Aircraft Without Contrail.

It's been a lovely blue clear sky here all day with wall to wall sunshine. I have spent most of the day outside in the garden.

I live on the flight path into Birmingham airport, but also aircraft are constantly flying overhead at much higher altitudes into and out off airports north and south of Birmingham.

Every aircraft i have observed during the day have left behind a contrail. All that is apart from one that i observed about 2 hours ago. It appeared to be flying at a similar height as every other one i had seen.

My question is, why no contrail ? This is possibly quite normal but just asking out of curiosity. Mods, if this is not the correct forum then please move.


Edit:

I should also add, that as it flew over, an aircraft flew past it in the opposite direction ( with a contrail ). However the distance between the two aircraft did seem to be narrower that usual.

a reply to: alldaylong

Judging height at those distances is an exercise in futility. Planes tend to not fly at the same altitude towards each other, so I would bet one was lower than the other.

a reply to: OccamsRazor04

so I would bet one was lower than the other.

Would that cause a " No Contrail " ?

Out of the 100 or so aircraft i have seen fly overhead today, just one with no contrail.

a reply to: alldaylong

Air pressure in my limited understanding.

For the record I'm a Chemtrail believer but they suddenly stopped a few years ago.

originally posted by: alldaylong
a reply to: OccamsRazor04

so I would bet one was lower than the other.

Would that cause a " No Contrail " ?

Out of the 100 or so aircraft i have seen fly overhead today, just one with no contrail.

Yes, altitude plays a crucial role in contrail formation.

originally posted by: OccamsRazor04

originally posted by: alldaylong
a reply to: OccamsRazor04

so I would bet one was lower than the other.

Would that cause a " No Contrail " ?

Out of the 100 or so aircraft i have seen fly overhead today, just one with no contrail.

Yes, altitude plays a crucial role in contrail formation.

Thank you for that.

Hopefully that answers my question.

originally posted by: Wide-Eyes
a reply to: alldaylong

Air pressure in my limited understanding.

For the record I'm a Chemtrail believer but they suddenly stopped a few years ago.

Alldays poses an excellent question and something been thinking about quite recently living beneath the Manchester going south air lane. Indeed I just can't help looking up very frequently and you can watch like a dozen planes on exactly the same path going say south and they all have contrails then one flies over with no contrail and it does raise this question in your mind, like what's going on up there?

a reply to: ufoorbhunter

I'm not discounting UFO.

I've seen a few myself as you probably know. We've both been here a few years now.

The atmosphere is not homogenous.

There are three primary requisites for the formation of contrails; temperature, pressure, and relative humidity. All three vary in both the horizontal and vertical. It's entirely possible for conditions conducive to the formation of contrails to occur at one flight level and not at a level above or below. Likewise, such conditions can exist to the east but not to the west.

Under marginal conditions another factor to consider is the type of engine. Older jet engines (not of the high bypass variety) might not produce contrails under these conditions while newer ones may.

originally posted by: Wide-Eyes
a reply to: ufoorbhunter

I'm not discounting UFO.

I've seen a few myself as you probably know. We've both been here a few years now.

Oh yeah and total respect to you WMD and like you say go back a bit somethink like one seventh the way back to WW2

originally posted by: alldaylong
It's been a lovely blue clear sky here all day with wall to wall sunshine. I have spent most of the day outside in the garden.

I live on the flight path into Birmingham airport, but also aircraft are constantly flying overhead at much higher altitudes into and out off airports north and south of Birmingham.

Every aircraft i have observed during the day have left behind a contrail. All that is apart from one that i observed about 2 hours ago. It appeared to be flying at a similar height as every other one i had seen.

My question is, why no contrail ? This is possibly quite normal but just asking out of curiosity. Mods, if this is not the correct forum then please move.


Edit:

I should also add, that as it flew over, an aircraft flew past it in the opposite direction ( with a contrail ). However the distance between the two aircraft did seem to be narrower that usual.

Same thing in New Jersey. Apparently there is great fluctuations in temperature at 30,000 feet.

I think there are additives in the fuel that creates the chemtrails so the airlines save money on fuel but it has nothing to do with some evil conspiracy. Profit is the motive. You know something is going on because just like frakking it's not possible to find out exactly what is being done.

after flying halfway round the world on a KC 135 towing lawn darts I can tell you it can change from place to place, sometimes you get a contrail shortly after 10k feet, other times you might not see it till 30k feet due to the variety in pressure, humidity, and temp.

Also it can look from the ground like planes are passing close to wach other, but here stateside its a minimum of 1000 feet between planes unless its an inflight refueling (which means air trafic control has released you from their control because their system will say you crashed) or someone really screwed up.

I am not certain about Europe but I would imagine its similar.

originally posted by: Irishhaf
after flying halfway round the world on a KC 135 towing lawn darts I can tell you it can change from place to place, sometimes you get a contrail shortly after 10k feet, other times you might not see it till 30k feet due to the variety in pressure, humidity, and temp.

Also it can look from the ground like planes are passing close to wach other, but here stateside its a minimum of 1000 feet between planes unless its an inflight refueling (which means air trafic control has released you from their control because their system will say you crashed) or someone really screwed up.

I am not certain about Europe but I would imagine its similar.

All of Europre is now under RVSM rules, which stands for Revised Vertical Separation Minimums. The rules used to require at least 2000 feet separation, but under RVSM it is now 1000. The US now has RVSM also. There are also aircraft instrumentation and autopilot and crew training requirements.

originally posted by: alldaylong
a reply to: OccamsRazor04

so I would bet one was lower than the other.

Would that cause a " No Contrail " ?

Out of the 100 or so aircraft i have seen fly overhead today, just one with no contrail.

Three words...high pressure system.

originally posted by: Thecakeisalie

originally posted by: alldaylong
a reply to: OccamsRazor04

so I would bet one was lower than the other.

Would that cause a " No Contrail " ?

Out of the 100 or so aircraft i have seen fly overhead today, just one with no contrail.

Three words...high pressure system.

Air pressure has a minimal effect on the time of sublimation, but no effect on formation. High pressure systems exist in the lower atmosphere but if you look at an the isobars on a 250 millibar chart you will see that at those flight levels, pressure systems are trivial. If you burn a hydrocarbon fuel with oxygen as the oxidizing agent, and eject the result out into -50C air at any atmospheric pressure, a trail of ice crystals will form. That's a contrail.