102 pounds

[Warren Dunes]

Looking through the paperwork on an aircraft I am considering, it was delivered with a number of avionics and radios that have been replaced (at least once) over the years. The list of items replaced included:

"Lear ADF-12, with low-frequency and entertainment bands.
Narco Omnigator 8 channel VHF, with omninav, and primary VHF comm
Narco Marker beacon receiving unit for VAR (? typo) and ILS
Narco Simplayer 12 channel standby VHF"

The weight difference between these items along with the old intercom, antennas, altimeter, vertical speed gauge, and their current replacements which includes a transponder and ADS-B is 102 pounds. A vacuum is weightless, vacuum tubes OTOH...

 

[scarcherpilot]

I bought my plane and one of the items I wanted done after some avionics upgrades i had done was to get a fresh weight and balance, not just an add or subtract number here and there. The old W&B was done in the 80's. Turns out my plane was heavier by about 40lbs than the W&B showed. Glad I did it though. Just ditched my vacuum for dual G5s and that trimmed 7lbs off the weight of my 172. ~1 more gallon of gas!

 

[asicer]

one of the items I wanted done after some avionics upgrades i had done was to get a fresh weight and balance, not just an add or subtract number here and there. The old W&B was done in the 80's. Turns out my plane was heavier by about 40lbs than the W&B showed.

I've heard that several times. Maybe if you had skipped the scales and instead go through a few more upgrade cycles, you could perhaps get a lighter-than-air rating in your airplane

 

[flyingron]

I've weighed mine after major changes. Oddly it didn't really make a whole log of difference over what had been computed over decades.

 

[k9medic]

I did some avionics work and has a weight and balance done since the last one was done in 1996. I LOST 87lbs!

 

[thito01]

In the original owners manual include in the plane upon purchasing it, I found the W&B page for my a/c actually had all the blanks blank. There had be a document update and someone replaced the page without copying the original data into the blanks. The a/c was 29 years old and there was no W&B for it even though several maintenance entries said that it was updated. So, I had it weighed. I also had it re-weighed after the overhaul and I installed a stand-by alternator and electronic engine gauges. That has be about 10 years ago, so I plan to re-weigh it at the next annual. I have made some changes but a lot of the entries say that new equipment weighs the same as the old equipment.
Weighing is not hard if you first fill the tanks then just subtract the total fuel weight. The "empty all the tanks first" method is for the birds.

 

[ktup-flyer]

I’m up to 1325lb useful load in my 182. Just took out the vacuum pump and put AV30s in. It’s a fun game seeing what all you can do to lighten the plane up

 

[Craig]

We did an avionics upgrade on an A-26 I was involved with. Took almost 400 pounds of radios, racks and wire out. When the guys redid the panel, dropped another 100+ pounds of dead wire, instruments and dirt.

 

[Jon Wilder]

Anytime we do major avionics upgrades we always do a fresh W&B. Not a calculation...the aircraft is actually jacked up on scales and weighed. Any shop that does not do this is probably not equipped with scales to do it. When you're looking for shops to do avionics upgrades, be sure and ask if they're equipped to weigh the aircraft to update the W&B.

 

[N747JB]

I upgraded the avionics in my old 421, took out the old King Gold Crown remote boxes, I think they weighed 80lbs! The new Garmin stuff added maybe 10 lbs.

 

[Brad W]

Weighing is not hard if you first fill the tanks then just subtract the total fuel weight. The "empty all the tanks first" method is for the birds.

I've never done it so this is worth nothing....but wouldn't it be useful though, to confirm your usable fuel while you're at it?