• Hi Guest! Forum rules have been updated. All users please read here.

Two Small Helicopters to ID

hesham

CLEARANCE: Above Top Secret
Joined
May 26, 2006
Messages
26,321
Reaction score
3,225
From Krila 1-2/1957,

I can't ID this two helicopters,the first was familiar,and they mentioned the world krakov,is that
mean Kharkov ?,who can help ?.
 

Attachments

flateric

CLEARANCE: Above Top Secret
Staff member
Top Contributor
Senior Member
Joined
Apr 2, 2006
Messages
9,000
Reaction score
787
Why for the God's sake you can't use Google translator knowing that you are reading magazine in Slovenian language?
 

Attachments

hesham

CLEARANCE: Above Top Secret
Joined
May 26, 2006
Messages
26,321
Reaction score
3,225
OK my dear Flateric,

I used the google translate,but you know it's not precisely perfect,so I check only.
 

walter

CLEARANCE: Secret
Joined
Jan 31, 2008
Messages
376
Reaction score
100
Hi Hesham!
I think the twin-fin heli is German. I have it as the Fluro-Schliesske Libelle. Attached a photo and some info.
Fluro apparently stood for Flugroller and free translated this could be described as roadable flyer.
Story goes that the project was fraudulous and that the designer attracted quite some money from investors, without performing and reportedly he went to prison for that.
Whether the Libelle ever flew? Depends on who you want to believe.
Some info:
2-seat (single-seat?) helicopter
three Schmidt-Argus pulse jets
estimated cruise 100+ mph
main rotor diameter 24.278ft; fuselage length 14.763ft; height
DETAILS: The Libelle experimental helicopter was a homebuilt project designed and built by Mr. Walter Schlieske and Fluro was synonym for Flugroller. The aircraft appeared during the mid-1950s, but possibly not flown, although other sources claimed that the aircraft actually did. Only a single example was built.
Production: 1
Construction said to be mainly steel tube and bamboo(?) and powerplan(s) were described as either pulsejets or a 100cc two-stroke engine.
 

Attachments

walter

CLEARANCE: Secret
Joined
Jan 31, 2008
Messages
376
Reaction score
100
Hi Hesham!
Your other heli is the Bensen B-4 Skyscooter (registration N3762C). I always though it was a single-seater. Maybe your photo is somewhat confusing. View the 40hp engine, a 2-seater seems unlikely.
Some details:
single-seat helicopter (2-seat?)
one 40-42hp Nelson H-59 two-stroke piston engine
max. speed 70 mph, cruise 55 mph, icr 750ft/minute, range 118 miles
main rotor diameter 26.167ft; length 11.975ft; height 7.972ft
DETAILS: The B-4 Sky Scooter was Mr. Igor Bensen's second helicopter design and it was intended as inexpensive and simple helicopter for private use. The B-4 featured a unusual rotor and drive system with a small propeller installed in leading-edges of the two rotor blades and driven by one 40-42hp Nelson H-59 engine (installed centrally on the rotor hub) through a belt system. Only a prototype was constructed by the Bensen Aircraft Corporation and this aircraft first flew during 1955. Only limited testing took place and further work on the B-4 was halted.
Production: 1
 

Attachments

Stingray

Resident retro rainbow rotorhead nerdy girl, uwu
Senior Member
Joined
Nov 30, 2007
Messages
413
Reaction score
79
Website
sites.google.com
Regarding the Bensen B-4: It's interesting seeing a design like this from that particular time period (and from Bensen), using propellers to drive the rotors, while others were experimenting with ramjets. Seems rather archaic but also less expensive, which I suppose was the point. Other designs I've seen using this drive method dated back to 20s and 30s, like the Curtiss-Bleecker SX-5-1, Isaaco Helicogyre, and the Hellesen-Kahn machine which used two whole plane fuselages instead of blades (lol), just to name a few. There was also the Czech Maier helicopter, but I'm not sure when that was made (probably late-40s). I realize that there are some more contemporary examples that use this method too, but are mostly homebuilt garage projects.

In the case of Bensen's design it was referred to as the HEPARS drive system (High Efficiency Propulsion and Rotor System). I found claims that the development has General Electric / US Navy program roots, but I can't seem to verify this. Help please?

The purpose of the design was to consume less power than that of a conventional helicopter, as the belt system between the props and hub and lack of torque-balance was supposed to reduce mechanical complexity and required hp from the main powerplant, and to save weight (since no tail rotor was required).
 

Stingray

Resident retro rainbow rotorhead nerdy girl, uwu
Senior Member
Joined
Nov 30, 2007
Messages
413
Reaction score
79
Website
sites.google.com
Fluro was synonym for Flugroller
Not only that, but a shortened variation of "FLUR-Flugroller and Hubschrauber Entwicklung" (FLUR Flying Scooter and Helicopter Development), which was the name of Walter Schlieske's fraudulent company that he "founded" in Minden, Germany to build this machine.

I also find this one listed as "Libelle III". Since only one of these was built, I assume the name itself is also part of the facade, to delude one to believe other types were developed before it (by what would seem like a legitimate company with real projects).

EDIT: I looked more into it, and you can see in one of the pictures that "Libelle 2" is marked on the tailboom. The design seems to vary a bit in its evolution, first shown publicly with a bare airframe, so perhaps the name just denotes what stage of development it was in rather than being part of the fraud. Not sure.
 
Last edited:
Top