Info on the XB-15 and XB-19 for those who wanted it:
Boein XB-15 Quote:
The Boeing XB-15 (Boeing Model 294) bomber aircraft was first designed in 1934 as a test for the United States Army Air Corps to see if it was possible to build a heavy bomber with a 5,000-mile range. It was originally designated the XBLR-1 (experimental bomber, long range, model 1). When it first flew, it was the most massive and most voluminous aeroplane ever built in the United States. It set a number of load-to altitude records, including a 31,205-pound flight to 8,200 feet (1939 July 30). One notable product of this size was that the crew could use passages in the wing to make minor repairs while the plane was flying. Due to limits on the technology it used, a 5,000 mile flight took several days. Thus, the crew had bunks to sleep on between shifts. It was meant to use liquid-cooled 1,000 hp (750 kW) engines. Unfortunately, these were not available, so 850 hp (637 kW) engines were used instead. These engines significantly underpowered the plane; its top speed of 200 mph (322 km/h) was far too slow for an acceptable bomber, and the project was eventually scrapped. No B-15s were put into service; the USAAC converted the only XB-15 to a cargo carrier, designated the XC-105.
Despite its failure, the XB-15 did have a number of significant features:
Automatic Pilot
De-icers
Auxiliary power units independent of the main engines to power the electrical system
Engines serviseable in flight using an access tunnel inside the wing
Crew compartment with rest bunks, galley and lavatory
Double wheel main landing gear. http://en.wikipedia.org/wiki/Boeing_XB-15 |
General Characteristics
Crew: 10
Length: 87 ft 7 in (32.6 m)
Wingspan: 149 ft 0 in (45.5 m)
Height: 18 ft 0 in (5.5 m)
Wing area: ft² ( m²)
Empty: 65,000 lb (30,001 kg)
Loaded: 69,000 lb (31,000 kg)
Maximum takeoff: 77,000 lb (37,000 kg)
Powerplant: 4× Pratt & Whitney R-1830-11 of 850 hp (640 kW) each
Performance
Maximum speed: 200 mph (346 km/h)
Cruising speed: 152 mph (294 km/h)
Combat Range: 3,400 miles (2,200 km)
Ferry Range: 5,130 miles (8,250 km)
Service ceiling: 18,900 ft (7,380 m)
Wing loading: lb/ft² ( kg/m²)
Power/Mass: 0.0490 hp/lb (0.0813 kW/kg)
Armament
3× .30-calibre (7.26 mm) machine guns, 3× .60-calibre (14.5 mm) machine guns
12,000 lb (5,400 kg) bombs
She was deffinatly underarmed and would have been and easy target for Luftwaffe fighters. Martin XB-16
The XB-16 was pretty much the same only larger then the XB-15 but was never built.
Quote:
Like the Boeing XB-15, the Martin XB-16 was designed to meet the U.S. Army's request for a bomber that could carry 2,500 lb (1,134 kg) of bombs 5,000 miles (8045 km). Its design was very similar to that of the XB-15, but it was 30% longer.
The XB-16 was to use four Allison V-1710 liquid-cooled inline engines. (All other contemporary aircraft used radial air-cooled engines.)
In 1935, Martin revised the XB-16 design. The wing span was increased to from 140 ft (42.7 m) to 173 ft (52.7 m), and a set of V-1710 engines added to the trailing edge. This version had a wingspan 20% greater than that of the first Very Heavy Bomber, the B-29 Superfortress.
The XB-16 was cancelled for essentially the same reason that the B-15 project was: it wasn't fast enough to meet the requirements set by the army. Since both were cancelled around the same time, Martin did not have time to produce an XB-16. http://en.wikipedia.org/wiki/Martin_XB-16 |
General Characteristics
Crew: 11
Length: 115 ft (35.0 m)
Wingspan: 173 ft (52.7 m)
Empty: 104,880 lb (47,573 kg)
Powerplant: 6× Allison V-1710 liquid-cooled inline engines of 850 hp (640 kW) each
Performance (estimated)
Maximum speed: 190 mph (310 km/h)
Cruising speed: 140 mph (230 km/h)
Combat Range: 3,300 miles (5,300 km)
Wing loading: lb/ft² ( kg/m²)
Power/Mass: 0.0486 hp/lb (0.0800 kW/kg)
Douglas XB-19 Quote:
The Douglas XB-19 was the largest bomber built for the United States Army Air Corps prior to 1938. Its combined length and wingspan of 344 ft (105 m) was only 12% less than that of the Convair B-36 with 392 ft (119 m), the largest bomber ever made for the United States. It was originally given the designation XBLR-2 (eXperimental Bomber, Long Range, model 2).
The purpose of the XB-19 project was to test the flight characteristics and design techniques associated with giant bombers. Douglas Aircraft Company strongly wanted to cancel the project, because it was extremely expensive. Despite advances in technology that made the XB-19 obsolete before it was even completed, the Army felt that it would be very useful for testing. Its construction took so long that competition for the contracts to make the XB-35 and XB-36 occurred two months before its first flight.
The plane finally flew on 1941 June 27, more than three years after the construction contract was awarded. In 1943, the original engines were replaced with Allison V-3420-11 inline engines. After completion of testing, the XB-19 served as a cargo carrier until it was scrapped in 1949. http://en.wikipedia.org/wiki/Douglas_XB-19 |
General characteristics
Crew: ≤18
Length: 132 ft 2 in (40.2 m)
Wingspan: 212 ft 0 in (64.6 m)
Height: 42 ft 9 in (13.0 m)
Wing area: 4,492 ft² (417 m²)
Empty: 140,230 lb (63,500 kg)
Loaded: 158,930 lb (72,000 kg)
Maximum takeoff: 164,000 lb (74,400 kg)
Powerplant: 4× Allison V-3420-11 inline engines, 2,600 hp (1940 kW)
Performance
Maximum speed: 265 mph (427 km/h)
Cruise speed: 165 mph (266 km/h)
Combat range: 7,750 miles (12,500 km)
Service ceiling: 39,000 ft (12,000 m)
Rate of climb: ft/min ( m/min)
Wing loading: 35.4 lb/ft² (173 kg/m²)
Power/Mass: 0.0654 hp/lb (108 W/kg)
Armament
5× .50 calibre (12.7 mm) machine guns
6× .30 calbre (7.62 mm) machine guns
2× 36 mm cannon
18,700 lb (8,480 kg) of bombs
Just in my opinion the XB-19 had some promise. Her armament was not that bad and she could have upgraded to better armaement and even better engines. This aircraft had promise.