Need help with summary about the Fokker G.I
Eerst, te excuseren gelieve mijn het posten in het Engels, is mijn Nederlands droevig onbestaand. En hoewel ik in Zuid-Afrika voor wat tijd leefde, mijn is Afrikaans niet lang aan het schrijven van om het even wat en dan ervoor zorgend werkt het in het Nederlands. And while translation software is useful, it's not perfect. And second, thanks to Mathieu for providing me with the link to this forum - really interesting info and photos here.
I've been interested in the Fokker G1 for quite a while - my main interest was in the Finnish Air Force in the 1939-40 Winter War, which meant I spent a lot of time reading up on the Fokker D.XXI's used by the Ilmavoimat. Somewhere along the line I saw the Fokker G1 mentioned as a possible purchase for the Finss that didn;t work out and started researching that. Which is a bit tough as most of the material is in either Dutch or Finnish and I don't speak or read either (altho I'm learning thru necessity...).
Anyhow, for myself, I put together the following summary. I'd be really interested in getting feedback / corrections / additional information if anyone has anything - and I don't mind what language it comes in - I can always get help translating from Dutch if needed as I work with a couple of people from the Netherlands. Here's what I had put together for myself...
The Fokker G1 Heavy Fighter is an interesting might have been that almost was as far as the Finnish Air Force was concerned. Finland actually ordered 26 of these aircraft, but construction was only partially completed before the outbreak of the Second World War. If they had been completed and delivered, they would have been a useful adjunct to the Finnish Air Forces front line fighter strength. The small number of Fokker G1s that were in service with the Dutch Air Force (Luchtvaartafdeeling) certainly made an impact on the Luftwaffe in the limited air combat that took place after Germany invaded the Netherlands.
The Fokker G1 was a heavy twin-engined fighter plane comparable in size and role to the German Messerschmitt Bf 110 and the British Mosquito and somewhat similar in concept and appearance to the American Lockheed P38 Lightning or Northrop Black Widow. Designed as an 'air cruiser' (i.e. patrolling the air space and denying it to enemy planes, especially bombers; a role seen as important at the time, by the followers of Giulio Douhet's theories on air power) the Fokker G.1 was a twin-boom, twin-engined fighter aircraft that could also be used for ground attack and light bombing missions (it could carry a bomb load of 400 kg). It was intended for a crew of two or three (a pilot, an optional bombardier/radio operator and a rear gunner). With its heavy armament and clean lines, the G1 was the best aircraft the Netherlands Air Force had in May 1940.
The G1 was designed and built in 1936 by Fokker head engineers Beeling and Schatzki; with the design and building of the prototype taking just 7 months. Work had actually started in March 1935 after receipt of a specification from the French Airforce for a two engined heavy fighter that was supposed to utilize French equipment: Hispano Suiza engines, instruments, and a landing gear to be delivered by OLA. French interest disappeared after several French designs subsequently appeared. Fokker however thought the design had potential and continued development under their own initiative as Project 129. The aircraft received a twin boom configuration, something which was not new, but which caused a great sensation with the public when first seen.
In the fuselage there was room for both the crew and the aircrafts armament. Like all Fokker aircraft of the period (and many aircraft constructed by other manufacturers as well), the G1 was of mixed construction; the front of the central pod and the tail booms were built around a welded frame of steel tubes, covered with aluminium plating. The back of the central pod, however, as well as the wings, had a wooden frame, covered with triplex, a technique also used in Fokker's successful passenger aircraft at that time. The steel tubular frame was attached to the frontal wingspar with the middle wing made of wood. The armament was in the nose: the prototype had 2x23mm Madsen cannon with 100 shells and 2x7.9mm machineguns with 550 cartridges, and was connected to this frame
The rear part of the cockpit consisted of a wooden frame covered with triplex. The many small windows in the rear part of the fuselage were made out of Perspex and hung in a Dural framework. The belly of the fuselage had two large doors with perspex windows, helpful for observation. There was also a bomb bay that could hold a 400 kg bombload. The rear part of the fuselage ended in a beautiful conical turret that could turn completely around its axis, giving the rear gunner a full 360 degree aim. The machine gun could be aimed by opening perspex panels running the full length of the turret. The wingspars went through the cockpit, right behind the pilot, and before the rear gunners compartment. 550 Liter fuel tanks with a reserve tank of of 150 liters were located in the wing, between the fuselage and the engine nacelles.
The wing edges, on both sides of the engine, contained the oil tanks. The outer parts of the wings were also made out of wood covered with triplex, glued together the same way Fokker used with their successful range of passenger planes and with plywood arches. All control flaps were made out of a Chromemolyb-denumsteel frame covered with linen, The tail booms and tails were made out of aluminum except for the gear compartments. From the firewall on, the whole engine bonnet and struts were made out of aluminum. Directly behind the gear compartments the twin booms were again made of aluminum. The horizontal stabilizer, between the tail booms was also made out of aluminum and had the tail wheel in the middle, while the rudders were covered in canvas. The main landing gear was retractable into the engine nacelles.
Fokker decided to send the G1 to the Paris Air Show (which in those days did not have a flying display but only a static exhibition in the Grand Palais) even before its first flight, anticipating a lot of interest. His expectation was correct, with the G1 becoming the sensation of the show. The prototype was hung under steel cables between aircraft of the Polish and Russian manufacturers. The concept of a twin-boom twin-engined fighter, later adopted for the Lockheed P-38 Lightning, was quite revolutionary at the time, and the new aircraft was the centre of much critical appraisal. Interest was also generated as a result of the heavy armament of 8 machine guns in the nose. The G1 was given the nickname Mower (le faucheur in French) by the French and Reaper by the English, nicknames that pointed to the heavy armament in the nose. There is some doubt that the French came up with that name themselves; a lot of people think that Fokker made that name up himself. Its twin-engine, twin-boom design was also used for the Lockheed P-38 Lightning, conceived and designed around the same time. It is possible, although unlikely, that the P-38 Lightning designed was derived from the slightly earlier Fokker G1 design.
After the Paris Air Show, the G1 was taken to Eindhoven/Welschap airfield, from where its first flight was made on 16 March 1937. A Czech pilot, Maresc, main test pilot for the Czechoslovakian government and senior pilot of the manufacturer Avia, made the maiden flight with the prototype (registration code X-2, and painted in green with medium blue belly). The flight went without flaws and after 20 minutes the pilot landed again. For the audience the G1 was a spectacularly promising plane that had minor problems. After 4 test flights this proved to be not quite so true. On the fifth test flight, problems occurred with one of the Hispano Suiza engines - due to overheating the engine broke down and threw several parts out through the exhaust pipes. Before this incident it was already well known that the Hispano engines were badly designed. One of the tail booms was also damaged.
The G1 was initially powered by two 559kW Hispano-Suiza 80-82 counter-rotating radial engines, but problems with these prototype units (they used too much oil) resulted in a change to similarly rated Pratt & Whitney SB4-G Twin Wasp Juniors during rebuilding (after the G1 suffered brake failure and rammed a hangar at Schiphol on 4 July 1937). A quick and dirty solution was to add extra oil coolers, placed underneath the engines. This solution was not very elegant and finally Fokker did choose another engine, the Pratt & Wittney Jr. SB4-G This engine produced less power but was much more reliable. For the Dutch Air Force, other engines were mounted; the more powerful Bristol Mercury VIII engines that where also used for the Fokker DXXI (this engine was specified as standard by the Dutch Air Force for all its aircraft). The aircraft design consequently had to be adjusted as the engines had a larger diameter and a different shape and the propellers were larger, meaning the engines had to be moved further away from the fuselage. The wider central wing meant that the fuel tank capacity could be increased.
The tail design was also slightly changed. The redesign incorprated higher landing gear to keep the propeller of the ground. These changes were incorporated in the X2 prototype which satisfied the LVA. Actually, the designers wished to replace the engines with Rolls-Royce Merlin engines (which would have made the G1 the fastest fighter in the air at the time), but those were not available.
The design of the nose section of the G1 also caused problems. The armament chosen by the Dutch Air Force, 8 machine guns in the nose, caused the aircraft to become nose-heavy and made the plane difficult to manage during take-off and landing. Several G-1s ground looped during landing and a good solution for this problem was not found although in 1939 there was a plan to give the G.1. a different setup. In this design modification, 4 of the machineguns were relocated to the bomb bay firing from underneath the pilot. In use the machineguns also proved to be very unreliable, partly due to the low temperatures at high altitude. This sensitivity to subzero temperatures was partially resolved by using a different lubricant. Despite that the armament kept on causing problems; firing them on the ground was no problem, but in the air usually 2 or 3 of them jammed. This problem was not solved.
During the short development period of the test G1, a number of variations were explored. None of these came to fruition with the exception of the fitting of one G1 prototype with an observation dome under the fuselage. This was nicknamed the "Bathtub" and was not a success. However, Sweden, when they placed an order for the G1, ordered 12 of the aircraft with these observation domes. Besides the Netherlands Air Force, several foreign air forces also showed an interest in the G1. The aircraft was originally built to a French Air Force specification, but the French preferred French-built aircraft such as the Dewoitine D.520 or the Breguet 69 and did not, in the end, place orders for any G1s. The Danish Air Force showed great interest in the aircraft as a dive bomber. To test this concept, the 302 prototype was equipped with dive brakes, similar to that of the Junkers Ju 87, and extensively tested. Denmark subsequently ordered 12 G1s for use as dive bombers. These were to be built under license (a licence-production agreement was in negotiation when war broke out), and were not completed because of the German invasion, but were delivered in parts and subsequently captured by the Germans during Operation Weserübung before they could be assembled. (Just before the German invasion of Denmark, an order for a further 24 aircraft was placed. These additional aircraft were never delivered). The rest fell intact in German hands.
Overall, interested countries were: Spain (26 or 36 ordered, none delivered), Sweden (18 G1-As and a 77 machine manufacturing license ordered on 5 April 1940, none delivered and none built under the license), Estonia (9 ordered, none delivered), Finland (26 ordered, none delivered) as well as Belgium, Turkey, Hungary and Switzerland. Test Pilots from Finland, Sweden, Belgium and Turkey flew the aircraft. Licensing negotiations were also underway with Manfred Weiss in Hungary. Due to the German attack on the Netherlands, no aircraft were delivered to these countries. The Dutch embargo on weapons exports before World War II had killed the Spanish order (these airfract were taken over by the LVA), but the Finnish batch was under construction when the Winter War broke out and a ban was then placed on its export. After lengthy negotiations a contract was drawn up to permit the G1B's export on 17 April 1940, by which time 12 had been completed, apart from armament. Swedish Air Force officer Bjorn Bjuggren wrote in his memoirs how he test-flew the aircraft in the late 1930s and found it tricky to use as a dive-bomber because of the difficulty in breaking out of the steep dive (the P-38 Lightning had similar problems breaking out of dives).
In the end, two versions were actually built: The first production G1s were produced as a single-seat series for the Spanish Republican Air Force, who had ordered 26 or 36 aircraft (the number depends on the source). Construction of these aircraft began in the autumn of 1937, but the embargo on the sale of military equipment to Spain meant the delivery of the aircraft was halted before the aircraft left Fokkers hands.After the final defeat of the Republicans in 1939, Estonia had decided to take over part of this order. Ten of the aircraft were assembled when Germany attacked the Netherlands and the Dutch Air Force took these over, although the Dutch had difficulties finding armament for these aircraft, eventually managing to arm only four of them where, from May 10 1940 on, they joined combat operations. Demonstrations had already been given to the Netherlands army air corps at Soesterberg, and considerable interest was shown, resulting at the end of 1937 in an order by the Dutch Luchtvaartafdeeling for 36 of the larger three-seat version G1s with Bristol Mercury VIII engines (the standard engine used by the Dutch air force), in order to equip two squadrons. This decision brought delays because although G1A production began immediately there was a hold-up in the supply of engines. Thus the first production aircraft to fly, actually the second of the batch, became airborne only on 11 April 1939. It remained with the makers for production testing and modifications, and the first aircraft was delivered to Soesterberg on 10 July 1939. Two versions were built: The singe seat G1A originally produced in series for Spain, and the larger G1B three-seat version for the Dutch airforce. In the end both types were used exclusively by the Dutch LVA. In total 62 were built.
When Nazi Germany invaded the Netherlands on May 10, 1940, 23 of these G1s were ready (12 with the 4th Fighter Group at Alkmaar and 11 with the 3rd Fighter Group at Rotterdam / Waalhaven), with four more R-1535-equipped aircraft originally intended for Spain also in services. The Germans, were surprised by the ferocity of the supposedly docile Dutch. One advantage of small size is that the Belgian and Dutch aircrews tended to be of high quality. Turnover of Air Force personnel was low, and as it was difficult to get into the air services, they developed into something of an elite. One enduring myth from the campaign is the destruction of the Dutch air force on the ground by the Luftwaffe at dawn on 10 May 1940. Only at Bergen airfield, on the North Sea coast west and north of Amsterdam, were the Dutch caught on the ground, where they lost a dozen of the new Fokker G1 fighters. This loss was bad enough, but at every other airfield, the Germans met a determined defence. The G1 squadron at Waalhaven got eight of its 11 aircraft into the air. The ensuing air battle proved to be one of the most lopsided of the whole battle of France. The Luftwaffe lost 13 aircraft shot down (eight bombers, three Messerschmitt fighters and two Ju52s). Just one G1 was lost (the tail gunner of this aircraft was killed by bomb splinters while running to his plane).
Noteworthy was the action of Lieutenant Bram (Bob) van der Stok, based at De Kooy, during another of the largest dogfights of the first day. Eight Fokker D21s from De Kooy faced nine Messerschmitt Bf109Es from II(J)/TrGr186 (part of the air unit slated to serve on the never completed German aircraft carrier Graf Zeppelin). It was another surprise defeat for the ostensibly superior Germans. Although slower, the Dutch used the better manoeuvrability of the Fokker D21 to advantage. Five 109s were shot down, including the squadron leaders machine, with another two damaged. The Dutch lost no aircraft. After May 1940, van der Stok escaped to Britain and flew Spitfires with the RAF until he was shot down and made a POW. He participated in the Great Escape from Stalag Luft III in March 1944, and became one of only three POWs to successfully get away. He eventually came to command No. 322 Squadron. In the film The Great Escape, his character was turned into an Aussie.
Over the next five days, the Dutch Air Force fought a grim battle of attrition, heavily outnumbered and with only negligible aid from the French and British. Most action took place on 10 May, the first day, with more than 100 sorties. The Dutch alone faced the full onslaught of the whole of Luftflotte 2s 600 combat aircraft (not counting the air transport fleet of 500 Ju52s). Managing only about 30 sorties on May 11, it looked as if the Dutch Air Force had collapsed, yet the next day close to 100 sorties were mounted again. The two single largest concentrations of Dutch aircraft, less than a dozen aircraft each, were seen on 12 May during the battle for the Grebbeberg, but this day proved to be the last gasp. Still, on the morning of 14 May, just before the capitulation of the Dutch Army, the Air Force was mounting defensive patrols, singly or in groups of two, three or four, with whatever could be scraped together, patched up and sent into the air: seven D.21s, four G.1s and a C.5.
Of the Dutch Air Forces Fokker G1s, one G1 squadron was almost completely destroyed on the ground, but the other scored thirteen confirmed kills. The Gls were successful in destroying several Junkers Ju 52/3ms during the early stages of the German invasion, but by the fifth day, when Dutch resistance ended, only one G1 was in fighting condition. Twelve were destroyed on the ground, nine were lost in battle and a Mercury and a Wasp were lost by accident. During attacks on German troops on the Grebbe-linie, several Fokker G1s successfully strafed the German lines while under very heavy anti aircraft fire. Dutch pilots had discovered they could evade the Luftwaffe fighters by flying very very low. This was called "HuBoBe" flying, which stands for Huisje Boompje Beestje, freely translated as: HouseTreeAnimal flying, because they would be so near the ground.
The Germans occupied the Fokker factory, ordering completion of 12 Gls that had been intended for Finland. These were used subsequently by the Luftwaffe as fighter trainers for Me-110 crews and for testing. There are no cases known of German G1s participating in combat. Test flights from the factory were made under German supervision, but on 5 May 1941 two Dutch pilots (Leegstra and Vos) flying from Schipol on a test flight succeeded in evading an escorting German-flown G1 and escaped to England. Their G1B was taken to the Royal Aircraft Establishment, Farnborough, for examination, and used subsequently by Phillips and Powis (Miles Aircraft) at Reading for research into wooden construction, specifically to test the wooden wing for the English climate. A total of 62 G1s are believed to have been built - none survived the war. Only a replica in the Dutch Air Force Museum in Soesterberg remains. There is no clear count of how many G1 's eventually fell into German hands. It can be assumed that several Dutch Mercury and many Wasp versions fell undamaged into German hands. It may also be assumed that a number of Danish aircraft were seized by the Germans as well as 20 of the aircraft that were to have been delivered to Finland. The Luftwaffe almost certainly had between twenty and thirty in service.
The Fokker G1 was first offered to the Finnish Air Force in May 1937. The Ilmavoimat Commander, Major-General Jarl Lundqvist, was interested in buying one completed aircraft from Fokker together with a 23 aircraft manufacturing license. It is probable that Lundqvist planned this purchase as an alternative to further Bristol Blenheims. A Finnish Air Force team visited the Fokker factory in June 1937 and agreed to carry out test flights. Captain Gustaf Magnusson was at the Fokker factory in autumn 1937 carrying out delivery test flights for the Fokker D.XXIs purchased by the Finnish Air Force and at the same time, on 27 September 1937, test flew the Fokker G1, reaching a speed of 650km/h, which attracted attention in the local press. In April 1938, the Ilmavoimat decided that the Fokker G1 was not needed.
In February 1939, Ilmavoimat Captain Erkki Olavi Ehrnrooth visited the Fokker factory and on 9 February test flew the G1, although he damaged the booms and tail in an accident. The aircraft was repaired and Ehrnrooth flew more test flights. In his opinion, the G1 was a good aircraft, however, the Ilmavoimat was not interested as it was considering the G1 aircraft as a bomber and the Ilmavoimat already had the Bristol Blenheim. At the same time as they were considering the Fokker G1, the Ilmavoimat placed an order for 5 Fokker T.VIII twin-engined torpedo-bomber and reconnaissance floatplane (The W/C version ordered by Finland were a larger version with more powerful engines. All five ordered by Finland were captured and used by the Luftwaffe). In the autumn of 1939, as the international situation grew more tense, Finland was trying to acquire aircraft and sending inquiries to aircraft factories around the world.
Fokker offered Finland the G1-B machines which had been manufactured for the Spanish Air Force but Major General Lundqvist, commander of the Ilmavoimat (the Finnish Air Force), thought that the price was too high and delivery was suspended. After the Winter War broke out, the order was reinstituted. Fokker advised that they would be able to deliver 12 aircraft in a 4 to 5 month timeframe, with a further 6 aircraft in 6 months time. On the 2nd of February 1940, Lundqvist decided to abandon the order due to difficulty sourcing engines and propellors. The aircraft were instead sold to the Dutch Air Force.
The G1A was powered by 2 x Bristol Mercury VIII 9-cylinder engines with a maximum power of 840 hp, while the G1B was powered by 2x Pratt & Whitney Twin Wasp Junior R-1535 SB4-G 14-cylinder, two stroke engine, with a maximum power 825 hp. Maximum speed for the G1A was 475km/h while the G1B reached 430km/h. Range was 1,900km and max altitude was 9,300m for the G1A and 8,700m for the G1B. The G1A was armed with 2x23mm cannon and 2x7.9mm machineguns in the mose and one rear 7.9mm machinegun. The Finnish verson was to have 2x20mm cannon with 60 rounds each, together with 2x7.7mm machineguns with 600 rounds per gun in the nose and a read 7.7mm machinegun with 600 rounds. The aircraft could carry a 400kg bombload. The reconnaisance version carried a third crew member rather than bombs, some of the bombbay space being occupied by the third crew member. The dive-bomber version was designed for a 450kg bombload (1x250 kg + 2x100 kg bombs). The ground attack version was designed to carry 300-450 kg of bombs (36x12.5 kg, 200kg +4x25 kg or 2x100 kg + 8x25 kg).
My interest really is in getting a good summary of the G1's history along with the Finnish Air Force's interest with the aircraft. One of the reason's being I was working thru an "alternative history" scenario of the Winter War and using an expanded Finnish Air Force as part of the scenario - but using aircraft the Finn's in reality could have purchased, the G1 being a prime example. No use dreaming about Finnish Spitfires for example, the British just weren't selling them..... but on the other hand, a single-seat G1 with more powerful engines (the Merlins that were talked about?) and no bomb load, just cannon and machineguns, would probably have been on a par with an early P38 Lightning - imagine what a Finnish squadron or two of those would have done to the Soviet Air Force in the Winter War.