[WWII] Miles Libellula

[Phaelen Bleux]

Miles M.39B Libellula
During WWII, George Miles experimented with the concept of tandem wing aircraft. He produced two designs, both of which were named the Libellula (derived from the taxonomic name for dragonflies). The first, the M.35 was to be a carrier-based fighter. By using a tandem wing design, Miles envisioned avoiding the need for folding wings. The plane was unstable in flight, however, and never proceeded past a single prototype. However, the idea seemed promising, given some revisions of the design.
Hence, Miles proceeded with the M.39, a larger fighter-bomber with tandem wings. A wooden prototype was built in 5/8-scale and fitted with twin-propeller engines, although Miles ultimately envisioned a turbojet-powered aircraft. It was flight tested in 1944, prompting another reprimand from the Air Ministry for developing both the M.35 and the M.39 without official authorization. While the plane was helpful as a test bed, it never proceeded past its original small scale mock up.
The Miles M.39 has a crew of 1. The plane uses 5.2 gallons of aviation fuel per hour at routine usage. A full load of fuel costs $6.

Miles M.39B Libellula
Subassemblies: Light Fighter chassis +3; Light Fighter wings with High Agility option +2; 2 Small Weapon engine pods +0; 3 retractable Wheels +0.
Powertrain: Two 104-kW aerial HP gasoline engines with two 104-kW props and 30-gallon Ultralight fuel tank [Wings] (Fire 16); 2,000-kWs batteries.
Occ.: 1 CS
Cargo: 12 Body

Armor
All: 1/1W
Wheels: 2/3

Equipment:
Body: Medium range (10-mile) radio transmitter and receiver, autopilot, navigation instruments.

Statistics:
Size: 22'x38'x9' Payload: 0.20 tons Lwt.: 1.4 tons
Volume: 144 Maint.: 77 hours Cost: $6,693
HT: 9. HPs: 50 Body, 90 each Wing, 30 each Pod, 5 each Wheel.
aSpeed: 164 aAccel: 4 aDecel: 54 aMR: 13.5 aSR: 2
Stall Speed: 46 mph. Take Off Run: 212 yards. Landing Run: 212 yards.
gSpeed: 195 gAccel: 10 gDecel: 10 gMR: 0.5 gSR: 2
Ground Pressure: Very High. 1/8 Off-Road Speed.

Design Notes:
Historical wing area was 249 sf. Loaded weight was increased 12 lbs. to the historical. Design aSpeed was 157 mph. Fuel tankage is a guess based on available payload. Historical values were used for all calculations and substituted above when available.
I used an exceptionally oversized chassis because (a.) it made the loaded weight work out right, (b.) the prototype does not include any armament which would have been later added, and (c.) I plan to do just that.

[Phaelen Bleux]

Miles M.39J Libellula
This design is a hypothetical production version of the M.39B Libellula. It is fitted with jet engines, hardpoints, and autocannons in the nose. One thing I did not change much was the plane's size--it remains close to the 5/8 scale of the prototype, functioning more as a heavily armed fighter than a true bomber.
The Miles M.39 has a crew of 1. The plane uses 250 gallons of jet fuel per hour at routine usage. A full load of fuel costs $135.

Miles M.39J Libellula
Subassemblies: Medium Fighter chassis +3; Medium Fighter wings with High Agility option +2; 2 Medium Weapon engine pods +1; 3 retractable Wheels +0.
Powertrain: Two 2,500-lb. thrust turbojets [Pods] and 450-gallon Self-Sealing fuel tank [Wings] (Fire 13); 2,000-kWs batteries.
Occ.: 1 CS
Cargo: 5 Body

Armor
All: 2/3

Weaponry:
4xLong Aircraft AC [Body:F] (150 rounds each).*
4x500-lb. Bombs [Wings:U].
*Linked.

Equipment:
Body: Medium range (10-mile) radio transmitter and receiver, autopilot, navigation instruments, IFF, bombsight. Wings: 2 500-lb. hardpoints each.

Statistics:
Size: 25'x40'x10' Payload: 2.73 tons Lwt.: 6.73 tons
Volume: 200 Maint.: 42 hours Cost: $23,144
HT: 7. HPs: 120 Body, 105 each Wing, 50 each Pod, 12 each Wheel.
aSpeed: 413 aAccel: 7 aDecel: 13 aMR: 3 aSR: 2
Stall Speed: 94 mph.
gSpeed: 436 gAccel: 22 gDecel: 10 gMR: 0.5 gSR: 2
Ground Pressure: Extremely High. No Off-Road Speed.

Design Notes:
No deviations from standard MVDS design.
If one would prefer to maintain the aircraft as prop-driven, the pods as-is will accommodate two 495-kW aerial turbocharged HP gas engines. Fuel consumption drops to 50 gph. I reduced fuel tankage to 240 gallons; overall this reduces loaded weight to 10,311 lbs. Performance stats become: Stall speed 83, aAccel 6, aSpeed 318, aMR 4, aDecel 17.