Bushby Mustang II

The Bushby Mustang II is a two-seat, side-by-side, all-metal, low-wing sport aircraft designed by Robert W. Bushby of Minooka, Illinois. Bushby acquired the rights to the single-seat Long Midget Mustang in 1959 and in 1963 began development of an enlarged two-place derivative. The prototype Mustang II first flew on July 9, 1966, and plans were released to the homebuilder market shortly thereafter.

The Mustang II became one of the most successful all-metal plans-built designs of the pre-RV era, with roughly 480 examples flying worldwide. Its reputation is that of a honest, fast, efficient cross-country sport plane — essentially a scaled-up Midget Mustang with enough cabin for two adults and light baggage. Builders frequently describe it as a "poor man's RV," though chronologically it predates the vans-rv4 by more than a decade and directly inspired Dick VanGrunsven's early thinking about metal sport aircraft. Bushby sold the rights to both the Midget Mustang and the Mustang II to Mustang Aeronautics (Troy, Michigan) in 1992, which continues to support the design with plans, kits, and parts as of 2026.

Typical owners are experienced builder-pilots who want high cruise speed on modest fuel burn, tight-handling control response, and a classic riveted-aluminum airframe. The aircraft is frequently cross-shopped against the thorp-t18 (its closest contemporary in concept) and the wittman-tailwind (faster but steel-tube/fabric).

All variants share the same airframe; differences are builder-selected options rather than factory models.

Published numbers from Mustang Aeronautics are for the 160 hp O-320 at 1,500 lb gross: 208 mph cruise at 7,500 ft (75% power), 2,200 fpm sea-level climb, 450-ft takeoff run. Real-world owners with well-built, clean airframes routinely report 175–185 KTAS on 8–9 gph with the 160 hp engine. The 180 hp O-360 installation bumps cruise to 195–200 KTAS and climb to roughly 2,500 fpm; the 200 hp IO-360 pushes top speed past 220 KTAS but at the cost of range and useful load.

The CAFE Foundation's Aircraft Performance Report on a Mustang II documented excellent aerodynamic efficiency — the design's small frontal area, flush rivets (builder-dependent), and low wetted area give it a drag profile competitive with much newer composite sport aircraft. Density altitude affects takeoff roll less than heavier GA singles due to the low wing loading (15.4 lb/ft²) and strong power-to-weight ratio.

The airplane is stressed for +6/-3 g at 1,500 lb and is approved for basic aerobatics (loops, rolls, spins), though it is not a dedicated aerobatic mount — control forces harmonize for cross-country work rather than snap rolls.

With the standard 25-gallon tank and a 573 lb useful load (160 hp tailwheel example):

• Full fuel (150 lb) + 2 pax + baggage: 573 - 150 = 423 lb for occupants and bags. Two 190-lb adults + 43 lb baggage. Legal range ~370 nm with VFR reserves at 75% power.
• Full fuel, solo: 423 lb for pilot + bags. Plenty for long XC — 370 nm legs routine.
• Two 200-lb adults + 40 lb bags (440 lb): Limited to ~22 gal (132 lb) fuel → roughly 300 nm still-air range.
• Wet-wing mod (40 gal / 240 lb): Two 180-lb adults + 25 lb bags + full 40 gal → 625 nm range at 180+ KTAS cruise. This transforms the airplane into a genuine long-distance tourer and is the single most value-adding mod.

The Mustang II is fuel-limited, not payload-limited, in standard form — a reversal from many certified trainers. Builders planning cross-country use should seriously consider the wet-wing option during construction, as it is far more labor-intensive to retrofit later.

• Local fun flying (9/10): Crisp controls, high cruise, bubble canopy visibility, and classic looks make this a weekend-flying delight.
• Cross-country (7/10): 180+ KTAS on ~8 gph is exceptional efficiency. Penalty is the small 25-gal standard tank (~2.5 hours with reserves); wet-wing mod unlocks 5+ hour legs.
• Aerobatics (5/10): Certified by designer for basic aerobatics but control harmony favors cruise over hard maneuvering; no inverted fuel/oil system.
• Business travel (4/10): Speed is there, but VFR-only panels, tight 2-seat cabin with limited baggage, and non-standard experimental status limit utility.
• Flight training (3/10): Fast, tailwheel (most examples), and not suited to primary instruction. Fine for transition training to higher-performance experimentals.
• Surveying (3/10): Low wing blocks downward visibility; too fast for low-and-slow photo work.
• Backcountry (2/10): Small wheels, low-wing prop clearance, and no STOL provisions — strictly hard-surface airplane.
• Cargo hauling (1/10): 573 lb useful load, minimal baggage compartment, small cabin volume.

As an experimental, panel configurations vary enormously with builder preference and vintage. Typical tiers as of 2026:

• Budget / legacy ($3k–8k panel): Steam-gauge six-pack, single nav/com (King KX-155 or similar), basic transponder, handheld GPS. Typical of 1980s–2000s builds not yet upgraded.
• Mid-tier ($10k–20k): Single Garmin G3X Touch 7" or Dynon SkyView HDX 7", GTR 200 com, GTX 335 ADS-B Out transponder, uAvionix tailBeacon as alternative. VFR day/night.
• High-end ($25k–45k): Dual-screen Dynon HDX or Garmin G3X with integrated autopilot servos, GNX 375 GPS/transponder, ADS-B In, engine monitoring (EIS). Some owners fly light IFR, though structural IFR certification is not available for experimentals.

See avionics-pricing for experimental avionics detail.

Experimentals do not use STCs; modifications are builder- or owner-introduced with A&P/condition inspection signoff. Common mods:

• Wet wing fuel mod: Mustang Aeronautics offers plans/kits to convert outer wing bays to fuel, raising capacity from 25 to ~40 gal (common) or up to 61 gal (full wet wing). Adds ~300 nm range; ~$2,000–4,000 in parts plus significant labor.
• 180 hp O-360 conversion: Drop-in upgrade from 150/160 hp O-320. Requires new engine mount bushings and cowl tweaks. Gains ~15 kt cruise and ~500 fpm climb.
• Constant-speed propeller: Hartzell or MT composite CS props improve takeoff and climb; $8,000–14,000 installed.
• Sliding canopy conversion: A minority of builders have modified the original tip-up canopy to slider; not factory-supported.
• Tricycle gear conversion: Plans for the nosegear option have been available since 1968 for builders who prefer it; retrofitting a flying tailwheel example is uncommon and not recommended.

• Parts availability: Good. Mustang Aeronautics stocks airframe parts, drawings, and builder supplies. Lycoming O-320/O-360 engine parts are universally available through any FBO.
• Mechanic familiarity: Any A&P comfortable with experimentals can perform condition inspections; the airframe is conventional riveted aluminum with no unusual systems. Owner-builders with repairman certificates do most of their own maintenance.
• Annual condition inspection: $500–1,500 at an experimental-friendly shop, or free if builder holds the repairman certificate.
• Typical annual operating cost (100 hr/yr): $4,000–6,000 including fuel, oil, inspection, reserves, hangar, and insurance.
• Expensive items: Engine overhaul ($25k–32k for O-320, $30k–38k for O-360), propeller overhaul ($1,500 fixed-pitch, $3,500 constant-speed), canopy replacement ($3,000–5,000), paint refresh ($8k–15k).

See maintenance-ecosystem for experimental support detail.

The Mustang II market is thin — typically 3–8 examples for sale nationwide at any given time. Price drivers:

• Engine time & configuration: Fresh-overhaul 180 hp O-360 example vs run-out 150 hp O-320 swings value $15k–25k.
• Builder reputation: Well-known, EAA-award-winning builders command 20–30% premiums; "Joe's garage" builds with thin documentation discount heavily.
• Panel: Modern glass (Dynon/Garmin G3X) adds $15k–20k over steam gauges.
• Wet wing conversion: Adds roughly $3k–6k to value reflecting range improvement and labor.
• Airframe condition: Paint/interior matter more on experimentals than certified — a tired paint job often signals hangar-queen status.

2026 price tiers:

• $25k–35k: Run-out engine, older avionics, cosmetic fatigue, 150–160 hp.
• $35k–50k: Mid-time engine, decent panel, flyable condition, 160–180 hp — the typical market.
• $50k–70k: Low-time airframe, fresh or mid-time 180/200 hp, glass panel, wet wings, award-winning build quality.

Recent builds from kit cost $45k–55k per Mustang Aeronautics, so a well-finished low-time example near that figure reflects labor being largely unrecoverable — a value opportunity for buyers. See valuation-methodology.

Experimental amateur-built aircraft are not subject to ADs. However, Mustang Aeronautics has issued builder service bulletins over the years, and the owner community tracks recurring issues:

• Wing attach fitting corrosion: Steel-to-aluminum wing attach hardware in older (pre-1990) airframes can show crevice corrosion; inspection at condition inspection is critical.
• Canopy latch failures: Original latch design has opened in flight on several examples; many owners upgrade to a secondary locking pin.
• Fuel tank leaks: Wet-wing conversions using ProSeal have a finite service life (15–20 years) before seeping begins.
• Elevator balance weight: Some early builders under-weighted the elevator; flutter has been reported at high Vne-approach speeds in improperly rigged examples.
• Main gear leg cracks: The steel main gear legs have developed cracks on examples with high cycle counts or rough-field operation; dye-penetrant inspection recommended annually.
• Lycoming O-320 H2AD-style camshaft issues do not apply since Mustang II installations use E2D/D2J/D2G variants.

Pre-buy red flags: undocumented builder, missing builder logs, corrosion around wing attach points, fuel stains on wet-wing conversions, poor rivet workmanship (unset or smiley rivets indicate a rushed build).

Experimental tailwheel side-by-side seaters in this performance class are moderately hard to insure. Typical 2026 quotes from Avemco, Starr, and EAA-affiliated programs:

• Liability only ($1M smooth): $600–900/year
• Hull + liability ($40k hull): $1,400–2,000/year
• Low-time tailwheel pilot: Expect open-pilot refusal and 10+ hours dual required; premium may double or coverage refused entirely.
• High-time (500+ hr tailwheel, 25+ in type) pilot: Bottom of the quoted range.

Underwriters treat the Mustang II as higher-risk than a Cessna 172 due to tailwheel and speed, but lower-risk than aerobatic mounts or unusual designs since the type has a long, well-understood safety record. See insurance-underwriting.