MiG-9 single engine variants

Justo Miranda

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MiG-9 single engine variants

In February 1945 Pavel Sukhoi and Mikoyan Gurevich design bureaus were instructed to evolve a single seat heavy fighter of the Me 262 class around a pair of German turbojets.

Owing to the urgency with which the programme was attended, the Sukhoi Su-9 design, with two wing mounted Jumo 004B turbojets was very influenced by the Me 262 captured on March 30, 1945 and flight tested on August 15, 1945.

The MiG OKB-155 decided to use two BMW turbojets placed very close together inside the fuselage, allowed it to fly using only one of them in case of failure, without lateral stability problems.

This aerodynamic solution also generated less drag than the Me 262 formula allowing the new I-300 (MiG-9) fighter to reach higher speeds.

It is at that time the scientists of the TsAGI did not yet have enough data to design swept wings as efficient as those of the Me 262 and the Soviet industry proved to be unable to build reverse engineered copies of the German wings.

German ground tests carried out in November 1944 showed that the internal drag in air ducts reduced the turbojet thrust by 45 kg for each meter in length.

To best profit of the scarce power available the fuselage installation of the MiG-9 turbojets should have air-intake ducts and tailpipes as short as possible to minimize the jet power loss.

MiG OKB decided to incorporate into its design the mid-mounted straight wings, 27 degrees swept delta-style tailplane, tricycle undercarriage with the main gear retracting into the wings and ‘tadpole configuration’ used in the German night fighter project Focke-Wulf Hochleistung Nachtjäger Projekt II (Baubeschreibung Nr.251-251) from March 6, 1945.

The MiG-9 prototype was flight tested on April 24, 1946 reaching 572 mph (920 km/h) at 4,500 m. On July 11, 1946 the plane was destroyed as a result of tailplane structural failure.

MiG-9 technical data

Power plant: two Kuznetsov RD-20 turbojets rated at 850 kg static thrust, wingspan: 32.8 ft. (10 m), length: 32.2 ft. (9.83 m), height: 10.6 ft. (3.23 m), wing surface: 202.2 sq. ft. (18.20 sq. m), take-off weight: 10,956 lb. (4,963 Kg), maximum speed: 572 mph (920 km/h), service ceiling: 44,280 ft. (13,500 m).

To meet the April 1946 specification issued by the Council of People’s Commissars, calling for a jet fighter powered by the indigenous turbojet, the MiG OKB decided to build a lighter version of the MiG-9 powered by only one Lyulka TR-1A turbojet, rated at 1,500 kg. The prototype I-305/FL was completed at the end of 1947 but the Lyulka exploded on the test bench and the FL project was discontinued.

MiG I-305/FL technical data

Power plant: one Lyulka TR-1A turbojet rated at 1,500 kg static thrust, wingspan: 32.8 ft. (10 m), length: 31.8 ft. (9.70 m), height: 10.8 ft. (3.20 m), wing surface: 202.2 sq. ft. (18.20 sq. m), take-off weight: 10,088 lb. (4,570 Kg), estimated maximum speed: 557 mph (897 km/h), estimated service ceiling: 43,952 ft. (13,400 m), equipment: pressurized cockpit and ejector seat.

Following the failure of the Soviet Lyulka VRD-3, TR-1 and TR-1A turbojets and the difficulties encountered by the Soviet industry in obtaining reverse-engineered copies of German turbojets, on June 17, 1946 the Council of People’s Commissars ordered the purchase of ten Rolls-Royce Nene Mk.I and ten Rolls-Royce Derwent V British turbojets.

The British government did not granted manufacturing licenses but Klimov GAZ 116 started the mass production of unlicensed copies under the codenames RD-45 (Nene Mk.I with 2,230 kg thrust), RD-45F (Nene Mk.II with 2,270 kg thrust) and RD-500 (Derwent V with 1,590 kg thrust).

Late in 1947 a production MiG-9 was modified replacing the two RD-20 turbojets with one Nene Mk.I.

To accommodate the new centrifugal engine of 1,257 mm of diameter it was necessary to redesign the fuselage but the project, named I-320/FN (a project without any connection with the I-320 R-1 night fighter) was cancelled in favor of the new I-310 S (MiG-15) swept wing prototype.

MiG I-320/FN technical data

Power plant: one Rolls-Royce Nene Mk.I turbojet rated at 2,230 kg static thrust, wingspan: 32.8 ft. (10 m), length: 35.7 ft. (10.88 m), height: 10.76 ft. (3.23 m), wing surface: 202.2 sq. ft. (18.20 sq. m).
 

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Hi Justo,

MiG OKB decided to incorporate into its design the mid-mounted straight wings, 27 degrees swept delta-style tailplane, tricycle undercarriage with the main gear retracting into the wings and ‘tadpole configuration’ used in the German night fighter project Focke-Wulf Hochleistung Nachtjäger Projekt II (Baubeschreibung Nr.251-251) from March 6, 1945.

Thanks a lot, that's an interesting bit of information I hadn't been aware of before! I always thought the wing of the MiG-9 shared a certain resemblance to that of the He 162, but it seems the lineage was a bit different from that.

Do you have any pointers on where to read more about the Nachtjäger-Projekt II? I did a bit of googling on and off the forum, but it seems to be fairly elusive ... all I get are pictures of Ta 183 models with antler antennae :)

Regards,

Henning (HoHun)
 
Hi Justo,

MiG OKB decided to incorporate into its design the mid-mounted straight wings, 27 degrees swept delta-style tailplane, tricycle undercarriage with the main gear retracting into the wings and ‘tadpole configuration’ used in the German night fighter project Focke-Wulf Hochleistung Nachtjäger Projekt II (Baubeschreibung Nr.251-251) from March 6, 1945.

Thanks a lot, that's an interesting bit of information I hadn't been aware of before! I always thought the wing of the MiG-9 shared a certain resemblance to that of the He 162, but it seems the lineage was a bit different from that.

Do you have any pointers on where to read more about the Nachtjäger-Projekt II? I did a bit of googling on and off the forum, but it seems to be fairly elusive ... all I get are pictures of Ta 183 models with antler antennae :)

Regards,

Henning (HoHun)
Focke-Wulf 2-TL Nachtjäger Projekt II



By the beginning of 1945, the Luftwaffe did not need an all-weather interceptor moskitojäger, but a heavy night fighter with extended range and a great amount of electronic equipment.

On 27 February, the Technisches Amt published the Hochleistung Nachtjäger specification for a high-performance night fighter. It called for an advanced airplane, powered by two HeS 011 A turbojets, using the new search radar Telefunken FuG 244 Bremen 0, that had a parabolic mirror of 70 cm diameter and additional Schräge Musik weapons.

Several alternatives were presented to the contest. The Me 262 B-2 (12 February 1945) was a variant of the Me 262 HG III high speed project; the Dornier P.256 was a jet version of the Do 435 - a modified variant of the Focke-Wulf Nachtjäger Projekt I - and five flying wings: the Arado Ar.I was the two-seat version of the Ar E.583; the Blohm und Voss P.215-02, an scaled-up version of the P.212 project fighter; the Gotha P.60 version C; the Horten Ho 229 B-1 - that was the combat version of the Ho 229 V6 trainer - and the Junkers EF.128/N with the nose radome modified for the Bremen 0 antenna.

On 2 March 1945, the OKL requested the inclusion of a third crew member and the addition of a tail warning radar device Siemens/FFO FuG 218 Neptun R3 with Yagi aerial. This left the Junkers, Heinkel and Horten designs out of the contest, as they could not increase the crew area for structural reasons. Messerschmitt was forced to enlarge the fuselage and redesign the wings (version of 17 March 1945) and Gotha solved the problem with great difficulty, by installing the navigator and the radar operator inside the wing roots.

The Dornier P.256 design was aerodynamically inefficient, due to the large drag induced by tail surfaces and underwing nacelles, having an endurance of 1h 45 min that was considered insufficient. For the same reason, the designs of Arado Ar 234 Series P, Ar.II and Ar TEW 16/43-19 were also rejected. As well as the Dornier P.252 / I because of the shortage of 87-octane B3 fuel consumed by its two DB 603 LA piston engines.

Unfortunately for the Germans, the Horten brothers did not have the industrial capacity for the series-production of the 229. The OKL assigned this task to the Gothaer Waggonfabrik firm in May 1945. There was a confrontation there between the philosophy of design of the Hortens and the available production techniques. Finally, the Gotha design team, under direction of Dr. Ing. Hunerjäger, reached to the conclusion that the additional weight of the electronic equipment and extra crew member, penalised the longitudinal stability of the Ho 229 B-1 in such a way, that made the take-off impossible without a considerable ballast of about 500 kg at the rear of the airplane. This was the last pure wing design of Horten. After the crash suffered by the Ho IX 2 on 18 February 1945, the OKL banned the manufacturing or airplanes without a tailfin.

The Blohm und Voss P.215-02 had a very radical shape to be accepted by the Luftwaffe and was designed without any possibility to move the FuG 244 antenna. The Gotha, even in its heaviest version, was considerably faster than the Arado. However, the former was chosen when the Luftwaffe suggested a last modification (20 March 1945) recommending the use of rear firing armament to defend against the Mosquito N.F.30 night fighters with electronic equipment Monica, AI and ASH that were more advanced than those of the Germans. The Arado Ar.I could carry a rearwards gun turret, due to the location of its engines and crew. Like in the Ar 234, only a pair of fixed guns, aimed by radar, could be installed in the Gotha.

On 26 February 1945, during a meeting with the Technisches Amt held in Bad Eilsen, main criticism was the excessive length of the of the air ducts in the Projekt I. The Focke-Wulf team of designers tried to solve the issue of the loss of thrust by installing the engines under the cockpit floor, to reduce the length of the air ducts to just 2.7 m. To balance the weight displacement, the main landing gear and Schräge Musik were positioned in the rear section of the fuselage. New mid-wings were designed with a 5.18:1 aspect ratio and 36 degrees rear swept. The drag reduction allowed to estimate a maximum speed of 904 kph at 7,000 m, a ceiling of 12,800 m and the maximum take-off weight of 12,700 kg. The construction system, the armament and the tail surfaces were the same than those in Projekt I, the wingspan was of 16 m, the length of 15.3 m, the height of 5.12 m and the wing area of 48.4 sq. m. With 5,400 litres of internal fuel, its endurance was 2 hours and 45 minutes, having the capability to transport up to 1,200 litres of additional fuel in underwing detachable tanks.

All these modifications were part of the Baubeschreibung Nr.251-51 dossier proposed to the OKL on 6 March 1945 as Hochleistung Nachtjäger Projekt II.

The electronic equipment was updated with the installation of a search radar Bremen 0 with 70 cm diameter parabolic mirror, a tail warning radar Neptun R3 and an IFF discriminator Lorenz FuG 226 Neuling with two Breitbanddipolen vertical blade-aerials on the upper surface of the wing.

In 1949, the Soviets built the MiG I-320, an all-weather a Slepouckin Torii radar, equipped with a parabolic antenna of 60 cm diameter and two crew seated side-by-side. Some authors believe that its design might have been inspired on that of Projekt II.
 

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Hi Justo,

On 27 February, the Technisches Amt published the Hochleistung Nachtjäger specification for a high-performance night fighter. It called for an advanced airplane, powered by two HeS 011 A turbojets, using the new search radar Telefunken FuG 244 Bremen 0, that had a parabolic mirror of 70 cm diameter and additional Schräge Musik weapons.

Thanks a lot for the rundown on the history of the Hochleistungs-Nachjäger project, and the great drawings of the Focke-Wulf entry!

I now realize I had misinterpreted your statement about the wing, with the MiG-9 actually "inheriting" the fuselage configuration of the Focke-Wulf but having the different wing you described.

Regards,

Henning (HoHun)
 

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