Experiences with VL3 SLSA?

[fatsportpilot]

I'm thinking about a VL3 aircraft. Does anyone here have any experiences with them especially for big guys going on long cross-country flights?

I called a rep and was told I could expect 150 KTAS with the 914 UL engine at 5500 RPM at 8000 MSL even with fixed pitch prop and fixed landing gears, which I think is even faster than what the Bristell can do. Of course if I got the 915 iS and a PPL to go with it, I could go 200+ KTAS.

Like the Bristell their operating instructions limit the RPM at sea level in order to comply with regulations (no more than 120 KCAS at sea level) but those restrictions are removed at altitude. The stall speed is the limiting factor and they said that if I opted to go with the shorter wing, I wouldn't be able to use a 915 iS and stay within LSA limits, but could still use the 914 UL.

[jetcat3]

I got to check out one of the 915 VL3 demo’s at Sun N’ Fun this year and drooled all over it. With that said, I highly doubt you’d see 150 knots true with just the 914 and fixed gear. With 130hp definitely.

The problem with the Experimental Exhibition VL3’s is that you need 250 hours of retract time to be insurable. I love the VL3, Blackwing, Risen, Stream, Shark, Terragon, Prime, but the US rules need to accommodate them in full before they’ll be able to have a real stronghold here.

[fatsportpilot]

I got to check out one of the 915 VL3 demo’s at Sun N’ Fun this year and drooled all over it. With that said, I highly doubt you’d see 150 knots true with just the 914 and fixed gear. With 130hp definitely.

The problem with the Experimental Exhibition VL3’s is that you need 250 hours of retract time to be insurable. I love the VL3, Blackwing, Risen, Stream, Shark, Terragon, Prime, but the US rules need to accommodate them in full before they’ll be able to have a real stronghold here.

I'm looking at the SLSA not the experimental exhibition ones. The 135hp of the 915 also means the weight is so high that I'd need to use the longer wing to remain within LSA stall limits, which means speed goes down again.

[Mikey B]

Like the Bristell their operating instructions limit the RPM at sea level in order to comply with regulations (no more than 120 KCAS at sea level) but those restrictions are removed at altitude.

Is that really how it works? Granted I'm a newbie, but that's not how I read the regs, e.g. "A maximum airspeed in level flight with maximum
continuous power (VH) of not more than 120 knots CAS under standard atmospheric conditions at sea level." I wouldn't interpret that as meaning as soon as you leave sea level, you can go as fast as you want. Am I missing something?

[Warmi]

Like the Bristell their operating instructions limit the RPM at sea level in order to comply with regulations (no more than 120 KCAS at sea level) but those restrictions are removed at altitude.

Is that really how it works? Granted I'm a newbie, but that's not how I read the regs, e.g. "A maximum airspeed in level flight with maximum
continuous power (VH) of not more than 120 knots CAS under standard atmospheric conditions at sea level." I wouldn't interpret that as meaning as soon as you leave sea level, you can go as fast as you want. Am I missing something?

Well I would read it exactly that way ..and keep in mind that you won’t gain all that much going to higher altitude ( 10k in this case ) so it is not like somebody can boost their speed to 180 knots at 10 k while maintaining 120 under standard atmospheric conditions at sea level.

[JimParker256]

Is that really how it works? Granted I'm a newbie, but that's not how I read the regs, e.g. "A maximum airspeed in level flight with maximum
continuous power (VH) of not more than 120 knots CAS under standard atmospheric conditions at sea level." I wouldn't interpret that as meaning as soon as you leave sea level, you can go as fast as you want. Am I missing something?

Well, what you're "missing" is that few engines make "rated" power at 9,500 ft, so if you're derating a large engine (like the 180+ HP engine that Carbon Cub uses in their airplanes) to 80 or 100 HP at "sea level", but can maintain that same HP all the way to 10,000 ft MSL (max for LSA), the combination of reduced drag and full HP at altitude makes a fairly large difference.

The little Sonex experimental, for example, cruises at about 130 mph at sea level (STD ISA conditions), so is "legal" as an LSA, but can often make 145-150 mph (or even better) at 7-8 thousand feet. The "turbo" model does even better than that.

There are now quite a few LSA flying that meet the rules for max cruise of ≤ 120 knots at sea-level using max continuous cruise power, but that will fly considerably faster at slightly higher altitudes, or if you exceed max "continuous" cruise power. I even heard one company jokingly refer to their "max continuous" power rating as a "4-hour" time limit. (Said airplane had a four-hour fuel endurance.)

Thus far, the FAA has gone along with those manufacturers (Carbon Cub, RANS, Sonex, and several others).

Personally, my E-LSA cruises at 105-100 mph (not knots), with a "max continuous power" cruise speed of 110 mph. No doubt that I'm "legal"... Slow, but legal...

[fatsportpilot]

Exactly. The VL3 and other aircraft like Bristell have a notice on the firewall saying do not exceed 120 knots at sea level / do not exceed 4800 RPM at sea level or something similar to that. It's legal but because of stall speed limits you can't have both a heavy engine and low drag wings so the practical speed is not really unlimited. If you could put a 300 hp engine in a lightweight LSA then you could set a limit saying no more than 100 hp at sea level and then cruise at 200 knots at even 500 MSL but what prevents that isn't that it's illegal to go that fast (as long as max continuous is no more than 100 hp) but that any engine of that power would weigh too much.

[FastEddieB]

The 135hp of the 915 also means the weight is so high that I'd need to use the longer wing to remain within LSA stall limits, which means speed goes down again.

I thought longer wings meant less drag, all thing being equal. Is that not right?

[Warmi]

The 135hp of the 915 also means the weight is so high that I'd need to use the longer wing to remain within LSA stall limits, which means speed goes down again.

I thought longer wings meant less drag, all thing being equal. Is that not right?

Induced vs parasitic drag - parasitic drag is lower with shorter wings and it tends to increase with airspeed.
In other words, slower planes benefit more from lower induced drag while faster planes benefit more from lower parasitic drag.

[fatsportpilot]

The wings are only a few inches longer I think. I bet if they reduced the MTOW for the SLSA model a little below 1320 then it would meet the clean stall speed requirements.

[fatsportpilot]

I took a demo flight in a VL3 with retracts and a 915 engine recently.

It was too tight for a big guy like me but I talked with the factory through the US rep and they said they could customize the interior and remove the center tunnel to vastly improve legroom, and move the seats a little closer to the center. I'll probably be going to the factory in Prague some time next year so they can fit me and customize it for my size. Maybe after the MOSAIC NPRM comes out though.

Wonderful airplane other than the stock interior! Even the fixed gear SLSA version can go 165 KTAS at only 10,000 MSL! The retract one I flew in recently made >180 KTAS at 7,000 MSL and that was with 10 degrees of flaps (electric flaps got stuck there and we didn't know about it till we were back on the ground. Thank God they didn't get stuck at 50 degrees or they would have ripped right off).

[Ergo1]

I'm thinking about a VL3 aircraft. Does anyone here have any experiences with them especially for big guys going on long cross-country flights?

I called a rep and was told I could expect 150 KTAS with the 914 UL engine at 5500 RPM at 8000 MSL even with fixed pitch prop and fixed landing gears, which I think is even faster than what the Bristell can do. Of course if I got the 915 iS and a PPL to go with it, I could go 200+ KTAS.

Like the Bristell their operating instructions limit the RPM at sea level in order to comply with regulations (no more than 120 KCAS at sea level) but those restrictions are removed at altitude. The stall speed is the limiting factor and they said that if I opted to go with the shorter wing, I wouldn't be able to use a 915 iS and stay within LSA limits, but could still use the 914 UL
———————————- ———————————————————————————————————————-

Hi
I have a number of hours in the plane with the 100HP engine. With retractable gear and a constant speed prop, we saw about 135 knots TAS in hot summer weather, low altitude. The plane is narrow for two guys; you will be bumping shoulders.
The plane was a blast to fly and handled like a sports car. I went to the Czech Republic factory in hopes of purchasing one. Given the current FAA regulations, it’s almost impossible to get the plane into the US. You must build it as an experimental aircraft and then try to get it signed off in the US. I believe the insurance alone makes the cost of ownership prohibitive. Al least this was the case 4 years ago.

[fatsportpilot]

Hi
I have a number of hours in the plane with the 100HP engine. With retractable gear and a constant speed prop, we saw about 135 knots TAS in hot summer weather, low altitude. The plane is narrow for two guys; you will be bumping shoulders.
The plane was a blast to fly and handled like a sports car. I went to the Czech Republic factory in hopes of purchasing one. Given the current FAA regulations, it’s almost impossible to get the plane into the US. You must build it as an experimental aircraft and then try to get it signed off in the US. I believe the insurance alone makes the cost of ownership prohibitive. Al least this was the case 4 years ago.

Did you do any longer x/c in the plane? Was it comfortable for that purpose?

It doesn't seem too narrow. Not as wide as the Bristell but not much more narrow. About the same as an Evektor SportStar which isn't too bad.

I talked with the factory and they're selling it as SLSA now to the US so it won't have retracts or a constant speed prop but with the bigger engine it should be faster than an SR20 (with retracts and constant speed prop it'll be even faster than an SR22!).

[Ergo1]

I think you’ll find it tight for X/C flights depending on the size and weight of the occupants - two guys 200 lbs each will be cramped. One other thing, check the storage area behind the front seats, I remember limited storage space. I’d also check weight limitations in the storage area.
Good Luck!