One of the Erskine Park regulars with his VW homebuilt gyro Gyrocopter Gyroplane mid 1990s

[okikuma]

One of the Erskine Park regulars with his VW homebuilt gyro Gyrocopter Gyroplane mid 1990s

 

[Doug Riley]

That throaty VW sound brings back memories.

I wonder about the adequacy of the yaw control with that relatively flat V-tail dihedral and modest tail-surface area. Especially engine-out.

Of course VWs never quit on you...

 

[MikeBoyette]

That throaty VW sound brings back memories.

I wonder about the adequacy of the yaw control with that relatively flat V-tail dihedral and modest tail-surface area. Especially engine-out.

Of course VWs never quit on you...

Until the crank shaft snaps at the prop

 

[Doug Riley]

Mine never did that, Mike (though it was a worry; I used to read that SRC newsletter!).

It burned out big-end bearings pretty often, though. The "unreliable" 2-stroke Rotaxes turned out in fact to be a helluva lot more reliable than my homebrewed VW conversion.

 

[MikeBoyette]

Mine never did that, Mike (though it was a worry; I used to read that SRC newsletter!).

It burned out big-end bearings pretty often, though. The "unreliable" 2-stroke Rotaxes turned out in fact to be a helluva lot more reliable than my homebrewed VW conversion.

Well Chuck and others chose to machine the case out for a thrust bearing because it happened so much. I believe revmaster does this too. If I remember correctly Chuck also put his prop on the accessory end of the engine. There was enough aluminum in that area of the case for the thrust bearing there. I’m a little fuzzy on that so I could be wrong. The thing I didn’t like was the guys turning those Troyer and Tennessee props over 4000 pushing the Tips supersonic. It made Volkswagens and Subarus louder than a Mac.

 

[Doug Riley]

For sure, Mike, the VW was ear-splitting, especially when flown with the usual short straight pipes.

Revmaster's #3-4 + thrust combo bearing mod is state-of-the-art. It's also extensive and therefore expensive.

Bensen's VW conversion plans point out that the machined recess at the clutch end of the engine is a perfect fit for the OD of a standard bearing. But a clutch-end PTO conversion is considerable work as well; you must make a hub with 4 precisely-located pin holes to match the drive pin pattern on the crank, add a seal and housing, and come up with a mount frame that's strong enough. That last bit is tough, as there are no large, sturdy bosses on the fan-shaft end of the case -- which is the end that becomes the "firewall" end if you put the prop on the clutch end.

I made a clutch-end hub setup of this type, but ran out of money (temporarily, thanks) and never flew it. By then, the Rotaxes had appeared. Home-brewing engine conversions became an exercise similar to growing cotton, ginning and spinning it, and weaving your own T-shirts. I discovered that I'd rather buy a Rotax in a box, bolt it on and go flyin.'

 

[okikuma]

For sure, Mike, the VW was ear-splitting, especially when flown with the usual short straight pipes.

Revmaster's #3-4 + thrust combo bearing mod is state-of-the-art. It's also extensive and therefore expensive.

Bensen's VW conversion plans point out that the machined recess at the clutch end of the engine is a perfect fit for the OD of a standard bearing. But a clutch-end PTO conversion is considerable work as well; you must make a hub with 4 precisely-located pin holes to match the drive pin pattern on the crank, add a seal and housing, and come up with a mount frame that's strong enough. That last bit is tough, as there are no large, sturdy bosses on the fan-shaft end of the case -- which is the end that becomes the "firewall" end if you put the prop on the clutch end.

I made a clutch-end hub setup of this type, but ran out of money (temporarily, thanks) and never flew it. By then, the Rotaxes had appeared. Home-brewing engine conversions became an exercise similar to growing cotton, ginning and spinning it, and weaving your own T-shirts. I discovered that I'd rather buy a Rotax in a box, bolt it on and go flyin.'

Similar to this Doug?



Monnett had these prop drives (not a redrive) mounted at the flywheel end of the engine for the early sonerai racers.


Limbach has been successful with their series of VW based aero engines.



American Blimp Corporation power their A-60 Blimps with two Limbach VW based engines.


Wayne

 

[Mayfield]

Wayne,

I've never flown a VW engine. The only engine of this type I've worked on has been the Type 4 in my 914.

What is that crossover tube on the intakes? Does the Limbach use a bed mount?

How much horsepower can these engines reliably produce?

Jim

 

[WaspAir]

I flew Limbach powered motorgliders in the 1980s that were about 80 hp as I recall, with a 90hp option.

 

[Mayfield]

I flew Limbach powered motorgliders in the 1980s that were about 80 hp as I recall, with a 90hp option.

Thanks JR. They look relatively compact. About 200 pounds dry perhaps.

 

[okikuma]

Wayne,

I've never flown a VW engine. The only engine of this type I've worked on has been the Type 4 in my 914.

What is that crossover tube on the intakes? Does the Limbach use a bed mount?

How much horsepower can these engines reliably produce?

Jim

Hello Jim,

First, I don't know why the crossover tube is attached to each intake manifold. I'm guessing perhaps to prevent the possibility of "backfire" through the carbs. Exactly which model of Limbach engine the A-60 Blimps use, I don't know either. American Blimp Corporation did list each Limbach engine as 80 hp (59.680 kW) so it has to be at least one version or perhaps a special version of the following.

Wayne

Aircraft engines from 56 kW to 75 kW. Fuel-efficient powerhouses

limflug.de

 

[okikuma]

I flew Limbach powered motorgliders in the 1980s that were about 80 hp as I recall, with a 90hp option.

JR,

In my teens I was able to fly Fournier RF-4D. It had a 1200 cc 40 hp VW engine that I think was built by Limbach. It was fun to fly.

Internet photo, not me flying.

Wayne

 

[WaspAir]

Cool! I think I knew that as a "Sperber" in a different iteration, RF-5b. One of the ships I flew was the Valentin Taifun 17E. I'll grab an internet photo of it.

 

[okikuma]

Cool! I think I knew that as a "Sperber" in a different iteration, RF-5b. One of the ships I flew was the Valentin Taifun 17E. I'll grab an internet photo of it.

View attachment 1157332

About 10 - 15 yrs ago at Torrance Airport. I recall a CFI-G was using a Taifun 17E for add on Glider ratings. The motor glider had a full panel similar to the one below.



Conceivably, one with an ASEL Instrument rating and Glider rating with self launch enforcement could legally fly the Tailfun IFR with an instrument panel that meets FAR 91.205.

Wayne

 

[WaspAir]

Before competition rules were changed, people used to thermal up through cloud base. You can still do it under FAA rules as you suggest, but the international sanctioning body FAI/IGC doesn't permit it for racing anymore.

I don't need the self launch endorsement because I am grandfathered in from the motorglider flying I did prior to 1997. I had to take a full-blown FAA checkride (not just a CFI endorsement) back in the 80s to get winch launch privileges (removing an aero tow only restriction), before the '97 rule changes simplified everything.

 

[okikuma]

Before competition rules were changed, people used to thermal up through cloud base. You can still do it under FAA rules as you suggest, but the international sanctioning body FAI/IGC doesn't permit it for racing anymore.

I don't need the self launch endorsement because I am grandfathered in from the motorglider flying I did prior to 1997. I had to take a full-blown FAA checkride (not just a CFI endorsement) back in the 80s to get winch launch privileges (removing an aero tow only restriction), before the '97 rule changes simplified everything.

I don't have a self-launch endorsement either since my flight in the RF-4D was 45+ years ago. As with most in the USA, the majority of my gider time has been with aerotow. I have been launched by a winch about five times with one actual cable break during one launch (with CFI-G in the back) at Los Alamitos AAF (CAP Glider operation).

Wayne

 

[okikuma]

JR, I going to throw out a hypothetical question.

An individual has a Private Pilot ASEL and PP Glider ratings. They own a Tailfun 17E with a full legal IFR panel. This individual wants to add an ASEL Instrument Rating. Since the Tailfun 17B motorglider panel meets FAR 91.205, would the individual be able to receive all the required 15 hours minimum dual instrument instruction and log the remaining PIC 25 hours of simulated instrument time with a safety pilot towards the IFR rating in the 17E? Since the 17E is not an airplane, I'll add that the individual would most likely have to perform the IFR checkride in an airplane.

Wayne

 

[WaspAir]

Good question. I'll have to spend some quality time with FARs and think a bit before pontificating, but my initial intuition suggests that might work.

 

[okikuma]

After reviewing FAR 61.65, I highlighted in bold red, the requirements in an aircraft and in an airplane.This leads me to understand that some of the requirements can indeed be performed in an aircraft such as a motorglide, while some specifically required to be in an airplane.

Wayne

14 CFR § 61.65 - Instrument rating requirements.

§ 61.65 Instrument rating requirements.
(a) General. A person who applies for an instrument rating must:

(1) Hold at least a current private pilot certificate, or be concurrently applying for a private pilot certificate, with an airplane, helicopter, or powered-lift rating appropriate to the instrument rating sought;

(2) Be able to read, speak, write, and understand the English language. If the applicant is unable to meet any of these requirements due to a medical condition, the Administrator may place such operating limitations on the applicant's pilot certificate as are necessary for the safe operation of the aircraft;

(3) Receive and log ground training from an authorized instructor or accomplish a home-study course of training on the aeronautical knowledge areas of paragraph (b) of this section that apply to the instrument rating sought;

(4) Receive a logbook or training record endorsement from an authorized instructor certifying that the person is prepared to take the required knowledge test;

(5) Receive and log training on the areas of operation of paragraph (c) of this section from an authorized instructor in an aircraft, full flight simulator, or flight training device that represents an airplane, helicopter, or powered-lift appropriate to the instrument rating sought;

(6) Receive a logbook or training record endorsement from an authorized instructor certifying that the person is prepared to take the required practical test;

(7) Pass the required knowledge test on the aeronautical knowledge areas of paragraph (b) of this section; however, an applicant is not required to take another knowledge test when that person already holds an instrument rating; and

(8) Pass the required practical test on the areas of operation in paragraph (c) of this section in -

(i) An airplane, helicopter, or powered-lift appropriate to the rating sought; or

(ii) A full flight simulator or a flight training device appropriate to the rating sought and for the specific maneuver or instrument approach procedure performed. If an approved flight training device is used for the practical test, the instrument approach procedures conducted in that flight training device are limited to one precision and one nonprecision approach, provided the flight training device is approved for the procedure performed.

(b) Aeronautical knowledge. A person who applies for an instrument rating must have received and logged ground training from an authorized instructor or accomplished a home-study course on the following aeronautical knowledge areas that apply to the instrument rating sought:

(1) Federal Aviation Regulations of this chapter that apply to flight operations under IFR;

(2) Appropriate information that applies to flight operations under IFR in the “Aeronautical Information Manual;”

(3) Air traffic control system and procedures for instrument flight operations;

(4) IFR navigation and approaches by use of navigation systems;

(5) Use of IFR en route and instrument approach procedure charts;

(6) Procurement and use of aviation weather reports and forecasts and the elements of forecasting weather trends based on that information and personal observation of weather conditions;

(7) Safe and efficient operation of aircraft under instrument flight rules and conditions;

(8) Recognition of critical weather situations and windshear avoidance;

(9) Aeronautical decision making and judgment; and

(10) Crew resource management, including crew communication and coordination.

(c) Flight proficiency. A person who applies for an instrument rating must receive and log training from an authorized instructor in an aircraft, or in a full flight simulator or flight training device, in accordance with paragraph (g) of this section, that includes the following areas of operation:

(1) Preflight preparation;

(2) Preflight procedures;

(3) Air traffic control clearances and procedures;

(4) Flight by reference to instruments;

(5) Navigation systems;

(6) Instrument approach procedures;

(7) Emergency operations; and

(8) Postflight procedures.

(d) Aeronautical experience for the instrument-airplane rating. A person who applies for an instrument-airplane rating must have logged:

(1) Except as provided in paragraph (g) of this section, 50 hours of cross-country flight time as pilot in command, of which 10 hours must have been in an airplane; and

(2) Forty hours of actual or simulated instrument time in the areas of operation listed in paragraph (c) of this section, of which 15 hours must have been received from an authorized instructor who holds an instrument-airplane rating, and the instrument time includes:

(i) Three hours of instrument flight training from an authorized instructor in an airplane that is appropriate to the instrument-airplane rating within 2 calendar months before the date of the practical test; and

(ii) Instrument flight training on cross country flight procedures, including one cross country flight in an airplane with an authorized instructor, that is performed under instrument flight rules, when a flight plan has been filed with an air traffic control facility, and that involves -

(A) A flight of 250 nautical miles along airways or by directed routing from an air traffic control facility;

(B) An instrument approach at each airport; and

(C) Three different kinds of approaches with the use of navigation systems.

 

[Resasi]

In my teens I was able to fly Fournier RF-4D. It had a 1200 cc 40 hp VW engine that I think was built by Limbach. It was fun to fly.

At 17 I had just got my PPL and managed to get checked out on an Fournier RF-5 and they then let me take the RF-4 which was the single seat version. I seem to remember that to start the engine you pulled a T handle on the end of some rope sitting in the cockpit. Looking back I think that was incredibly trusting of them, however ,I did also have a gliding Certificate A and B which I had done as an RAF Cadet on the Slingsby Sedbergh T-21's.

These were winch launched. I remember the incredible climb angle, and also practising cable breaks. It was a good introduction to the PPL which I then went on to do in 3 weeks flying from the Isle of Wight on a school holiday from boarding school on a Cessna 150. The Fournier's were the next types I flew, then an Auster which I ground looped on my first attempted landing, another vivid memory.