As long as the topic is exploring the 747 speed envelope,
what’s the slowest speed for a 747?
I’m of the understanding it’s in the ballpark of 110 knots.
Of course, the actual stall speed depends of gross weight, vintage, configuration, flaps/gear....
what’s the slowest speed for a 747?
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—”what’s the slowest speed for a 747?’
A fun topic with many variables.
“The slowest theoretical speed is the stall speed with full flaps and slats. It depends on the aircraft mass, the center of gravity location and the air density (which is dominated by altitude and temperature). Let’s assume OWE (operating weight empty) plus one pilot and conditions at Verkhoyansk (ICAO code UEBW) in Siberia in Winter. The average temperature in January there is only -50°F, so this should be a perfect combination of low and cold to produce a density of 1.522 kg/m³.
Now plug in the numbers: Minimum weight for a 747–400 is 254,500 kg, and the same source gives the stall speed in landing configuration at 280 tons with 138 knots or 71 m/s. Now correct for the minimum mass and the higher density, and the result is 118 knots or 60.72 m/s. This is as low as it gets, but no longer safe.
Multi-engined aircraft have another speed limit, called minimum control speed, which the aircraft should never fall below to be safe if an engine fails. This speed is 1.73 times higher than the stall speed for the 747–400, and even during the final approach the pilot will not drop the speed lower than 1.3 times stall speed.”