Boeing SB-29 Superfortress Specifications (1954)

Boeing SB-29 Superfortress Specifications (1954)

Boeing SB-29 Superfortress Specifications (1954) tittle

Mission

The main mission of the SB-29 was air search and rescue of personnel stranded in water, primarily to provide rescue support for units flying long distances over water. This objective was achieved using radar and a disposable A-3 lifeboat.

The SB-29s served in the Korean War, carrying A-3 lifeboats over the Yellow Sea and the Sea of Japan. During B-29 bombing missions, the SB-29s would maintain a position off the enemy coast and search for downed aircrews. Upon locating the stranded crews, the SB-29 would deploy an EDO A-3 rescue boat, with its descent slowed by parachutes.

Boeing SB-29 aircraft with a droppable A-3 lifeboat attached. (U.S. Air Force photo)

Development

The success of the B-17H later referred to as the SB-17 Dumbo, prompted experimentation with a similar air-sea rescue aircraft based on the B-29 as early as 1944. The Superfortress’s extended range, increased lift capacity, and advanced features were all deemed improvements over the SB-17’s capabilities.

In 1949, a series of conversions for a select number of SB-29 aircraft commenced. According to recent research by Robert A. Mann, 25 such aircraft were primarily converted at Tinker Air Force Base.

Differences with B-29

The conversion from the Boeing B-29 to the SB-29 resulted in three distinct changes not found in the production B-29s:

  • First, the AN/APQ-13 radome was relocated from between the bomb bays to the position typically occupied by the lower forward turret.
  • Second, the 30-foot, droppable Edo A-3 lifeboat was mounted externally to the bomb bays.
  • Lastly, the radio operator’s position was moved from the right-rear corner of the forward compartment to the rear pressurized compartment.
An SB-29 from the A 3rd ARS flying in Korea
An SB-29 from the A 3rd ARS flying in Korea. (U.S. Air Force photo)

Despite these modifications, the remaining armament, which included the upper forward turret, two aft turrets, and tail guns, remained in the aircraft and operational.

Dimensions and Weights

Boeing SB-29 Superfortress Dimensions
DIMENSIONSUSMetric
Wing
  • Span
  • 141.2 ft43 m
  • Incidence
  • Dihedral
  • 4°29'23"4°29'23"
  • Sweepback(LE)
  • 7°1'26"7°1'26"
  • Wing Area
  • 1720 ft2159.8 m2
  • Aspect Ratio
  • 11.511.5
  • Wing Section
  • Boeing 117Boeing 117
  • M.A.C.
  • 154.4147.1 m
    Length99 ft30.2 m
    Height27.8 ft8.5 m
    Tread28.5 ft8.7 m
    Prop. Grd Clearance1.3 ft0.4 m
    WEIGHTS
    Loading
  • Empty (E)
  • 68,350 lbs31.003 kg
  • Basic (E)
  • 72,616 lbs32.938 kg
    Operating
  • Design
  • 120,000 lbs54.431 kg
  • Combat (*)
  • 99,410 lbs45.092 kg
  • Max Take Off (1)
  • 120,662 lbs54.731 kg
  • Max Landing (2)
  • 120,662 lbs54.731 kg

    (E) Estimated
    (*) For basic mission
    (1) Limited by performance
    (2) Limited by gear strength

    Engines

    Attribute Value
    POWER PLANT
  • No, & Model
  • (4) R-3350-57 or-83
  • Manufacturer
  • Curtiss - Wright Corp., Wright Aeronautical Corp. Division
  • Engine Spec
  • .787-C
  • Superch
  • 1 stg, 1 spd
  • Turbo superch
  • B-11 or B-31
  • Turbo Manufacturer
  • General Electric Co.
  • Red, Gear Ratio
  • 0.35
    PROPELLER
  • Propeller Manufacturer
  • United Aircraft Corp., Hamilton Standard Propeller Division
  • Blade Design No.
  • 6521A-6
  • Propeller Type
  • C.S., Full-Feathering, Hydromatic
  • No. Blades
  • 4
  • Propeller Diameter
  • 16' 7" (5 m)
    ENGINE RATINGS
  • Take Off
  • 2200/2800rpm
  • Military
  • 2200/2600rpm/2500ft
  • Normal
  • 2000/2400rpm/4000ft

    Electronics

    EquipmentUS Designation
    UHF CommandAN/ARC-27
    VHF CommandAN/ARC-3
    LiaisonAN/ARC-8
    InterphoneAN/AIC-2A
    Radio CompassAN/ARN-7
    Marker BeaconRC-193A
    Homing AdapterAN/ARA-8
    Glide PathAN/ARN-5B
    Radio AltimeterSCR-718C
    Radio Altimeter AN/APN-1
    InterrogatorSCR-729
    IFFSCR-695B
    LoranAN/APN-9
    Search RadarAN/APQ-13A
    Pulse DopplerAN/APA-52
    Remote ControlAN/URW-3

    Crew

    Boeing SB-29 Superfortress crew and sections

    The SB-29 had a normal crew of 11 that consisted of:

    1. Pilot
    2. Co-pilot
    3. Flight engineer
    4. Navigator
    5. Bombardier
    6. Remote control turret operator
    7. Radar operator
    8. (2) Radio operators
    9. Left scanner
    10. Right scanner

    EDO A-3 lifeboat

    The A-3 Airborne Lifeboat, or EDO Model 98, was created by the EDO Corporation in 1947 for the United States Air Force as a successor to the Higgins Industries A-1 lifeboat.

    The lifeboat measured 30.05 feet in length, weighed 2,736 pounds when fully loaded, and could rescue up to 15 survivors. Powered by a Meteor 20 gasoline engine, it reached speeds of 8 knots and was dropped from the SB-29 using a 100-foot parachute.

    The A-3 lifeboat featured various safety and functional components, such as a sail, a self-draining cockpit, and 20 watertight compartments. It was also equipped with bow and stern self-righting chambers that inflated automatically upon release, ensuring the boat was self-righting.

    As it descended from 800 to 5,000 feet, the lifeboat’s 100-foot parachute helped stabilize its flight characteristics. The boat’s propellers and rudder were protected by metal guards, and the parachute was designed to reduce impact shock when the boat hit the water. The parachute also triggered valves to fill self-righting chambers with carbon dioxide and activated a white electric beacon for nighttime visibility.

    Although not luxurious, the A-3 lifeboat was equipped with essential survival gear for aircrews in distress at sea. It featured ladders for easy boarding, a waterproof plexiglass shell to protect the engine, and storage for warm clothes, food, medical supplies, and other provisions for a crew of 15.

    The lifeboat also included a gasoline-operated distiller to convert saltwater into fresh drinking water, as well as other essential equipment such as a sea anchor, fire extinguisher, compass, navigational aids, bilge pump, heaving quoit, tool kit, salt water soap, and a cockpit compartment heater.

    Feature/EquipmentDescription
    US DesignationA-3 Airborne Lifeboat
    ModelEDO Model 98
    ManufacturerEDO Corporation, College Point, Long Island, New York
    Overall Length30.05 feet
    Weight (fully loaded)2,736 pounds
    Passenger Capacity15 survivors
    MaterialAluminum alloy
    EngineFour-cylinder, four-stroke Meteor 20 gasoline engine by Red Wing Motor Company
    PropellerAilsa Craig propeller
    Speed8 knots under calm water conditions
    Fuel Capacity100 US gallons
    Range500 nm
    ParachuteSingle 100-foot diameter parachute, 7,857 square feet of nylon
    Self-RightingEquipped with bow and stern rubberized fabric self-righting chambers
    Boarding LadderIncluded
    ProvisionsFood, water, and radio gear for rescued individuals
    Protective FeaturesMetal guards for propellers and rudder; waterproof plexiglass shell for engine
    Navigational EquipmentCompass, navigational aids
    Survival EquipmentWarm clothes, medical supplies, sea anchor, fire extinguisher, bilge pump, heaving quoit, tool kit, salt water soap
    Additional FeaturesGasoline-operated distiller for fresh water; cockpit compartment heater; self-draining cockpit; 20 watertight compartments

    Fuel system

    Boeing SB-29 Superfortress fuel system
    LocationNo. TanksGalsLiters
    Wing, outbond*226409993
    Wing, inbound*2283010713
    Wing, center*113335046
    Total680325752

    (*) Self Sealing tanks

    Bombs

    Bombs racks were installed but bombing capacities were not considered

    Guns

    During the conversion to SB-29 the upper forward turret, two aft turrets, and tail guns, remained in the aircraft. However, the B-29B Superfortress Standard Aircraft Characteristics of 1954 indicates that the Air Force removed all the guns.

    Performance

    The basic performance of the SB-29 was the following:

    Combat radius

    1685 nm

    with an A-3 lifeboat at 172 knots avg. in 19.80 hours

    Combat range

    ——–

    Combat speed

    239 kn

    at 10,000 ft alt, max power

    Maximum speed

    334 kn


    at 33,300 ft alt, max power

    Climb

    730/1345

    fpm sea level, take-off weight normal power
    /fpm sea level, combat weight max power

    Ceiling

    32,800/
    35,600 ft

    100 fpm, take-off weight, normal power
    /500 fpm, combat weight max power

    Loading and Performance

    ConditionsBasic missionBoat droppedFerry range
    TAKE-OFF WEIGHT 120,662 lb54.731 kg120,662 lb54.731 kg120,662 lb54.731 kg
  • Fuel at 6. 0 lb/gal (grade 100/130)
  • 40,818 lb18.515 kg40,818 lb18.515 kg40,818 lb18.515 kg
  • Payload (Boat)
  • 3,491 lb(4)1.583 kg3,491 lb1.583 kg3,491 lb(4)1.583 kg
  • Wing loading
  • 70.2 lb/sq ft342.7 kg/m270.2 lb/sq ft342.7 kg/m270.2 lb/sq ft342.7 kg/m2
  • Stall speed (power off)
  • 95.7 kn177 km/h95.7 kn177 km/h95.7 kn177 km/h
  • Take-off ground run at SL (1)
  • 3,475 ft1.059 m3,475 ft1.059 m3,475 ft1.059 m
  • Take-off to clear 50 ft (1)
  • 5,075 ft1.547 m5,075 ft1.547 m5,075 ft1.547 m
  • Rate of climb at SL (2)
  • 730 fpm223 m/min730 fpm223 m/min730 fpm223 m/min
  • Rate of climb at SL (one eng. out) (1)
  • 435 fpm133 m/min435 fpm133 m/min435 fpm133 m/min
  • Time: SL to 10, 000 ft (2)
  • 15.0 min 15.0 min 15.0 min
  • Time: SL to 20,000 ft (2)
  • 35.0 min 35.0 min 35.0 min
  • Service ceiling (100 fpm) (2)
  • 32,800 ft9.997 m32,800 ft9.997 m32,800 ft9.997 m
  • Service ceiling (one eng. out) (1)
  • 21,600 ft6.584 m21,600 ft6.584 m21,600 ft6.584 m
    COMBAT RANGE 3,445 n.mi6380 km
    COMBAT RADIUS1,685 n.mi3.121 km1,759 n.mi3.258 km
  • Average cruise speed
  • 172 kn319 km/h173 kn320 km/h173 kn320 km/h
  • Initial cruising altitude
  • 5,000 ft1.524 m5,000 ft1.524 m5,000 ft1.524 m
  • Search altitude
  • Sea levelSea level
  • Final cruising altitude
  • 5,000 ft1.524 m5,000 ft1.524 m5,000 ft1.524 m
  • Total mission time
  • 19.8 hr 20.6 hr 20.0 hr
    COMBAT WEIGHT99,410 lb45.092 kg95,119 lb43.145 kg82,579 lb37.457 kg
  • Combat altitude
  • Sea levelSea level5,000 ft1.524 m
  • Combat speed (1)
  • 239 kn443 km/h250 kn463 km/h254 kn470 km/h
  • Combat climb (1)
  • 1,345 fpm410 m/min1,520 fpm463 m/min1,780 fpm543 m/min
  • Combat ceiling (500 fpm) (1)
  • 35,600 ft10.851 m37,300 ft11.369 m39,500 ft12.040 m
  • Service ceiling (100 fpm) (2)
  • 38,600 ft11.765 m39,700 ft12.101 m42,600 ft12.984 m
  • Service ceiling (one eng. out) (2)
  • 32,400 ft9.876 m36,800 ft11.217 m38,800 ft11.826 m
  • Max rate of climb at SL (1)
  • 1,345 fpm410 m/min1,520 fpm463 m/min1,850 fpm564 m/min
  • Max speed at optimum altitude (1)
  • 334 kn/33,300 ft 619 km/h /10.150 m349 kn/33,300 ft 646 km/h /10.150 m344 kn/33,300 ft 637 km/h /10.150 m
  • Basic speed at 25, 000 ft (1)
  • 306 kn567 km/h318 kn589 km/h313 kn580 km/h
    LANDING WEIGHT82,579 lb37.457 kg79,037 lb35.851 kg82,579 lb37.457 kg
  • Ground roll at SL
  • 2,200 ft671 m2,120 ft646 m2,200 ft671 m
  • Total from 50 ft
  • 2,950 ft899 m2,840 ft866 m2,950 ft899 m

    Further reading

    Bibliography

    • B-29 Superfortress in detail & scale, Part 2 by Alwyn T. Lloyd
    • The B-29 Superfortress: A Comprehensive Registry of the Planes and Their Missions by e Robert A. Mann
    • SB-29 Superfortress Standard Aircraft Characteristics 15-JUN-1954, Air Materiel Command, U.S. Air Force
    • “Operation Splash” by Frank W. Penniman, Life of the Soldier and the Airman, U.S. Army, 1948

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    Javier Guerrero
    Javier Guerrero
    Javier is the editor @ Nuclear Companion and loves to investigate and write about the cold war.

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