-A Dornier Do 335 Pfeil on a snowy runway, some time in 1944 or '45. | Photo: Luftwaffe
FLIGHTLINE: 181 - DORNIER DO 335 PFEIL ("ARROW")
Initially designed in response to a request for a Schnellbomber, the Do 335 was reconfigured into a multi-role aircraft, though only a few were completed before Germany surrendered.
Claude Dornier founded the Dornier Flugzeugwerke ("Aircraft factory") in 1914, and was renowned for building large, all-metal flying boats as well as land-based passenger aircraft between the Great War and WWII. These included the record-breaking Do 16 Wal ("Whale") of 1924, the Do X of 1929, and the Komet ("Comet") and Merkur ("Mercury"), a favorite of Lufthansa and SCADTA in Colombia, as well as several South American militaries. A feature of many Dornier aircraft were tandem engines, a tractor and a pusher motor placed back to back. This arrangement allowed an aircraft to enjoy the extra power of having multiple engines without the associated drag of having multiple tractor installations. It also alleviated the issue of asymmetric thrust in case of an engine failure.
-A Do X in flight, circa January 1932. This was one of a number of Dornier flying boats to have a tandem engine configuration. | Photo: German Federal Archives
What became the Do 335 originated in 1939, while Dornier was working on the P.59 Schellbomber ("high-speed bomber"), which would have carried and equivalent load to a Ju 88 or Me 410, but featured a tandem engine arrangement. Work on the P.59 was cancelled in 1940, but Dornier had already commissioned a test aircraft, the Göppingen Gö 9, to test the feasibility of connecting a pusher prop via an extended drive shaft. The Go 9 was based on the Do 17 bomber, but scaled down 40% and with a cruciform tail. The test plane validated Dornier's designs, though the eventual fate of the Go 9 is not known (likely though, it was destroyed by Allied bombing or recycled).
-The Göppingen Gö-9 motor glider, designed by Wolf Hirth. flying c.1941. | Photo: Flightglobal
The P.59's general design was resurrected in 1942 when the RLM requested a high-speed bomber with a 1,000kg payload. Dornier submission, designated the P.231, was awarded a development contract and the model number Do 335. Late in 1942, the requirements were changed from a Schnellbomber to a multirole fighter, which resulted in extensive delays while the designs were updated.
The Do 335 was 13.85m long, with a wingspan of 13.8m and a height of 5m. Empty, the plane weighed 7,260kg, while at max TO the weight was 9,600kg (10,000kg for the two-seat trainers and night fighter variants). Power was provided by two Daimler-Benz DB 603E-1 liquid-cooled V-12s developing 1,324kW each. Due to the situation in late-war Germany, the engines were fitted to run on 87 octane "B4" lignite-derived synthetic fuel, and MW50 boost was also available for additional speed. The basic fighter/bomber variant was armed with a singe 30mm MK 103 cannon firing through the spinner and two 20mm MG 151/20 autocannon mounted in the front engine cowl and synchronized to fire through the prop disc. A single 500kg bomb could be carried internally, and two pylons on the wings could be fitted with bombs, gun pods or drop tanks, with a total load of 100kg. During flight tests, the Do 335 hit 763kmh with boost (686kmh without), making it the fastest production fighter the Luftwaffe fielded during WWII. Under single-engine operations, the plane could still fly at 563kmh. Service ceiling was 11,400m, and under ideal conditions the plane could climb to 8,000m in 14 minutes 30 seconds. Due to concerns over a pilot striking the dorsal fin or the rear prop (a common concern in pusher designs before ejector seats became common), explosive charges would sever the fin and propeller before the pilot would bail out.
-Orthograph of the Do 335 A-1. | Illustration: Richard Ferriere
-Cutaway drawing of the Pfeil showing the engines, linkages, and landing gear actuators. | Illustration: Dornier
-Mounting locations of the 335's guns and associated equipment. | Illustration: Dornier
Maiden flight of the Do 335 V1 prototype was on 26 October 1943. A total of 27 flights were made with the V1, which uncovered a weakness in the landing gear, and issues with the main landing gear wheel-well doors saw them removed for the majority of the flights. The second aircraft, V2, first flew on 31 December 1943, and featured uprated DB 603A-2 engines as well as aerodynamic changes informed by the V1's test flights as well as wind tunnel tests. Maiden flight of the V3 pre-production aircraft was on 20 January 1944, which was fitted with DB 603G-0 engines, which produced 1,400kW at take off. The V3 was also fitted with two rear-view mirrors, alleviating blind spots caused by the location of the aft engine. A total of ten preproduction aircraft were then ordered, and in January the RLM ordered five more prototypes of the night fighter variant, later designated the A-6. By war's end, at least 16 prototypes of the Do 335 and related programs had flown, accumulating some 60 flight hours.
-The Do 335 V1 during testing in 1943 or '44. | Photo: Luftwaffe
Production of the Do 335 was given maximum priority under Hitler's Jägernotprogramm (Emergency Fighter Program), issued on 23 May 1944, and the competing He 219 Uhu ("eagle-owl") Nachtjäger theoretically freed up needed DB 603 engines for the Pfeil, but in practice Heinkel continued production of the 219A. Dornier's factories in Friedrichshafen and Munchen were anticipated to produce 120 and 2,000 Do 335s, of various configurations, by March 1946, but an Allied attack on Friedrichshafen destroyed tooling for the Pfeil, which resulted in a new line being set up in Oberpfaffenhofen. The first preproduction Do 335 A-0 model was delivered in July 1944, and construction of the first production A-1 model began in late 1944. As the war progressed, various models of the Do 335 proliferated (as happened often with late-war aircraft programs) as the Nazis sought to turn back the Allied forces:
Do 335 A-2: single-seat fighter-bomber aircraft with new weapon sights, later proposed longer wing and updated 1,471 kW (1,973 hp) DB603L engines.
Do 335 A-3: single-seat reconnaissance aircraft built from A-1 aircraft, later proposed with longer wing.
Do 335 A-4: single-seat reconnaissance aircraft with smaller cameras than the A-3
Do 335 A-5: single-seat night fighter aircraft, later night and bad weather fighter with enlarged wing and DB603L engines.
Do 335 A-6: two-seat night fighter aircraft, with completely separate second cockpit located above and behind the original.
Do 335 A-7: A-6 with longer wing.
Do 335 A-8: A-4 fitted with longer wing.
Do 335 A-9: A-4 fitted with longer wing, DB603L engines and pressurized cockpit.
Do 335 A-11/12: A-0 refitted with a second cockpit to serve as trainers.
-A Do 335 A-12 trainer, known as the Ameisenbär ("anteater"), late in the war. | Photo: Luftwaffe
Do 335 B-1: abandoned in development.
Do 335 B-2: single-seat destroyer aircraft. Fitted with 2 additional MK 103 in the wings and provision to carry two standard Luftwaffe 300 litre (80 US gal) drop tanks.
Do 335 B-3: updated B-1 but with longer wing.
Do 335 B-4: update of the B-1 with longer wing, DB603L engine.
Do 335 B-6: night fighter.
Do 335 B-12: dual-seat trainer version for the B-series aircraft.
Do 435: a Do 335 with the redesigned, longer wing. Allied intelligence reports from early May 1945 mention spotting a Do 435 at the Dornier factory airfield at Lowenthal.
Do 535: actually the He 535, once the Dornier P254 design was handed over to Heinkel in October 1944; fitted with jet engine in place of rear piston engine.
Do 635: twin-fuselaged long-range reconnaissance version. Also called Junkers Ju 635 or Do 335Z. Mock up only.
P 256: turbojet nightfighter version, with two podded HeS 011 turbojet engines; based on Do 335 airframe.
In April 1945 the Allies captured the Oberpfaffenhofen factory in late April 1945, capturing 11 A-1 fighter/bombers and 2 A-12 trainers. That same month, a flight of four RAF Hawker Tempests, led by French ace Pierre Clostermann, encountered an unknown model of Do 335 over northern Germany at low altitude. The Pfeil pilot began evasive maneuvers, but Clostermann opted to not give chase as the enemy plane displayed superior speed. At the time of the German capitulation in 1945, 22 Do 335A-0, A-1 and A-11/12 aircraft were known to have been completed.
-Dornier Do 335 aircraft on the runway at Oberpfaffenhofen just after the end of the Second World War. | Photo: USAAF
-A Do 335 after being captured by the US, with American markings painted over the Luftwaffe ones. | Photo: Charles Daniels Collection/SDASM Archives
At least two Do 335s were brought to the US under Operation LUSTY, with one, Do 335 A-0, designated A-02, with construction number (Werknummer) 240 102, and Stammkennzeichen ("factory radio code registration") VG+PH being claimed by the Navy for testing. The aircraft was transported on HMS Reaper along with other captured German aircraft, then shipped to the Navy's Test and Evaluation center at NAS Pax River. Another Pfeil was tested by the USAAF at Freeman Field in Indiana, but nothing is known about its fate. In 1961 VG+PH was transferred to the Smithsonian Institution, though it remained outside at NAS Oceana until 1974, when it was shipped back to the Dornier factory in Oberpfaffenhofen for restoration. Over the next year, volunteers from Dornier (some of whom worked on the aircraft originally) found that the explosive charges meant to sever the tail and aft prop were still installed and live, thirty years later. After work was completed the aircraft was placed on display at the Hannover Airshow from 1 to 9 May 1976, and afterwards it was on loan to the Deutsches Museum until 1988. The aircraft was shipped back the States after that, and is now on display at the Udvar-Hazy Center along with other German aircraft brought over during Lusty like the only known Ar 234 Blitz jet bomber and the partially restored He 219A Uhu.
