Learjet 75

By Fred George fred_george@aviationweek.com
Source: Business & Commercial Aviation

Taxiing out of the chocks, the wheel brakes felt smooth and responsive. Not so, the nosewheel steering. It still takes some practice to make smooth turns at low speeds because the rudder pedals provide little or no centering feedback.

Demonstration pilot Greg Eastburn in the right seat conservatively computed 113 KIAS for the V1/Vr decision and rotation speeds, 123 KIAS for the V2 one-engine-inoperative takeoff safety speed and 148 KIAS for flap retraction based on the 18,000-lb. takeoff weight, Wichita Mid-Continent Airport's 1,333-ft. field elevation, 29.83 barometer setting and 31C temperature. Takeoff field length was 4,260 ft. When the aircraft earns certification, it's likely that 2 to 4 kt. will be shaved off those V speeds, according to Bombardier's flight test data.

Once cleared for takeoff on Runway 19R and I pushed up the power levers to the takeoff detent, it was immediately apparent that this aircraft may resemble the Model 45, but it doesn't perform like one. The combination of 10% more thrust and 200 lb. less weight had a palpable effect as the aircraft accelerated.

Rotation forces were as hefty as those of the Model 45, as were roll control forces. Control feel was much lighter in the old Model 20 and 30 series aircraft.

Once we stabilized at 250 KIAS, the aircraft settled into a 6,000- to 7,000-fpm initial rate of climb. Safety pilot Lyn Jacques logged our passing through FL 350 in 14 min. since beginning takeoff roll, even though we were climbing in ISA+12C to ISA+20C conditions.

We leveled at FL 430 in 19 min. and settled into Mach 0.78 normal cruise. At a weight of 17,000+ lb., the aircraft zipped along at 444 KTAS at ISA-4C while sipping 1,040 lb./hr. Pushing up the thrust levers to cruise at the Mach 0.81 redline, we trued at 460 KTAS at the same OAT while burning 1,240 lb./hr. Operators choose Learjets for speed and fuel efficiency and the Model 75 delivers.

We then headed to Hutchison, Kan., Municipal Airport (HUT) to fly the RNAV (GPS) Runway 13 LPV procedure. During the descent, we encountered a TCAS traffic advisory alert. Unlike some other Garmin display systems, the G5000 in the Learjet 75 does not provide 3-D traffic imagery on the PFD. Instead, a small bird's-eye view chart inset pops up, showing traffic in two dimensions with the intruder's altitude differential shown in numerical digits.

Eastburn requested clearance for the full RNAV procedure to demonstrate Vision's ability to compute the required guidance maneuvers to enter a procedure turn and fly the entire procedure. We flew most of the procedure with the autopilot coupled and the system guided the aircraft smoothly and precisely throughout.

At minimums, we executed a missed approach. Pressing the Go Around button on the throttle disengages the autopilot, thus initially the missed approach must be flown by hand. After the appropriate lateral and vertical flight guidance modes have been programmed, the autopilot again may be coupled.

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