or the jet lost all power.
Or it was hijacked by unicorns.
You consistently post hogwash.
Two days ago a jet flew over my land. Not overly high, clearly see from the ground 4 distinct contrails. It was a two engine plane and none of the 4 “contrails” lined up with an engine. I must be seeing things.
1. Throttled back for decent.
2. Was descending and encountered warmer air and thus condensation did not happen. Jets do not have contrails at lower altitudes due to air temperatures.
It is all about humidity of surrounding air, temperature of surrounding air, and humidity content of the exhaust and how much of the airflow is from bypass air from the turbine. The original non bypass engines like in the first 707 would produce contrails at lower altitudes and higher air temperature as there was no mixing of bypass air with the exhaust. The contrail is actually water vapor from the jet fuel. As it is burned in the turbine it turns into H20 and C02. The high content of H20 in the exhaust immediately turns in to water droplets (a cloud) when cooled by the surrounding cold air. The CO2 becomes plant food.