In the years following World War II, the American aviation market was flooded with surplus military aircraft. Most were scrapped or left to rust. A handful of visionary companies saw something different — the raw material for a new generation of executive transports. Howard Aero Inc. of San Antonio, Texas, was among the most ambitious of these converters, transforming battle-hardened Lockheed Ventura and Harpoon airframes into some of the most refined corporate aircraft of the 1950s and 1960s.
Origins: San Antonio and the Surplus Opportunity
Howard Aero Inc. was established in San Antonio, Texas, in the early 1950s. The company had no connection to the earlier Howard Aircraft Corporation of Chicago — the famous racing and DGA-series manufacturer associated with Benny Howard. Howard Aero was an independent venture, founded specifically to capitalize on the large inventory of surplus Lockheed PV-1 Ventura and PV-2 Harpoon patrol bombers available at low cost from military disposal programs.
The Ventura and Harpoon were robust, twin-engine aircraft with excellent range and load-carrying capacity — ideal candidates for executive conversion. Howard Aero's engineers stripped the military interiors, rebuilt the airframes to civilian standards, and created a series of increasingly sophisticated executive transports that competed directly with purpose-built business aircraft of the era.
The Howard Conversion Series
Howard 350
The Howard 350 was the entry point of the conversion line, based on the Lockheed PV-1 Ventura airframe. The designation reflected the approximate cruise speed in miles per hour — a marketing choice that emphasized performance. The 350 offered a comfortable executive cabin for small groups, retaining the twin Pratt & Whitney R-2800 powerplants in a refined installation. It established Howard Aero's reputation for quality workmanship and attention to interior finish.
Howard 400
The Howard 400 represented a step up in capability, with enhanced interior appointments and systems refinements over the 350. While documentation on the 400 variant is less comprehensive than the 350 and 500, it served as a transitional model that bridged the gap between the initial conversion concept and the fully developed flagship that would follow.
Howard 500
The Howard 500 was the pinnacle of the Howard Aero conversion program and the model for which the most comprehensive technical documentation survives. Based on the Lockheed PV-2 Harpoon — a larger, more capable development of the Ventura — the 500 offered pressurized cabin comfort, extended range, and a level of interior luxury that rivaled purpose-built executive aircraft from Convair and Grumman.
Powered by twin Pratt & Whitney R-2800 Double Wasp radial engines, the Howard 500 could carry up to ten passengers in a fully appointed executive interior, with a cruising speed in the region of 300 mph and a range that made transcontinental travel practical. The aircraft found favour with major corporations, oil companies, and wealthy private operators throughout the late 1950s and into the 1960s.
The Howard 500 was certificated under Civil Air Regulations (CAR) and operated under FAA oversight, giving it a legitimacy and airworthiness standing that pure surplus conversions often lacked. This certification, combined with the quality of Howard Aero's workmanship, made the 500 a genuinely competitive executive transport in its era.
Legacy and Surviving Aircraft
Howard Aero Inc. operated during a narrow but significant window in American aviation history — the transition from surplus military hardware to purpose-built business aviation. By the mid-1960s, the supply of suitable Ventura and Harpoon airframes was exhausted, and the market had moved toward turbine-powered aircraft. Howard Aero wound down its conversion activities, leaving behind a small but devoted community of operators and enthusiasts.
A small number of Howard 500 aircraft survive today, maintained by dedicated owners who value their unique combination of radial-engine character, executive heritage, and historical significance. Technical documentation for these aircraft — service manuals, overhaul instructions, parts catalogs — is increasingly rare and represents an essential resource for anyone maintaining or restoring a surviving example.
Howard 500 Technical Documentation at Online Aviation Library
Online Aviation Library holds a curated collection of Howard 500 technical documentation, covering the airframe systems, powerplant installation, and associated equipment. This material is drawn from original manufacturer and FAA sources and represents some of the most comprehensive Howard 500 documentation available in digital form.
Whether you are an owner, A&P mechanic, aviation historian, or collector, our Howard 500 collection provides the technical foundation needed to understand, maintain, and appreciate one of the most distinctive executive aircraft of the postwar era.
Explore the Howard 500 Manuals Collection →