[dtaylor]

Wow -- long thread!

As a Legacy flyer let me add that the Legacy is an absolute blast to fly. But, its a different kind of flying. If you've never flown in one it's hard to describe. I do all the aerobatics that the RVs do. (Loops require a high skill level, and we never spin our Legacies however.)

I can get in an out of 2000 foot strips with ease, (I only need about 1400 feet.) Although I will only take it onto smooth grass. RVs can go into much rougher grass than i will go to, so that is one drawback of the Legacy.

My big IO-550 engine can be operated just as efficiently as a 360 -- I get SFC's of .37 at low power settings.

Dave T
Legacy RG

 

[dhammer]

Hard to be sure but aren't the Blanik L23 and L33 aluminum gliders still in production?

Right you are - in the Czech Republic by LET. They are fairly popular for training and with clubs. The Air Force Academy still uses L-23's, I believe to train all new cadets.

I think the L-33 has an L/D of about 33 and the L-23 is 32 which is about 10 points less than a glass standard class or 20 or more lower than a glass open class. A comparable and more popular glass trainer is the Grob G103 with an L/D of 37 or so. I guess I should have said modern competitive sailplanes

I had to repair an L-23 one time that had the tail wheel knocked out and bent the tail cone structure from a PIO induced hard landing. I estimate it took at least 30 to 40 M/H after waiting three weeks for parts from the factory. The final repair showed where I had to splice in un-bent skin,new tail wheel bracket, bulkhead, etc. The tail cone was wrinkled forward about 3 feet. I was trading work for tows.

I did a similar repair that included damage to the rudder bottom and tail wheel structure to a G103 and it was back in service in about a day and a half with repairs that were totally invisible using standard resin, cloth, and gelcoat that I had on the shelf. I repaired another G103 that smashed down, also because of PIO, that drove the main wheel and brake assembly flush with the belly. That was a full 2 day job.

Incidentally, all three of these were damaged by airline pilots at an operation that trained many pilots from age 14 and up. Figure that one out.

Don

 

[gmcjetpilot]

Doha!

First, square, not square root

First, square, not square root

Facts? You want facts? My 125 HP Lancair cruises at 197 mph TAS at 5.7 gph at 14,500 dalt; that's 34.5 mpg. It stalls at 63 mph; (63/55)^2=131% more energy, not 233%! Great economy, great looks! But I like RVs, too. I design props for them! They're great planes! But, please, tell it like it truly is!

Don't tell any one I have a masters in engineering they'll take my degree. Thanks you are right.

A 125hp lancair cruses at 195 mph? OK. Stall at 63 mph? Really. That's a fantastic airplane and numbers; I stand corrected you have the best plane efficiency wise. Lancair is very clean no doubt.

Not to get into an arugment but the RV-9 stalls at 44 mph and an RV-7 at 51 mph so to the math: (63/51)^2=1.53. If comparing to a 125hp RV9 it would be (63/44)^2=2.05.

You should compete in the CAFE test by Cafe Foundation. As you might know it's a formula based on max speed, min speed and time to climb. It's not a fly off. They instrument the plane, record data, reduce the numbers to a CAFE number. The current winner is a RV-4, second (and not close) is a Rocket. Of course the RV-4 is Dave Anders and its not stock or typical.

No offense to any string and glue flyers. Its all good, just different strokes.

 

[elippse]

A 125hp lancair cruses at 195 mph? OK. Stall at 63 mph? Really. That's a fantastic airplane and numbers; I stand corrected you have the best plane efficiency wise. Lancair is very clean no doubt.

That's 197 mph TAS at 14,500' dalt, 2760 rpm. Down low I get 213-214 mph TAS at 2950 rpm, 1000' dalt. Rated rpm on this 9.7:1 O-235 is 2800. I have a closed cooling system with exhaust augmentation in specially designed exhaust nozzles immediately below each cylinder. I also have extended wingtips which give me an AR of 8.05, and I have my ELIPPSE high-efficiency three-blade prop. Along with this is my dual LSE Plasma I EI. My plane is still in primer on the fuselage and inner wing and Klaus tells me that with some smooth paint I'd probably pick up 2-4 mph! I know Dave and there's no way I could compete with his ship! My plane is written up in Contact! magazine #77.

 

[Alan Carroll]

CAFE reports

The OP should look at the CAFE Aircraft Performance Reports for what is probably the most objective information available: http://cafefoundation.org/v2/research_aprs.php

Probably the most appropriate comparison is the RV-6A vs. Lancair 320 tests. Here's quick summary of the numbers:

RV-6A (180 hp). Vso 52.1 mph, max cruise at 7079' DA 199.7 mph on 12.2 gph. Wing loading 15 lbs/ft^2.

Lacair 320 (170 hp). Vso 71.1 mph, max cruise at 5875' DA 233 mph on 11.8 gph. Wing loading 22.17 lbs/ft^2.

The Lancair was 17% faster in cruise, but 36% faster at stall. The ratio of cruise/stall was 3.2 for the Lancair, 3.8 for the RV.

The significantly higher wing loading of the Lancair appears to account for a much of the speed difference, and presumably gives a smoother ride in turbulence (not a strong point of the RVs). It also means longer runway requirements and a lot more energy in a crash.

The great thing about these tests were that they were done with calibrated instrumentation and professional test pilots, using uniform procedures. They also addressed a variety of non-performance aspects (stability, comfort, etc).

 

[ShannonEvans]

Good Info

Guy's

I have really appriciated your comments. Just to keep things on track. In considering a Lancair it would be a 235 or 320/360. Likely the 320. I will try to work a ride in a local 235 I know of (IF THE WIND EVER STOPS BLOWING OUT HERE). The RV's of interest would be 180hp 6a or 160hp 9a. The 2300 grass strip I sometimes fly my Super III into is kept up by a local ag pilot so I may not even want the RV in there. I have other options.. Also, I realize that I am low time & have little HP/CPLX time, but my cross counties will be vfr. I have not checked insurance rates (not that far along), but I know what they want for insurance if I bought a V35 bonanza with similar or more hull value. I do not intend to do arobatics. Most flights will be just me.

Thanks for your imput, with all the RV ers in my area they would be the easy choice, BUT THOSE LANCAIRS LOOK GREAT. As far at takeoff distance I assume it would be similar to my hanger mates Columbia 350. Thing burns alot of runway. Way more than the 6a did he traded for it.

Shannon Evans
N5650S

 

[osxuser]

Guy's

I have really appriciated your comments. Just to keep things on track. In considering a Lancair it would be a 235 or 320/360. Likely the 320. I will try to work a ride in a local 235 I know of (IF THE WIND EVER STOPS BLOWING OUT HERE). The RV's of interest would be 180hp 6a or 160hp 9a. The 2300 grass strip I sometimes fly my Super III into is kept up by a local ag pilot so I may not even want the RV in there. I have other options.. Also, I realize that I am low time & have little HP/CPLX time, but my cross counties will be vfr. I have not checked insurance rates (not that far along), but I know what they want for insurance if I bought a V35 bonanza with similar or more hull value. I do not intend to do arobatics. Most flights will be just me.

Thanks for your imput, with all the RV ers in my area they would be the easy choice, BUT THOSE LANCAIRS LOOK GREAT. As far at takeoff distance I assume it would be similar to my hanger mates Columbia 350. Thing burns alot of runway. Way more than the 6a did he traded for it.

Shannon Evans
N5650S

FWIW, I've got about 10 hours in N5696S (I'm assuming it's 46 airplanes after yours) also a Super Musketeer (200hp, FP prop). Awesome airplane, only true four seat 4 cylinder i've flown besides the Cardinal, but it beats out even that. That'll be a hard transition to a Lancair, but the RV would be much easier. Now let me pitch you the taildragger instead of the 6a...

 

[Piloto.Mendes]

War in progress!!!

I don't think it is important to discuss where you are supposed to crash better. I'm not planning to fall. In any case, your crash site depends on lots of circunstances. If you fall, you're in trouble, it doesn't matter if you're ina a jumbo jet, a can or a glass...

My chose: RV! Why? Cost-benefit.

It is correct that Lancair has a lot better fuel mileage, but airplane cost difference is enough to buy some thousands gal of gas.

Now I'm plannig to build the -12 to just getting started

 

[Rocketboy]

War in progress!!!

I don't think it is important to discuss where you are supposed to crash better. I'm not planning to fall. In any case, your crash site depends on lots of circunstances. If you fall, you're in trouble, it doesn't matter if you're ina a jumbo jet, a can or a glass...

Your are correct about being in trouble, but by using good judgment, careful planning and discipline, a pilot will find himself in MUCH less trouble when it happens. (IT WILL HAPPEN! ARE YOU READY?)

Regards,

Bob

 

[mikegraycmg]

choice

I flew in a Lancair 360 awhile back, and I absolutely loved it. I loved the looks, the speed, the handling in the air, and everything about it. I went with an RV8 when it came time to build, however, for several reasons.

First, the kit is much more well established and probably alot easier to build. I know that's not one of your considerations, but it was for me.

Second, there are a lot of issues with the Lancair 320/360 about the tail, flutter, and lowspeed handling. Some people think it's a big deal and others don't. Nobody really knows, but you might want to make sure you get one built with the larger Mark II tail.

I think there is no dispute, however, that the RV is much easier to fly and especially to land. The Lancair's speed comes with a penalty, and the Lancair is definitely not easy. If you buy one, invest in some really good training. That's my 2 cents worth.

 

[Bevan]

basic math error

[QUOTE Facts? You want facts? My 125 HP Lancair cruises at 197 mph TAS at 5.7 gph at 14,500 dalt; that's 34.5 mpg. It stalls at 63 mph; (63/55)^2=131% more energy, not 233%! QUOTE]

I believe the energy difference between 63 and 55 mph is 31%, not 131%. I'm sure that's what you meant to say but if a less technical reader took your words literally, it's grossly misleading.

Correct me please if I'm wrong.

Bevan

 

[Steve Brown]

It's not about energy anyway - its deceleration

I hate to nitpick, but the difference between the two has a very important influence on whether you live or die.

a = 1/2 * V^2 / d
a: acceleration (deceleration in our case)
d: distance (that you decelerate over)

(someone check my math)

I pretty sure it's G forces that break the body and turn the airplane into mush.

It is still V^2 function, so velocity is a concern, but the d term, to a large degree, is under pilot control. The decision to go between two large trees (tearing the wings off) rather than into one of them dramatically increases d. This effect is much more dramatic than the small V^2 differences between RV & Lancair. Which, after the facts were corrected, are about equivalent to the difference between and RV9 & RV7.

An RV pilot who gives up and hits the tree will likely be dead, while the Lancair pilot who keeps flying till the airplane stops moving, going between the trees, will likely live to tell a wild tale.

Increasing d from 5 feet to 20 feet cuts the deceleration force by a factor of 4. "Land" the plane and take your punishment from the softest obstacles possible, or panic and stall out at 100 AGL. Hit a wall, or hit some bushes. Those are life or death decisions.

Back to V^2. The decision to hit the bushes at 50 kts rather than 71kts will reduce deceleration forces by a factor of two. The Lancair pilot who understands how to fly his airplane slow will fare much better than the RV pilot who is afraid to slow down.

Bottom line:
The decision between a lancair and an RV will have much less influence on whether you live or die if the engine quits, than the flying decisions you make after it quits.

Also,
From Alan Carroll: Its harder to do this because of the way the registration data are reported (would require a bit of a research project). However, I looked at the fatal vs. total accident ratios, and by this measure Mooney's and Skylanes are about the same (21% vs. 18%).

Alan,
Your statistic makes my point exactly. Your statistical probability of dying in a particular airplane relates to the fatals per hours flown. That is in the 2x to 3x range, Mooney's verses Skylanes. It includes many factors. Mission profile is a huge one that one pilot already referred to, then complexity, pilot profiles, etc.
What your quoted ratio shows, however, is that once you crash the difference in stall speeds has comparatively little influence on whether you live or die.

 

[elippse]

[QUOTE Facts? You want facts? My 125 HP Lancair cruises at 197 mph TAS at 5.7 gph at 14,500 dalt; that's 34.5 mpg. It stalls at 63 mph; (63/55)^2=131% more energy, not 233%! QUOTE]

I believe the energy difference between 63 and 55 mph is 31%, not 131%. I'm sure that's what you meant to say but if a less technical reader took your words literally, it's grossly misleading.

Correct me please if I'm wrong.

Bevan

Percentage is 100 times the decimal value. 63 is 1.31 times 55, so 100 times 1.31 is 131%. 31% is the difference between 55 and 63! OK? You now stand corrected!

 

[elippse]

Speaking of comparing stall speeds, when you get down to the basics of the math, the stall speed will be propertional to the square-root of the wing loading. Jim Smith's RV-6 weighs 1440 lbs when he does my tests, and my plane weighs 1350 lb. His has 110 sq. ft, and mine has 77. his wing-loading is 13.09 lb / sq.ft. and mine is 17.53. That means mine stalls 15.7% faster, and will have 33.9% more energy to get rid of in a crash. So if mine stalls at 63 mph, then his stalls at around 54.4 mph!

 

[elippse]

As I understand it, Dave Anders was allowed 17" MAP for his slow flight, which he did at 3000 rpm. That's a lot of power which is directed upward, allowing flight at a speed much below stall-speed. Another tidbit: Because of the low 4.8:1 AR of an RV-6, the 3-point attitude of its landing gear does not supply a sufficient AOA to achieve stall in that attitude; to do a full-stall landing would require the tail-wheel to hit first!

 

[Alan Carroll]

Alan,
Your statistic makes my point exactly. Your statistical probability of dying in a particular airplane relates to the fatals per hours flown. That is in the 2x to 3x range, Mooney's verses Skylanes. It includes many factors. Mission profile is a huge one that one pilot already referred to, then complexity, pilot profiles, etc.
What your quoted ratio shows, however, is that once you crash the difference in stall speeds has comparatively little influence on whether you live or die.

Steve,

I think we agree that there are tradeoffs involved in choosing between different airplanes, and each person gets to choose what they want (or not to fly at all). Its important though that they also fully understand the risks that come with this choice. Higher stall speed means more risk, all other factors being the same. This isn't to say that a Lancair can't be safely landed following an engine failure, but the same pilot flying an RV toward the same trees is going to have a higher probability of survival. If a Lancair pilot knows this and decides that the added risk is acceptable, then there's no problem.

I'm not sure the Mooney vs. Skylane comparison completely works, because the difference in stall speed is a lot less than the for the Lancair vs. RV (based on CAFE data).

 

[breister]

I flew in a Lancair 360 awhile back, and I absolutely loved it. I loved the looks, the speed, the handling in the air, and everything about it. I went with an RV8 when it came time to build, however, for several reasons.

First, the kit is much more well established and probably alot easier to build. I know that's not one of your considerations, but it was for me.

Second, there are a lot of issues with the Lancair 320/360 about the tail, flutter, and lowspeed handling. Some people think it's a big deal and others don't. Nobody really knows, but you might want to make sure you get one built with the larger Mark II tail.

The most famous article is here, and that suggests that THEORETICALLY there might be a flutter consideration with the LARGE tail.

There has never been a flutter-related incident in any of the homebuilt Lancairs, certainly not in the 235. The 360's have been turbocharged and flown at 25,000' close to Vne INDICATED (much higher than TRUE, which is the factory specified limit on the RVs) without any problems.

This should not be a deciding factor, as it is really into the realm of "myth."

 

[Steve Brown]

Understanding, choosing, & managing risk

Steve,

I think we agree that there are tradeoffs involved in choosing between different airplanes, and each person gets to choose what they want (or not to fly at all). Its important though that they also fully understand the risks that come with this choice......

Alan,

We do agree on that.

I get fired up on threads like this one because of the important difference between "Too dangerous for me" and "too dangerous to do" seems to get lost in the noise. (not saying by you)

By the way, I checked VSO on the skylane and a Mooney:
Skylane: 36kts ---> 41.4 mph
Mooney M20R: 59kts ---> 67.9mph
Mooney 64% higher, which is greater than the ratio you quoted for RV and Lancair. Earlier mooney's had lower stall speeds. I checked the poh on a vintage Mooney and the ratio over the skylane was 36%, exactly the same as the RV & lancair.

 

[dhammer]

We're all going to die sometime

I guess if you follow the stall speed logic we should all park our RV-9's etc and build Cub replicas. GEESH!!!

The Arrow I rent stalls at 64mph, a Glassair SII RG with slotted flaps at 63 mph, and a 300 HP Lancair Legacy at 65 mph. SO WHAT??? If everyone is so worried about their butt then they need to be riding on an American Airlines 777 and not an experimental anything. God forbid you'd get on a Harley.

 

[elippse]

Apology to Bevan. When I went back and looked at the response I made to you, "You now stand corrected", I realized that it sounded sort of snotty! Believe me, I meant it in a humorous manner; I should have put a "smiley face" with it. If you knew me you would see that I have a somewhat acerb or biting humor, which comes across better in person than in writing. I apologise! And I stand corrected!

 

[Bill Wightman]

Quoted by Ellipse

63 is 1.31 times 55

My HP48 says:

1.31 x 55 = 72.05

Better replace your calculator batteries...

 

[n5lp]

By the way, I checked VSO on the skylane and a Mooney:
Skylane: 36kts ---> 41.4 mph
Mooney M20R: 59kts ---> 67.9mph
Mooney 64% higher, which is greater than the ratio you quoted for RV and Lancair. Earlier mooney's had lower stall speeds. I checked the poh on a vintage Mooney and the ratio over the skylane was 36%, exactly the same as the RV & lancair.

I suppose by referring to VSO you mean an indicated speed but indicated speeds aren't meaningful for the math. I don't know what model 182 you have the POH for but I have one for the 182P. It lists stall speed at full flaps and 0 bank as 50 KCAS. The worst case at 0 bank is with flaps up and most forward CG of 59 KCAS.

I have noticed that things like approach speeds are very similar in my RV-6 and the Cessna 182s I used to fly. I just looked up the stall speed of the RV-6 at the Van's site and they list it as 47 knots, real close to the 182. Pretty good company for a nice safe slow landing speed. That slow landing speed was a BIG reason for me to choose the RV.

 

[elippse]

Quoted by Ellipse



My HP48 says:

1.31 x 55 = 72.05

Better replace your calculator batteries...

Another Brain F**t! I didn't go back to check where the 1.31 came from, but it was from the square of 63/55. Apologys again! BTW, Bill; aren't you the lucky one to still have an operating HP48. I have one, too, a 48GX! But I also have an HP45, so there! 'Want to have a 45 vs 48 discussion, like the RV-Lancair thingy?