UNITED STATES MILITARY AIRCRAFT by Jos Heyman

Air Force

LB = Light Bomber (1925-1932) Last update: 1 February 2015

LB-1 Huff Daland Pegasus Specifications: span: 66'6", 20.27 m length: 46'2", 14.07 m engines: 1 Packard 2A-2540 max. speed: 121 mph, 195 km/h

(Source: USAF, via 10af.afrc.af.mil/photos)

A light bomber with a crew of three, a single prototype with serial 23-1250 was ordered as XLB-1. This aircraft had a length of 47'4", 14.43 m and a 1A-2540 engine. It was also flown with Wright Field serial P-395. This was followed by 10 LB-1s with serials 26-376/385. Of these 26-376 and 26-379 were also flown with Wright Field serials P-438 and P-450 respectively. A LB-1A version was ordered in 1927 but subsequently cancelled. Refer also to B-1, HB-1

LB-2 Atlantic 5 Specifications: span: 72'10", 22.20 m length: 51'5", 15.67 m engines: 2 Pratt & Whitney R-1340-1 max. speed: 123 mph, 198 km/h

(Source: hawaii.gov/hawaiiaviation/aviation-photos)

Based on the C-2 transport, a single example of the XLB-2 was ordered with serial 26-210. It was later fitted with Pratt & Whitney R-1690-1 engines.

LB-3 Huff Daland Specifications: span: 66'6", 20.27 m length: 45', 13.72 m engines: 2 Liberty V-1710-1 max. speed: 110 mph, 177 km/h

(Source: USAF, via 10af.afrc.af.mil/photos)

A single XLB-3 was built with serial 27-333. Later the aircraft was fitted with Pratt & Whitney R-1340-1 engines and redesignated as XLB-3A. It was also flown with Wright Field serial P-498. Refer also to B-3, B-4, B-5, B-6, LB-1, LB-5, LB-6, LB-7, LB-8, LB-9, LB-10, LB-11, LB-12, LB-13, LB-14

LB-4 Martin 75 Specifications: span: 76', 23.16 m length: 44'8", 13.61 m engines: 2 Pratt & Whitney R-1690-1 max. speed: 111 mph, 179 km/h

(Source: S. Beaumort)

A single XLB-4 was ordered with serial 27-332 but was cancelled before construction was commenced.

LB-5 Keystone Specifications: span: 67', 20.42 m length: 44'8", 13.61 m engines: 2 Liberty V-1650-3 max. speed: 107 mph, 172 km/h

(Source: USAF, via 10af.afrc.af.mil/photos)

The LB-5 light bomber design was developed by Huff Daland and built by Keystone, which took over Huff Daland. The latter company built the single example of the XLB-5. The aircraft had a single fin, a span of 66'6", 20.27m and a length of 45', 13.72m. The serial was 26-208 and it was also flown with Wright Field serials P-453 and P-509. Keystone built 10 LB-5s with serials 27-335/344. Of these 27-344 was converted as XLB-6. These aircraft had a triple fin whilst the LB-5A, of which 25 were built with serials 28-001/025, had twin fins. Refer also to B-3, B-4, B-5, B-6, LB-1, LB-3, LB-6, LB-7, LB-8, LB-9, LB-10, LB-11, LB-12, LB-13, LB-14

LB-6 Keystone Panther Specifications: span: 75', 22.86 m length: 49'3", 15.01 m engines: 2 Wright R-1750-1 max. speed: 117 mph, 188 km/h

(Source: USAF, via 10af.afrc.af.mil/photos)

The last LB-5 was fitted with a different tail unit and extended wing span. The serial was 27-344 and the aircraft, redesignated as XLB-6, had a length of 44', 13.41 m. It was also flown with Wright Field serial P-499. This was followed by 17 LB-6s with serials 29-011/027. The first one of these was originally built as LB-9. The designation ZLB-6 is known for aircraft that had been withdrawn from use. Serials included 29-010-012, 29-026. Refer also to B-3, B-4, B-5, B-6, LB-1, LB-3, LB-5, LB-7, LB-8, LB-9, LB-10, LB-11, LB-12, LB-13, LB-14

LB-7 Keystone Panther Specifications: span: 75', 22.86 m length: 49'3", 15.01 m engines: 2 Pratt & Whitney R-1690-3 max. speed: 114 mph, 183 km/h

(Source: USAF, via 10af.afrc.af.mil/photos)

Being similar to the LB-6 except for the powerplant, 18 LB-7s were built outright with serials 28-388/395 and 29-001/010 whilst three LB-6s with serials 29-013, 29-014 and 29-016 were also converted to this standard. The first aircraft, 28-388, was used for tests and was redesignated as XLB-7. It was also flown with Wright Field serial P-540. The designation ZLB-7 is known for aircraft that had been withdrawn from use. Serials included 28-390/395, 29-001, 29-002, 29-003, 29-005. Refer also to B-3, B-4, B-5, B-6, LB-1, LB-3, LB-5, LB-6, LB-8, LB-9, LB-10, LB-11, LB-12, LB-13, LB-14

LB-8 Keystone Specifications: span: 75', 22.86 m length: 49'3", 15.01 m engines: 2 Pratt & Whitney GR-1860-3 max. speed: 112 mph, 180 km/h

(Source: USAF, via 10af.afrc.af.mil/photos)

In 1929 a single LB-7 with serial 29-009 was converted with a different engine and redesignated as LB-8. Refer also to B-3, B-4, B-5, B-6, LB-1, LB-3, LB-5, LB-6, LB-7, LB-9, LB-10, LB-11, LB-12, LB-13, LB-14

LB-9 Keystone Specifications: span: 75', 22.86 m length: 49'3", 15.01 m engines: 2 Wright GR-1750-B max. speed: 118 mph, 190 km/h

(Source: USAAF?)

In 1929 a single LB-7 with serial 29-010, was re-engined and redesignated as XLB-9. The aircraft was later converted to LB-6 standards. Refer also to B-3, B-4, B-5, B-6, LB-1, LB-3, LB-5, LB-6, LB-7, LB-8, LB-10, LB-11, LB-12, LB-13, LB-14

LB-10 Keystone Specifications: span: 74'9", 22.79 m length: 48'10", 14.88 m engines: 2 Pratt & Whitney R-1690-3 max. speed: 114 mph, 183 km/h

(Source: USAF, via 10af.afrc.af.mil/photos)

In 1929 a single LB-6 was fitted with a different tail unit. The aircraft, which had serial 29-027, was redesignated as LB-10. It had a span of 75', 22.86 m, length of 49'3", 15.01 m, 2 Wright R-1750-1 engines and a max speed of 116 mph, 187 km/h. It was also flown with Wright Field serial P-563. The production version was the LB-10A to which the specifications apply. 63 were ordered with serials 30-281/343 but these were eventually delivered as B-3A. Aircraft with serials 30-344/353 were originally ordered as LB-13 but were for some time included in the LB-10 batch. They were eventually delivered as Y1B-4 (30-344/348) and Y1B-6 (30-349/353). In addition three LB-14s, which had been ordered with serials 30-354/356, were for some time included in the LB-10 batch but were further redesignated as Y1B-5. They were probably never completed as the serials were re-assigned. Refer also to B-3, B-4, B-5, B-6, LB-1, LB-3, LB-5, LB-6, LB-7, LB-8, LB-9, LB-11, LB-12, LB-13, LB-14

LB-11 Keystone Specifications: span: 75', 22.86 m length: 49'3", 15.01 m engines: 2 Wright R-1750-3 max. speed: 115 mph, 185 km/h A single LB-6 with serial 29-026 was fitted with a different engine and redesignated as LB-11 (or XLB-11) on 3 March 1931. Later the aircraft was re-engined with GIR-1750 engines and redesignated as LB-11A (or XLB-11A) on 1 April 1931 until it was converted back to LB-6 standards on 31 May 1932. Eventually it was redesignated as ZLB-6. Refer also to B-3, B-4, B-5, B-6, LB-1, LB-3, LB-5, LB-6, LB-7, LB-8, LB-9, LB-10, LB-12, LB-13, LB-14

LB-12 Keystone Specifications: span: 75', 22.86 m length: 49'3", 15.01 m engines: 2 Pratt & Whitney R-1860-1 max. speed: 116 mph, 187 km/h

(Source: USAF, via 10af.afrc.af.mil/photos)

A single LB-7 with serial 28-388, was converted as XLB-12 for evaluation. Refer also to B-3, B-4, B-5, B-6, LB-1, LB-3, LB-5, LB-6, LB-7, LB-8, LB-9, LB-10, LB-11, LB-13, LB-14

LB-13 Keystone Specifications: span: 74'9", 22.78 m length: 48'10", 14.88 m engines: 2 Pratt & Whitney GR-1690 max. speed: Seven LB-13s were ordered with serials 30-344/350 but were then included in the LB-10 batch. They were eventually delivered as Y1B-4 (30-344/348) and Y1B-6 (30-349/353). Refer also to B-3, B-4, B-5, B-6, LB-1, LB-3, LB-5, LB-6, LB-7, LB-8, LB-9, LB-10, LB-11, LB-12, LB-14

LB-14 Keystone Specifications: span: 74'9", 22.78 m length: 48'10", 14.88 m engines: 2 Pratt & Whitney GR-1860-3 max. speed: Three LB-14s were ordered with serials 30-354/356 but these were eventually included in the LB-10 batch and further were redesignated as Y1B-5. They were probably never completed as the serials were re-assigned. Refer also to B-3, B-4, B-5, B-6, LB-1, LB-3, LB-5, LB-6, LB-7, LB-8, LB-9, LB-10, LB-11, LB-12, LB-13