Learjet 85
The Learjet 85 was a mid-size business jet development program initiated by Bombardier Aerospace, intended to be the largest and first all-composite "clean sheet" design in the Learjet family, accommodating up to eight passengers and two crew members with a maximum cabin height of 5 feet 11 inches.[1][2][3] Launched on October 30, 2007, the program aimed to bridge the gap between mid-size and super mid-size jets, featuring advanced composite materials for the fuselage and wings to reduce weight and manufacturing costs while meeting FAA Part 25 certification requirements.[1][4][5] Planned specifications included a maximum takeoff weight of 33,500 pounds (15,195 kg), a high-speed cruise of Mach 0.82 (approximately 541 mph or 871 km/h), a range of approximately 3,000 nautical miles (5,556 km), and Pratt & Whitney Canada PW307B turbofan engines each providing 6,100 pounds of thrust.[6][7] The prototype achieved its maiden flight on April 10, 2014, from Bombardier's facility in Wichita, Kansas, demonstrating the aircraft's potential for efficient performance in the business aviation market.[3] Despite initial progress, including significant investment in composite tooling and assembly processes, the program faced challenges from weak market demand and financial pressures at Bombardier.[8][4] On January 15, 2015, Bombardier suspended development indefinitely, resulting in a $1.4 billion impairment charge and the layoff of approximately 1,000 employees across its Kansas and Mexico operations.[9][10] The cancellation was confirmed on October 29, 2015, marking the end of the project without any production deliveries, as the company shifted focus to other Learjet models and broader portfolio rationalization.[11][12] This outcome highlighted the risks of ambitious clean-sheet designs in a competitive business jet sector during economic uncertainty.[13]Development
Announcement and initial goals
The Learjet 85 program was publicly launched by Bombardier Aerospace on October 30, 2007, at the National Business Aviation Association (NBAA) convention.[6] The initiative represented the first all-new design under the Learjet brand since the 1980s, positioning the aircraft as a clean-sheet midsize business jet intended to challenge established competitors such as the Cessna Citation Sovereign and Embraer Legacy 500 in the growing segment for efficient transcontinental travel.[14] This launch built on Learjet's legacy of high-performance light jets while expanding into a larger category to meet demand from operators seeking enhanced range and capacity without the operational demands of larger aircraft. The core objectives for the Learjet 85 centered on achieving certification under FAR Part 25 regulations for transport-category aircraft, delivering a maximum range of approximately 3,000 nautical miles (5,556 km), and accommodating 8 to 9 passengers in a configuration optimized for productivity and comfort.[7] Bombardier emphasized innovations in fuel efficiency and reduced operating costs through extensive use of composite materials in the airframe, which promised lower weight and maintenance requirements compared to traditional aluminum structures.[15] The design also aimed to uphold Learjet's reputation for speed, targeting a high-speed cruise of Mach 0.82, enabling faster point-to-point travel for business users while incorporating advanced avionics for improved situational awareness. Market projections at the time anticipated entry into service by 2013, with the jet appealing primarily to corporate flight departments and charter operators desiring transcontinental capabilities—such as nonstop flights across North America or Europe—without the complexity and higher costs associated with ultra-long-range models.[16] Early interest was evident through letters of intent from prospective customers and announced supplier partnerships, notably with Pratt & Whitney Canada for PW307B engines, which were selected to provide the necessary thrust and efficiency for the aircraft's performance envelope.[17] Commitments included a firm order for six units from ExecuJet Aviation Group, valued at approximately $103 million, signaling strong initial backing from the industry.[18]Engineering and testing phases
The engineering and development of the Learjet 85 began with conceptual design work in 2007, following its announcement by Bombardier Aerospace as a clean-sheet midsize business jet featuring an all-composite airframe.[6][19] A full-scale mockup was first unveiled at the National Business Aviation Association (NBAA) convention in October 2008, with a revised version displayed at the European Business Aviation Convention and Exhibition (EBACE) in May 2010, allowing potential customers and stakeholders to evaluate the proposed cabin layout and cockpit ergonomics.[20] By mid-2009, all wind tunnel testing had been completed, including low-speed evaluations at the National Institute for Aviation Research (NIAR) in Wichita, Kansas, using an 11% scale model, as well as high-speed tests at facilities like Calspan in Buffalo, New York, and the National Research Council in Ottawa, Canada.[21][16] Critical design review was achieved in October 2011, marking the transition to production tooling and assembly of initial structures.[22] A key engineering innovation was the adoption of pre-preg carbon fiber composites for the entire primary airframe, including the fuselage, wings, and empennage, representing approximately 85% composite material by structural volume and enabling a seamless, one-piece pressurized fuselage barrel to reduce assembly complexity and maintenance compared to traditional aluminum designs.[23][4] This approach prioritized manufacturing efficiency and cabin volume gains over primary weight savings, though it contributed to an overall lighter structure supporting a projected range of 3,000 nautical miles.[24] Structural validation relied on finite element analysis (FEA) integrated with composite draping software like FiberSIM, conducted by teams in Montreal and Wichita to simulate loads and ensure integrity across the airframe.[25] Computational fluid dynamics (CFD) simulations were employed for aerodynamic optimization, particularly for the tailplane and high-speed stability at Mach 0.82 cruise.[26] Prototyping efforts focused on ground-based validation rather than extensive flight articles initially, with two proof-of-concept fuselages completed in Montreal by 2009 to test composite layup and curing processes using pre-preg materials.[27] By 2010, a production-representative pressure vessel fuselage had been built on final tooling, followed by assembly of a full-length composite fuselage in 2011 at the Querétaro facility in Mexico.[22] Static test articles, including a complete aircraft static test (CAST) airframe for fuselage and wing load evaluation, were constructed in Wichita, Kansas, with NIAR conducting coupon-level and full-structure fatigue testing to verify damage tolerance.[28] Wings for the first flight-test vehicle (FTV1) arrived from Belfast and Querétaro in November 2012, enabling mating to the fuselage by early 2013, though only one flight-capable prototype was ultimately built before program suspension.[29] Certification efforts targeted compliance with FAR Part 25 transport category standards, with particular emphasis on composite-specific requirements such as damage tolerance, lightning strike protection, and bird strike resistance, validated through static and dynamic ground tests at NIAR.[27] Supplier integration included Honeywell's Primus Epic avionics suite for fly-by-wire controls and Pratt & Whitney Canada PW307B engines, each rated at 6,100 pounds of thrust, which underwent ground rig endurance and performance testing as part of the powerplant development program.[30] The PW307B engines were specifically scaled for the Learjet 85 to provide efficient hot-and-high performance.[31] Development faced several delays due to supply chain disruptions, including the 2008 insolvency of initial composite prototype partner Grob Aircraft, which necessitated an in-house redesign of manufacturing processes, and challenges with avionics integration and software validation for the fly-by-wire system.[27] These issues shifted the planned first flight from late 2012 to April 2014, when FTV1 completed a successful 2-hour 15-minute maiden flight from Wichita, reaching 30,000 feet and validating basic flight controls despite prior holds for weather and a brake-by-wire software fix.[32] By mid-2014, approximately 70 hours of flight testing had accumulated, focusing on systems checkout and handling qualities ahead of anticipated certification.[6]Suspension and cancellation
On January 15, 2015, Bombardier Aerospace announced the indefinite suspension of the Learjet 85 program, citing insufficient market demand and an order backlog that failed to materialize despite initial interest.[9][33] The company had secured approximately 64 orders by that point, but these were deemed inadequate to justify continued investment amid broader weakness in the light and midsize business jet segment.[34] Development costs for the program had already surpassed $1 billion, prompting Bombardier to pause all work immediately to conserve resources.[35] The suspension carried significant financial repercussions, including a $1.4 billion pre-tax impairment charge recorded in the fourth quarter of 2014, which reflected the write-down of capitalized development expenses and related assets.[36] This charge contributed to ongoing pressures on Bombardier's balance sheet, exacerbating losses across its aerospace division.[37] By the third quarter of 2015, the program factored into an additional $1.2 billion writedown, helping drive the company's reported net loss of $4.9 billion for that period.[11][12] Bombardier confirmed the full cancellation of the Learjet 85 program on October 29, 2015, stating there were no plans for revival due to persistent lack of sales in the segment.[11] The decision aligned with a strategic refocus on more viable product lines, as the midsize jet market had not recovered sufficiently to support the aircraft's projected $17-20 million price point.[13] The suspension led to approximately 1,000 job cuts, with 620 positions eliminated at the Wichita, Kansas facility where the aircraft was to be assembled.[38][39] The program's demise occurred against a backdrop of subdued demand for midsize business jets, stemming from the lingering effects of the 2008 global financial crisis, which curtailed corporate and private aviation spending.[40] Launched in 2007 at the height of the pre-recession boom, the Learjet 85 faced intensified competition from more fuel-efficient alternatives, including the HondaJet and the emerging Pilatus PC-24, which offered versatility and lower operating costs in overlapping market niches.[41][42] Industry trends also shifted toward larger, longer-range aircraft, further eroding interest in new midsize entrants like the Learjet 85.[9] In the aftermath, Bombardier repurposed elements of the Learjet 85's development assets, such as composite manufacturing expertise and tooling, for other programs including upgrades to existing Learjet models.[43] Although one flight-test vehicle (FTV1) had completed testing, no production aircraft were completed, and the prototypes were not advanced to certification; static test articles and mockups were placed in storage.[6] The episode influenced Bombardier's Learjet division to prioritize enhancements to proven platforms, such as the Learjet 75 Liberty, rather than pursuing additional clean-sheet designs in the near term.[44]Design
Airframe and materials
The Learjet 85 featured a low-wing monoplane configuration with a T-tail empennage and swept wings, designed to optimize aerodynamic efficiency for high-speed business jet operations. The fuselage adopted a circular cross-section to facilitate pressurization and streamline internal space utilization. Overall dimensions included a length of 20.75 m (68 ft 1 in), a wingspan of 18.75 m (61 ft 6 in), and a height of 6.07 m (19 ft 11 in).[1] As the first Learjet model to employ a primarily composite airframe, the aircraft utilized carbon fiber reinforced polymer (CFRP) for the fuselage, wings, and empennage, representing a significant departure from the aluminum structures of prior models. This material choice enabled a lighter structure compared to a metallic equivalent, contributing to improved fuel efficiency without increasing overall empty weight. The composites provided exceptional strength-to-weight ratios and corrosion resistance, allowing for complex shaping that enhanced both structural integrity and aerodynamics.[4][45][46] Bombardier adopted an out-of-autoclave resin transfer molding (RTM) process, specifically resin transfer infusion (RTI), to fabricate large composite panels for the wings and fuselage, reducing reliance on energy-intensive autoclaves. Integrated stringers and frames were co-cured into the primary structures, minimizing the number of discrete parts and assembly joints to streamline production and lower manufacturing costs. This approach facilitated the creation of seamless, one-piece sections for the pressure vessel, enhancing durability while simplifying maintenance.[47][48][49] The fuselage was designed as a pressurized vessel extending from the cockpit to the aft bulkhead, capable of maintaining cabin comfort at high altitudes through composite construction that supported differential pressures typical for midsize jets. Sandwich panels incorporating honeycomb cores were used for floors and interior elements, providing rigidity and impact absorption while keeping weight low. These features allowed for a robust yet efficient structure suited to demanding flight profiles. Safety was prioritized in the design, with the composite airframe engineered to leverage the material's toughness for structural integrity. The program included plans for extensive fatigue and environmental testing to validate long-term durability, though these were not fully realized due to the project's cancellation in 2015.[4][24]Propulsion and aerodynamics
The Learjet 85 was designed to be powered by two Pratt & Whitney Canada PW307B turbofan engines, each providing 6,100 lbf (27.1 kN) of takeoff thrust.[1][28] These engines incorporated advanced technologies for improved fuel efficiency and reliability, including full authority digital engine control (FADEC) and an engine diagnostic system (EDS).[1] Mounted in underwing pods, the PW307B powerplants were selected for their low noise signature and high dispatch reliability, contributing to the aircraft's overall performance in the midsize business jet category.[1][28] The wing design featured an all-composite structure, marking the first such application by Bombardier in a FAR Part 25 certified business jet for both fuselage and wings.[4] With a span of 18.75 m (61 ft 6 in) and area of 37.25 m² (401 sq ft), the wing employed a curved aerofoil section equipped with removable winglets to enhance efficiency.[1][27] High-lift devices included two Fowler flaps and two spoilers per wing, but no leading-edge slats, optimized for the aircraft's targeted transonic cruise capabilities.[27] The composite materials facilitated smoother surfaces, aiding in drag reduction compared to traditional aluminum constructions.[4] Aerodynamic features emphasized high-speed performance, with a targeted cruise speed of Mach 0.82 and extensive wind-tunnel testing conducted to validate the design.[1][28] The overall configuration, including the winglets, supported efficient transonic flight while maintaining short-field capabilities through the flap system.[27] The fuel system comprised integral wing tanks with an approximate usable capacity of 11,310 lb (5,130 kg), supplemented by a fuel-tank inerting system for safety.[50][51] For noise and emissions, the PW307B engines were engineered to meet stringent standards, featuring low-emission combustors and contributing to the aircraft's classification as one of the quieter options in its class.[1] The composite airframe further supported reduced fuel burn through minimized drag.[4]Avionics and systems
The Learjet 85 was equipped with the Rockwell Collins Pro Line Fusion glass cockpit avionics suite, designed to provide pilots with enhanced situational awareness and operational efficiency through integrated digital technologies.[52] This system featured three high-resolution 15.1-inch active matrix liquid crystal displays (AMLCDs) arranged in a landscape configuration, along with dual touch-screen controllers for intuitive interaction with flight planning and system management functions.[50] A standard Synthetic Vision System (SVS) was incorporated to deliver a 3D real-time view of terrain and obstacles, aiding navigation in low-visibility conditions.[53] Navigation and flight management on the Learjet 85 relied on dual Flight Management Systems (FMS) supporting GPS/WAAS/LPV approaches for precision navigation, including graphical flight planning interfaces to streamline route modifications.[53] Safety enhancements included a Traffic Collision Avoidance System (TCAS II) for traffic alerts and resolution advisories, a Terrain Awareness and Warning System (TAWS), and an Enhanced Ground Proximity Warning System (EGPWS) to mitigate controlled flight into terrain risks.[1] The suite was fully compliant with Automatic Dependent Surveillance-Broadcast (ADS-B) requirements for modern airspace operations.[54] Communication systems supported dual VHF radios for primary air traffic control interactions, with options for HF radios and SATCOM to enable reliable oceanic and remote operations.[55] Controller-Pilot Data Link Communications (CPDLC) was integrated for efficient digital messaging in continental and oceanic airspace, reducing voice congestion.[1] The Learjet 85 incorporated electro-hydraulic flight controls, with fly-by-wire elements managing spoilers for roll control and flaps for high-lift operations, contributing to precise handling and reduced pilot workload.[56] The environmental control system (ECS) utilized high-efficiency air conditioning packs to maintain cabin pressurization and temperature, drawing conditioned air from engine bleed sources.[1] Electrical power was supplied by engine-driven brushless starter/generators, providing redundant 28V DC output for all avionics and systems.[57] Human factors design emphasized automation to minimize crew workload, with the Pro Line Fusion suite including electronic checklists and integrated alerting.[53] An optional head-up display (HUD) was available to project critical flight information onto the windshield, further enhancing heads-up situational awareness.[27]Cabin and operational features
The Learjet 85 featured a spacious midsize cabin designed for business travel, measuring 22 ft 7 in (6.88 m) in length from the cockpit bulkhead to the aft lavatory, with a maximum width of 6 ft 1 in (1.85 m) and height of 5 ft 11 in (1.80 m), yielding a total volume of 665 cu ft (18.8 m³).[1][50] The interior layout supported a standard club arrangement for 8 passengers, with an optional setup accommodating 9 via modular divans; it included a forward galley for refreshments and an aft lavatory equipped with a vanity and vacuum toilet system.[58][5] An external baggage door facilitated access to 100 cu ft of dedicated storage, supplemented by 30 cu ft of internal space.[1] Passenger comfort was enhanced by an environmental control system (ECS) and a cabin altitude maintained at 6,000 ft during 45,000 ft cruise, reducing fatigue on long flights.[59][60] Additional amenities comprised LED lighting with individual reading lamps, aisle illumination, and race track options; 110V AC and USB power outlets at each seat position; and provisions for Wi-Fi and SATCOM communications.[1][61][62] Large oval windows along both sides allowed ample natural light into the cabin, while entry was provided through a single airstair door on the port side, with an optional overwing escape hatch for added safety.[63] Operationally, the Learjet 85 was engineered for short-field performance to access smaller airports, with takeoff distances around 4,800 ft at sea level.[50] Maintenance was planned for 600-hour intervals to minimize downtime, and direct operating costs were estimated at $2,500 per hour, supporting efficient business operations.[64]Specifications
General characteristics
The Learjet 85 was configured for a crew of two pilots and a typical passenger capacity of eight, with a maximum of nine or ten occupants depending on interior layout.[13] Its overall dimensions included a length of 68 ft 1 in (20.76 m), a wingspan of 61 ft 6 in (18.75 m), a height of 19 ft 11 in (6.08 m), and a wing area of 401 sq ft (37.25 m²).[7][1] Key weights comprised an empty weight of 24,200 lb (10,977 kg), a maximum takeoff weight of 33,500 lb (15,195 kg), and a maximum landing weight of 30,150 lb (13,676 kg).[7][13] The aircraft featured a usable fuel capacity of 1,209 US gal (4,576 L or 8,100 lb at standard density), allowing for a payload of about 1,200 lb with full fuel under maximum takeoff weight constraints.[7][13] Propulsion was provided by two Pratt & Whitney Canada PW307B turbofan engines, each delivering 6,100 lbf (27.1 kN) of thrust.[28][1] Additional characteristics included a service ceiling of 49,000 ft (14,935 m) and a cabin pressurized to maintain a 6,000 ft (1,829 m) altitude equivalent at the maximum operating altitude. All specifications are projected design targets, as the program was canceled in 2015 without production.[7][65]| Characteristic | Specification |
|---|---|
| Crew | 2 |
| Passengers (typical) | 8 |
| Maximum occupants | 9–10 |
| Length | 68 ft 1 in (20.76 m) |
| Wingspan | 61 ft 6 in (18.75 m) |
| Height | 19 ft 11 in (6.08 m) |
| Wing area | 401 sq ft (37.25 m²) |
| Empty weight | 24,200 lb (10,977 kg) |
| Maximum takeoff weight | 33,500 lb (15,195 kg) |
| Maximum landing weight | 30,150 lb (13,676 kg) |
| Usable fuel capacity | 1,209 US gal (8,100 lb / 3,674 kg) |
| Payload with full fuel | ~1,200 lb (544 kg) |
| Engines | 2 × Pratt & Whitney Canada PW307B turbofans |
| Engine thrust (each) | 6,100 lbf (27.1 kN) |
| Service ceiling | 49,000 ft (14,935 m) |
| Cabin pressure (max diff.) | Equivalent to 6,000 ft altitude at 49,000 ft cruise |
Performance
The Learjet 85 was designed to achieve a maximum speed of 470 knots (541 mph, 871 km/h) at Mach 0.82, enabling rapid transcontinental travel for a midsize business jet. Its high-speed cruise was targeted at 470 knots (541 mph, 871 km/h) at Mach 0.82, balancing velocity and efficiency for typical missions. The long-range cruise speed was projected at 447 knots (515 mph, 829 km/h) at Mach 0.78, optimizing fuel use for extended flights. These speed profiles were derived from aerodynamic simulations and engine performance modeling during the design phase.[64][1] The aircraft's range was anticipated to reach 3,000 nautical miles (5,556 km) with four passengers and NBAA IFR reserves, supporting nonstop operations from New York to Los Angeles or London to Moscow.[64][1] Climb performance was expected to include an initial rate of 2,500 feet per minute (12.7 m/s), allowing quick ascent to cruise altitudes. Takeoff distance at maximum takeoff weight, sea level, and ISA was targeted at 4,800 feet (1,463 m), while the balanced field length measured 4,800 feet (1,463 m). Landing distance was projected at 2,700 feet (823 m), facilitating access to shorter runways. These metrics highlighted the Learjet 85's versatility, powered by its Pratt & Whitney PW307B engines.[64][1][7]| Performance Metric | Projected Value |
|---|---|
| Maximum Speed | 470 knots (Mach 0.82) |
| High-Speed Cruise | 470 knots (Mach 0.82) |
| Long-Range Cruise | 447 knots (Mach 0.78) |
| Range (4 passengers, NBAA IFR) | 3,000 nm |
| Initial Climb Rate | 2,500 ft/min |
| Takeoff Distance (MTOW, SL, ISA) | 4,800 ft |
| Balanced Field Length | 4,800 ft |
| Landing Distance | 2,700 ft |