Copyright 2011 by Brandon Cope
Focke-Achgelis Fa 247 tilt-wing transport
In
1938 Weser began a project involving a two-man tilt-wing aircraft,
the P.1003. The engine was located in the fuselage and drove rotors
in wingtip pods through geared shafts running through the wings,
which rotated midwing with up and forward positions. The project
never produced a prototype, perhaps because of the limited
capabilities of such a small plane.
In 1941, Focke-Achgelis, wishing to improve the Fa 223 (p.W:MP76)
decided to modify one example; replacing the outriggers with
tilt-rotor wings similar to those used in the P.1003, but with the
fuselage 746-kW engine removed and and one 746-kW engine added to
each wingtip rotor pod. Although the plane was somewhat limited in
capacity; with six passengers (eight in an emergency) or 3.2 tons of
cargo (only half that internally), it could take-off and land like a
helicopter but fly like an airplane.
The Fa 247 was not
considered a great success; it was not a great deal more capable than
the fa 223 but cost three times as much. In the end, only around 50
were built, split between the A-1 cargo and A-2 passenger versions,
plus a very small number of the A-3 ASW version. Theses craft were
heavily used, however. The much larger Fa 338 which followed was
significantly more capable.
Crew consists of a pilot and copilot. The Fa 247 uses 67 gallons of aviation fuel per hour.
Subassemblies: Huge Helicopter Chassis with MMR option +3,
Heavy fighter wings +2, 2xMedium AFV engine pods +2, two rotors -1,
three fixed wheels +1
P&P: 2x746 kW aerial HP gasoline
engine w/2x746-kW tilt-wing transmission, 150 gallon and 120 gallon
ultralight tanks [Body]
Occ: 2 CS Cargo: 34 Body.
Armor
Body: 2/2C
Wings/Pods: 2/3
Rotor: 3/10
Wheels: 3/5
Equipment
Body: medium range radio receiver and
transmitter, navigational instruments, 30 VSP cargo hold, 4x1,000-lb
hardpoints
Statistics
Size: 40'x80'x14' |
Payload: 2.6 tons |
Lwt: 7.6 tons |
Volume: 400 |
Maint.: 27 hours |
Price: $56,800 |
HT: 10
HP: 360
[body], 50 [each rotor], 120 [each wing], 200 [each pod], 10 [each
wheel]
as Helicopter
aSpeed: 117 |
aAccel: 3 |
aDecel: 18 |
aMR: 4.5 |
aSR: 2 |
Stall: 0 mph |
as Plane
aSpeed: 226 |
aAccel: 6 |
aDecel: 15 |
aMR: 3.5 |
aSR: 2 |
Stall: 106 mph |
Design Notes
As helicopters tend to have too high a
speed under MVDS, aSpeed was reduced by 20%. Wing cost, weight and HP
were divided by two.
Space is provided for the addition of an internal 120 gallon auxiliary fuel tank, included in the stats above. If omitted, subtract 0.4 tons from payload, decreasing Stall to 103 and aMR to 4.75 as a helicopter. One or two 300 liter (79 gallon) drop tanks are also often fitted to increase range, weighing 600 lbs each.
The stats above assume a 1.5 ton internal cargo load and no external stores. Up to 1.5 more tons can be carried on four hardpoints under the fuselage (if any cargo is slug underbody, the Fl 247 can't fly faster than 115 mph). At maximum lift (3.2 tons, no auxiliary tank) Stall is 115 (leaving a very narrow transition window), aMR is 3.5/3, aDecel is /1412 and HT is 9.
The tilt-wing was based on the tilt-rotor rules (p.VE34). The helicopter must use the multiple main rotors option (p.W:MP1) and the helicopter's cost, weight and volume are increased by 50%; the basic transmissions go into two pods, at each wingtip, with the extra going into the wings. The wings cannot mount weapons or fuel tanks, and their hardpoint capacity is halved. The aircraft must be traveling above stall speed to transition from plane. Transitioning either way takes 4 seconds and the pilor is -5 to Dodge.
Variants
The Fa 247A-2 carried six passengers and the
internal auxiliary tank. Stall is 100, aMR is 5/4 and aDecel is
20/16. Three MG 15's (Aircraft LMGs) with 750 rounds per gun can
optionally be carried, but must be fired by the passengers. One is
located in each beam position and one dorsal firing to the rear. Some
were converted to use in the medivac role, with three patients on
stretchers and one medic. These were generally unarmed, except on the
Eastern Front.
The Fa 247A-3 carried two drop tanks and either four 400-lb depth charges or two 500mm torpedoes. It added three gunners with three MG 131's (Medium Aircraft HMG) with 500 rounds per gun.