Weight and balance

[AirBorn]

I’m a new owner of a 1989 A1 Husky. Is anyone else having this problem?

My question is about “weight and balance“ why is it way off?

It was weighed in 2018 with full fuel and oil. The new CG is 70.60 @ 1290lbs after deducting 300lbs for fuel. When it was new from the factory the CG was 73.4”. I am NOT able to get the CG in the envelope with 50lbs of cargo in the back and I’m 220 in the front seat. it flys just fine but landing I have full up nose trim and the stick is still very heavy.

Any help would be appreciated. I am scheduled for a new W&B next week, but I’m going to defuel the plane, and strip her down, before weighing it.

 

[belloypilot]

3" CG movement is a heck of a lot. For my A-1B, that's the difference between me having nothing in the cabin or tail baggage compartment versus both being loaded to the limit (50 in cabin baggage, 30 in the tail). Seems to me there would have to be visible aircraft parts added or missing to have it change that much. Maybe a prop change? But hard to believe that could make anything close to a 3" shift.

I'm of the belief that its always better to fully drain the fuel system before weighing, but the calculation I just did showed the difference between 300 lbs and 0 lbs fuel made 1.1" difference in the loaded CG so that's not going to move the needle much for you.

It will be interesting to see how this gets resolve. Please keep us posted.

Edit: I meant to say ‘fully drain’ fuel before weighing.

 

[AirBorn]

Also looking at the new from the factory W&B the wheel weights were 550 each and the tail at 120. In 2018 the wheel weights were 750 left 720 right 120. (Minus the fuel 300 lbs) There is a 370pound difference with nothing being changed from the original except some radios which was deemed negligible. So that mysterious 70 pounds has everything to do with it. can scales be that much off?

 

[Flying Dave]

Airplane holds closer to 54 gallons most likely. Are you comparing it with or without oil? Make sure you are comparing apples to apples on the WB.

Also Aviat’s scales were notoriously off back then. I think it had something to do with how far away they are from the earth’s core…. If you have not made an official entry in the log book you may not want to enter the new numbers if you know what I’m saying. Maybe let that dog be. Once it’s entered it’s official.

 

[Snowbirdxx]

Good advice from Dave. You may check also the landing gear. If it is a new long one, the arms are different. But weighting with fuel, then subtract is not worth the effort. Go with the better numbers and have a nice day. If you fly very nose heavy, do not use full flaps untill really necessary. The plane lands much nicer with 2 flaps and better elevator authority. And of course with Super SGS on the landing gear.

 

[belloypilot]

Also Aviat’s scales were notoriously off back then. I think it had something to do with how far away they are from the earth’s core…. If you have not made an official entry in the log book you may not want to enter the new numbers if you know what I’m saying. Maybe let that dog be. Once it’s entered it’s official.

Is the basic empty weight and CG for each aircraft leaving the factory determined by weighing each individually, or is it based on some 'representative' example at some point in the certification process then put and takes applied based on the equipment list? If the latter and considering these are all hand built machines I can see a lot of variability from one serial number to the next that would go undocumented until the first time on scales.

 

[dogday]

AirBorn

You stated "but landing I have full up nose trim and the stick is still very heavy."

Do you have the auxiliary chain link installed which lightens the stick load a bit?
If not, search this site using the term "chain link"

 

[Flying Dave]

Is the basic empty weight and CG for each aircraft leaving the factory determined by weighing each individually, or is it based on some 'representative' example at some point in the certification process then put and takes applied based on the equipment list? If the latter and considering these are all hand built machines I can see a lot of variability from one serial number to the next that would go undocumented until the first time on scales.

I have always been under the assumption that they were weighed individually since the W/B has the serial number on it.

 

[airplanebrad]

This is probably unrelated. But always make sure there’s no wheel chocks in front of the tires. That could be taking weight from the scales.

 

[Jeb]

And that the plane is properly leveled and the rear weigh point is correct. I think I remember it not being the tailwheel on the scale.

 

[FlyingDog]

 

[AirBorn]

Airplane holds closer to 54 gallons most likely. Are you comparing it with or without oil? Make sure you are comparing apples to apples on the WB.

Also Aviat’s scales were notoriously off back then. I think it had something to do with how far away they are from the earth’s core…. If you have not made an official entry in the log book you may not want to enter the new numbers if you know what I’m saying. Maybe let that dog be. Once it’s entered it’s official.

I wish I could but the last W&B was 2018 and that’s what I’m dealing with. I inherited the plane after my friend died and I was surprised when I did a W&B.

 

[AirBorn]

View attachment 6856 View attachment 6856

Thank you this looks helpful. Last weighing might have been dome wrong?

 

[FlyingDog]

If possible, check original factory and any subsequent w&b paperwork to look for errors or other issues. Maybe a subtle mistake in math, scale positions or weight on scale can be identified.

 

[Ak Kurt]

Make sure you drain ALL the useable fuel out of it before weighing. These tanks hold more than 5 gallons. My Cessna 185 held 9 more usable gallons than published. Had I weighed it full and subtracted published useful I would have weighed 54 pounds more. Also, clean everything out of the airplane. Ropes, spare headset batteries, headsets, chocks and so on. Make sure you put the FOM (manual) in the airplane, preferably in the front seat pocket on the rear of the seat. The FOM is a required item so it must be included in the empty weight.

Kurt

 

[Ak Kurt]

If possible, check original factory and any subsequent w&b paperwork to look for errors or other issues. Maybe a subtle mistake in math, scale positions or weight on scale can be identified.

This! We found factory errors on a buddy’s Husky. It can happen.

 

[AirBorn]

This! We found factory errors on a buddy’s Husky. It can happen.

I did and the CG moved 3”forward on a weighing in 2018. But no idea as to why. Almost everything was still stick except garmin 430 was added. You would think the person doing the scales would notice a 3” shift and maybe check their equipment or make sure everything was set up correctly. People today are always in a hurry! Done now give me my money.

 

[Flying Dave]

76" Hartzell prop or the 80"??

 

[belloypilot]

I think it's safe to say that there's no way both W&B calculations can be correct so looking for 'what's changed' with the aircraft isn't likely to turn up anything useful. One of them pretty much has to have a significant error either in the math or the weighing method/equipment. There would have to be well over 100 lbs of weight either added forward of the firewall or shifted forward by a significant amount. Maybe those gold bars you've been hiding under the floorboards got loose

 

[LOWandSLOW]

As info, when I converted from an aluminum Hartzell 76" to an 80" composite trailblazer, my CG moved aft one inch from 74.49 to 75.39. It's really hard to believe the CG is really 70". My Husky lands with full nose up trim as well, in fact I really only use the rearmost 1/2" of travel.