Useful load increase from instrument removal?

[Tx_Aggie]

My new to me M20J is getting a GTX-345 installed. I’m considering the list of ‘while we’re there’ items and that includes possibly removing the DME and insight strike finder. It also has an 2nd extra attitude indicator  (3rd inidicator if you include the Aspen as the 1st.) Has anyone else removed these items and if so what was the resulting UL increase?  I appreciate it. 

Edited August 9, 2020 by Tx_Aggie

[carusoam]

There are lots of opportunities to save weight...

While not removing things of value...

Tens of pounds...

Find the pics that have all the wire bundles in a heap on the floor..

Proper removal of all the wire is needed...

What are you replacing the strike finder with?

Strategic vs. tactical weather avoidance discussion...

The bonus for LBs... removing heavy stuff on the front... has a similar effect on Charlie weights in the back... a 2X bonus... 

hmmmmm... Js don’t have CWs....

Extra bonus for a composite prop..

 

Best regards,

-a-

[Tx_Aggie]

Not sure what a Charlie weight is. I’m just planning to have the GTX feed weather onto my Garmin 480.

[PT20J]

If the components were original, weights should be in the equipment list. If they were added later, there should be 337s. If you have all the old W&B computations, weights should be available there. 

Skip

[ArtVandelay]

The WX10 is ~10lbs, my vacuum system included electric backup was 20lbs...any of the old avionics will be heavy...kns80 was something like 6lbs.

[LANCECASPER]

14 hours ago, Tx_Aggie said:

My new to me M20J is getting a GTX-345 installed. I’m considering the list of ‘while we’re there’ items and that includes possibly removing the DME and insight strike finder. It also has an 2nd extra attitude indicator  (3rd inidicator if you include the Aspen as the 1st.) Has anyone else removed these items and if so what was the resulting UL increase?  I appreciate it. 

If your Strikefinder is working and you'e planning on summer flying I definitely wouldn't remove it. It's real time weather. Even if it's not working, Insight still supports these units for a reasonable price.

You would only save 1.3 lbs. for the display/processor, .77 lbs for the antenna and if you went to all the work of removing the cable, another 1.9 lbs. So less than 4 pounds total. A good colon cleanse might be a better choice  

[carusoam]

On 8/8/2020 at 9:43 PM, Tx_Aggie said:

Not sure what a Charlie weight is. I’m just planning to have the GTX feed weather onto my Garmin 480.

In your Long Body...

Charlie weighs are balance bricks put in the area where the batteries are...

If you add things like anti ice systems, AC, or an O2 bottle... an equivalent lead weight gets removed...
 

If your nose gets a bit lighter... a similar weight X Distance gets removed from the lead pile...

 

Just how weight and balance works in the long bodies...

In other Mooneys... there isn’t as much of a cache of lead in the tail to work with...

Keep your eyes on the W and the B...
 

PP Thoughts only, not a mechanic...

Best regards,

-a-

[ArtVandelay]

Are Charlie weights listed in the W&B, I assume yes, how much weight are we talking about?

[V1VRV2]

X2 on the Strikefinder. Valuable piece of equipment.

[Tx_Aggie]

7 hours ago, V1VRV2 said:

X2 on the Strikefinder. Valuable piece of equipment.

Thanks good to know

[Oldguy]

The biggest weight savings would be to eliminate the vacuum need. As @ArtVandelay noted you can lose almost 20 lbs. when you have an electric backup in the avionics bay. 

[bradp]

I put a strike finder in with one of my recent upgrades.  Find it useful to correlate the nexrad with.  

[Hank]

3 hours ago, bradp said:

I put a strike finder in with one of my recent upgrades.  Find it useful to correlate the nexrad with.  

There's no delay as with the Nexrad, either; the Nexrad is often 10-15 minutes old when it is broadcast, and may be 20 minutes old, due to the procesing time required to compile the many little radar bits into a larger picture and prep it for broadcast. The StrikeFinder shows what's around you right now.

[Tx_Aggie]

3 hours ago, Hank said:

There's no delay as with the Nexrad, either; the Nexrad is often 10-15 minutes old when it is broadcast, and may be 20 minutes old, due to the procesing time required to compile the many little radar bits into a larger picture and prep it for broadcast. The StrikeFinder shows what's around you right now.

Thanks all, didn’t realize the usefulness to be honest. I’ll plan on keeping it in for now!

[PT20J]

I ditched my ADF. But, I kept my KX165 with ILS and DME. If the GPS goes down, I have old school backup. I’m installing a Surefly, but like having the second mag as a backup. I kept a vacuum attitude indicator as a backup for the Aspen and the electrical system. I did remove the standby vacuum pump since it is now a backup for a backup and even I am not that paranoid. 
 

Skip

[carusoam]

On 8/10/2020 at 12:31 AM, ArtVandelay said:

Are Charlie weights listed in the W&B, I assume yes, how much weight are we talking about?

Yes...

They weigh the same as the equipment that was selected to go back there...  FIKI pumps and tanks, AC, and O2...

If you don’t buy the options, you get two or three bricks of nicely shaped lead...

Long Body POHs are fine documents... they include everything, specific to the airframe... 

Unlike the 1965 version of the same thing where the owners manual was one part a welcome statement, and congratulations for being such a wise aircraft buyer... the WnB data was one piece of paper folded and slipped into the log book....  

Best regards,

-a-

[MooneyBe]

Along the same lines, if you gut the attitude indicator, DG/HSI, and vacuum system (primary and secondary) to replace them with a single G5 backup instrument... How much weight savings are we talkin'? 

[thomas1142]

My avionics shop weighed my airplane after a completely new panel, got rid of almost everything including electric standby vacuum pump, for     2-G3Xs, G5, EDM 900, GFC500., I gained about 2lbs in useful load. Moral of the story don’t get airplane weighed, do the math.

[jlunseth]

On 8/10/2020 at 10:23 PM, PT20J said:

I ditched my ADF. But, I kept my KX165 with ILS and DME. If the GPS goes down, I have old school backup. I’m installing a Surefly, but like having the second mag as a backup. I kept a vacuum attitude indicator as a backup for the Aspen and the electrical system. I did remove the standby vacuum pump since it is now a backup for a backup and even I am not that paranoid. 
 

Skip

I have done part of that and am shortly going to do the rest. I am putting in a GTN750Xi and already have a 430AW so will have two GPS/VOR/ILS receivers. The ADF will go, and with a little bit of a wince, the KNS80. It is a good system and has the only DME currently on board. I have an old King radio that will also go, wince there also because it has always been a better radio than the Garmin 16 Watt. I hope the radio in the 750 is better quality. I am keeping the vacuum, I don’t have a backup vacuum, but am putting in a 275 in place of the current electric Turn Coordinator and it will also be a backup AI. Lastly, I am putting in a plain vanilla ball. The older 14V aircraft like mine and your J don’t have the best electrical systems in the world, and I am not going to trust my life or my passengers to a half hour or hour backup battery in a backup AI. Gotta be a little paranoid.

[ArtVandelay]

G5 has 4 hour backup.

[jlunseth]

18 hours ago, ArtVandelay said:

G5 has 4 hour backup.

That got me all excited until I looked in the STC. For IFR aircraft the existing AI must be retained. So I would gain nothing over a 275 as a backup instrument, the vacuum system would have to stay. The 275 has more functionality as a backup, and can substitute for the TC as primary, so the existing TC can come out.

[ArtVandelay]

That got me all excited until I looked in the STC. For IFR aircraft the existing AI must be retained.

Not in a dual G5 installation. Assuming you can find a need for an HSI.

[jlunseth]

What might work would be a 275 in the TC hole that is certified primary for AI, and a G5 in the current AI slot driving the AP. That would give me four hours backup. I will look in to that. 

[rbridges]

I think I gained a few pounds going to the Aspen panels.  The big weight savings will come when I install the electric step and can completely remove the vacuum and backup vacuum systems.  Also, I can remove a few redundant instruments when I put in a primary engine monitor.  

[philiplane]

I definitely wouldn't remove a Strikefinder. It's far more useful than XM weather, when you need to avoid the scary stuff.

I wouldn't remove a working DME either, since it's also useful during GPS outages, which seem to happen more frequently. And it's handy as a TFR avoidance tool. You can use it to fly a DME arc around a TFR, since virtually all of them are referenced to a VOR. Set it to the station, and remain 35 miles away at all times. That gives you a 5 mile buffer. I set up my KN62 DME to work from nav 2. It serves as an independent system from nav 1, so if the GPS/NAV/COM goes T/U, nav 2 gives me VOR/ILS/DME capabilities, and also is hooked to the backup Century 1 autopilot, in case the attitude portion (Aspen EFD AHRS) of the Century III should fail. 

In any event, 5 or 20 pounds of useful load gain is nice, but we really need 100-200 pounds increase to make these planes truly useful.

 

Edited August 16, 2020 by philiplane