[FlyingFwyFreeman]

I'm still learning my 2007 model. Listed in the POH, the Gross Weight is 2270 pounds (Normal Category). It also says 6 G's 1600 pounds and 5 G's 1800 pounds. Would I be legal to fly above 1800 lbs as long as the CG is not aft of 86.82 inches and limit the G's to 3.8 (the old Normal Category limit)? I have an AeroSport IO-390, 210 HP, CS prop. I just weighed it and it's 24 pounds heavier than in 2007. It was already on the heavy side, and now 1254 lbs.

 

[PhatRV]

When in doubt, refer to Vans Aircraft. Also the aerobatic gross weight is 1600#. You may want to get a new W&B for your aircraft since the POH numbers are strange.
Link: https://www.vansaircraft.com/rv-8/

 

[AN23]

"Legal" in the experimental world is whatever you (or the builder) can get approved by the DAR. That being said, as a three time RV owner, twice with RV-8s, there is no way in heck I'd consider flying it anywhere near 2200#! Ask yourself, "Did the builder do ANY testing to verify structural loads at that weight or did they just pull a number out of the air?" Even true test pilots demand engineering verification before pushing the envelope. .

 

[DanH]

...there is no way in heck I'd consider flying it anywhere near 2200#! Ask yourself, "Did the builder do ANY testing to verify structural loads at that weight or did they just pull a number out of the air?"

He pulled it out of a much darker place....

BTW, 1254 lbs empty is a very heavy RV-8.

 

[AN23]

Very

 

[chrispratt]

Another vote for complying with Van''s numbers. 1800 pounds for GW, 1600 for aerobatic weight. If you add a back-seater, the -8 trims out very nicely at cruise but the handling on the landing can get squirrely very fast, so pay even closer attention when you have a passenger. My personal goal for aerobatics is to keep maneuvers at about 3G max. That way if you screw up, you have plenty of room to recover. 6Gs? Nope. Save that for when you own an Extra 300 or Pitts. The previous owner appears to have taken great license with the word "experimental."

Chris

 

[moespeeds]

I'm sure I'll get hammered for this, but here goes. I'm 6'3" 250 lbs. I have flown my 8 many times over gross, 1850-1880 lbs with no issues. I would not do it at 2200 lbs. I'm careful about CG, always checking the numbers with minimum fuel as the CG moves aft as you burn fuel. Obviously no aerobatics and be careful in turbulent air.

I would at least get an updated W&B as other have said.

 

[Ralph Inkster]

Based on that written POH information, I’d meet with a well respected RV builder/DAR inspector/advisor (many on this forum) and REVIEW & REWRITE a new POH.
There might be other morsels of fanciful fiction in your document.

 

[Webb]

Are the scales accurate?

 

[RV8Squaz]

I'm still learning my 2007 model. Listed in the POH, the Gross Weight is 2270 pounds (Normal Category). It also says 6 G's 1600 pounds and 5 G's 1800 pounds. Would I be legal to fly above 1800 lbs as long as the CG is not aft of 86.82 inches and limit the G's to 3.8 (the old Normal Category limit)? I have an AeroSport IO-390, 210 HP, CS prop. I just weighed it and it's 24 pounds heavier than in 2007. It was already on the heavy side, and now 1254 lbs.

Realize that the POH for an Experimental Amauteur Built aircraft is generally created by the builder. Sometimes they follow Vans, Lycoming, Hartzell, and FAA guidance and sometimes they don’t. They can put whatever they want in their POH. I wouldn’t consider a POH for an Experimental Amateur Built aircraft as an official document like I would for a certificated aircraft.

 

[Mikeyb]

How could you load a -8 to 2270#?

 

[RV8JD]

A few notes:

- The Aerobatic Gross Weight is 1550 pounds for RV-8s with the non-Dash One wing, and 1600 pounds for RV-8s with the Dash One wing (Aerobatic Category g-limits of +6.0/-3.0g).

- Between the Aerobatic Gross Weight and the Design Gross Weight of 1800 pounds, the RV-8 is stressed for the Utility Category g-limits of +4.4g/-1.75g.

- Not sure what Van's did regarding design landing gear loads, and what that means for landing weights above the Design Gross Weight of 1800 pounds.

- As a side note, the Normal Category g-limits are +3.8/-1.5g.

 

[Walt]

There are at least a few threads on increasing gross weight.

 

[FlyingFwyFreeman]

Thanks for all the replies. It has been repainted over the original and 4.5-gallon tip tanks, but other than that what might be so heavy? Yes, the scales were accurate. How do you know dash one or non-dash one wing? Between 1600 and 1800 lbs it's stressed for 5 Gs, right?

 

[RV8JD]

Between 1600 and 1800 lbs it's stressed for 5 Gs, right?

No. As stated in post #12, between the Aerobatic Gross Weight and the Design Gross Weight of 1800 pounds, the RV-8 is stressed for the Utility Category g-limits of +4.4g/-1.75g.

The reference for that is directly from Van's webpage, "Flying an RV", quoted below: https://www.vansaircraft.com/flying-an-rv/

"The RV-3B, RV-4, RV-7/7A, RV-8/8A and RV-14/14A have been designed for the operational stress limits of the aerobatic category (+6.0/-3.0 G) at and below their aerobatic gross weights. The operational stress limits for these aircraft between their aerobatic gross weights and their maximum design gross weights are utility category (+4.4/-1.75 G). The RV-9/9A, RV-10 and RV-12 are not designed for aerobatic flight.​

​

The design operational stress limit for the RV-9/9A is utility category (+4.4/-1.75 G) at less than 1600 pound gross weight and is standard category (+3.8/-1.5 G) between 1600 pounds and the aircraft’s design gross weight. The design operational stress limit for the RV-10 is standard category (+3.8/-1.5 G).​

​

No RV should ever be operated above its design gross weight limit."​

​

Also, since you may be new to RV's, note that Vne is now in terms of TAS and not IAS. The Vne for the RV-8 is 200 KTAS/230 MPH TAS.

 

[RV8Squaz]

Thanks for all the replies. It has been repainted over the original and 4.5-gallon tip tanks, but other than that what might be so heavy? Yes, the scales were accurate. How do you know dash one or non-dash one wing? Between 1600 and 1800 lbs it's stressed for 5 Gs, right?

I’m not sure what makes your RV-8 so heavy. Mine is considered quite heavy at 1197 lbs. I have an angle valve IO-360A1A, a Hartzell constant speed prop, a full Christen inverted oil system, old school avionics and six pack, O2, a partial leather interior, and a Concorde RG-25XC battery. That’s about as heavy as they come.

 

[walkman]

How could you load a -8 to 2270#?

Have you seen some people?

I'm not the most svelte any more, but damn!

I suspect the builder was a large person, possibly with a large spouse, and the inflated numbers were related to that.

One thing I was do if I was the OP, is to have a look at what might have been damaged or stressed by flying or bounding a landing at that weight.

 

[Majorpayne317641]

Also don’t forget there is a maximum nose wheel weight on the vans construction manual.

 

[Kahuna]

How could you load a -8 to 2270#?

Easily and regularly.

 

[rbenua]

One thing I was do if I was the OP, is to have a look at what might have been damaged or stressed by flying or bounding a landing at that weight.

Question from a non-builder for the more structurally inclined:

Let's say I go to look at a plane for sale, and I see a POH like this or other documentation that indicates it may have been flown significantly over the design weight on a regular basis.
What should I look for (or ask a mechanic to look for) during an inspection to identify whether there's been any long-term damage or fatigue that could lead to a failure down the line? Any particular components or symptoms to be aware of? Or is the whole thing a potential time bomb and you wouldn't touch it at all?

 

[skylor]

Thanks for all the replies. It has been repainted over the original and 4.5-gallon tip tanks, but other than that what might be so heavy? Yes, the scales were accurate. How do you know dash one or non-dash one wing? Between 1600 and 1800 lbs it's stressed for 5 Gs, right?

I suspect that whoever wrote the POH for your aircraft used some overly-simplistic math when coming up with the 5G number by assuming a linear relationship between spar loading and aircraft weight (i.e. 1600 x 6 / 1800 = 5.3).

Unfortunately this would be a very dangerous and poor assumption because structural loads often do not increase linearly with total aircraft weight.

Skylor
RV-8

 

[Berchmans]

Mine came in at 1,123 lbs....I would not trust the 2,200 plus weight at all. I have landed with a 240ish passenger in the back. Was within CG but keep you speed up, the tail gets soft.

 

[Snowflake]

How could you load a -8 to 2270#?

Tip tanks were mentioned in this case, which explains both the empty weight and the gross weight increases. Doesn't justify them, but it does explain them.

 

[Snowflake]

Let's say I go to look at a plane for sale, and I see a POH like this or other documentation that indicates it may have been flown significantly over the design weight on a regular basis.
What should I look for...

You should look for the exit. Find another plane.

 

[DanH]

Let's be realistic. It's not unusual to find 7's and 8's with 1900 lb max gross on the paperwork. It's ramp check protection. And sometimes they fly in excess of 1800, on purpose. Ever haul your wife to a wedding weekend?

That said, original builders are generally aware of the design numbers. If a bit heavy, they fly carefully.

The problem is obvious...where to draw the line? Opinions vary, and Lord knows, we have plenty of opinions.