I am a fairly new enthusiast to flight simulation.

I would like to know what are the takeoff and landing speeds of a Learjet 45? If they are not fixed, what factors influence those speeds?

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    $\begingroup$ HOW is this question "not about aviation"??? The motivation is perhaps a little outside of what av.se geneally covers, but so what? Asking for the takeoff & landing speeds of a Lear 45 is entirely about aviation. Why are folks so spring loaded to VTC questions just because the motivation behind it is stated as "flight simulation" instead of "wanted to learn more about this model of Learjet"? VTLO. $\endgroup$ – Ralph J Dec 4 '16 at 23:25

The takeoff and landing speeds of aircraft can usually be found in the performance section of the aircraft light manual. They are not fixed and vary over a wide range depending on various factors like,

  • temperature,

  • density altitude

  • weight etc.

The table below gives the takeoff speeds for Learjet 45, taken from Learjet 45 AFM:

Takeoff speed

Learjet 45 Takeoff speeds; table from Learjet 45 AFM

Here, $V_{1}$ is the critical engine-failure speed. Below this speed, the pilot should abort and bring the plane to a stop if an engine fails. If the engine fails after the aircraft has exceeded $V_{1}$, he/she should continue the takeoff using the remaining engines.

$V_{r}$ is the rotation speed, which is the speed at which the aircraft can begin to rotate its nose into the air and $V_{2}$ is the takeoff climb speed, which must be reached at an altitude high enough to clear a given obstacle. For FAR 25 aircraft, the obstacle clearance height is 35 ft (10.7 m).

You can also see from the table (and conditions listed on the right) the various factors affecting the takeoff speeds like runway condition, flap setting etc.

The minimum control speed landing $V_{MCL}$ is also a function of altitude and temperature and varies between 98 and 105 KIAS depending on the flap setting.

The landing approach speed $V_{REF}$ is the airspeed used for landing climb gradient and depends on the factors given above. The following table from the same document gives the $V_{REF}$ speeds for various configurations.

Landing speed

Learjet 45 Landing Approach; table from Learjet 45 AFM

*Speed definitions from www.aerospaceweb.org

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Like all turbojet aircraft, takeoff and landing numbers are not fixed. Takeoff numbers are affected by WAT (weight, altitude, temperature), wind, runway contamination, runway slope, anti-skid, and ant-ice.

$V_1$ is affected by those listed above and is restricted to a number between $V_{MCG}$ and $V_R$. 105 - 122 KIAS.

Takeoff distance for normal conditions will be around 4,000 FT but can be as low as 3,000 FT and as high as 11,000 FT.

$V_R$ and $V_24$ change only with weight and will be between 107 - 122 KIAS ($V_R$) and 116 - 132 KIAS($V_2$).

Landing $V_{REF}$ is also only affected by weight with speeds ranging from 106 to 131 KIAS.

Landing distance is approximately 2,500 FT but can be as low as 1,900 and as high as 5,300 FT. This distance is also affected by those listed above.

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    $\begingroup$ 'Turbojet' in the first line could be deleted. $\endgroup$ – Hugh Dec 5 '16 at 7:54
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    $\begingroup$ Considering the OP is new to Aviation, how about explaining some of the V speed nomenclature? $\endgroup$ – Notts90 supports Monica Dec 5 '16 at 9:58
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    $\begingroup$ Source: current version of Learjet 45 AFM "F". $\endgroup$ – wbeard52 Dec 5 '16 at 14:33

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