How do I choose the right aircraft cruising speed?

In Aviation & Real-World Flying, choose an aircraft’s cruising speed from its POH or AFM performance data, matching altitude, weight, temperature and your aim: speed, range or endurance. Normal cruise is a power setting or IAS/Mach schedule—not the red line—and must leave adequate fuel reserve and remain within every operating limitation.

What is the cruising speed of an aircraft?

Cruising speed is the steady speed used during the level cruise portion of a flight, but most aircraft do not have one universally correct cruise speed. A piston pilot may select power and accept the resulting true airspeed, while a jet normally follows an IAS or Mach schedule calculated for the flight.

Maximum permitted speed is not a cruise target. VNO, VMO and MMO are limitations; manoeuvring and turbulent-air speeds serve different purposes. On a conventional light-aircraft airspeed indicator, the green arc shows the normal operating range rather than a recommended cruise setting.

What are the A320, Boeing 737 and Airbus A330 cruise speeds in knots?

Modern commercial airliners generally cruise at about 430–500 knots true airspeed, commonly between Mach 0.75 and Mach 0.85. The figures below are representative planning ranges, not speeds to enter without checking the exact variant, weight, altitude, temperature and operator procedure.

An A320 cruise speed in knots cannot be reduced to one permanent number: Mach 0.78 converts to a different KTAS as temperature changes. The Boeing 737 MAX and Airbus A320neo have broadly similar normal cruise speeds, so speed alone does not establish which is more economical or better suited to a route. The larger Airbus A330 normally uses a slightly higher cruise Mach number.

For more detail on normal, economy and high-speed schedules, see our breakdown of typical commercial-airliner cruise speeds.

What is the landing speed of a Boeing 737?

A Boeing 737 commonly approaches at roughly 130–150 KIAS, but there is no fixed 737 landing speed. The crew obtains VREF for the actual landing weight and flap setting from approved aircraft data; the approach target is often VREF plus the wind correction required by the applicable procedure.

Approach speed is not touchdown speed, and this broad range must not be used for an actual flight. Variant, weight, flap selection, runway conditions, wind and system status can all move the calculated value outside it. It is also an indicated airspeed, whereas published airliner cruise figures in knots are usually true airspeed.

How do I select cruise speed from the POH or AFM?

Select cruise speed by matching the aircraft’s approved performance data to the planned conditions and mission.

1. Define the priority. Decide whether time, trip fuel, maximum range, endurance or passenger comfort matters most. These goals do not produce the same speed.
2. Choose a practical altitude. Check terrain, weather, regulations, winds and aircraft capability. Altitude changes available power, true airspeed, fuel flow and—in a jet—the useful Mach schedule.
3. Open the correct performance table. Match the exact aircraft variant and the closest pressure altitude, temperature and weight. Our method for matching POH and AFM performance charts to flight conditions explains how to handle table entries and interpolation. Never extrapolate beyond published data unless the manufacturer explicitly permits it.
4. Identify what the number represents. Determine whether the manual specifies power, KIAS, KCAS, KTAS or Mach. Do not compare values until they use the same reference.
5. Set the documented configuration. Retract the landing gear and flaps, close or position cowl flaps as required, and set power, propeller, mixture or autothrottle modes according to the aircraft procedure.
6. Stabilise before measuring. Establish trimmed level flight and allow speed, engine indications and fuel flow to settle. Continually chasing the indication with pitch and power makes comparison unreliable.
7. Apply wind and check fuel. Convert true airspeed to expected groundspeed using the forecast wind, calculate trip time and fuel, then retain the required contingency and reserve. If the plan fails, change speed, altitude, route, fuel load or departure time.
8. Check limiting conditions. Observe engine limits, VMO/MMO, buffet margins, icing procedures, turbulence guidance and any ATC restriction. The fastest technically attainable setting may not be an acceptable cruise setting.

Which speed indication should I use during cruise?

Use IAS for aerodynamic control and many limitations, TAS for aircraft performance, Mach at high jet-cruise altitudes and groundspeed for navigation and arrival time.

One knot is one nautical mile per hour, equal to 1.852 km/h. At the same indicated airspeed, true airspeed generally rises with altitude because the air is less dense. Mach also has no fixed conversion to knots because the local speed of sound changes with temperature. Our practical explanation of IAS, TAS and Mach in cruise covers the crossover used by turbine aircraft.

How does cruise-speed selection differ by aircraft type?

The method is aircraft-specific because piston engines, turboprops and jets express cruise performance in different ways.

Piston aircraft

A piston-aircraft cruise is usually selected by percentage power or by a combination of manifold pressure and rpm. The POH then predicts fuel flow and KTAS. Mixture affects power, fuel consumption and engine temperature, so use the manufacturer’s leaning procedure rather than copying a generic exhaust-gas-temperature target.

With a fixed-pitch propeller, rpm is often the principal cockpit indication, but the same rpm does not produce identical power at every altitude and temperature. In this case, published cruise speed is mainly the expected result of the correct power and configuration—not a number to force with extra throttle.

Turboprops

Turboprop cruise normally uses an aircraft-specific combination of torque or shaft power, propeller rpm and fuel flow. Torque, turbine temperature and rotational-speed limits can become controlling factors, so an IAS target by itself is insufficient.

Jet aircraft

Jets generally fly an IAS schedule lower down and a Mach schedule higher up. Airliner flight-management systems can calculate an economy speed from weight, altitude, wind and an operator-defined cost strategy, while pilots monitor fuel progress, buffet margin, weather and VMO/MMO.

A lower economy or cost setting usually trades time for fuel, but it is not automatically the maximum-range or maximum-endurance schedule. Our guide to trading cruise power and speed against fuel flow, range and endurance covers that decision without treating the fastest setting as the best one.

How do altitude, weight, temperature and wind change cruise speed?

Altitude, weight, temperature and wind can change either the appropriate cruise schedule or the speed produced by a given power setting.

• Altitude: TAS usually increases relative to IAS as altitude rises. Normally aspirated piston engines lose available power, while turbocharged engines and turbines have different limits. A jet’s optimum flight level may increase as fuel burns.
• Weight: A heavier aircraft needs more lift and generally has higher optimum and manoeuvring speeds. Do not reuse a speed calculated at a substantially different weight.
• Temperature: Non-standard temperature changes air density, engine performance and the conversion between IAS, TAS and Mach.
• Wind: Wind changes groundspeed rather than aerodynamic limits. A strong headwind may make a slightly faster cruise economical if approved planning data support it, but adding power merely to recover a preferred groundspeed can destroy the fuel plan.
• Turbulence: Use the published turbulent-air speed or IAS/Mach schedule. Manoeuvring speed is weight-dependent and should not automatically be treated as the aircraft’s rough-air recommendation.
• Icing: Ice protection can increase fuel burn or reduce available performance, while some aircraft prescribe minimum speeds in icing. Follow the aircraft-specific procedure rather than simply slowing down.

Why is the aircraft slower than its published cruise speed?

A cruise-speed shortfall usually comes from comparing different speed references or reproducing conditions that do not match the performance table.

• Confirm that book KTAS is not being compared with cockpit KIAS or wind-affected groundspeed.
• Check pressure altitude, outside-air temperature, aircraft weight and centre of gravity.
• Verify that landing gear, flaps, spoilers, speedbrakes and cowl flaps are in the documented configuration.
• Check rpm, manifold pressure, torque, propeller setting, mixture, anti-ice use and autothrottle mode.
• Make sure the aircraft is holding level flight rather than climbing slowly or oscillating around the selected altitude.
• Account for external equipment and configuration differences included in—or omitted from—the published data.

A mistake we see constantly is adding power to force a piston aircraft to reach a book KTAS even though the specified cruise power is already set. If the table predicts speed from power, speed is an output. In a real aircraft, a persistent unexplained shortfall should be recorded and assessed through the appropriate maintenance process.

How should I test cruising speed in a flight simulator?

A meaningful simulator test must reproduce the handbook conditions before the flight model is judged.

1. Match the aircraft. Load the correct variant, weight, fuel, payload and external configuration.
2. Control the atmosphere. Use the specified temperature and pressure conditions, with wind, turbulence and icing disabled for the initial test.
3. Establish the test point. Reach the stated pressure altitude, level off, trim and set the documented engine, propeller, mixture or thrust schedule.
4. Check automation. Confirm that the autopilot is holding altitude and that autothrottle, managed-speed, auto-mixture or assistance features are not overriding the intended setting.
5. Let the aircraft stabilise. Wait for airspeed and fuel flow to settle instead of reading them immediately after level-off.
6. Compare like with like. Record KIAS, KTAS, Mach, groundspeed and fuel flow separately. Use KTAS when the manual publishes TAS, and introduce wind only after the no-wind result is understood.

Aircraft add-ons differ in engine, propeller and drag modelling, so an exact match is not guaranteed. Large discrepancies point first to the wrong units, weather, loading, speed reference, mixture, propeller setting or partially extended drag device—not to a need to cruise at the aircraft’s maximum permitted speed.