Van's over-engineering compared to certified aircraft

[Captain Avgas]

Originally Posted by BJohnson

I have two main concerns over the RV engineering.

First is the location of the fuel tanks which can easily impact a post or tree and rupture during an off field landing. Other designs put the tank behind the main wing spar providing better protection.

Second is the tendency of the fuselage to buckle behind the cabin but in front of the shoulder harness anchor point during a hard landing causing the occupant to be more likely to impact the glairshield.

I love flying my -9a. It is an amazing machine. Those are the only two design details that give me some pause when contemplating an off field landing.

My biggest concern (by far) when contemplating an off field landing in my RV7A is the very high probability of the nose gear collapsing leading to the aircraft tipping over and me being trapped inside, possibly injured, and with fuel leaking. To be honest I think that the chances of not ending up inverted in an off field emergency landing are not good. As I?ve said before, I love flying my RV7A...but I?d much rather crash a Cessna.

[RV6_flyer]

RV's are NOT over engineered according to the Collins English Dictionary.

Copy / Paste:
over-engineered
unnecessarily complicated

End Copy / Paste

The FREE Dictionary by FARLEX has the same definition.

[plehrke]

Originally Posted by David Paule

"Over-engineering" is a rather vague term. To some it means over-strength and to others, it approaches the infamous "paralysis by analysis," excessive use of engineering time.

Are the RVs over-strength? Apparently not, from all I've read. They seem to be adequately designed for their mission, without a whole lot of margin. Remember, their mission includes being built by amateurs.

Has Van's wasted excessive engineering on them? Probably not, because they are still in business.

Dave

Concur.

“Over engineered” means doing too much engineering. Definitely not a description on a Vans aircraft as prices are so reasonable there probably was not an excess of analysis or testing. In my day job we do lots more engineering to maximize performance and reduce risk. It is a cost vs performance trade.

“Over designed” is the correct terminology for making it stronger than it needs to be. Also not a trait of a Vans aircraft as performance shows low weight was high on the trade priority. Over designing is a weight vs performance trade.

Over engineered and over designed are related. If you want to do more engineering you are able to minimize material to meet the strength requirements. If you do not want to do the detailed analysis and over engineer, you tend to add some material to make up for the lack of analysis. Usually called conservative design and not over designed in the aero biz.

Over engineered and over designed are sliding scales that need to be judged for each airplane not compared across different designs. More analysis maybe required for very similar aircraft missions just based on construction material and methods.

The only place to really compare is in a cost vs performance vs risk trade. That is what the market does and based on sales, Vans must not be over engineered or over designed.

[Capt]

Vans has good basic designs, simple, strong enough where they need to be and fairly efficient. I wouldn't say over engineered etc just adequate for the task at hand.
Remember AC revolved around one main criteria, weight which can be looked as ......more doesn't necessarily mean better

[rongawer]

Originally Posted by mfleming

I've heard people exclaim about Van's being overbuilt ...but it's just not true IMHO.

My -7 is NOT over engineered, far from it. It's a great aircraft but the total performance comes from the light weight design. Some Beechcraft's may be considered over designed...they're built like a tank.

Now that's a very true statement. I had a midair collision with a helicopter years ago in my Debonair; it smacked my right wing and ripped it open, but I was still able to make it back to the airport and make a "good landing" (The FAA's term for we walked away, but the airplane wasn't reusable).

The NTSB investigator's comment was, "that would have ripped through a Piper's spar, but Beechcraft, they're built like a bank vault." The Debonair, hence Bonanza and Baron's, the spar is a box design, so pretty stout.

Having built a couple RV's, currently a -10, and having owned several Beech's that I personally maintained, the RV's are pretty stout, but not the same structure as a Beech - if we're comparing wings and spars. They have thicker skin too on a Beech; mostly 0.032.

Now, comparing to the Zenith 601XL, my first build, there is no comparison to the RV in structural strength, IMHO.

Overall, I'd say RV's are a very well designed and engineered aircraft. Not overly engineered - just right.

[506DC]

I think airplanes have to be broken down into flyability, reliability, durability and crashabilty.

No question in my mind the Vans aircraft are the best flying aircraft ever made for the general aviation public. They are faster, more fun to fly and less expensive than just about any aircraft produced today. They are truly a total performance airplane. I never worry about density altitude period. I hope to never sell my RV but one day?

Designed both using approved aircraft engines and construction procedures; they are simpler than most GA aircraft and very reliable. I do not hesitate to take a long cross country trip in my RV-4

Durability not so much. They are designed light for the above reasons. I have a Cessna 170 that has 7000 hours on the airframe and it still looks good. I give tail dragger instruction on a fairy rough grass strip and have dropped it in many times with no side effects. I would not give instruction in my RV-4 because it?s not durable enough. The gear is weak compared to a Cessna. I owned a Bonanza. I would run and jump on the wing flap. Try that in an RV. I never once worried about damaging any part of the Bonanza. It was built like a tank. RV-4, not so much, I have replaced cracked control surfaces after only a few hundred hours. I always land like a feather because firewall damage can and will result otherwise. Cracks on the firewall are ?normal. ?Compared to Cessna or a Beechcraft, I can?t imagine what it would look like if not handled gently after 7000 hours.

Crashabilty not so much. Thin metal bends easily. Not much steal or reinforcements surrounding a RV driver. As the above contributor stated, I much rather be in a Cessna than an RV in case of a crash. A friend of mine crashed landed his Cessna 210 in a field and slid through a fence. They hauled it out of the field and he was flying it a year later. Another friend of mine landed his Bonanza on a sandy beach. The gear sunk in the sand and he traveled less than 50 feet with no damage to the gear or airframe. Try that in an RV.

In summary, if you want a pickup truck get a Cessna, if you want a super fast fun to drive vehicle get a sports car, motorcycle or RV.

[Capt]

Originally Posted by 506DC

I think airplanes have to be broken down into flyability, reliability, durability and crashabilty.

No question in my mind the Vans aircraft are the best flying aircraft ever made for the general aviation public. They are faster, more fun to fly and less expensive than just about any aircraft produced today. They are truly a total performance airplane. I never worry about density altitude period. I hope to never sell my RV but one day?

Designed both using approved aircraft engines and construction procedures; they are simpler than most GA aircraft and very reliable. I do not hesitate to take a long cross country trip in my RV-4

Durability not so much. They are designed light for the above reasons. I have a Cessna 170 that has 7000 hours on the airframe and it still looks good. I give tail dragger instruction on a fairy rough grass strip and have dropped it in many times with no side effects. I would not give instruction in my RV-4 because it’s not durable enough. The gear is weak compared to a Cessna. I owned a Bonanza. I would run and jump on the wing flap. Try that in an RV. I never once worried about damaging any part of the Bonanza. It was built like a tank. RV-4, not so much, I have replaced cracked control surfaces after only a few hundred hours. I always land like a feather because firewall damage can and will result otherwise. Cracks on the firewall are “normal. ”Compared to Cessna or a Beechcraft, I can’t imagine what it would look like if not handled gently after 7000 hours.

Crashabilty not so much. Thin metal bends easily. Not much steal or reinforcements surrounding a RV driver. As the above contributor stated, I much rather be in a Cessna than an RV in case of a crash. A friend of mine crashed landed his Cessna 210 in a field and slid through a fence. They hauled it out of the field and he was flying it a year later. Another friend of mine landed his Bonanza on a sandy beach. The gear sunk in the sand and he traveled less than 50 feet with no damage to the gear or airframe. Try that in an RV.

In summary, if you want a pickup truck get a Cessna, if you want a super fast fun to drive vehicle get a sports car, motorcycle or RV.

I like that, sums it all up nicely:-)

[jrs14855]

The round spring gear as designed by Steve Wittman is one of the strongest landing gears ever installed on a light airplane. The problem on the RV's is the fuselage area where the gear mounts. Having said that Rosie is approaching 5000 hours on the RV6 with no apparent problems.

[jrs14855]

If I were try to correct all the nonsense that has been posted here about Bonanza, Cessna etc, it would take a week. The Bonanza, Commanche, Lance and non strut braced 210's all have box spar wing center sections. The rest of the spars are channel sections or I section, NOT BOX SPARS.
The Bonanza main gear is very strong, the nose gear relatively fragile. Most single Cessna nose gears are fragile with the 182 having the worst record because of the weight on the nose. Piper is probably the best. If you do break a Piper nose gear it is by far the easiest repair of the three.
Of the first 1000 Bonanzas 100 crashed due to structural failures. Typically loss of control in IMC. Commanche is the safest in that regard.
The basic design of the Bonanza wing evolved to the outer wing panels of the Twin Bonanza, Queen Air and King Air. The basic Commanche wing evolved to the outer wing panels of the entire Cheyenne series.
I don't trust the structure of the Cessna 210. I don't like the wing attach design on the Beechcraft's except for the later model King Airs which are different.
To say that any of the above are built like a tank is absurd. Each has its own unique design features. Each has its own unique weaknesses.

[Waiex-guy]

Most, I?m probably not qualified to say all, tanks, they don?t seem to fly so good.