"And then we'll drop down to, oh … 15,000 or so and do some stalls if you're up for it," Learjet demo pilot Chris Barnett said casually during our preflight briefing. As a jet pilot for many years, I've tried to keep the words jet and stalls in separate corners of the universe. "Are we really going to stall this airplane — intentionally?" I asked myself.
Yes, we were. And yes, we did.
One of the "big takeaways" after flying the Lear 45XR is the wing. It's a nicely balanced combination of fuel efficiency, runway performance and high- and low-speed handling qualities. At 15,000 feet, with a large block altitude assigned by ATC in which to play, I pulled the thrust levers back to idle and let the aircraft decelerate through the visual and aural low-speed warnings and, finally, stick shaker. I continued to hold the control yoke in my lap until is was full back — and the airplane just began to sink at 3,000 to 4,000 fpm, with no aggressive tendency to pitch down or roll off on a wingtip; that's a very benign stall for a jet.
Lear is proud to tout the fact that its test pilots did more than 3,000 stalls during certification flights to dial in the qualities that I witnessed. I'd say their efforts paid off; this is a very comfortable jet aircraft at slow speeds that can also fly fast and efficiently when asked.
I hope you'll never even get close to stalling the Lear 45XR when you're transporting corporate passengers to their Very Important Meetings, but that demo quickly created a high level of comfort for me after only a short time in the aircraft. That kind of comfort makes it a lot more likely pilots will use the aircraft for those shorter runways that we're often asked to accommodate.
The Lear 45 was first certified in 1998 under FAR Part 25, transport category rules. When compared with FAR Part 23 aircraft, this translates into more robust system redundancy; it also guarantees performance numbers in the aircraft's POH. The identical but 24.5-inch-shorter sibling, the Lear 40, was first delivered in 2003.
More than 525 of the two models have been delivered, which means all the inevitable "new airplane bugs" should be worked out by now.
The XR version of the Lear 45 was first delivered in 2004 and includes up-rated TFE731-20-BR engines flat-rated at 3,500 pounds of thrust at 104 degrees F, up from the original Lear 45's rating of 86 degrees F. This power increase reduced balanced field length, especially under high and hot conditions and, of course, improved the aircraft's climb performance. The XR upgrade also upped the gross weight by a thousand pounds, greatly increasing the type's utility.
Variations of the TFE731 engines have powered various jets for decades and have proved to be reliable and efficient. The 45XR's engines are equipped with a DEEC, or digital electronic engine control, which governs N1 speed and limits fuel during acceleration and deceleration, making power management a simple task. There is an engine synchronizer that keeps the big fans synced and passengers happy; it's a good thing, since engine noise is not easy to detect from the cockpit.
During the walk-around inspection, you'll notice large, fixed surfaces, called delta fins, extending prominently below the tail of the aircraft. They greatly increase the pitch-down moment at high angles of attack and add to the yaw stability of the aircraft; because of these fins, there is only a single yaw damper installed, and it is not required for dispatch as on many other jets.
The Lear 45XR's wing is a beautiful, 13-degree-swept, supercritical airfoil that looks like it was carved from a single bar of Ivory soap; in fact, the upper and lower skins are machined from a solid piece of aluminum. It has no fences or leading edge slats, yet it does have vortilons along the leading edge to prevent spanwise flow, and interesting little metal triangles along the leading edge to prevent flow separation at high angles of attack. The entire polished leading edge is heated by bleed air (as are the horizontal-tail leading edges). Gracefully swept winglets add to the wing's slow speed abilities and boost its efficiency at high altitude by about 20 percent. This is not your father's Learjet wing.
A single point pressure refueling system (SPPR), located under the right engine pylon, is a welcome addition to an airplane in this category; the entire 904-gallon fuel system can be filled in about 10 minutes, expediting quick turnarounds. The fueling panel and associated valves are powered by the emergency battery bus, thus obviating the need for the aircraft system to be powered when filling the tanks. That's a nice feature.
Something else that will be welcomed by any corporate pilot or ground crewman who has juggled a too-full potty or collection bag down the aisle of a corporate jet is an external access door to service the potty. Oh, the simple things!