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Many factors affect flight planning and aircraft operation, including aircraft weight, weather, and runway surface. The recommended flight parameters listed below are intended to give approximations for flights at maximum takeoff or landing weight on a day with International Standard Atmosphere (ISA) conditions.
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Important: These instructions are intended for use with Flight Simulator only and are no substitute for using the actual aircraft manual for real-world flight. Note: As with all of the Flight Simulator aircraft, the V-speeds and checklists are located on the Kneeboard. To access the Kneeboard while flying, press SHIFT+F10, or on the Aircraft menu, click Kneeboard. Note: All speeds given in Flight Notes are indicated airspeeds. If you're using these speeds as reference, be sure that you select "Display Indicated Airspeed" in the Realism Settings dialog box. Speeds listed in the specifications table are shown as true airspeeds. |
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By default, this aircraft has full fuel and payload. Depending on atmospheric conditions, altitude, and other factors, you will not get the same performance at gross weight that you would with a lighter load. |
Required Runway Length
Takeoff: 4,700 feet (1,432 meters), flaps 8
Landing: 3,200 feet (975 meters), flaps 20
The length required for both takeoff and landing is a result of a number of factors, such as aircraft weight, altitude, headwind, use of flaps, and ambient temperature. The figures here are conservative and assume:
Weight: 20,000 pounds (9,072 kilograms)
Altitude: sea level
Wind: no headwind
Temperature: 15° C
Lower weights and temperatures will result in better performance, as will having a headwind component. Higher altitudes and temperatures will degrade performance.
Engine Startup
The engines are running by default when you begin a flight. If you shut the engines down, it is possible to initiate an auto-startup sequence by pressing CTRL+E on your keyboard. If you want to do the startup procedures manually, follow the checklist procedures on the Kneeboard.
Taxiing
To taxi the Learjet, use just enough power to get it rolling, and then bring the thrust levers back to idle. Idle thrust will work fine for keeping you moving.
Takeoff
All of the following occurs quite rapidly. Read through the procedure several times before attempting it in the plane so you know what to expect.
Run through the Before Takeoff checklist, and set flaps to 8 or 20 as desired (press F7, or drag the flaps lever). With the aircraft aligned with the runway centerline, advance the throttles (press F3, or drag the levers) to approximately 40 percent N1. This allows the engines to spool up to a point where uniform acceleration to takeoff thrust will occur on both engines. The exact amount of initial setting is not as important as setting symmetrical thrust.
After the engines are stabilized, advance the thrust levers to takeoff thrust—generally 93 to 96 percent N1 (less with high outside air temperatures).
Directional control is maintained by use of the rudder pedals (twist the joystick, use the rudder pedals, or press 0 [left] or ENTER [right] on the numeric keypad).
At V1, approximately 136 knots indicated airspeed (KIAS), is decision speed. Above this speed, it may not be possible to stop the aircraft on the runway in case of a rejected takeoff (RTO).
At Vr, approximately 143 KIAS, smoothly pull the stick back (use the joystick or yoke, or press the DOWN ARROW) to raise the nose to 10 degrees above the horizon. Hold this pitch attitude and be careful not to over-rotate.
At V2, approximately 146 KIAS, the aircraft has reached its takeoff safety speed. This is the minimum safe flying speed should an engine fail. Hold this speed until you get a positive rate of climb.
As soon as the aircraft is showing a positive rate of climb (both vertical speed and altitude are increasing), retract the landing gear (press G on the keyboard, or drag the landing gear lever). The aircraft will quickly accelerate to the flap-retraction speed. This number is V2+ 30, or about 176 knots. Retract the flaps (press F6, or drag the flaps lever).
Climb
After retracting the gear and flaps, you don't need to reduce power unless you level off below 10,000 feet (3,048 meters) and you need to remain below FAA speed limits. To remain level at 200 KIAS at 2,000 feet (610 meters), for example, pull the power back to 53 to 55 percent N1. A power setting of 60 to 63 percent will get you 250 KIAS while level at this altitude.
If you continue your climb above 10,000 feet, leave the power up as long as it remains below the "max continuous temperature" on the interstage turbine temperature gauge (ITT). You should be climbing at 1,800 to 2,000 feet per minute. Learjet drivers run their engines at maximum a good deal of the time.
Increase the pitch attitude to maintain 250 knots until reaching 0.7 Mach. Then, maintain 0.7 Mach for the rest of the climb. The changeover from indicated airspeed to Mach number typically occurs as you climb to altitudes in the high 20s or low 30s.
You'll have to increase power as you climb to maintain the profile just described. Like piston engines, turbine powerplants slowly lose power as the air gets thinner.
Cruise
Cruise altitude is normally determined by winds, weather, and other factors. You might want to use these factors in your flight planning if you have created weather systems along your route. Optimum altitude is the altitude that gives the best fuel economy for a given configuration and gross weight. A complete discussion about choosing altitudes is beyond the scope of this section.
The Learjet is designed to fly high. You can cruise as high as FL450 (the airplane is certified to 51,000 feet), but the only payoffs for burning the fuel it takes to get there would be getting above a weather system or taking advantage of especially favorable winds.
Let's say you've filed a flight plan for FL350. When you approach your cruising altitude, begin leveling off at about 50 feet (15 meters) below your target altitude.
You'll find it's much easier to operate the Learjet in cruise if you use the autopilot. The autopilot can hold the altitude, speed, heading, or navaid course you specify. For more information about using the autopilot, see Using an Autopilot.
Normal cruise speed is 0.77 Mach. Set power at around 90 percent N1. If you're showing indicated airspeed on the airspeed gauge, the needle will settle down at about 280 KIAS.
Remember that your true airspeed is actually much higher in the thin, cold air. At FL370, you can count on a speed over the ground of about 429 knots (794 kilometers per hour, or 494 mph).
In cruise, the Learjet 45 gives its best maximum-weight speed performance at 33,000 feet (10,058 meters), where it zips along at 444 KIAS, burning around 1,715 pounds of fuel per hour.
Descent
A good descent profile includes knowing when to start down from cruise altitude and planning ahead for the approach. Normal descent is done with idle thrust and clean configuration (no speed brakes). A good rule for determining when to start your descent is the 3-to-1 rule (three miles distance per thousand feet in altitude.) Take your altitude in feet, drop the last three zeros, and multiply by 3.
For example, to descend from a cruise altitude of
35,000 feet (10,668 meters) to sea level:
35,000 minus the last three zeros is 35.
35 x 3=105
This means you should begin your descent 105 nautical miles from your destination, maintaining a speed of 250 KIAS and a descent rate of 1,500 to 2,000 feet per minute, with thrust set at flight idle to 53 percent N1. Add two extra miles for every 10 knots of tailwind.
To descend, disengage the autopilot if you turned it on during cruise (or use the autopilot hold features and let it fly for you). Reduce power to idle, and lower the nose slightly. Remember not to exceed the regulation speed limit of 250 KIAS below 10,000 feet (3,048 meters). You may have to adjust power to maintain your speed and rate of descent. Continue this profile down to the beginning of the approach phase of flight.
Deviations from the above can result in arriving too high at the destination (requiring circling to descend) or arriving too low and far out (requiring expenditure of extra time and fuel). Plan to have an initial approach fix regardless of whether or not you're flying an instrument approach.
Approach
A good target speed as you enter the downwind for VFR flight or at your initial approach fix for IFR flight is 200 KIAS. As you begin the approach but before you turn toward the runway, bring the power back, and hold altitude to reduce speed. Extend 8 degrees of flaps. Let the airplane stabilize at 180 knots.
During the first turn toward the runway (either on the base leg or when turning inbound on an ILS), extend 20 degrees of flaps.
Landing
When you're approaching the normal descent point on a visual approach, or one dot below the glideslope approaching the final approach fix on an ILS approach, extend the landing gear.
Smoothly increase power to maintain 140 knots, your final approach speed. As you intercept the glideslope, set 40 degrees of flaps. This configuration should hold airspeed at 140 knots with a good descent angle toward the runway.
Hold 140 knots all the way down on final approach. Use small power adjustments to stay on the glidepath. Look for a descent rate of about 700 fpm.
At about 50 feet above the runway and past the runway threshold, bring the thrust levers to idle. Hold the pitch attitude you've used during final approach. Don't try to raise or lower the nose. When you touch down, deploy the spoilers (press the SLASH [ / ]), and add reverse thrust (press F2, or drag the thrust levers into the reverse position), and apply brakes.
Make sure you come out of reverse thrust (press F1, or drag the thrust levers), and lower the spoilers as airspeed drops below 60 knots. Exit the runway, and taxi to parking.