Why Jet Planes' Tails Are Not Always Visible

In summary, the visibility of a jet plane's vapour trails, also known as contrails, depends on various factors such as temperature, humidity, atmospheric pressure, and engine load. These trails are caused by the hot water vapour and ice crystals expelled from the engine's exhaust, and are more likely to form at higher altitudes. However, in warmer regions like the Sahara, they may not be visible at all. The variability of these factors can explain why sometimes planes have visible trails and sometimes not.
  • #1
temujin
47
1
Hi,

Sometimes when a jet plane is flying above you you can see the white tail from the motors, and sometimes not.
What is the reason for this?
Why isn´t this visible all the time?


regards
t.
 
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  • #2
Vapour trails are caused by jet planes expelling hot water vapour into the cold air due to the combustion they use. If the air is cold enough, ice crytals form. These crystals are the 'vapour trails'.

Thats why you see them in a lot of jets above 30,000 feet (its ultra cold up there), however not always. For example, over the Sahara you would not see them because it would be too hot for the crystals to develop.

-NewScientist
 
  • #3
thanks,
However, even where I live (Hamburg) I see planes both with and without these vapour trails...

t.
 
  • #4
Clouds caused by jet engines are an example of contrails (con)densed water vapor (trail)ing from the exhaust of a turbine engine. There are many variables (temperature, relative humidity, atmospheric pressure, engine load etc...) that make contrails form. Hamburg, Germany must be somewhat similar to the weather here in Maine, USA. We mostly see contrails but in the warmer months there may be planes without them.
 
  • #5
Temujin. Those factors listed by pete depend drastically on altitude. A higher flying plane is more likely to produce contrails than one flying at less altitude.

This issue was discussed here recently (last 2 weeks or so), have a search for it!
 
  • #6
brewnog said:
This issue was discussed here recently (last 2 weeks or so), have a search for it!

How about your holidays?

I don't think he will be able to find it, specially if you are referring to my last thread about "Water <Weaks> behind aircrafts". :rofl:
 

1. Why are jet planes' tails not always visible in the sky?

The visibility of a jet plane's tail depends on several factors such as the lighting conditions, the angle of the aircraft, and the speed of the plane. The tail may become less visible at higher altitudes and faster speeds due to the thinning of the air and the blurring effect of the plane's movement.

2. Can a jet plane fly without its tail being visible?

Yes, a jet plane can fly without its tail being visible. The tail is primarily used for stability and control during takeoff, landing, and maneuvering. Once the plane has reached cruising altitude, the tail is not as crucial, and the pilot can adjust the plane's flight path using other controls.

3. Are there any safety concerns related to not being able to see a jet plane's tail?

No, there are no safety concerns related to the visibility of a jet plane's tail. The tail is designed to be visible in most situations, but its absence in certain conditions does not affect the safety or performance of the aircraft.

4. Is there any significance to the shape and design of a jet plane's tail?

Yes, the shape and design of a jet plane's tail are carefully engineered to provide stability and control during flight. The tail's size, angle, and shape are all crucial factors in the plane's overall aerodynamics and performance.

5. Are there any technological advancements that have made jet planes' tails more visible?

Yes, there have been advancements in lighting technology that have made jet planes' tails more visible, especially during low light conditions. Some planes also have reflective materials or lights on their tails to enhance visibility for other aircraft and air traffic control.

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