Learjet’s largest and longest-range model will be world’s first all-composite Part 25 certified bizjet.
Bombardier announced the Learjet 85 during NBAA last October, released performance data and major suppliers during EBACE in May and has begun converting more than 120 letters of interest (LOIs) into firm orders. With 3000-nm range at Mach 0.78, high-speed cruise of Mach 0.82, stand up double club cabin and 42% greater MTOW than the 60XR, the all-new Learjet 85 is big news.
A larger cabin and more range, while retaining legendary Learjet performance, is a win-win for both Bombardier and the market and gives existing Learjet owners a reason to stay within the iconic Learjet product line.
But there’s more, of course. The Learjet 85 will be the first all-composite Part 25 certified business jet. Composite technology represents the future, in my opinion, as it gives you the ability to reduce weight and parts count, fabricate more complex aerodynamically fine-tuned shapes and extend maintenance intervals while simplifying the manufacturing process.
I’ve been flying Learjets from the beginning and I still operate a 1964 Learjet 24 for personal use. Just recently (Pro Pilot Apr 2008, pp 84–88) I had the opportunity to flightcheck the Learjet 60XR and I’m also very familiar with the Learjet 45XR and the 40XR—all wonderful aircraft. Learjets have always had excellent power to weight ratios and they remain the best performing business aircraft in the industry.
I have to admit that, prior to announcement of the 85 I’d thought Learjet had gone as far as it could in its product line with the model 60. Bombardier, however, identified a worthwhile product gap between the 60XR and the Challenger 300 and found a way to take advantage of it with the Learjet 85. At MTOW of 33,500 lbs the $ 20 million model 85 sits nicely between the $ 13.652 million (2008 dollars) 23,500 lb MTOW Learjet 60XR and the $ 20.971 million (2008 dollars) 38,850 lb MTOW Challenger 300.
Bombardier’s strategy on the Learjet 85 has been to minimize risk says Mgr Product Planning and Strategy Brad Nolen. The Learjet 85 uses next generation Pratt & Whitney Canada PW307Bs, recently certified on the Dassault Falcon 7X, Rockwell Collins Pro Line Fusion similar to the new Global Vision flightdeck on the Global Express and a composite manufacturing process that has been perfected by Grob Aerospace over the past 30 years. The Learjet 85 wing, at 400 sq ft and 25° sweep with new larger and more blended winglets, really pushed aerodynamic efficiency to achieve a range of 3000 nm at Mach 0.78. The key here is range. 3000 nm with 4 passengers and IFR reserves, is a significant step up from the 60XR’s 2351 nm and close to the Challenger 300’s 3100 nm.
FAR Part 25 FAA certification is anticipated 2011 with entry into service planned for fiscal year 2012/ 2013. I believe, however, that Bombardier may end up competing somewhat against itself with the large-midsize Learjet 85 and the supermidsize Challenger 300. The price difference is not considerable and some operators will opt to move up to the larger, longer range Challenger 300.
While Bombardier says that it will continue to produce the 60XR I can see the sun setting on this program. Modern Learjets, like the 40XR, 45XR and 85, are much less labor intensive to construct than the hand-built 60XR and have simpler 3 spar wings compared to the 60XR’s Learjet 23-like 6 spar airfoil. I suspect that once Learjet 85 production begins the 60XR may go away or be replaced with a new all-composite alternative. However, as Nolen points out, the 2-mould hand layup low temperature process on the Learjet 85 may not be scalable upwards beyond midsize business jets. Large composite aircraft, like the Boeing 787, use composite sections attached to aluminum stringers and frames rather than this very straightforward, simple, 2 mould process.
Prior to announcing the model 85, Bombardier program objectives included a double-club cabin, large cabin cross section with stand up (5 ft 11in) headroom, speed and agility of a Learjet, transcontinental and west coast to Hawaii range. Three customer steering teams were created to support the Learjet 85 development program—an interior focus group (Jan 2008), maintainability focus group (Feb 2008) and a flightdeck focus group (Mar 2008). In January Grob was selected to develop the all-composite structure and, in February, high and low-speed wind tunnel testing was completed.
Supplier agreements were finalized, and the joint definition phase initiated, in April. Design has been frozen and a full-scale digital mockup has been completed. This summer a build strategy will be announced prior to unveiling of a full-scale mockup at NBAA in October.
The Learjet 85 program is progressing on schedule and on track for first customer deliveries in about 4 years. I had a chance to walk through a partial mockup of the Learjet 85 last NBAA and was impressed. Cabin length, at 24 ft 9 in (flightdeck divider to rear pressure bulkhead) provides a larger, more comfortable cabin, than current midsize jets.
Cabin width, at 73 inches is 2 inches wider than the 60XR and just 13 inches narrower than the Challenger 300. Use of composites maximizes cabin volume with thinner structural sidewalls. Total baggage volume is 130 cu ft, much more than the model 60s and close to the 150 cu ft of the Challenger 300. Exterior dimensions are longer and higher than the model 60XR with wingspan of 61 ft 5.75 in—a full 17 ft 8.15 in wider than the Learjet 60XR and just 2 ft less than the Challenger 300.
Wider span may be an issue for some owners and their hangars, and it may cost a little more to hangar your Learjet 85, but these are relatively minor considerations. Learjet 85 partners Grob Aerospace—with over 37 years composite technology experience and a track record of more than 3500 composite aircraft including the industry’s first all composite Grob SPn business jet—is a strategic partner on the Learjet 85 and will play a significant role in development of the world’s largest Learjet.
While Learjet will be responsible for certification, design and control Grob will provide expertise in the composite arena and manufacture at least the first 2 prototypes. Following certification, Bombardier’s Queretano Mexico facility will manufacture composite structures for the Learjet 85 together with the electrical harness and subassembly system installation.
Final assembly, interior completions, flight tests, paint and customer delivery will be accomplished in Wichita KS. To power the Learjet 85 Bombardier has selected Pratt & Whitney Canada PW307Bs with 6100 lbs of thrust per side flat rated to 86° F. The PW307Bs will feature full authority digital engine control (FADEC) with engine diagnostic system (EDS). Noise level will be 23 dB below Stage III with nitrous oxide emission 30% lower than new ICAO standards. PW307Bs will be on condition engines, explains Nolen, however operators will have the option of a hard 7200-hr TBO if they choose. Power-to-weight ratio of the Learjet 85, at 1:2.747, will be close to my very agile Learjet 24.
This will give operators all the power they’re ever going to need! Learjet 85 performance targets include 4800 ft takeoff distance (MTOW, SL, ISA), 2700 ft landing distance (MTOW, SL, ISA) and time to climb to FL 410 (MTOW, SL, ISA) under 18 min. Max cruise altitude is targeted at 49,000 ft with Mach 0.82 high-speed cruise and Mach 0.78 long-range cruise. Rockwell Collins Pro Line Fusion, it was announced during EBACE, has been selected for the Learjet 85’s integrated avionics suite.
This is the second application of Pro Line Fusion in a Bombardier business aircraft. The top-of-the-line avionics suite was first launched as a key component of Bombardier’s Global Vision flightdeck in Sep 2007 and is now available the Global Express XRS and the Global 5000. Learjet 85 Pro Line Fusion configuration features three 15-inch diagonal LCD displays, synthetic vision system (SVS) and paperless charts, airport diagrams and manuals together with latest generation navigation and communications technology.
Pro Line Fusion will also be aboard the Cessna Citation Columbus and the newly announced Embraer Legacy 450 and 500. The objective with Rockwell Collins’ Fusion primary flight displays (PFD) and multifunction display (MFD) is enhanced situational awareness and reduced pilot workload.
Bombardier VP & General Mgr Learjet David Coleal explained, during EBACE, that it was decided, right at the beginning, that the Learjet 85—fuselage, wings and empennage—needed to be all-composite.
While Coleal admits that there can be risks in any new aircraft certification program, composite technology is well known today, FAA is familiar with it and suppliers have developed expertise in integrating components with composite structures. Composite benefits for the Learjet 85, explained Coleal, include less labor, greatly reduced parts count, improved aerodynamics and minimized drag due to better fabrication of fuselage curvature and maximum cabin volume as a result of a thinner wall structure.
The Learjet 85 fuselage will be built in less than 7 days, quicker than an aluminum structure. More and more service centers in the field now have composite repair experience. The Learjet 85 will be built with a low temperature composite technique so field reparability will be straightforward. Grob has vast experience, and over 7 million hours of flight time, with low temperature composites.
Its hand lay-up process is cured at relatively low temperatures of 60–80° F without need for autoclaves. Considering that Boeing is using all-composites on the 787 I see no reason why Bombardier would not consider building future-generation Global Express and Challenger airframes with composites.Ecofriendly and low operating cost
Environmental friendliness, carbon footprints and fuel burn have become more important considerations for business aircraft buyers these days. Composite construction is a green and cleaner solution in that it proves more environmentally friendly in the aircraft construction process. Grob Aerospace’s low temperature composite curing process is inherently energy efficient and does not require high-temperature autoclaves for curing.
This amounts to a 25% reduction in primary energy consumption for production of the Grob SPn airframe and, compared to an all-aluminum airframe energy needed to produce the same airframe, a 25–38% reduction in related CO2 emissions.
According to Grob Aerospace CEO Niall Olver only 5 kg of raw materials are required to produce 1 kg of the final product for the SPn vs 33 kg to produce 1 kg with an aluminum aircraft. In the case of the Grob SPn fuel burn savings are 35%, says Olver, over a comparable cabin sized all-aluminum aircraft. The manufacturing process is also much quieter.
I visited the Grob production facility in Switzerland and it was so quiet in there—no rivets or hammering—that it was almost eerie! Grob’s SPn, the world’s only existing all-composite business jet, has turned out to be particularly fuel-efficient. With max ramp weight of 14,000 lbs it burns fuel more efficiently, and has a better specific range, than a comparably weighted all-aluminum business jet. On a typical trip of 600 nm the SPn achieves 35% fuel burn savings than comparable cabin sized all-aluminum aircraft. This sort of technology will obviously bode well for the Learjet 85 program.
I’ve observed a trend, over the past year or so among certain segments of the charter and traditional flight department market, of moving down to supermidsize and midsize aircraft to save on fuel and operating costs.
I believe more and more owners are considering smaller aircraft as they’re often more than adequate for transcontinental flights. You’ll save about $ 20,000 flying round trip VNY (Van Nuys CA)–TEB (Teterboro NJ) chartering a Challenger 300 vs a Gulfstream IV. The Learjet 85 creates a new class of even more affordable transcontinental-capable midsize aircraft.
With a comfortable cabin, low fuel burn and low DOCs, I expect to see attractive emerging markets. In fact, I’d love to have a few managed Learjet 85s available for charter at Clay Lacy Aviation!
Front office technology
Learjet approached Rockwell Collins, as a prospective supplier, about 2 years ago. “Bombardier came to us with a concept for an aircraft that was radically different from anything they’d done before and, at that point, we were well down the path with Global Vision,” says Rockwell Collins Senior Dir Business and Regional Systems Colin Mahoney. “Core features and benefits of Rockwell Collins Fusion will reside in the Learjet 85 as they do in the Global Express.”
Due to flightdeck real estate constraints the Learjet 85 will have three 15-inch displays but you’ll be able to display a lot more on 3 large 15-inch screens than you can on 4 smaller Learjet 60XR Pro Line 21 displays.
Key to Fusion is enhanced situational awareness by way of a very graphically oriented environment, a cursor control device (CCD) and an open architecture system which accept standard ARINC protocols to interface with anything Rockwell Collins, or anyone else, may invent in the future.
Standard with Fusion on the Learjet 85 will be SVS, electronic chart and manual capabilities, tactical weather datalinks and new multiscan radar. Mahoney envisions future mandates for surface taxi management and this will be easily adaptable with Fusion as will enhanced vision system (EVS) and heads up display (HUD) capabilities as they become available.
Flight controls, systems and maintainability
While the Learjet 85 will be the world´s first all-composite Part 25 certified business jet flight controls and systems continue in Learjet´s tradition of simplicity and excellent handling characteristics.
This is not a fly-by-wire aircraft, flight controls are mechanically operated and Fowler flaps are electrically controlled and electromechanically actuated. This latest Learjet features 2 sets of hydraulically driven spoiler panels and an electrically driven aux pump supplying 3000 psi.
The fuel system has 2 wing tanks and 1 center fuselage tank with a single point refueling system. Ice protection is engine bleed air for wing leading edges and nacelle inlet lips. The electrical system will feature 3 AC variable frequency brushless starter/generators and electronic circuit breakers.
Pressurization and environmental system utilizes engine bleed air for a 6000-ft cabin at FL 490. An APU will be standard on the Learjet 85 however Bombardier has not yet released details on APU make or model.
Exceptional strength-to-weight ratio, reduced maintenance and extended service life are key characteristics of all-composite airframes. The Learjet 85´s composite structure should ease maintenance as a result of a greatly reduced parts count and less vulnerability to corrosion or fatigue damage than equivalent metal structures. While you´ve still got the same systems to maintain-generators and starters etc-Bombardier may be able to stretch airframe inspection intervals and inspections may be simpler.
The model 85 will be the largest and longest range Learjet while not sacrificing performance and handling characteristics that Learjet operators like so much. I´m glad that they´re calling this all-new airplane a Learjet as this is one of the best names in business aviation. It´s a truly iconic name and there will be people who buy this airplane because it is a Learjet.
While the model 85 will have a price premium over the 60XR, 3000 nm range is important to the market. My only negative comment on the Learjet 60XR, when I flew it earlier this year, was that range seemed too short for its very comfortable cabin. With the model 85, Bombardier not only addresses the range issue but also creates an important new large-midsize market segment.
Learjet design, combined with Grob´s composite technology experience, is a winning combination in my opinion. Grob is one of the world´s largest and most experienced composite aircraft manufacturers and the´re making a sizeable investment to prepare for the Learjet 85. Burkhart Grob, who founded Grob Aerospace in 1971 and produced the world´s first all-composite glider, would, I´m sure, be proud of how far company capabilities have evolved.
In fact, low temperatures lay-up composite technology perfected by Grob on the SPn and now and destined for the Learjet 85, may open the door to many more all-composite Bombardier business aircraft in future.
There´s no reason why a Challenger or Global Express business jet could not benefit from an all-composite structure. In fact, I´d better check my stock portfolio to make sure that I´m not too heavily invested in rivets or rivet machinery! I believe Bombardier has a real winner with the Learjet 85.
It gives the market what it´s looking for, in terms of cabin comfort, range and performance while achieving an effective mix of new technology and existing, proven, systems.