[WWII] Fokker A.IV heavy gyrocopter bomber (Netherlands, fictional)

[copeab]

This is even more of a pulp design than the light autogyro bomber from last week. In a world where autogyros developed faster, this might possibly be able to survive against biplane fighters with top speeds of around 175-200 mph (maybe about 1927-1933). I have given it a WWII color text just in case.

For those wondering, the outer engines are mounted on the wing tips and I counted the engines against the wings' hardpoint limit.

Also, while my altered performance formula for autogyros works well for those in the historical size range, they may not hold well for very large ones like the last two.
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Fokker A.IV heavy autogyro bomber
Copyright 2012 by Brandon Cope

As the A.III neared production, it was decided an aircraft with longer range and a heavier bomb load was desired to 'take the fight to the enemy'. The resulting autogyro was a massive design, with wings to support four engines and improve agility (which was still poor). While it was the most impressive autogyro at the time it entered service, it was too ambitious of a design and was asked to do too much for the technology.

The A.IV had the range to hit any target in German with 4,000 kg of bombs. A major problem was, that with it's low speed, it would take it a long time to reach targets as far as Berlin, Dresden or Munich. Perhaps to fend off German concerns, the Dutch pointed out that the A.IV could also reach London or Paris, although no one (especially the Germans) really believed that the autogyro would ever bomb these two cities.

Crew of the A.IV is 7: pilot, navigator/radio operator, bombardier (who also operates the nose LMG), and four gunners (tail, ventral, and port and starboard beam positions). The A.IV uses 144 gallons of aviation fuel per hour.

Subassemblies: Gargantuan Helicopter Chassis +4, Heavy Fighter wings with High Agility option +3, 3xLarge Weapon engine pods [Wings:F], Rotors +1, three fixed Wheels +1
P&P: 4x800 kW turbo HP gasoline engines w/4x800-kW props, 1,170 gallon standard tanks [Wings and Body]
Occ: 7 CS Cargo: 75.

Armor
Body: 2/2
Rotors: 3/10
Wheels: 3/5

Weaponry
Aircraft LMG [Body:F] (1,000)
Aircraft LMG [Body:R] (1,000)
Aircraft LMG [Body:L] (1,000)
2*Aircraft LMG [Body:B] (1,000 each)
Aircraft LMG [Body:U] (1,000)

Equipment
Body: Long range radio receiver and transmitter, bomb sight, navigational instruments, 8,800-lb bomb bay..

Statistics
Size: 90'x5\70'x12'
Payload: 8.5 tons
Lwt: 19.1 tons
Volume: 800
Maint.: 29 hours
Price: $46,500

HT: 7
HP: 450 [body], 72 [rotor], 240 [each wing], 120 [each engine pod], 45 [each wheel]

aSpeed: 146
aAccel: 5
aDecel: 8
aMR: 1.25
aSR: 1
Stall: 27 mph
Take-off roll (loaded): 27 yards. Landing roll (loaded): 7 yards
Take-off roll (no bombs, max fuel): 18 yards. Landing roll (no bombs, 10% fuel): 5 yards

Design Notes
The autogyro can sacrifice internal bomb load for more fuel. For each 1,100 lbs of bombs not carried, 17- gallons of auxiliary fuel tanks can be fitted.

To better match historical autogyros, rotor area was raised to the 1.75 power in stall calculations and 1.5 power in speed calculations. Takeoff was divided by 3 and landing distances by 10.

Variants
The A.V was the transport version, with 28 passengers or 700 cf (140 vsp) of cargo. The bomb bay was removed, the four gunners but their positions were retained. Large oval doors were added to the port and starboard sides and the nose was hinged to fold down and serve as a loading ramp. A dozen were built and most A.IV's that survived the German invasion were converted to A.V's, where they proved useful short-field transports.

[johndallman]

I'm starting to feel a bizarre WWII parallel Earth coming on where everything that flies is autogyros. I just need to find a semi-plausible excuse.

[copeab]

Originally Posted by johndallman

I'm starting to feel a bizarre WWII parallel Earth coming on where everything that flies is autogyros. I just need to find a semi-plausible excuse.

Autogyros and zeppelins ;)

[RogerBW]

Originally Posted by johndallman

I'm starting to feel a bizarre WWII parallel Earth coming on where everything that flies is autogyros. I just need to find a semi-plausible excuse.

Off the top of my head: the advantage the gyro has over the fixed-wing plane is in low-speed flight, which splits out to takeoff/landing distance and stall speed. For the former to be important, you need lots of little air bases without the large fields that are all that's needed for inter-war aircraft to take off - perhaps there's better observation for finding the fields, and/or a better air-to-ground weapon for rendering them useless. For the latter, you need lots of choppy air near the ground, making a conventional landing dangerous.

[Anthony]

Originally Posted by copeab

Autogyros and zeppelins ;)

Unfortunately, the easiest weirdness to encourage zeppelins (denser atmosphere) also discourages autogyros (as stall speed becomes less of a problem, whereas high speed drag is more of a problem).