hole in the back of the RSM. You can see the sticker and how it is peeling away in these shots below. I have no idea if this sticker is supposed to be there, if it should be covering that hole or if it should have been removed. Or if it has anything to do with these RSM issues... but it doesn't look right to me.

Pic of the RSM/metallic sticker -

IMG_8954.JPG

IMG_8955.JPG

So that got me wondering - is this metal sticker supposed to be there? If so, should it be covering the hole? (it seems to have pulled away). If the sticker is not supposed to be there, should I remove it? And... the million dollar question (or at least the 1 AMU question) - would this have anything to do with the RSM errors and the AI/DG red Xs?

This is super frustrating. We will probably have the avionics folks look at it anyway since I'm not sure I trust this thing in IMC or on approaches anymore.

Thanks in advance!
 
Deelee said:
I am going to get this looked at by an avionics shop/Aspen installer, but wanted to see if anyone with the Aspen EFDs has ever seen this.

Short story - Every once in a while, we'll get the double X on the EFIS - Attitude Fail and Direction Indicator Fail. This has happened to me once on the ground and to my partner in the air - each time, the EFIS went back to normal pretty quickly.

Pic of double Xs:

View attachment 92936

Today, I had the issue on the ground as I was doing a run-up. I decided to stay in the run-up box and try to reset the EFD. Powered it off, then back on. This time, when it came back up, I got an error on the startup/initialization screen on the RSM status line - RSM fail [4] check link.

Pic of init error:
View attachment 92937

Couldn't get that to clear. Reset the EFD and this time it passed the initialization stage, but went to double X mode (as described above) right away. I did a lap in the pattern to see if this would clear, but it didn't. Landed, taxied back and shut down. Reset a few more times then decided to check the RSM itself (since the init failure mentioned the RSM).

That is when I noticed there is a little metallic sticker that seems to be peeling away from a small hole in the back of the RSM. You can see the sticker and how it is peeling away in these shots below. I have no idea if this sticker is supposed to be there, if it should be covering that hole or if it should have been removed. Or if it has anything to do with these RSM issues... but it doesn't look right to me.

Pic of the RSM/metallic sticker -

View attachment 92938

View attachment 92939

So that got me wondering - is this metal sticker supposed to be there? If so, should it be covering the hole? (it seems to have pulled away). If the sticker is not supposed to be there, should I remove it? And... the million dollar question (or at least the 1 AMU question) - would this have anything to do with the RSM errors and the AI/DG red Xs?

This is super frustrating. We will probably have the avionics folks look at it anyway since I'm not sure I trust this thing in IMC or on approaches anymore.

Thanks in advance!
Click to expand...
I can’t remember the specifics of my recurring and and annoying red x problem, but my issue was that the ASI was set to a incorrect airspeed (it was not zero) such that on the ground, depending on the direction my airplane was pointing with respect to the wind, and if the stationary wind was strong enough, the computer would fail almost all functionality with red Xs almost everywhere.
Cannot comment about the tape.
 
@MajorTurbulence thanks for the reply! That is very very interesting about your ASI. Our Aspen consistently registers a non-zero airspeed on the ground when the airplane is stationary. I wonder if that is related to our issue. Do you remember how you got your unit to register a proper airspeed while on the ground? Thanks again!
 
If that is the problem, what a PIA until I associated the occurrences to increased surface winds. When I mentioned the frequent occurrences in the setting of higher surface winds, my installer saw the airspeed indication of, I think, 20 or more kts. While I was in the plane, I think he adjusted that in the Aspen settings menu, but don’t hold me to that. If that is the case, your manual will give you direction. If not call Aspen up directly. Certainly, your best bet is to have your avionics shop adjust it, like I did. I do recall saying to myself ‘was that all it was,’ and assumed that my installer could have helped me avoid the aggravation by a proper initial install. It certainly makes sense that the Aspens computer checking airspeed and comparing it with gps ground speed would cause issues and think there was an error.
Good luck!
 
Last edited:
Thanks! One of the things on our list for the avionics folks to look at is the incorrect airspeed on the ground. Talked to the shop today and they are going to calibrate it, if needed. They also think it may be the RSM itself - they said they had 2 RSMs replaced under warranty last week..... ours is pretty new and they said given the serial number we may be covered if the RSM itself is the issue. So here's to hoping.....

Still a fan of the Aspen - when it works.
 
hindsight2020 said:
So other than the shooting, how was the play Mrs. Lincoln?........
:D
Click to expand...

Good phrase and good point....

Yeah, we sort of inherited it... so I tell myself every once in a while that I'm a fan of it.......

If I had to do an install from scratch........ um no.
 
Mine is doing this as well. @Deelee how did you manage to get this sorted?
 
Deelee just curious… how old was your RSM and was the replacement covered under warranty?
 
..that's sort of a horrifying failure to have. One thing on the ground or VFR, but if you're IMC that is not the time to lose that

Dumb, or potential n00b question.. but why would an issue with the airspeed/pitot/static have any effect on the attitude indicator? In the Garmins it will just X out the speed and/or altitude. To lose the entire functionality seems weak sauce. Or put another way, why does the AI AHARS need airspeed to know up from down?

PS - in the OP's pic also odd that it shows him with an IAS, and TAS, of 33 knots, while the GS is zero
 
Tantalum said:
..that's sort of a horrifying failure to have. One thing on the ground or VFR, but if you're IMC that is not the time to lose that

Dumb, or potential n00b question.. but why would an issue with the airspeed/pitot/static have any effect on the attitude indicator? In the Garmins it will just X out the speed and/or altitude. To lose the entire functionality seems weak sauce. Or put another way, why does the AI AHARS need airspeed to know up from down?
Click to expand...

Your question has been addressed before.

Basically, the nerds at Aspen and Garmin tried to flank the cost-certification problem that generally leads to prohibitively expensive laser ring gyro based inertial units. They do this by opting to rely on velocity information in order to back-solve for the gravity vector, instead of sensing it directly via additional accelerometers. Or, you know... those pendulous vanes us pooah's have been using to erect our mechanical direct sensing attitude indicators ever since Wilbur and Orville started the pilot race to the bottom lol.

That's why these tinker toys are dependent on air data for flight attitude as you point out. Cray cray.

Early Aspens do it with pitot airspeed only. Then they got shamed by simple pitot pressure failures (whether by blockage or external indicator component failure). Which was also the reason the STC required an additional attitude indicator (existing mechanical was the most common) for certification. So Aspen caught up and went the Garmin+ route, by adding GPS GS as the backup data source when pitot information goes tango uniform. Algorithm which they rolled out with their E5 and Pro max offerings.

IRUs in "big boy" airplanes don't rely on air data exclusively. They have inertial units based on laser ring gyros which are capable of direct gravity vector sensing. It is true that big boy INS aid the total navigation solution with GPS and air data, but loss of the air data bus does not yield loss of attitude information.

The only electronic AI I'm aware of that doesn't rely on velocity to sense gravity vector in our sector of the industry, is the RC allen 2600-2/3.
 
hindsight2020 said:
Your question has been addressed before.

Basically, the nerds at Aspen and Garmin tried to flank the cost-certification problem that generally leads to prohibitively expensive laser ring gyro based inertial units. They do this by opting to rely on velocity information in order to back-solve for the gravity vector, instead of sensing it directly via additional accelerometers. Or, you know... those pendulous vanes us pooah's have been using to erect our mechanical direct sensing attitude indicators ever since Wilbur and Orville started the pilot race to the bottom lol.

That's why these tinker toys are dependent on air data for flight attitude as you point out. Cray cray.

Early Aspens do it with pitot airspeed only. Then they got shamed by simple pitot pressure failures (whether by blockage or external indicator component failure). Which was also the reason the STC required an additional attitude indicator (existing mechanical was the most common) for certification. So Aspen caught up and went the Garmin+ route, by adding GPS GS as the backup data source when pitot information goes tango uniform. Algorithm which they rolled out with their E5 and Pro max offerings.

IRUs in "big boy" airplanes don't rely on air data exclusively. They have inertial units based on laser ring gyros which are capable of direct gravity vector sensing. It is true that big boy INS aid the total navigation solution with GPS and air data, but loss of the air data bus does not yield loss of attitude information.

The only electronic AI I'm aware of that doesn't rely on velocity to sense gravity vector in our sector of the industry, is the RC allen 2600-2/3.
Click to expand...
Thanks for the detailed insight! Makes me feel less bad that my favorite plane in the club still has a vacuum based AI.
 
hindsight2020 said:
The only electronic AI I'm aware of that doesn't rely on velocity to sense gravity vector in our sector of the industry, is the RC allen 2600-2/3.
Click to expand...

I'm impressed with the RC Allen 2600. I installed one in the Bellanca when the turn coordinator was making ugly noises. Easy to install, since it just needs power and ground. The display graphics don't win any awards, but the slip indicator, rate of turn indicator, and the attitude indicator are all rock solid with no pitot/static or GPS. RC Allen must have worked hard on the sensor package, and it seems like they got it right. Even when I'm doing repeated steep turns in each direction, it rolls out to dead on every time. I'd trust it in the clouds without a second thought. Definitely more than I would have trusted the vacuum AI, before that was removed.
 
hindsight2020 said:
IRUs in "big boy" airplanes don't rely on air data exclusively. They have inertial units based on laser ring gyros which are capable of direct gravity vector sensing. It is true that big boy INS aid the total navigation solution with GPS and air data, but loss of the air data bus does not yield loss of attitude information.

The only electronic AI I'm aware of that doesn't rely on velocity to sense gravity vector in our sector of the industry, is the RC allen 2600-2/3.
Click to expand...
Huh, nfw... chip-scale RLGs.
www.nature.com

Earth rotation measured by a chip-scale ring laser gyroscope - Nature Photonics

A Sagnac gyroscope based on Brillouin ring lasers on a silicon chip is presented. The stability and sensitivity of this on-chip planar gyroscope allow measurement of the Earth’s rotation, with an amplitude sensitivity as small as 5 deg h−1 for a sinusoidal rotation, an angle random walk of...
www.nature.com www.nature.com
 
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