In the summer of 1935, Fiesler Chairman Gerhard Fieseler, Chief Designer Reinhold Mewes and Technical Director Erich Bachem designed a practical STOL aircraft, the Fieseler Fi 156. It was seen as fulfilling numerous roles both in civil life and for the recently resurgent Luftwaffe. The Fieseler Fi 156 Storch (Stork) was a STOL (short take-off and landing) aircraft, a three-seat extensively glazed cabin, high-winged machine with the wing liberally endowed with slats and flaps and a stalky landing gear arrangement, well suited to cushioning arrivals at unprecedentedly steep angles. The high-lift devices allowed a take¬off run of only about 60 m (200 ft) and it could land in about one-third of that distance. Fieseler’s chief designer, Reinhold Mewes, decided for ease of maintenance that the airplane should be completely conventional in its construction, and so utilized a steel tubing and fabric fuselage with wooden wings with a conventional braced tail unit and fixed tailskid landing gear. The wings were made of wood simply because they could be made in low grade factories using forced labour. The original wooden wings contained only 2 x 74 lt tanks. The engine was the then-common Argus As 10C inverted V-8 aircooled 240-hp model.

Fieseler Fi-156 Storch Article

The big 46-foot wing had full-length fixed slats (projected movable slats never materialized), Fowler-type flaps that increased wing area by 18 percent, and ailerons that drooped with the flaps when they were extended past 20 degrees. The wings could be folded back along the fuselage, allowing it to be carried on a trailer or even towed slowly behind a vehicle. The long legs of the landing gear contained oil and spring shock absorbers that compressed about 450 mm (18 inches) on landing, allowing the plane to set down almost anywhere. In flight they hung down, giving the aircraft the appearance of a very long-legged, big-winged bird, hence its nickname, Storch. With its very low landing speed the Storch often landed “in place” or sometimes even backwards, if the wind was blowing strongly from directly ahead.

The Fieseler Fi 156 Storch (stork) V1 prototype was first flown during the early months of 1936. The Argus As 10C V8 engine gave the plane a top speed of only 175 km/h (109 mph), enabling the Storch to fly as slow as 50 km/h (32 mph), take off into a light wind in less than 45 m (150 ft), and land in 18 m (60 ft). In response to the prototype, in 1937 the RLM (Reichsluftfahrtministerium, Reich Aviation Ministry) put out a tender for a new Luftwaffe aircraft suitable for liaison, army co-operation – today called Forward Air Control – and medical evacuation to several companies.

Designs from from Messerschmitt (the Bf 163) and Siebel (the Si 201) and an auto gyro from Focke-Wulf (the Fw 186) based on Cierva technology were submitted, but the Fieseler entry was by far and away the most advanced in terms of STOL performance, needing a take-off run of only about 200 ft (60 m) and landing in about one-third of that distance. The first Fi 156 prototype was followed up by the second V2 prototype and then the third V3 prototype, the ski-equipped V4, plus one V5 and ten Fi 156A-0 pre-production aircraft. Flight testing of the first three prototypes (Fi 156 V1, V2 and V3) showed that the capability of this aircraft more than exceeded its STOL expectations, with little more than a light breeze blowing it could take off inonly a few feet. One of these prototypes was demonstrated publicly for the first time at an international flying meeting at the end of July 1937 in Zürich, by which time the general-purpose Fi 156A-1 was in production. The Storch repeatedly demonstrated full-load take-offs after a ground run of never more than 148 ft (45 m), and a fully controllable speed range of 32-108 mph (51-174 km/h). Service tests confirmed that Ger¬many’s armed forces had acquired a ‘go-anywhere aircraft, and for the re¬mainder of World War II the Storch was found virtually everywhere Ger¬man forces operated.

It was immediately ordered into production by the Luftwaffe with an order for 16 planes, and the first Fi 156A-1 production aircraft entered service in mid-1937. Fieseler then offered the Fi 156B, which allowed for the retraction of the leading edge slats and had a number of minor aerodynamic cleanups, boosting the speed to 208 km/h (130 mph). The Luftwaffe didn’t consider such a small difference to be important, and Fieseler instead moved on to the main production version, the C.

Operation Niwa and Hedderich

The Fi 156C was essentially a “flexible” version of the A model. A small run of C-0s were followed by the C-1 three-seater liaison version, and the C-2 two-seat observation type carrying a single camera (which had a rear-mounted MG 15 machine gun for defense). Both models entered service in 1939. Some late examples of the Fi 156 C-2 were equipped to carry one stretcher for casualty evacuation.

In 1941, both were replaced by the “universal cockpit” C-3. The Fl 156C-3 was the first to be a equipped for multi-purpose use, the majority of the type being powered by the Argus As 10P engine, which was also standard in the generally similar Fi 156C-5 which had provision to carry an under fuselage camera or jettisonable fuel tank. Last of the Cs, the C-5, a C-3 with a belly hardpoint for a camera pod or drop tank. Some were fitted with skis, rather than wheels, for operations on snow.

Other versions of the Fi 156 were the C-3/Trop, which was a tropicalised version of the Fi 156C-5, and the Fi 156D which was an air ambulance version. The first two Fi 156D models were the D-0 pre-production aircraft, and the D-1 production aircraft, powered by an Argus As 10P engine.

Ten unusual pre-production aircraft were built under the designation Fi 156E-0, intended for operation from rough terrain with the standard landing gear was replaced by main units that each incorporated two wheels in tandem, the wheels of each unit, being linked by pneumatic rubber track.

A total of about 2,900 Fi 156s, mostly Cs, were produced from 1937 to 1945. When the main Fieseler plant switched to building Bf 109s in 1943, Storch production was shifted to the Mráz factory in Choceň, Czechoslovakia as the Benes-Mráz J-65 ‘Èáp’.

During the occupation of France, the Fi 156 was built by the Morane-Saulnier company at its Puteaux factory as the Morane Ms.502, and post-war as the MS.505. A lot of Luftwafe parts were collected by Morane Saulnier and reused to build the MS.500 Criquet. The wings on the original were wood but Moraine Saulnier reproduced the wings, tail and controls in metal. While heavier, the wings contained additional fuel. The original wooden wings held 2 x 74 lt tanks, and the MS wings an additional 100 lt in each wing. Moraine Saulnier used the Argus engines until supplies dried up.

A large number were also built at the captured Morane-Saulnier factory in France, starting in April 1942, as the M.S.500 Criquet.

French production models included the MS-500 (Argus As 410C), the MS-501 (Renault 6Q), and the MS-502 (Salmson 9AB). In early 1964 a re-engined version, the MS-505 with a 300 hp Jacobs R-915A began trials.

Both factories continued to produce the planes after the war for local civilian markets (in Czechoslovakia it was made as K-65 Čáp, 138 were made by 1949). Licenced production was also started in Romainia in 1943 at the ICAR (Īntreprinderea de construcţii aeronautice româneşti) factory in Bucharest. Only 10 were built by the time Romania switched sides, with a further 70 aircraft being built by the Romanians before production ended in 1946. During the war at least 60 Storchs were captured by the Allies, one becoming the personal aircraft of Field Marshal Montgomery.

A total of 2,549 Fi 156s were built.

Tests against fighters appeared to confirm that, at around 34 mph (55 km/h), it was a very difficult target for fighters. There was almost trouble when Udet’s camera-gun film showed not one picture of the elusive Storch. Another Fi 156A-0 was tested with three SC-50 (50 kg/110 lbs) bombs, with aim marks painted on the Plexiglas windows, while another did successful trials against a U-boat with inert 298 lbs (135 kg) depth charges. Less unexpected were supply-dropping tests and trials with smoke apparatus.

Between 1940 and 1943, Germany exported 34 Fieseler Fi 156Cs to Romania. A further Storch was assigned for Marshall Ion Antonescu’s personal use. Further Fi 156s were received in 1944 and some were probably captured after August 23, 1944, from the retreating German forces. In the so called ‘People’s Democracy’ the remaining dozens of Storchs received civilian registrations and were relegated to AVIASAN, the Romanian national air ambulance service. The last ones were finally retired in the late 1960s.

The Ilmavoimat / Maavoimat / VL Team evaluated the aircraft and carried out a series of flight tests early in 1938. As expected, the Fi 156 rated highly, with the STOL performance in particular impressing the the test team. Excerpts from the Flight Test reports written at the time reveal some of the impressions that aircraft made on the Test Pilots:

“…..nothing could possibly convey its general ungainliness. It stands so high off the ground that an average man can barely see in the side windows…”

“…..once in the cockpit, the nose didn’t even begin to block my vision because I was sitting so high above it. The cockpit area is huge, big enough to stand up in, and it’s cluttered with cranks, wheels and levers, all labeled in German. The stick and rudder are where they should be, but the rudders are big cast-aluminum footprints with safety straps of their own and the stick resembles a telephone pole. The flaps are lowered by a crank, not a dainty little crank, but a man-sized Model “T” Ford type crank that sticks out of the left wall. By winding in the Aus direction, wing-size boards flop out of the trailing edges and the ailerons race to catch up. In the spar carry-through structure over the pilot’s head is a pointer that indicates how much flap is hanging out, and in this airplane, any flap at all is a lot……”

“….. I must have made at least 15 takeoffs and landings, all of them incredibly short and none of them where I wanted them to be. On takeoff, I found that even with the correct trim, I couldn’t pull back hard enough to come even close to stalling it. As soon as I had a minimum of 35 knots, I could pull back all I wanted and do nothing but climb. I had absolutely no head-wind component and my initial climb angle was nearly 45 degrees. This airplane really will leap off the ground. Taking off three-point in a headwind, I doubt that it would need more than 20 feet to get off, although I was using close to 100 most of the time……”

“……To make short-field landings on a chosen spot, you usually like to get the airplane slow enough so you have to use power to drag it in. I was constantly frustrated in the Storch, because I never got it slow enough to need power. Almost every landing was power-off, and eventually I was so exasperated that I was approaching at 25 knots indicated. At that speed, I needed power to soften the touchdown, but it still wasn’t slow enough to hang on the prop. …… the really hot-shot German Pilot that instructed us in the Fi 156 would come creeping in over the trees at practically zero airspeed, letting it fall on command and catching it at the last moment with a burst of power…..”

“….. I tried to stall it while at altitude and found that it not only refuses to stall, but as long as I had the slightest amount of power in to give it elevator effectiveness, I could easily fly the airplane where I wanted while holding the stick all the way back. Once you master that kind of approach, you could land backwards on an outhouse roof…..”

“……I had a lot of silly things happen while flying this airplane but the silliest was when I tried slipping it. I was high, per usual, so I figured I’d just use a max deflection slip. It works on other airplanes, why not? As I leaned the aileron into it and got on the opposite rudder everything was going just fine until I got about half rudder. At that point, the rudder pressure disappeared and the rudder pedal sank to the floor with no effort from me and stayed there. So, there I was, coming down final sideways with a rudder that was stuck to the floor of its own accord. That scared the living hell out of me! I had to practically stand on the other rudder to get things straighted out. I guess the aerodynamic balance on the rudder is so big that when enough of it catches the wind, it overpowers the surface and yanks it to full deflection……”

“….Maneuvering in the Storch is a real physical workout. The controls feel the way the airplane looks—gawky and loose. The stick forces are anything but light and to keep it completely coordinated, your feet have to thrash in and out as if you were working a treadle sewing machine….”

Given the low cost of the Fieseler Fi 156, this was a feasible proposition and in August 1938, the Ilmavoimat announced twenty Fi 156’s were to be bought direct from Fiesler – delivery was rapid and these aircraft were shipped and arrived before the end of the year. Additionally, a manufacturing license was bought from Fiesler and the Finnish company Veljekset Karhumäki was awarded a contract to build an initial 100 aircraft (Veljekset Karhumäki were also advised that further orders would be placed, with the objective being to ensure that all Regimental Battle Groups were fully equipped). This was a large expansion in business for Veljekset Karhumäki and two additional factory buildings were acquired, one to construct the Argus engines and one to construct the aircraft. Setup moved as rapidly as possible with production starting towards the end of 1938 and the first Finnish-manufactured Fi 156 rolling out the doors in early February 1939. Delivery averaged six Fi 156’s per month through the first half of 1939, increasing to 2 per week from July on and in the event, some 70 Fiesler Fi 156’s had been delivered by Veljekset Karhumäki by the time the Winter War broke out.

Finland entered the Winter War with some forty Fw 189 aircraft in service, in addition to the ninety odd Fieseler Fi 156 Storch’s. When the Winter War broke out, it was obvious that despite the intensive manufacturing effort over the previous six months there were nowhere near enough of the aircraft, even with the older aircraft being utilised. Despite limited numbers of observation aircraft being bought abroad and continuous production from Veljekset Karhumäki (some 10 per month by January 1940), demand for the aircraft always exceeded the supply available throughout the Winter War.

The Ilmavoimat Fi 156 production variant was a two crew (Pilot and Observer / Controller) with an enlarged loading/unloading hatch for a single stretcher so as to allow for casualty evacuation. A more powerful engine was fitted and the aircraft could carry up to three passengers in addition to the crew of two. Given that the aircraft was expected to operate from rough terrain, the standard landing gear was replaced by main units that each incorporated two wheels in tandem. For Forward Air and Artillery Control, provision was made for additional Finnish-supplied radio equipment to be installed to allow for simultaneous communication with ground units, artillery and aircraft. Mountings for 30lb phosphorus “marker” bombs were also installed and a single machinegun was fitted.

The Finnish Fieseler Fi 156 Storchs remained in service until 1960.

The Storch could be found on every front throughout the European and North African theaters of operation in World War II. It will probably always be most famous for its role in Operation Eiche, the rescue of deposed Italian dictator Benito Mussolini from a boulder-strewn mountain top near the Gran Sasso, surrounded by Italian troops on 12 September 1943. German commando Otto Skorzeny dropped with 90 paratroopers onto the peak and quickly captured it, but the problem remained of how to get back off. A Focke Achgelis Fa 223 helicopter was sent, but it broke down en route. Instead, pilot Walter Gerlach flew in a Storch, landed in 30 m (100 ft), took aboard Mussolini and Skorzeny, and took off again in under 80 m (250 ft), even though the plane was overloaded.

Gallery

Replica:
RagWing Aviation RW19 Stork
Slepcev Aircraft Storch

Fieseler Fi 156 Storch
Engine : Argus 10 E/1, 175 hp
Length : 32.48 ft / 9.9 m
Height : 10.007 ft / 3.05 m
Wingspan : 46.752 ft / 14.25 m
Wing area : 279.864 sqft / 26.0 sq.m
Max take off weight : 2910.6 lb / 1320.0 kg
Weight empty : 1896.3 lb / 860.0 kg
Payload: 837.9 lb / 380.0 kg
Max. speed : 94 kts / 175 km/h
Initial climb rate : 1574.80 ft/min / 8.00 m/s
Service ceiling : 17388 ft / 5300 m
Wing load : 10.46 lb/sq.ft / 51.0 kg/sq.m
Range : 324 nm / 600 km
Endurance : 5 h
Crew : 1+2

Fi 156A-1

Fi.156C-2
Engine: 1 x Argus As 10C-3, 179kW (240-hp)
Max take-off weight: 1325 kg / 2921 lb
Empty weight: 930 kg / 2050 lb
Wingspan: 14.25 m / 46 ft 9 in
Length: 9.9 m / 32 ft 6 in
Height: 3.05 m / 10 ft 0 in
Wing area: 26 sq.m / 279.86 sq ft
Maximum speed 170 kmh (109 mph) at sea level
Economical cruising speed 130 km/h (81 mph)
Landing speed: 25 mph
Slow cruise: 31 mph
Service Ceiling: 4600 m / 15100 ft
Range: 385 km / 239 miles
Armament: one rear-firing 7.92-mm (031-in) machine-gun on trainable mount

Fi 156D-0 –

M.S.502
Engine: 230 hp Salmson 9AB
Wingspan: 46 ft 9 in
Wing area: 279.7 sq,ft
Length: 31 ft 8 in
Height: 10 ft
Empty weight: 2100 lb
Loaded weight: 3140 lb
Max speed: 106 mph at SL
Cruise: 85 mph
Service ceiling: 14,100 ft
Climb to 3280 ft: 5.5 min
Range: 435 mi at 72 mph