Thorp T18 Aircraft for Sale — Buy or Sell Homebuilt Low-Wing Sport Planes Worldwide
The Thorp T18 is one of the most celebrated and beloved homebuilt aircraft designs in American aviation history. Designed by the legendary engineer and aviator John Thorp — a designer whose career spanned military trainers, agricultural aircraft, and general aviation designs — the T18 established itself as a benchmark of homebuilt performance, efficiency, and construction quality from the moment plans became available through the Experimental Aircraft Association (EAA) in the early 1960s. Decades after its introduction, the Thorp T18 continues to attract builders, buyers, and sellers who appreciate its timeless aerodynamic efficiency, outstanding performance for its size, and the rich community that surrounds this enduring homebuilt design.
Whether you are searching to buy a completed Thorp T18, looking for a project aircraft to finish, or ready to sell your T18 and find a qualified new owner, Airplane Trade connects homebuilt aviation enthusiasts, private sellers, and dealers across the United States and worldwide.
About John Thorp and the T18 Design Heritage
John Thorp was one of the most gifted and versatile aircraft designers of the twentieth century. His design portfolio included work on the Lockheed aircraft family, the Piper Cherokee series, and numerous other influential designs. When he turned his attention to the homebuilt market, he applied the same rigorous engineering principles to create an aircraft that would be both outstanding to fly and achievable for the skilled amateur builder. The result was the Thorp T18 Tiger, a design that distilled decades of aeronautical engineering experience into a compact, efficient, and fast low-wing monoplane.
The T18 became one of the first homebuilt aircraft to regularly cruise at speeds exceeding 200 miles per hour — performance that rivaled or exceeded many certified production aircraft of the era at a fraction of the cost. This remarkable performance, combined with Thorp's reputation for engineering excellence, made the T18 an immediate success within the EAA homebuilder community and cemented John Thorp's legacy as one of sport aviation's most important figures.
Design and Construction
The Thorp T18 is an all-metal, low-wing monoplane with side-by-side seating for two occupants. The aircraft is constructed entirely from aluminum alloy using aircraft-standard riveted construction techniques — the same methods used in certified aircraft production. This approach, while demanding considerable builder skill and patience, produces a structurally superior and durable airframe that holds up well over decades of operation when built to correct specifications.
The T18's wing design is one of its most distinctive features. The laminar-flow wing profile contributes significantly to the aircraft's exceptional speed and fuel efficiency, allowing it to achieve high cruise speeds on modest horsepower. The wing incorporates fixed main landing gear in a low-wing arrangement with inward-retracting gear on the T18W (retractable gear) variant, or fixed gear on the standard T18 — both configurations sharing the same clean aerodynamic fuselage and wing design.
The fuselage is compact and streamlined, with a canopy providing good pilot visibility and a comfortable, close-coupled cockpit environment. Builders frequently report that the T18's cockpit, while snug by modern standards, is well-arranged and ergonomically logical — a testament to Thorp's attention to pilot usability in the original design. The aircraft's control system provides responsive, well-harmonized handling that experienced pilots consistently praise for its sport flying character.
Powerplant Options and Performance
The Thorp T18 was designed around the Lycoming O-320 and O-360 series engines, which provide 150–180 horsepower depending on variant and builder choice. Some builders have also installed Continental engines or more powerful Lycoming variants such as the IO-360 or O-540, with performance scaling accordingly. The Lycoming O-360 (180 HP) is considered the definitive powerplant choice for T18 builders seeking maximum performance, while the O-320 (150 HP) offers a more economical option with still-impressive performance figures.
Performance highlights of the Thorp T18 include:
- Cruise speed — 160–200+ mph depending on engine and configuration, exceptionally fast for an aircraft of its size
- Rate of climb — 1,500–2,000+ feet per minute with the O-360, outstanding for a two-seat homebuilt
- Stall speed — approximately 65 mph, providing adequate slow-speed margin
- Range — approximately 600–800 miles depending on fuel capacity, engine, and power setting
- Empty weight — typically 800–900 lbs, impressively light for the performance delivered
- Gross weight — typically 1,500–1,650 lbs depending on builder specification
The T18's power-to-weight ratio and aerodynamic efficiency combine to deliver performance that surprises many pilots accustomed to production aircraft. Stories of T18s outrunning certified singles of much larger displacement are common within the homebuilt community.
The T18 Builder and Owner Community
One of the greatest assets of owning or flying a Thorp T18 is access to a dedicated and knowledgeable community of builders, restorers, and pilots who have accumulated decades of collective experience with the design. The T18 Association and active online groups maintain a wealth of builder notes, construction tips, modification histories, and technical advisories that represent an invaluable resource for both current owners and prospective buyers evaluating a specific aircraft.
This community support is especially valuable when purchasing a used T18, as prospective buyers can draw on community expertise to evaluate build quality, identify common issues or modifications, and assess the airworthiness history of a specific aircraft. The T18's all-metal construction means that a well-built example can last for many decades with proper maintenance — making the evaluation of build quality a critical step in the purchase process.
Buying a Thorp T18 — What to Look For
When purchasing a Thorp T18, prospective buyers should prioritize:
- Builder's log and construction records — a complete builder's log with photographs documenting construction is the gold standard for homebuilt aircraft purchases
- EAA technical counselor or DAR sign-off documentation — confirming the aircraft was built and inspected to appropriate standards
- Airframe condition inspection — particular attention to wing spar attachment points, main gear mounting, and control system rigging
- Engine logbooks and condition — Lycoming TBO compliance and annual inspection currency
- Avionics and electrical system — ensuring ADS-B Out compliance for operating in modern US airspace
- Pre-purchase inspection by an A&P mechanic familiar with homebuilt aircraft
Key Features of the Thorp T18
- John Thorp design pedigree — engineered by one of aviation's most respected designers
- All-metal aluminum construction — durable, repairable, and proven over 60+ years
- Laminar-flow wing — exceptional aerodynamic efficiency for outstanding speed
- High cruise performance — 160–200+ mph on modest Lycoming power
- Side-by-side two-seat cockpit — for pilot and passenger in a compact, efficient fuselage
- Fixed or retractable gear variants — T18 (fixed) and T18W (retractable) configurations
- Lycoming O-320/O-360 powerplant — proven, supportable engines with global parts networks
- Active owner/builder community — decades of accumulated technical knowledge and support
Browse Thorp T18 Listings on Airplane Trade
Find the latest Thorp T18 aircraft for sale on Airplane Trade and connect with sellers offering completed examples, project aircraft, and partial builds. Whether you're a seasoned homebuilt pilot looking for a specific high-performance T18, or a first-time homebuilt buyer exploring your options, our marketplace provides direct access to private sellers and dealers with T18 aircraft across the United States and beyond. List your Thorp T18 for sale today and reach thousands of homebuilt aviation enthusiasts actively searching for this iconic American sport aircraft.