Originally posted by Gmoneycricket
I find all forms of engine exhaust harmful, no matter the year they were created.
And Ice crystals with fuel byproducts mixed in does not sound harmless.
So do you have links to back up that statement?
And if the pilots left contrails, they could be seen and possibly shot down with anti-aircraft guns.
Can you prove that no plane has ever been shot down because someone saw its harmless contrail.
So do you have links to back up that statement?
I want to see all the proof you have that contrails are harmless during war.
- Aircraft exhaust, like any hydrocarbon combustion exhaust, contains chemicals you would not want to breath, like carbon monoxide. This is not disputed.
- Aircraft contrails are a problem for planes in wartime, and during WWII they were dangerous as they made the planes more visible. This is not disputed.
- Contrails are made of ice crystals. This is not disputed.
- If a contrail forms, or does not form, then the exhaust gasses are the same. This is not disputed.
- So, if a contrail forms, the exhaust is no more dangerous than if a contrail does not form. So it makes no sense to say the contrail is harmful. The contrail is simply the same exhaust, made visible by the addition of water.
- The formation of contrails is fairly well understood. Even back in 1921, the basic mechanism was known:
contrailscience.com...
The end products of complete combustion of gasoline are water vapor
and carbon dioxide, and it is found that if the water vapor were condensed,
there would result a little more than 1 gallon of water per
gallon of gasoline consumed. It was found by Wells and Thuras, in
studying the fog off the Newfoundland coast (see U. S. Coast Guard ,
Bull. 5, 1916) that there were 1,200 water droplets of diameter 0.01 mm.
in a cubic centimeter of air in a dense fog. If we assume that an airplane
travels 3 miles on a gallon of gasoline (approximately the figure
given by the Aerial Mail Service) it is possible to show that if only a
small part – a fourth or fifth – of the water vapor were condensed,
there would be abundant cloud to produce the effect observed at the
Argonne Battle. It should be stated, however, that this water vapor
would have to be discharged into air which was very cold and nearly
saturated.
And at that same time, contrails that persisted, spread, and had gaps, we observed. In 1921:
An altitude flight was made in the morning at McCook Field recently by Lieut. J. A. Macready in a La Pere with supercharged Liberty [engine]. When the airplane reached a height of 26,000-27,000 feet at 11:50 a.m., a long feathery white streamer was observed forming behind a rapidly moving dark speck. The cloud was of the cirrus variety, well defined at the edges and apparently 10 to 15 times the width of the plane. The sky behind the first portion was clear blue with no clouds in the near neighborhood. The first streamer seemed perhaps 2 miles long. Then a gap of one-quarter mile. The second streamer formed with a background of light cirrus cloud and after 2 or 3 miles the plane seemed to go into the cirrus background, for the streamer formation ceased while an apparent path of blue continued beyond for a way in the cirrus cloud. The whole streamer may have been 3 miles long. After 20 minutes the streamer had drifted and spread until it merged indistinguishably with the other cirrus clouds visible.
See that? In 1921, persistent spreading contrails.
More details:
contrailscience.com...




