Design

“The Boomerang is a new high performance pressurized 5 place light twin intended for personal transportation. Its basic goals were to provide optimum performance from two turbocharged 200 hp Lycoming reciprocating powerplants. Probably one of the most difficult tasks faced in the development of this aircraft was explaining why I would design a configuration that is asymmetric.  In fact, an early comment as the aircraft arrived at the Experimental Aircraft Association International Air Show at Oshkosh, Wisconsin this year, was from a fellow who ran up and remarked, “What in the hell were you smokin’ when you laid that one out?”  

– Burt Rutan (1996)

In trying to explain how Burt Rutan developed the idea of the Boomerang, he used a step-by-step comparison of a “traditional” twin-engine aircraft (Beech Baron BE58) and his design.

Step-by-Step Comparison : Baron vs. Boomerang

Boomerang and Baron design comparison

Baseline Baron 58P

Span = 37.8 ft. Wing area = 188 sq.ft. Stab area = 56 sq.ft
Vert Area = 24.4 sq.ft. Total BHP = 650 Empty Weight = 4018 lb
Useful Load = 2222 lb Max Fuel = 1140 lb Gross Weight = 6240 lb
Stall = 78 kt Cruise (75% 20kft) = 224 kt Range (75% 20kft) = 975 nm

 

Boomerang and Baron design comparison

Left engine moved outboard to improve symmetry at low speeds and to reduce cabin noise.

 Boomerang and Baron design comparison

Both engines moved inboard to reduce MCS. Right engine moved forward to clear fuselage. Left engine moved aft to balance.

Boomerang and Baron design comparison

Wing skewed to support engines and to reduce left engine interference.

Boomerang and Baron design comparison

Composite construction allows smaller, higher aspect ratio wing. but configuration is now nose-heavy, thus left wing is swept forward. This helps, but configuration is still nose-heavy.

Boomerang and Baron design comparison

The weight savings allows smaller engines and tail area can be reduced.

Boomerang and Baron design comparison

Higher aspect ratio tail flutter problem is fixed with nacelle boom. This allows additional baggage room in boom.

Boomerang and Baron design comparison

Right engine is moved to the fuselage to reduce weight, cost and drag. Lateral balance is restored by moving entire wing to the left. MCS is now well below stall.

Boomerang and Baron design comparison

Left engine is moved outboard to reduce cabin noise and to eliminate prop interference. Entire wing is moved left to restore lateral balance.

Boomerang and Baron design comparison

Twin small vertical tails improve low speed handling, reduce weight and allow low-drag pressure-recovery aft fuselage.

Boomerang and Baron design comparisonContinue evolution

  • Round fuselage, increased room.
  • Laminar flow flying surfaces.
  • Higher wing loading.
  • Aspect Ratio to 13.2.
  • Full-span camber control for aileron/flap/wing optimization

Boomerang and Baron design comparisonBoomerang and Baron design comparison

Baron 58P Boomerang
3.8psi cabin 4.6psi cabin
6 seats 5 seats or 4 seats+1 bed
3% more span 15% wider cabin
84% more wing area 20% longer cabin
65% more tail area 92% more aspect ratio
59% more engine power 10% higher stall speed
62% more empty weight 45% more climb rate
13% more fuel 41 kt higher cruise speed
45% more gross weight 56% more range at 75%
92% more max range
Immune from MCS accidents