Stupid questions about aviation

By the the airfoil shape, do you mean that they are curved to optimally direct the airflow?

I'm asking because in my mind an airfoil (shape that's thicker in the front than rear) doesn't have to be curved to be an airfoil. Some aerobatic planes use a symmetrical airfoil wing which has no curve.

So it confuses me as in my mind, airfoil shape is exactly what creates the diffuser by being thicker in the front.

I don't mean to be a smart ass, just trying to clear confusion. :)

It's interesting by the way how hard it's to see the thickness difference of stator vanes with bare eyes. Just looking at a stator stage doesn't make me see the obvious diffuser there. They are so thin that they just look like flat plates without creating a divergent path. Amazing how subtle shape creates so much compression.

With the airfoil nature I meant the typical purpose of directing flow. This is kind of hair splitting but it's not the flow direction or the shape of one airfoil that creates the diffusion effect but that they form a diverging duct as they are placed close together that is the essential feature for diffusion. I just wanted to point out that it's not the flow redirection but the diverging duct feature why stators slow the the flow and increase pressure. It's true that the stators thickness variation is like in typical airfoil (or at least something like it).

Yeah sorry for that. Just had to make sure I didn't misunderstand which I did. :)

I agree 100%.

Ok, this is my stupid question about aviation. Being spammed constantly with NATO aircrafts intercepting Russian planes news articles, I have to ask.

How does air traffic in international airspace actually work? I know that the majority of the internation airspaces are controlled airspaces (i.e. the Bodø Oceanic FIR in the Norwegian sea), allowing only cleared IFR traffic with a filled flight plan. So the civilian side seems trivial. This is logical, the need for assitance with separation doesn't magically end with some virtual line on the map.

But how does military fall into this? Do they too fill flight plans? Do they cooperate with ATC in any way, so they aren't "violators" on the ATCs radars? Do they cooperate with the responsible authority during exercises, so the authority can issue some temeporaly prohibited airspace notam for the civilian aviation part? Or the military just doesn't care about such formalities and the ATC has to suck it up? In such cases, how is it decided if it is actual violator or just a military doing its military thing? Is every such violation an intercept?

Also, please, no political nonsense, I'm only interested in the rules and procedures aspect.

I think I read in one of the recent articles about the russian air activities that military planes should but don't have to follow the rules of civil aviation. I think it also said that at least some of those russian flights even turned their transponders off, so they could only be tracked by radar. I'll try to find the article again.

[...]

In such cases, how is it decided if it is actual violator or just a military doing its military thing? Is every such violation an intercept?

[...]

That's why interceptions occur: If there is an unidentified plane or a plane is not following the flight plan and doesn't respond to radio calls you send interceptors to check what is going on. From what I've heard most interceptions here are due to radio problems involving rather small private planes.

Edit:

I found a NATO-statement about that, reffering to the russian activities:

The bomber and tanker aircraft from Russia did not file flight plans or maintain radio contact with civilian air traffic control authorities and they were not using on-board transponders. This poses a potential risk to civil aviation as civilian air traffic control cannot detect these aircraft or ensure there is no interference with civilian air traffic.

How does air traffic in international airspace actually work?

AFAIK, there is rarely a military flight crossing international lines, if they do cross, it has to be with permission from the country and a flight plan has to be approved. I think during the Libyan bombing in 1986, aircraft had to travel around several countries that did not authorize the flight over their territory. Additionally, I think civilian aircraft have specific corridors or high/medium/low altitude airways they have to travel. Further more, in general, military flight ( in the US anyway) file a flight plan and once over a military controlled airspace they can cancel it and fly freely ( so they can perform low altitude missions, BFM, etc.).

Interesting topic!

That makes me wonder: are military aircraft equipped with TCAS?

Wikipedia says:

[TCAS] is a type of airborne collision avoidance system mandated by the International Civil Aviation Organization to be fitted to all aircraft with a maximum take-off mass (MTOM) of over 5,700 kg (12,600 lb) or authorized to carry more than 19 passengers.

So I guess this doesn't apply to military aircraft, but it would make sense, wouldn't it?

I'd just install a TCAS circuit breaker to military aircraft that I'd rather not install in any civilian plane so that suicidal pilots can't override the system from within the cockpit.

http://en.wikipedia.org/wiki/Hughes_Airwest_Flight_706

Old news but back then they didn't have it and i still don't think they have.

SAS flights have, recently, on a couple of occasions, been close to colliding with russian bombers showing off over the Baltic. But it was SAS pilot visual awareness that avoided that.

Interesting topic!

 

That makes me wonder: are military aircraft equipped with TCAS?

 

Wikipedia says:

 

 

 

So I guess this doesn't apply to military aircraft, but it would make sense, wouldn't it?

 

I'd just install a TCAS circuit breaker to military aircraft that I'd rather not install in any civilian plane so that suicidal pilots can't override the system from within the cockpit.

Looking through some FAA manuals, it seems large Military aircraft ( Tankers, Cargo, etc) Do carry TCAS II version 7. But not sure about all the information regarding this.

In the U.S. effective Jan 1, 2005, for those

aircraft required to carry TCAS II, Version

7.0 must be installed in all new installations.

For installations of TCAS II made prior to

Jan 1, 2005 under certain conditions,

Version 6.04a can continue to be used.

Taken from this PDF

AFAIK, there is rarely a military flight crossing international lines, if they do cross, it has to be with permission from the country and a flight plan has to be approved. I think during the Libyan bombing in 1986, aircraft had to travel around several countries that did not authorize the flight over their territory. Additionally, I think civilian aircraft have specific corridors or high/medium/low altitude airways they have to travel. Further more, in general, military flight ( in the US anyway) file a flight plan and once over a military controlled airspace they can cancel it and fly freely ( so they can perform low altitude missions, BFM, etc.).

But those FIRs are big (map at pg 10 - http://www.faa.gov/air_traffic/publications/media/NAT%20IGA%202004.pdf), so basicaly any flight into international airspace has to enter those. So military can violate these airspaces easily, even without getting close to any airway.

But those FIRs are big (map at pg 10 - http://www.faa.gov/air_traffic/publications/media/NAT%20IGA%202004.pdf), so basicaly any flight into international airspace has to enter those. So military can violate these airspaces easily, even without getting close to any airway.

Not sure if I understand.

I'll try to better explain myself :)

You said that military avoids operations close to international lines, but when I look at the volume of oceanic controlled airspaces, then this seems insufficient for me. Every flight over high seas has to take place in one of those controlled airspaces. So the military can be away from international routes, but, from the ATC point of view, they would still be violating the airspace.

I'll try to better explain myself :)

You said that military avoids operations close to international lines, but when I look at the volume of oceanic controlled airspaces, then this seems insufficient for me. Every flight over high seas has to take place in one of those controlled airspaces. So the military can be away from international routes, but, from the ATC point of view, they would still be violating the airspace.

My original respond was because you mention intercepts and international lines. I saw it as US Military aircraft crossing Canada's borders or Spanish military aircraft crossing into France's, etc. Talking about Oceanic Flight, Military aircraft traveling on those do not have to enter Control air spaces, if they do, A flight plan would have to be entered AFAIK. I never mention they avoided operations close to international lines. I posted

...rarely a military flight crossing international lines...

I think we might be miss understanding each other and I lack enough expertise or knowledge on the subject of control airspace or aircraft intercepts.

My original respond was because you mention intercepts and international lines. I saw it as US Military aircraft crossing Canada's borders or Spanish military aircraft crossing into France's, etc. Talking about Oceanic Flight, Military aircraft traveling on those do not have to enter Control air spaces, if they do, A flight plan would have to be entered AFAIK. I never mention they avoided operations close to international lines. I posted

Maybe I should made it clearer that I'm talking about international airspace only.

Have you taken a look at the chart in the FAA manual I linked? Basically the whole northern atlantic is divided into controller airspaces starting from FL060, so you're in controlled airspace the moment you enter atlantic.

I think we might be miss understanding each other and I lack enough expertise or knowledge on the subject of control airspace or aircraft intercepts.

Well, me too. Only bits here and there from manuals/aips that end up in my hands in work.

Anyway, I was finally able to find some relevant info on the ICAO web.

http://www.icao.int/EURNAT/EUR%20and%20NAT%20Documents/NAT%20Documents/NAT%20Doc%20007/_NAT%20Doc007_Edition%202013%20with%20%20bkmrks.pdf

After quick look in the document it looks like

-There is a 'military' flight type in the flight plan template, so I guess militaries do fill flight plans.

-Military can assume responsibility for separation, just by stating that in the flight plan.

-Some regions can be restricted for military activities (exercise, formation flights etc). These restricted regions will be published via NOTAM.

-There are regions permanently reserved for military operations

Why don't we (humans) build bi planes anymore? Or an aircraft with foldable wings like an x wing

Looking through some FAA manuals, it seems large Military aircraft ( Tankers, Cargo, etc) Do carry TCAS II version 7. But not sure about all the information regarding this.

Thx, that's pretty much the info I was looking for! :)

Why don't we (humans) build bi planes anymore? Or an aircraft with foldable wings like an x wing

Probably too ineffective due to high drag and also just not necessary. The old bi-planes were slow and probably needed the larger wing surface to stay airborne while modern(ish) planes can generate enough lift without relying on such additional wing surface. That is at least how I explain it to myself (as layman).

Why don't we (humans) build bi planes anymore? Or an aircraft with foldable wings like an x wing

We as Humans still build biplanes

and X-wings

:D

^^^ nice

Earlier in this thread someone asked about external tracking for a guided missile system on a aircraft, I do know the U.S. Air force was experimenting with this idea on B1s, to find a modern use.

Essentially what the idea is, you would have 2 to 4 F22s so far ahead of the B1s and the B1s would lag back, when the 22s get targets pop up on radar they would essentially lock on for the B1s who would have AA missiles on the wings and launch the attack out of range of the enemy. With the carrying capacity of the B1 they could pack a punch with a limited amount of aircraft exposed to enemy aircraft. This research was being done when I was in 7 years ago, not sure what has become of it.

Earlier in this thread someone asked about external tracking for a guided missile system on a aircraft, I do know the U.S. Air force was experimenting with this idea on B1s, to find a modern use.

 

Essentially what the idea is, you would have 2 to 4 F22s so far ahead of the B1s and the B1s would lag back, when the 22s get targets pop up on radar they would essentially lock on for the B1s who would have AA missiles on the wings and launch the attack out of range of the enemy. With the carrying capacity of the B1 they could pack a punch with a limited amount of aircraft exposed to enemy aircraft. This research was being done when I was in 7 years ago, not sure what has become of it.

Sounds familiar:

https://www.youtube.com/watch?v=c9EvY9kSKTc#t=902

This is achieved using Data Links - so for example an AWACs picks up some enemy aircraft on Radar it can transmit that information to friendly fighters over a data link.

There are various types of data links in operation today.

Yep just like that. Data links are neat but fragile in my opinion, all it takes is losing one section and the entire operation falls apart.

Hi, i'm wondering why nearly all planes have a greenish paint below the final paint layer. A lot of WW2 planes had a green cockpit, and even nowdays, planes missing final coating have a green paint. By exemple the F35s http://www.operatorchan.org/v/thumb/139162710590s.jpg

I know that russian cockpits are green to reduce eye-fatigue, but why are aeronautics companies putting a green coating prior to the final paint?

It's just primer that's all, it just happens to be green because that's the colour it's made with. Not all aircraft primer coats are green, but it is a common colour for primers in general.

Thank you :)