Possible Aspen installation

[Steve]

There is no "mesh" in the wing skin. But there is a layer of carbon fiber, so compromise of GPS signal is a possibility.

There are both carbon fiber cloth and carbon/aluminum mesh cloth in my wings (see AMM pages below). The carbon/aluminum mesh is in two areas at the wing root and wing tip, so it wouldn't be near the desired RSM location, but as you state, the carbon fiber layers are conductive as well, and would likely interfere with the GPS signal.

I believe that this layer was eliminated in later SNs.

Steve

[Rich]

There is no "mesh" in the wing skin. But there is a layer of carbon fiber, so compromise of GPS signal is a possibility.

There are both carbon fiber cloth and carbon/aluminum mesh cloth in my wings (see AMM pages below). The carbon/aluminum mesh is in two areas at the wing root and wing tip, so it wouldn't be near the desired RSM location, but as you state, the carbon fiber layers are conductive as well, and would likely interfere with the GPS signal.

I believe that this layer was eliminated in later SNs.
Steve

Gone by the time of the AMM revision 7 (2017). Hard to say just when it was eliminated. A very plausible time would be when production shifted to Canada, but that's a guess. There were a number of obvious changes made in that transition.

[Steve]

Changed sometime before AMM Rev. 6 (April, 2013). I don't suppose it really makes much of a difference, unless you have to make a repair in that area...

[johnu]

Rich,

I sent you a message directly but for general knowledge the RSM can be mounted on the fuselage using a wedge. I have attached pictures.

Since I have a multi-tube Aspen system I have one installed on the fuselage and one in the wing. The OAT reading from the one in my wing is usually one degrees different from the one installed outside. However if you install it in the wing you lose the use of the back up GPS so I would not recommend it for an E5 or single tube install.

In any case let me know if anyone has any questions.

John

[johnu]

Rich,

Inside the wing I mounted the RSM in the cover plate. Pictures below:

John

[Rich]

Rich,

Inside the wing I mounted the RSM in the cover plate. Pictures below:

John

That's good to know. I don't see how it fits, but I guess I'm wrong. It's certainly where I'd prefer it to go.

[Rich]

The RSM for my E5 will be externally mounted on the rear fuselage after all. No big deal, as at this moment I don't see how to get the thing into the existing magnetometer space in my plane. I know John's was somehow fit in there, but there might be a small difference in the location of that access plate in the pre-Canadian planes. The intrusion of that wing rib I see is definitely a factor.

In other news:

Unlike other such devices, the E5 standby battery is supposed to be changed out every 4 years, based on the current ICAW instruction. The documentation for replacement has one removing the unit to replace the battery, But I don't think that'll be necessary in the DA40, as once the instrument cover is off the E5 battery compartment will be fairly accessible (taking extreme care not to drop the screws ). This would not be true of other aircraft, where the connections, etc. behind the panel are only accessible from below.

[johnu]

Rich,

Still confused about the RSM not fitting but maybe you are right about the different configurations. Although you have moved forward, this one has me curious so I am going to keep looking at this one!

As far as the battery goes every battery installed has some sort of "lifetime limit" Some are done after a period of time like Aspen, others have on condition tests that need to be performed about every year and would have to be replaced if they did not pass. So in any case replacement of batteries would occur in any unit at some point.

John

[Rich]

Rich,

Still confused about the RSM not fitting but maybe you are right about the different configurations. Although you have moved forward, this one has me curious so I am going to keep looking at this one!

As far as the battery goes every battery installed has some sort of "lifetime limit" Some are done after a period of time like Aspen, others have on condition tests that need to be performed about every year and would have to be replaced if they did not pass. So in any case replacement of batteries would occur in any unit at some point.

John

True about battery life. I've had occasion to see what happens to LiPo packs when they fail - they kind of bulge. In some situations they can be difficult to remove when this happens.

[Rich]

The plane goes into the shop this week

On a note not applicable to me, I found in the E5 documentation the explicit affirmation that GPSS is available with the Avidynes. I haven’t shared this with my friend that now has the dual-G5s, as it’s water under the bridge. It might be worth sending out some sort of bulletin to the Aspen installation shops to clear up this misconception.

I’m looking forward to launching into a 400 ft. Ceiling upon picking it up next week NOT!!! Lots of nuance to relearn about dealing with new procedures and certainly making sure everything works.