Mission

The main objective of the B-29B is to destruct enemy materials and facilities through aerial bombardment.

Development

The B-29B, a lightened version of the Superfortress, was exclusively manufactured by Bell-Atlanta. Production commenced with the first acceptance from Bell in January 1945 and was completed by September 1945. Instead of being ordered in a single large batch, the B-29Bs were ordered in small batches, sometimes individually, from the B-29-BA production lines. Between January and September 1945, a total of 311 B-29Bs were constructed.

Differences with B-29

The B-29B is a streamlined version of the B-29 airplane, featuring several notable modifications. These changes include a transfer type fuel system, a reduced crew of ten, the removal of all turrets and accessories except for the tail turret (which houses three .50 caliber guns and a gunner), smooth closures for all turret and sight openings, and the incorporation of radar systems for navigation, bombing through overcast conditions, and night fighter protection in the tail.

Distinguishing B-29Bs from the ‘ordinary’ B-29s, which were also stripped of their machine gun turrets to save weight during General LeMay’s firebombing campaign against Japan in 1945, can be challenging. However, the B-29Bs can be identified by their serial numbers and the presence of an external radar antenna located at the extreme tail.

Dimensions and Weights

DIMENSIONS	Imperial	Metric
Wing
Span	141.2 ft	43 m
Incidence	4°	4°
Dihedral	4°29'23"	4°29'23"
Sweepback(LE)	7°1'26"	7°1'26"
Wing Area	1720 ft2	159.8 m2
Aspect Ratio	11.5	11.5
Wing Section	Boeing 117	Boeing 117
M.A.C.	154.41	47.1 m
Length	99 ft	30.2 m
Height	27.8 ft	8.5 m
Tread	28.5 ft	8.7 m
Prop. Grd Clearance	1.3 ft	0.4 m
WEIGHTS
Loading
Empty (A)	68,821 lbs	31.217 kg
Basic (A)	68,821 lbs	32.061 kg
Operating
Design	120,000 lbs	54.431 kg
Combat (*)	96,126 lbs	43.602 kg
Max Take Off (1)	137,014 lbs	62.149 kg
Max Landing (2)	135,000 lbs	61.235 kg

(A) Actual
(*) For basic mission
(1) Limited by performance
(2) Limited by gear strength

Engines

Attribute	Value
POWER PLANT
No, & Model	(4) R-3350-57 or-57A
Manufacturer	Curtiss - Wright Corp., Wright Aeronautical Corp. Division
Engine Spec	95-28266-5
Sup	(Dual Turbo) B-11 or B-31
Red, Gear Ratio	0.35
PROPELLER
Propeller Manufacturer	United Aircraft Corp., Hamilton Standard Propeller Division
Blade Design No.	6521A-6
Propeller Type	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

The electronic suite of the B-29B, as of 1950, consisted of the following components:

Equipment	US Designation
VHF Command	AN/ARC-3
Interphone	AN/AIC-2A
Liaison	AN/ARC-8
Radio Compass	AN/ARN-7
Marker Beacon	RC-193A
Homing Adapter	AN/ARR-1
Localizer	RC-103
Glide Path	AN/ARN-5A
Radio Altimeter	SCR-718C
Interrogator	SCR-729
Radar	AN/APQ-7 or AN/APQ-23A
Loran	AN/APN-9 or AN/APN-4
IFF	SCR-695
Raven	RCM

Crew

The B-29B’s crew composition was streamlined due to the changes in its defensive armament. As a result, right and left-side gunners were no longer needed, and the central fire control gunner sometimes served as an observer. Additionally, the radar operator could often take on the bombardier’s responsibilities. This allowed the aircraft to operate with a reduced crew of seven to eight members, as fewer gunners were necessary.

However, the B-29B typically carried up to ten crew members including two scanners. The role of the scanners was to keep an eye out for both friendly and enemy aircraft in the vicinity.

The B-29B crew list was:

1. Pilot
2. Co-pilot
3. Navigator
4. Flight engineer
5. Bombardier
6. Radio operator
7. Radar operator
8. Left scanner
9. Right scanner
10. Tail gunner

Fuel system

Location	No. Tanks	Gals	Liters
Wing, outbond*	2	2640	9993
Wing, inbound*	2	2830	10713
Wing, center*	1	1333	5046
Bomb bay	2	2560	9691
	Total	9363	35443

(*) Self Sealing tanks

Bombs and Guns

Defensive armament

The B-29B aircraft underwent modifications to its defensive armament in response to combat experiences in the Pacific, where the primary enemy fighter attacks were observed to come from the rear. As a result, all fuselage turrets, removable turret structures, related turret equipment, and armament were removed, leaving only the tail gun and sighting station. Flush covers were placed over the turret and sighting blister locations.

The tail gun was upgraded with the addition of a third .50cal machine gun, increased ammunition provisions, and an advanced AN/APG-15B airborne radar-directed fire control system called the Airborne Radar Gun Sighting System. This innovative system was designed to detect approaching enemy aircraft, lock on to them, and automatically fire the necessary guns. It made all the necessary calculations for tracking and firing on enemy aircraft by coupling to the GE gun computer and IFF (“Ella”) units.

To reduce weight, the armor was removed from the B-29B except for the glass in front of the airplane commander’s position and the armor and glass in the tail gunner’s position. Flak protection was also removed, except for the Dural plate situated behind the airplane commander’s position.

No.	Calibre/ Rounds each	Location
2	.50 / 500	Tail turret
1	.50 / 380	Tail turret

Bombs

In practice, the B-29B was capable of carrying even larger payloads by operating at lower altitudes, which optimized fuel consumption. While its maximum bomb load was 20,000 lb, it could reach up to 22,800 lb when carrying a mixed incendiary load.

No.	Size	Type
4	4000 lbs	General-purpose (G.P.)
8	2000 lbs	General-purpose (G.P.)
12	1600 lbs	Armor-piercing (A.P.)
12	1000 lbs	General-purpose (G.P.)
40	500 lbs	General-purpose (G.P.)

Performance

By removing the turrets and the related General Electric computerized gun system, the B-29B Superfortress gained an increase in top speed. This made the aircraft well-suited for swift, unescorted bombing raids and reconnaissance missions that relied on hit-and-run tactics.

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

Loading and Performance

Basic mission, Max bombs mission, High alt. mission

Conditions	Basic mission		Max Bombs Mission
TAKE-OFF WEIGHT	135,744 lb	61.572 kg	136,464 lb	61.899 kg
Fuel at 6. lb/gal	48,498 lb	21.998 kg	40,818 lb	18.515 kg
Military load (Bombs)	10,000 lb	4.536 kg	20,000 lb	9.072 kg
Wing loading	79.0 lb/sq ft	385,7 kg/m2	79.3 lb/sq ft	387.,1 kg/m2
Stall speed (power off)	102 kn	189 km/h	102 kn	189 km/h
Take-off ground run at SL	4,800 ft	1.463 m	4,860 ft	1.481 m
Take-off to clear 50 ft	7,125 ft	2.172 m	7,225 ft	2.202 m
Rate-of-climb at SL (3)	618 fpm	188 m/min	602 fpm	183 m/min
Time: SL to 10,000 ft (3)	18.5 min		18.8 min
Time: SL to 20,000 ft	43.5 min		45.0 min
Service ceiling (100 fpm)	30,250 ft	9.220 m	29,900 ft	9.114 m
Service ceiling (one engine out)(2)	26,200 ft	7.986 m	25,800 ft	7.864 m
COMBAT RANGE	3,926 n.mi	7.271 km	3,076 n.mi	5.697 km
Avg cruising speed	191 kn	354 km/h	195 kn	361 km/h
Cruising altitude	10,000 ft	3.048 m	10,000 ft	3.048 m
Total mission time	20.73 hr		15.94 hr
COMBAT RADIUS (5)	2,122 n.mi	3.930 km	1,725 n.mi	3.195 km
Avg cruising speed	208 kn	385 km/h	210 kn	389 km/h
Cruising altitude (s)	10,000 ft & 25,000 ft	3.048 m & 7.620 m	10,000 ft & 25,000 ft	3.048 m & 7.620 m
Total mission time	20.66 hr		16.69 hr
COMBAT WEIGHT (6)	96,126 lb	43.602 kg	92,353 lb	41.891 kg
Combat altitude	25,000 ft	7.620 m	25,000 ft	7.620 m
Combat speed (2)	344 kn	637 km/h	345 kn	639 km/h
Combat climb	1,480 fpm	451 m/min	1,610 fpm	491 m/min
Combat ceiling (500 fpm) (2)	38,000 ft	11.582 m	38,750 ft	11.811 m
Service ceiling (100 fpm) (3)	41,400 ft	12.619 m	42,300 ft	12.893 m
Service ceiling (one engine out)(3)	37,200 ft	11.339 m	38,100 ft	11.613 m
Max rate-of-climb at SL(2)	1,820 fpm	555 m/min	1,925 fpm	587 m/min
Max speed at 10,000 ft(2)	360 kn	667 km/h	361 kn	669 km/h
LANDING WEIGHT	78,071 lb	35.412 kg	77,687 lb	35.238 kg
Ground roll at SL(4)	2,100 ft	640 m	2,090 ft	637 m
Total from 50 ft(4)	2,800 ft	853 m	2,790 ft	850 m

NOTES
(1) Take-off power
(2) Max power
(3) Normal power
(4) Take-off and landing distances are obtainable at sea level using normal techniques. For airport planning, distances should be increased by appropriate factors to determine runway requirements.

High Alt. Mission, Ferry Range

Conditions	High Alt. Mission		Ferry Range
TAKE-OFF WEIGHT	135,744 lb	61.572 kg	135,024 lb	61.246 kg
Fuel at 6. lb/gal	48,498 lb	21.998 kg	56,178 lb	25.482 kg
Military load (Bombs)	10,000 lb	4.536 kg
Wing loading	79.0 lb/sq ft	385,7 kg/m2	78.5 lb/sq ft	383.2 kg/m2
Stall speed (power off)	102 kn	189 km/h	102 kn	189 km/h
Take-off ground run at SL	4,800 ft	1463 m	4,725 ft	1.440 m
Take-off to clear 50 ft	7,125 ft	2.172 m	7,025 ft	2.141 m
Rate-of-climb at SL (3)	618 fpm	188 m/min	625 fpm	191 m/min
Time: SL to 10,000 ft (3)	18,5 min		18.2 min
Time: SL to 20,000 ft	43,5 min		43.0 min
Service ceiling (100 fpm)	30,250 ft	9.220 m	30,600 ft	9.327 m
Service ceiling (one engine out)(2)	26,200 ft	7.986 m	26,550 ft	8.092 m
COMBAT RANGE	3,505 n.mi	6.491 km	4,939 n.mi	9.147 km
Avg cruising speed	267 kn	494 km/h	185 kn	343 km/h
Cruising altitude	25,000 ft	7.620 m	10,000 ft	3.048 m
Total mission time	13.27 hr		26.83 hr
COMBAT RADIUS (5)	1,959 n.mi	3.628 km
Avg cruising speed	235 kn	435 km/h
Cruising altitude (s)	25,000 ft & 30,000 ft	7.620 m & 9144 m
Total mission time	16.86 hr
COMBAT WEIGHT (6)	95,320 lb	43.236 kg	81,263 lb	36.860 kg
Combat altitude	30,000 ft	9.144 m	10,000 ft	3.048 m
Combat speed (2)	360 kn	667 km/h	308 kn	570 km/h
Combat climb	1,375 fpm	419 m/min	2,210 fpm	674 m/min
Combat ceiling (500 fpm) (2)	38,200 ft	11.643 m	41,450 ft	12.634 m
Service ceiling (100 fpm) (3)	41,650 ft	12.695 m	44,950 ft	13.701 m
Service ceiling (one engine out)(3)	37,400 ft	11.400 m	40,900 ft	12.466 m
Max rate-of-climb at SL(2)	1,840 fpm	561 m/min	2,330 fpm	710 m/min
Max speed at 10,000 ft(2)	360 kn	667 km/h	368 kn	682 km/h
LANDING WEIGHT	78,071 lb	35.412 kg	81,263 lb	36.860 kg
Ground roll at SL(4)	2,100 ft	640 m	2,180 ft	664 m
Total from 50 ft(4)	2,800 ft	853 m	2,900 ft	884 m

NOTES
(1) Take-off power
(2) Max power
(3) Normal power
(4) Take-off and landing distances are obtainable at sea level using normal techniques. For airport planning, distances should be increased by appropriate factors to determine runway requirements.

Further reading

• Boeing B-29 Superfortress Specifications (1950)
• Boeing B-29A Superfortress Specifications (1950)
• Boeing KB-29P Superfortress Specifications (1951)
• Boeing SB-29 Superfortress Specifications (1954)
• Tupolev Tu-4 Standard Specification & Performance
• Boeing B-29 Superfortress Facts: 11 things to know

Bibliography

• B-29 Superfortress: Giant Bomber of World War 2 and Korea by Graham Simons
• Boeing B-29 Superfortress: The Ultimate Look: From Drawing Board to VJ-Day by William Wolf
• B-29B Superfortress Standard Aircraft Characteristics 19-APR-1950, Air Materiel Command, U.S. Air Force