Ask anything Thread (Air Force)

siegecrossbow

General
Staff member
Super Moderator
It reminds me so much on what the Chinese aviation industry wanted with its J-9 program: more, more, and more again. All that "more" completely alone and once a design was finalised, the PLAAF, the politics or what/who-ever came and wanted more again.
In the end the industry nor the technology itself necessary was not mature enough ... and all failed.

Happened during the Cultural Revolution, when unrealistic goals are considered politically correct.
 

plawolf

Lieutenant General
Here is a bit of a random question, but how much danger do fighter radars pose to pilots when engaged in WVR combat?

With modern fighter radars getting more and more powerful, and some sets said to be able to effective cook small animals if they are caught in the beam, I have to wonder what kind of damage such radars could do to pilots as they engage in WVR combat against each other and get concentrated blasts of radar energy at fairly close range?

I know a lot of modern fighters have canopies tinted with radar absorbent materials, that no doubt help a lot, but are even those enough protection?
 

vesicles

Colonel
radar uses radio wave, which is inherently much less energetic than visible light. I think its wavelength is in the millimeters. So it won't cause any effects on human health.

I think it's a complete myth about radar waves cooking animals. In fact, Mythbusters have tested this using a turkey or chicken. They literally put the poultry on the beam of a powerful radar and switched it on. And there was no significant temp change after hours of cooking. In fact, the poultry was actually slightly colder...

There has been many myths about different waves causing damage to human. Microwave is a another example. People have been saying that cooking food using microwave damages food and produce carcinogens. However, these people fail to recognize that microwave can only cause molecular bonds to vibrate and rotate, only enough energy to heat up water molecules in the food. All those "studies" that tested toxic chemicals in foods cooked by microwave failed to compare to other conventional ways of cooking. Any method of heating will produce toxic agents since many chemical reactions producing carcinogens are initiated by heat. So I am not surprised at all that microwave cooking generates toxic chemicals. The question is whether microwave cooking generates more toxins than conventional cooking. My feeling is NO. Since it is still the most gental way of cooking, much like boiling (only heating up water).
 

no_name

Colonel
Well, microwave oven generally use about 2.4GHz, which is around the same as your wifi. (the other being 5.8GHz). But microwaves inside ovens are isolated within the cavity and cannot dissipate except through being absorbed by the stuff you are trying to cook, which is why you should not run a microwave on empty, put metals in or anything that is not supposed to be cooked with a MW oven.
 

delft

Brigadier
radar uses radio wave, which is inherently much less energetic than visible light. I think its wavelength is in the millimeters. So it won't cause any effects on human health.

I think it's a complete myth about radar waves cooking animals. In fact, Mythbusters have tested this using a turkey or chicken. They literally put the poultry on the beam of a powerful radar and switched it on. And there was no significant temp change after hours of cooking. In fact, the poultry was actually slightly colder...

There has been many myths about different waves causing damage to human. Microwave is a another example. People have been saying that cooking food using microwave damages food and produce carcinogens. However, these people fail to recognize that microwave can only cause molecular bonds to vibrate and rotate, only enough energy to heat up water molecules in the food. All those "studies" that tested toxic chemicals in foods cooked by microwave failed to compare to other conventional ways of cooking. Any method of heating will produce toxic agents since many chemical reactions producing carcinogens are initiated by heat. So I am not surprised at all that microwave cooking generates toxic chemicals. The question is whether microwave cooking generates more toxins than conventional cooking. My feeling is NO. Since it is still the most gental way of cooking, much like boiling (only heating up water).
I remember reading years ago that men working in the radar shops of US aircraft carriers have fewer children than men working on these flattops not working in radar shops.
 

delft

Brigadier
I remember reading years ago that men working in the radar shops of US aircraft carriers have fewer children than men working on these flattops not working in radar shops.
Those radar workers will have had a much higher exposure that the pilots considered. The effect was seen by looking at hundreds or thousands of men. It was not immediately obvious. So the effect on the pilots is most probably insignificant. If a similar effect is found in the pilots it will almost certainly have another cause.
 

winton

New Member
Registered Member
Hi everyone, my first post.

Question: why did china design the Y20 to be smaller than the C17? Are there limitations in technology or did her requirments only necessitate such a design?
 

GreenestGDP

Junior Member
Hi everyone, my first post.

Question: why did china design the Y20 to be smaller than the C17? Are there limitations in technology or did her requirments only necessitate such a design?


Welcome aboard. Have you introduce yourself in the Self--Introd thread ?
And, I hope you can post more often.

Many nations all across the Globe does not have Long & Hardened Runway to handle any Cargo plane that is heavier than Y-20.
Thus, Y-20 size and weight was designed to optimize Y-20 ability to land in Short & Un Hardened Runway, as many as possible all over the Globe.
 

winton

New Member
Registered Member
Welcome aboard. Have you introduce yourself in the Self--Introd thread ?
And, I hope you can post more often.

Many nations all across the Globe does not have Long & Hardened Runway to handle any Cargo plane that is heavier than Y-20.
Thus, Y-20 size and weight was designed to optimize Y-20 ability to land in Short & Un Hardened Runway, as many as possible all over the Globe.

I have not introded. Didn't know. I've been lurking on here for a while and this question really perplexed me.

Is the C17 designed to land on unhardened runways? Could china have built a similar sized plane as the C17. The Y20 just looks very narrow. So am wondering if its going to do the sort of strategic lift that china needs?

Are china's runways that short?
 

Blitzo

Lieutenant General
Staff member
Super Moderator
Registered Member
Hi everyone, my first post.

Question: why did china design the Y20 to be smaller than the C17? Are there limitations in technology or did her requirments only necessitate such a design?

The Y-20 is only a little bit smaller than the C-17 in terms of overall dimensions and only a little smaller than C-17 in maximum take off weight as well, when it gets its intended WS-20 engines.

The Y-20 would have been designed to fulfill Air Force requirements with whatever economic and industrial or technological constraints they had. But the fact that they chose a slightly smaller design than the C-17 could reflect a combination of those reasons. For instance, maybe they were quite capable of building a C-17 or bigger aircraft, but it would have cost an extra amount which the Air Force did not deem worthwhile for the investment versus the size of the present Y-20.
It is also best to avoid thinking that the C-17 would somehow represent the epitome of airlifter capability which the Y-20 needs to match. Other things such as development cost and time, procurement cost, production time, operating costs, operational requirements, availability rate, are all very important as well, and the Y-20 would have had to balance a variety of different prerequisites to get to its assigned specifications.



I have not introded. Didn't know. I've been lurking on here for a while and this question really perplexed me.

Is the C17 designed to land on unhardened runways? Could china have built a similar sized plane as the C17. The Y20 just looks very narrow. So am wondering if its going to do the sort of strategic lift that china needs?

Are china's runways that short?

First of all, the Y-20 is for all intents and purposes, a similar sized aircraft to the C-17. In fact a Y-20 with WS-20 engines will probably be the aircraft closest to C-17 dimensions, weight and configuration to the C-17 in the world.

Second, yes, Y-20 is intended to be capable of operating from unprepared runways to a degree. C-17 is also technically able to do so, but it generally. The Y-20 is also not very narrow, comparatively speaking -- its fuselage is much wider than say the Il-76, and similar to the A400M or the Kawasaki C-2. The Y-20's landing gear is also similar in configuration to that of the A400M, which of course is also intended to operate from unprepared runways.

Third, I want to re emphasize that Y-20 needs to be viewed within the context of Chinese Air Force requirements, and to not simply assume that developing a C-17 sized aircraft for the Chinese Air Force would have fulfilled their requirements.


So to answer your question about whether Y-20 can do the "sort of strategic lift that China needs" -- well the Y-20 will likely be able to meet its design requirements once it is mature and once it operates with its intended WS-20 engines. So if that can be achieved then Y-20 should well be able to fulfill the strategic lift that the Chinese Air Force "needs".
But the Y-20 won't be carrying loads that a C-5 or An-124 can carry, but it will be able to supplement and complement current Il-76s in service (it is important because Y-20 can be fully domestically produced without being reliant on a foreign manufacturer), and once Y-20s get their intended engines they will be able to exceed current Il-76s in indiviidual capability by a meaningful margin.
 
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