Down Memory Lane - From the Log Books #2

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Kranich 3.

 

 

The only real similarity between this type and its wartime predecessor was the name, it had two seats and it was damn big!

 

 

Produced in 1954 by Focke Wulf, the machine was primarily designed as a high performance two seater rather than a training machine. The long mainskid with mainwheel mounted well aft, nearly eighteen and half metres of wing and a flying weight of 530 kg – it was not something you wanted to be pushing around more than you had to.

 

 

Not many were built and they still remain popular today in vintage glider circles. The 30:1 glide angle does not sound spectacular by modern standards but is sharply brought into focus when you realise that at the time this exceeded or equalled most of the competition ‘hot ship’ single seaters.

 

 

Marking part of Germany’s post war aviation recovery, the Kranich 3 actually emulated the pattern of training gliders that were to dominate the German clubs until the advent of the glass fibre two seaters many years later – it was just that the Kranich was so much bigger than the more routine Bergfalke and Ka7/ASK13 marques that were in the process of getting underway as basic trainers. This glider does not look dissimilar to a much larger and rather angular ASK13.

 

 

The aircraft was a tandem two seater with a steel tube fuselage covered in fabric. The wings and tail unit were conventional wood D boxes and fabric covered main surfaces. The wing was mid mounted and slightly swept forward which gave good visibility from the rear seat, but the wing was a conventional straight wing and not gull winged. The wing tips had wooden ‘pods’ as protector skids on landing similar to the Blanik set-up.

 

 

The one I flew was a bit unique in that it was fully IFR equipped and at the time was the only glider in Germany allowed to perform IFR instruction including in cloud. This was I believe the main reason the club had it and the student was shoved in the curtained out back seat for the exercises. At weekends it was used for general club work of an advanced training nature.

 

 

Flying the Kranich 3 was quite straight forward. The design was right and there were no problems with it. Take off was by aerotow as she was far too heavy for even the powerful German winches – and made the Cub tugs pant quite a bit towing her. Departure was a bit of a spine jarring affair from the front seat (bit better in the back) until the glider was fast enough to get the main skid off. After that the tow was straight forward and she flew as if on rails – very solid and stable in the air.

 

 

This reflected in all of her flying. The ‘on rails’ bit made her easy but at the same time manoeuvring her was a tad ponderous and although not heavy on ailerons she was a bit sedate and took her time rolling. The aileron drag/rudder interface was well balanced so it was not hard work in that area other than you would normally be used to.

 

 

Stalling was straight forward but although she was docile enough you would not want to spin that weight low down and she would spin – very well! To some extent this situation was reflected in the designs of the GRP trainers of later years that were made very docile (especially the Twin Astir – but more on that in a later story). To a great extent that invalidated them as all round trainers as full spin training will ever be a standard part of gliding – it has to be – and you definitely do not want to lose control of half a tonne of glider at a few hundred feet!

 

 

Approach control was very steady in terms of flight path, if a tad shallow in no wind conditions, and the large double paddle airbrakes gave good control of getting the big machine exactly where you wanted. The landing was a perfectly normal full hold off. If the nose skid was allowed down early then the weight could be brought under control and the glider would stop in a satisfyingly short area.

 

 

I loved the Kranich 3 (just as I was such a fan of her predecessors) and count the type as one of the treasured parts of my log books.

 

 

DoppleRaab.

 

 

I am sorry but this glider was such a hoot that I really do have to have a bit of fun with the story!

 

 

The first, and only, meeting I have had with one was at a sleepy little German gliding club out in the hills. I was there allegedly as crew on a regional gliding competition but primarily for the beer, frauleins and as much flying as I could get. The order of these was prioritised according to the time of day and weather (damn I had a misspent youth!).

 

 

On the first day I espied this funny looking little humpbacked glider that seemed to be a single seater but had to be a two seater as two people kept getting in and out of it at regular intervals. It was in fact the small club’s main trainer! I discovered that it was a DoppelRaab and just had to fly it!.

 

 

The DoppelRaab was one of the early 1950’s efforts at getting German gliding going again. It was made as a kit so small clubs could get into the air again cheaply but the expense of considerable labour and woodworking skills.

 

 

With the kit you got a pre-welded steel tube fuselage, some bits and pieces of hardware and a stack of timber lengths to build the wings and tail from. There would be NO problem meeting our 51% rule in RAAus after building one of these!

 

 

The wing was a copy of the single strutted Grunau Baby wing so was 13.2 metres span (small for a two seater) and the glide angle was 20:1. Approach control was via the normal Grunau spoilers and very adequate – anything disturbing a 20:1 glide angle is always ‘very adequate’!

 

 

But it was the detail design of the beast that really got me in. The machine got its name from ‘Double Rope’. This was because there was a custom yoke that attaches to special rotating fittings either side of the cockpit, under the centre of gravity, at about shoulder level. Those readers who have done a bit of winch or autotowing know that the nearer you get to the top of the launch then the harder you have to pull.

 

 

With the DoppleRaab’s launching point there is virtually no load so the aircraft effectively launches itself providing the motive power remains present. On the other hand you have to be a bit more careful in cross winds because if you start drifting then one side of the yoke begins bearing on the side of the cockpit and can scratch the paintwork.

 

 

This is akin to the modern requirement of having to aerotow gliders with only belly release hooks in high tow otherwise you get the tow rope sawing away around the nose cone in low tow.

 

 

To keep the ‘double image’ going the aircraft has two tandem main wheels and a front skid. This seemed like a bit of an over kill to me as moving the glider around was no problem at all and the double wheels in fact got in the way a bit. I suppose that is why they were there! On take off the glider would tend to run straight and not wander off to one side and interfer with this double yoke business.

 

 

But the fascinating feature is that the type is not actually a two seater but a 1.5 seater!

 

 

The front cockpit is quite conventional (well almost) and is a bit bigger than a Ka8 – probably more along the lines of what you get with the French Javelot range. The main difference is this huge control column that has a flat horizontal plate welded to it that angles back towards the rear and then a second vertical portion is welded to this.

 

 

The student gets the bottom half to fly with and the instructor can reach over the student’s shoulder and gets the top bit to fly with. There is no problem with this because the instructor is not really seated but is perched on a bench arrangement that has him/her leaning forward all the time. This angle is such that the rear rudder pedals are horizontal with the cockpit floor so the whole thing is a bit weird.

 

 

I am here to tell you that this arrangement is bloody cosy! It may be great with a female student as a lot of the German girls are very well endowed but for two males it is a bit too cosy so plenty of showers and no garlic is the order of the day when on instructional duties!

 

 

On the postitive side the student gets plenty of passive feedback on the instructor’s peace of mind. This was demonstrated to me clearly on the first approach which was towards the edge of a cliff. so we really had to clear that in a low performance glider. I needed to see how effective the spoilers were so took a handful and the edge of the cliff rose promptly in front of us.

 

 

The impassioned intake of breath an inch from my right ear nearly had my ear drum out so I closed the spoilers and things returned to normal except for some mutterings in German that I took to be religious in nature – but he did leave me with it.

 

 

I came away from the entire experience feeling that the launch is virtually on auto-pilot and after that you fly the glider on feedback from the instructor. If things are going OK then all is reasonably quiet but the degree they are not going well is directly proportional to the level of panting and gasps that you are very proximal to!

 

 

Flying the DoppelRaab was no great problem – she flys very much like a heavy Grunau. It does require good aileron/rudder co-ordination but generally she is a bit of a float box with poor glide and penetration. Approach control is ample and landing is easy with the dual mainwheels keeping line organised for you as well.

 

 

But for all the novelty of some of the design features she did do a great job in helping getting a gliding movement going again and people back into the air. Certainly not one of my favourite gliders but a good one to spin a yarn about!