Your Nation's Air Force Mark III: Best Korea Edition

by **The Technocratic Syndicalists** » Sat Jan 07, 2017 2:08 am

Allanea wrote:I see that some countries maintain fleets of 'civilian' airliners to use in airlifting troops, military advisors, etc.

Is there something wrong with this idea?

They don't technically "own" them but USTRANSCOM and the USAF Air Mobility Command will frequently rent 747-400F freighters from National Air Cargo and other airlines to haul troops and military equipment. The 747-400F can carry as much cargo as a C-5 and although it isn't wide enough to carry a bradley or abrams the one that crashed at Bagram was carrying five 16 ton MRAPS. Back during ODS 747 freighters carried 220,000 tons of cargo and 640,000 troops to and from the middle east. The 747s actually owned and operated by the air force is the fleet of four E-4s aka the "doomsday planes" and VC-25 aka air force one.

by **Allanea** » Sat Jan 07, 2017 2:40 am

[region-tag=][/region-tag]

The Akasha Colony wrote:
Allanea wrote:I see that some countries maintain fleets of 'civilian' airliners to use in airlifting troops, military advisors, etc.

Is there something wrong with this idea?

No. Not for moving personnel around.

Do you mean 'no it's not wrong', or 'no it's not done'?

Because I certainly know several countries do this - Russia certainly does this.

by **Pavelania** » Sat Jan 07, 2017 7:28 am

The Technocratic Syndicalists wrote:
Pavelania wrote:Can anyone give me some advice for a mach 3+ or hypersonic bomber/interceptor type aircraft?

Mach 3 isn't hypersonic. Hypersonic is usually defined as mach 5+. You don't anything hugely exotic to go mach 3+, a low pressure-ratio afterburning turbojet should get the job done. The design of the inlets is much more important as you need a way to decelerate the mach 3+ flow to subsonic speeds without causing excessive spillage drag in the compressor.

If you want a mach 3 bomber/interceptor I would recommend looking at the Lockheed A-12/SR-71 family and the North American XB-70. After all those are the only aircraft ever built with sustained mach 3+ cruise ability. You could also look into the Convair Kingfish, the design that lost to the A-12 in the CIA's "Oxcart" program, and the North American F-108 Rapier, a proposed Mach 3+ interceptor that would have used the same engines as the XB-70.

Yea I know Mach 3 isn't hypersonic.

Also I heard that a Mig-25 pilot actually went Mach 3 before, but he destroyed the engines in the process. So the Mig-25 can go mach 3.2, but it's not ideal as said the engines get destroyed.

-"The first prototype flew in 1964, and the aircraft entered service in 1970. It has an operational top speed of Mach 2.83 (Mach 3.2 is possible but at risk of significant damage to the engines)..." -Wikipedia

Obviously with a Mach 3+ aircraft I'm not looking at stealth this time as well. I'm thinking of using the intake style from the F-108 Rapier/Mig-25. I'm pretty sure a DSI intake won't work well for mach 3+ flight so that's not being used.

Also have anyone ever heard of the RF-4X Peacejack? It was a US-Israeli project to develop a Mach 3 RF-4 spyplane. The US stopped funding due to the fear of it becoming an interceptor and could be used against the SR-71 if Israel were to sell it to anyone.

"F-4X
Proposed high-performance reconnaissance version with HIAC-1 LOROP camera for Israel developed under the Peace Jack program in conjunction with General Dynamics. Water injection was projected to give the aircraft a top speed in excess of Mach 3 (over 2,000 mph (3,200 km/h) at high altitudes). The water would be contained in a pair of 2,500 US gal (9,600 l) conformal tanks on the sides of the fuselage spine. The US State Department became worried about developing an aircraft with performance similar to the SR-71 Blackbird and offensive capability beyond anything in domestic inventory for a foreign customer and forbade its export. The proposal was then modified to the RF-4X standard with the camera in the nose and removal of weapon carriage. However, the US Air Force withdrew from the project over concerns that a high-performance Phantom would jeopardize funding for the anticipated McDonnell Douglas F-15 Eagle. Without United States financial support, Israel settled for the simpler, less expensive F-4E(S), which was given the nickname 'Shablool', or 'Snail'."
-Wikipedia

For a Mach 3+ interceptor I'd use a variable intake like the F-15/Mig-25/F-108 Rapier, and use a delta layout with twin tails. Looks like I'll have to develop a Variable Cycle Engine for this. For dealing with heat, I''m not gonna use a bubble canopy, and obviously a JP-6 or JP-7 type fuel will have to be developed to cope with the high temperatures. For structure, Lockheed went with loose panels that expand at high temperatures along with Titanium for the A-12/SR-71, while North American did stainless steel Honeycomb panels with Titanium for the XB-70. I might go with the honeycomb/titanium idea.

Ok here is a concept I had in mind. The engines continue under the wing to variable inlets like the Rapier or F-15, except there under the wing. This drawing is mainly to show the configuration of what I had in mind. Also the red line on the nose was a drawing reference that indicated the center line of the aircraft.

by **Autonomous Eastern Ukraine** » Sat Jan 07, 2017 8:49 am

I'm thinking of writing my nation replacing it's old MiG 29s with a more modern multi-role fighter via a design competition. It ends up as a toss up between the Su-35, the Su-30SM or the MiG-35. Which one would you guys suggest (I'm not really good with air forces)? The idea is that while it will replace the MiG 29, it will serve alongside the Su-27 to keep costs down.

by **Crookfur** » Sat Jan 07, 2017 9:03 am

Allanea wrote:I see that some countries maintain fleets of 'civilian' airliners to use in airlifting troops, military advisors, etc.

Is there something wrong with this idea?

No nothing at all wrong with using jetliners of various degrees of militarisation.

Generally they are a cheaper and more efficient means of shifting personnel and palletised cargo around than using dedicated air lifters.

There is an increasing trend to merge these aircraft into MRTTs but that approach has been around since wide bodies first appeared in military service (DC-10s and tristars).

by **Pavelania** » Sat Jan 07, 2017 9:41 am

I'm thinking of writing my nation replacing it's old MiG 29s with a more modern multi-role fighter via a design competition. It ends up as a toss up between the Su-35, the Su-30SM or the MiG-35. Which one would you guys suggest (I'm not really good with air forces)? The idea is that while it will replace the MiG 29, it will serve alongside the Su-27 to keep costs down.

If you want to replace the Mig-29, replace it with a common aircraft like the Mig-35 to reduce the amount of time, training, and cost for crews to switch over to the Mig-35 from the Mig-29. The Mig-35 will be a cheap deadly fighter, featuring AESA radar, stealth coatings, increased fuel and range, and thrust vectoring. Mig-35 is not a bad fighter for a nation that can't afford the newer western fighters. We almost put an order for the SU-35 and Mig-35, but decided to go all western, and placed large orders on the F-15SE, F/A-18F Advanced Super Hornet, and the F-16E to our specs and liking's. I must warn however, that yes the Mig-29 and the Mig-35 are very rugged and tough airplanes, they have a VERY short airframe life at just 2,500 hours before it starts deteriorating. So your Migs will last about 10-15 years, but it also could depend on how often the Migs fly. Not sure if the SU-27 series has this issue.

Crookfur wrote:
Allanea wrote:I see that some countries maintain fleets of 'civilian' airliners to use in airlifting troops, military advisors, etc.

Is there something wrong with this idea?

No nothing at all wrong with using jetliners of various degrees of militarisation.

Generally they are a cheaper and more efficient means of shifting personnel and palletised cargo around than using dedicated air lifters.

There is an increasing trend to merge these aircraft into MRTTs but that approach has been around since wide bodies first appeared in military service (DC-10s and tristars).

We operate heavily modified 747-200Fs, 300Fs, and 400Fs, called C-742s, C-743s, and C-744s, as our air lifters. They have a refueling port like the VC-25 installed, as well as radar/missile warning system, chaff/flare dispenser, nose-opening door, and a rear ramp for air dropping vehicles and packages if necessary. The C-743 has the upped deck modified with luxury seats for VIP transport. The C-743s were also to be tankers, but that never happened, so the C-743 remains as "combi" aircraft, with the upper deck for passengers, and the rest of the aircraft for cargo.

The C-742 is being replaced by our new C-17s in 2018 and in 2020. Our C-743s and C-744 will be replaced by the 747-8F (designated as "C-748" if won), or a westernized An-124 if Antonov resumes An-124 production (Antonov temporarily shutdown An-124 production).

by **The Akasha Colony** » Sat Jan 07, 2017 11:23 am

Allanea wrote:[region-tag=][/region-tag]
The Akasha Colony wrote:
No. Not for moving personnel around.

Do you mean 'no it's not wrong', or 'no it's not done'?

Because I certainly know several countries do this - Russia certainly does this.

No, it's not wrong.

by **Oultremer** » Sat Jan 07, 2017 1:01 pm

Current inventory of the Oultremer Air Force (only helicopters for now).

Any other helicopters you suggest? For other roles or something.
Oultremer is not a particularly large country geopgrahically speaking. Spanning roughly the borders of modern Lebanon and or without Cyprus.

May go with the Gripen fighter plane because why not I've already have one drawn and stuff.

by **Gallia-** » Sat Jan 07, 2017 1:02 pm

AH-1?

by **Oultremer** » Sat Jan 07, 2017 1:15 pm

Yeah maybe, would fit with the hueys.

by **Crookfur** » Sat Jan 07, 2017 2:23 pm

Perhaps some sort of cheap single engine training helicopter? Maybe something by Robinson or Schweizer. IIRC the Robinson R44 is used by lebanon IRL but I have idea how much bearing that may or may not have on your choice.

if you are getting aid or assitance from any kind of uncle sam then OH-58/TH-57s might be on the cards

by **Oultremer** » Sat Jan 07, 2017 3:17 pm

Crookfur wrote:Perhaps some sort of cheap single engine training helicopter? Maybe something by Robinson or Schweizer. IIRC the Robinson R44 is used by lebanon IRL but I have idea how much bearing that may or may not have on your choice.

if you are getting aid or assitance from any kind of uncle sam then OH-58/TH-57s might be on the cards

Sounds good, aid would most likely be French or American yes, will look into the trainer helicopers and going with the cobra huey.

by **The Technocratic Syndicalists** » Sat Jan 07, 2017 5:10 pm

Pavelania wrote:Yea I know Mach 3 isn't hypersonic.

Also I heard that a Mig-25 pilot actually went Mach 3 before, but he destroyed the engines in the process. So the Mig-25 can go mach 3.2, but it's not ideal as said the engines get destroyed.

-"The first prototype flew in 1964, and the aircraft entered service in 1970. It has an operational top speed of Mach 2.83 (Mach 3.2 is possible but at risk of significant damage to the engines)..." -Wikipedia

Obviously with a Mach 3+ aircraft I'm not looking at stealth this time as well. I'm thinking of using the intake style from the F-108 Rapier/Mig-25. I'm pretty sure a DSI intake won't work well for mach 3+ flight so that's not being used.

Also have anyone ever heard of the RF-4X Peacejack? It was a US-Israeli project to develop a Mach 3 RF-4 spyplane. The US stopped funding due to the fear of it becoming an interceptor and could be used against the SR-71 if Israel were to sell it to anyone.

"F-4X
Proposed high-performance reconnaissance version with HIAC-1 LOROP camera for Israel developed under the Peace Jack program in conjunction with General Dynamics. Water injection was projected to give the aircraft a top speed in excess of Mach 3 (over 2,000 mph (3,200 km/h) at high altitudes). The water would be contained in a pair of 2,500 US gal (9,600 l) conformal tanks on the sides of the fuselage spine. The US State Department became worried about developing an aircraft with performance similar to the SR-71 Blackbird and offensive capability beyond anything in domestic inventory for a foreign customer and forbade its export. The proposal was then modified to the RF-4X standard with the camera in the nose and removal of weapon carriage. However, the US Air Force withdrew from the project over concerns that a high-performance Phantom would jeopardize funding for the anticipated McDonnell Douglas F-15 Eagle. Without United States financial support, Israel settled for the simpler, less expensive F-4E(S), which was given the nickname 'Shablool', or 'Snail'."
-Wikipedia

For a Mach 3+ interceptor I'd use a variable intake like the F-15/Mig-25/F-108 Rapier, and use a delta layout with twin tails. Looks like I'll have to develop a Variable Cycle Engine for this. For dealing with heat, I''m not gonna use a bubble canopy, and obviously a JP-6 or JP-7 type fuel will have to be developed to cope with the high temperatures. For structure, Lockheed went with loose panels that expand at high temperatures along with Titanium for the A-12/SR-71, while North American did stainless steel Honeycomb panels with Titanium for the XB-70. I might go with the honeycomb/titanium idea.

Ok here is a concept I had in mind. The engines continue under the wing to variable inlets like the Rapier or F-15, except there under the wing. This drawing is mainly to show the configuration of what I had in mind. Also the red line on the nose was a drawing reference that indicated the center line of the aircraft.

(Image)

The configuration looks fine although you might want to add variable-geometry wingtips or chines to the forward fuselage. As you go supersonic the aerodynamic center shifts rearward which causes the aircraft to become more stable which in turns means you need more trim angle which in turns leads to more drag which is bad. The XB-70 (and proposed F-108) had VG wingtips which would shift downwards to move the ac forward to offset this. They also added increased directional stability which mean the vertical tails could be smaller, reducing drag. The chines on the forward fuselage of the A-12/SR-71 serve the same purpose; chines generate vortex lift proportional to the square of the mach number and thus shift the ac forward as mach number is increased. If you want a interceptor/bomber as opposed to a fighter I would recommend either cone or quarter-cone F-111 style triple plow inlets which are less draggy than traditional VG intake ramps but conversely are more sensitive to flow disturbances at high AoA.

You definitely want a VCE if you want to cruise at mach 3+. The YF120 was designed with the ATF supercruise requirement in mind but its double-bypass system would actually be quite suited to mach 3+ operation. The YF120 is afterall planned to be used as the core section's of the mach 4+ GE57 hyperburning turbojet (the Yf120 core being mated to marquardt ramjet acting as a hybrid afterburner/ramjet or "hyperburner"). At mach 3+ you would cruise in partial-afterburner like the SR-71 and XB-70 in single bypass "turbojet" mode and for takeoff and subsonic cruise you be in double bypass "turbofan" mode. With the YF120 there are two bypass streams, each controlled by a VABI or variable area bypass injector located inside the split-fan section located in front of the low-pressure compressor. For takeoff and subsonic cruise both VABIs would be open to allow air from the fan section to bypass the combustor and be reinjected aft of the turbine to cool the exhaust air. For mach 3 cruise you would close the first VABI to increase the mass flow into the core and keep the second one open to allow air to bypass the combustor and be injected directly into the afterburner. This is essentially mimicking the bleed-bypass system of the J58. You should note that most of the air bypassed around the combustor is used for backside cooling of the afterburner walls rather than for thrust augmentation. This isn't a huge loss though because most of the thrust at mach 3 is coming from the inlet, not the engine.

by **Gallia-** » Sat Jan 07, 2017 5:31 pm

The obvious problem is maintaining a rapid turnaround with high landing temperatures.

by **Rich and Corporations** » Sat Jan 07, 2017 5:43 pm

Gallia- wrote:The obvious problem is maintaining a rapid turnaround with high landing temperatures.

ultimately I'm interested in the Musk Electric Jet.

by **North Viet Cong** » Sat Jan 07, 2017 5:50 pm

North Viet Cong Air Force

by **I didnt vote for Trump** » Sat Jan 07, 2017 6:10 pm

It's very difficult to see how a variable cycle engine would be of net benefit to a Mach 3 bomber or a dedicated interceptor. The simpler, lighter and more pragmatic choice of a turbojet makes much more sense when considering this sort of aircraft, it's typical flight path and how it will be used.

Before deciding on a variable intake, decide on an engine first. You're only focusing on using the intake to limit the airflow into the engine to be no more than the maximum of what the engine will require, therefore you need to know whether that's an issue first. If you don't need variable intakes, you don't want them. The more weight you can save on items like this, the greater the payload and range.

My advice would be to flesh out the background behind this aircraft first instead of going through the shopping list of what you may or may not need on it.

by **The Technocratic Syndicalists** » Sat Jan 07, 2017 7:09 pm

I didnt vote for Trump wrote:It's very difficult to see how a variable cycle engine would be of net benefit to a Mach 3 bomber or a dedicated interceptor. The simpler, lighter and more pragmatic choice of a turbojet makes much more sense when considering this sort of aircraft, it's typical flight path and how it will be used.

A VCE is undoubtedly the best choice. Turbojets are bad because to fly at mach 3 continuously it will need a very low pressure ratio so that the turbine blades don't melt. What's wrong with a low pressure ratio? Terrible fuel efficiency at low altitudes and/or subsonic speeds. Even a supersonic bomber or interceptor is going to spend a significantly number of time flying at subsonic speeds when its landing/taking off/refueling/etc so a VCE, which can give you much better subsonic efficiency compared to a turbojet, is a much better choice. And a mach 3 turbojet like a J93 isn't much simpler than a VCE and most certainly is not "lighter" (I'm guessing you're referring to T/W). VCE devices will add at most a few pounds to the engine and the presence of the fan and the much higher pressure ratio will give you a significant T/W advantage over a conventional single-spool turbojet.

I didnt vote for Trump wrote:Before deciding on a variable intake, decide on an engine first. You're only focusing on using the intake to limit the airflow into the engine to be no more than the maximum of what the engine will require, therefore you need to know whether that's an issue first. If you don't need variable intakes, you don't want them. The more weight you can save on items like this, the greater the payload and range.

My advice would be to flesh out the background behind this aircraft first instead of going through the shopping list of what you may or may not need on it.

That's not the primary job of the intake. The intake has to decelerate the Mach 3 free-stream air to subsonic speeds before it can be ingested by the compressor. Since the supersonic shock angle is a function of mach number as you go faster you need to change the geometry to ensure that the compressor isn't getting hit with supersonic cshocks which would cause it to stall. This is what a VG or "variable-geometry" inlet is for and it's most certainly required to get to mach 3+ speeds. Limiting airflow to the engine is done to minimize splillage drag and is handled by a set of suction and bleed doors in the intake.

Gallia- wrote:The obvious problem is maintaining a rapid turnaround with high landing temperatures.

The whole "when it landed it was too hot to touch" is a myth. I have the sanitized SR-71 flight manual and it never mentions the plane being too hot to touch when it lands. When the pilot begins the deceleration from 85,000 feet the plane is kept at a constant 365 KEAS descent until you level off at 30,000 feet and then begin the final landing approach. The plane is flying subsonic through cold air (-60 F at 30k feet) long enough so that when it finally lands the plane has mostly cooled to ambient temperature. The part of the aircraft that was "too hot to touch" after landing was the landing gear. After the SR-71 landed large fans would be placed in front or behind the landing gears to cool the gear and brakes.

by **Pavelania** » Sat Jan 07, 2017 7:32 pm

Oultremer wrote:Current inventory of the Oultremer Air Force (only helicopters for now).

Type Huey 2 Origin USA Class Helicopter Role Utility/Transport/Utility
(Image)

Type CH-46 Sea Knight Origin USA Class Helicopter Role Transport/ASW
(Image)

Type MD 500 Defender Origin USA Class Helicopter Role Light multi-role helicopter

Type AH-1 Cobra Origin USA Class Helicopter Role Attack helicopter
(Image)

Type Gripen Origin Sweden Class Jet Role Fighter, attack and reconnaissance aircraft
(Image)

Any other helicopters you suggest? For other roles or something.
Oultremer is not a particularly large country geopgrahically speaking. Spanning roughly the borders of modern Lebanon and or without Cyprus.

May go with the Gripen fighter plane because why not I've already have one drawn and stuff.

Yes go with the gripen. It's an awesome cheap n' deadly multirole fighter. Very easy and cheap to maintain, and it has good STOL, meaning it can take-off from unprepped airfields and roads. Also its very agile.

Oh yea I also added VG wingtips to my interceptor concept.

Also its gonna have internal weapons bays so nothing has to be stored externally. I would also develop a Long-Range Missile that could be used as well. Also should I make the engines closer to the fuselage?

by **The Technocratic Syndicalists** » Sat Jan 07, 2017 7:49 pm

Pavelania wrote:
Oh yea I also added VG wingtips to my interceptor concept.
(Image)

Also its gonna have internal weapons bays so nothing has to be stored externally. I would also develop a Long-Range Missile that could be used as well. Also should I make the engines closer to the fuselage?

You could move the engines and nacelles closer together and have the inlets be flush with the fuselage (to use quarter-cone triple plow inlets like the F-111). If you keep the engines spaced further out you could use half-cone inlets like this from the F-23A EMD. You would need an additional splitter plate and a movable inlet cone but the basic layout could be similar (minus the twisting S-duct which would be unnecessary).

For missiles you just need an AIM-57 or AIM-54 clone. Assuming your aircraft is F-108 sized you could easily carry 3-4 of them in a center-line weapons bay. Launching from mach 3 at 70k+ feet would give you some pretty insane F-Pole performance. An AIM-152 AAM clone, specifically something like the ramjet powered Hughes/Raytheon version, would give you even more performance.

by **Pavelania** » Sat Jan 07, 2017 7:59 pm

The Technocratic Syndicalists wrote:
Pavelania wrote:
Oh yea I also added VG wingtips to my interceptor concept.
(Image)

Also its gonna have internal weapons bays so nothing has to be stored externally. I would also develop a Long-Range Missile that could be used as well. Also should I make the engines closer to the fuselage?

You could move the engines and nacelles closer together and have the inlets be flush with the fuselage (to use quarter-cone triple plow inlets like the F-111). If you keep the engines spaced further out you could use half-cone inlets like this from the F-23A EMD. You would need an additional splitter plate and a movable inlet cone but the basic layout could be similar (minus the twisting S-duct which would be unnecessary).

For missiles you just need an AIM-57 or AIM-54 clone. Assuming your aircraft is F-108 sized you could easily carry 3-4 of them in a center-line weapons bay. Launching from mach 3 at 70k+ feet would give you some pretty insane F-Pole performance. An AIM-152 AAM clone, specifically something like the ramjet powered Hughes/Raytheon version, would give you even more performance.

Whats F-Pole?

by **The Technocratic Syndicalists** » Sat Jan 07, 2017 8:08 pm

Pavelania wrote:
The Technocratic Syndicalists wrote:
You could move the engines and nacelles closer together and have the inlets be flush with the fuselage (to use quarter-cone triple plow inlets like the F-111). If you keep the engines spaced further out you could use half-cone inlets like this from the F-23A EMD. You would need an additional splitter plate and a movable inlet cone but the basic layout could be similar (minus the twisting S-duct which would be unnecessary).

For missiles you just need an AIM-57 or AIM-54 clone. Assuming your aircraft is F-108 sized you could easily carry 3-4 of them in a center-line weapons bay. Launching from mach 3 at 70k+ feet would give you some pretty insane F-Pole performance. An AIM-152 AAM clone, specifically something like the ramjet powered Hughes/Raytheon version, would give you even more performance.

Whats F-Pole?

Range between the launch aircraft and target at the time of missile intercept. It's the primary number you look at when discussing the BVR capability of a specific aircraft/missile combination. For example with a stealth fighter you want the F-pole range of your missile to be greater than the detection range of your fighter versus the target's radar so that the target gets hit before he detects you. Essentially faster aircraft plus faster missile = greater f-pole range.

by **I didnt vote for Trump** » Sat Jan 07, 2017 8:15 pm

The Technocratic Syndicalists wrote:
I didnt vote for Trump wrote:It's very difficult to see how a variable cycle engine would be of net benefit to a Mach 3 bomber or a dedicated interceptor. The simpler, lighter and more pragmatic choice of a turbojet makes much more sense when considering this sort of aircraft, it's typical flight path and how it will be used.

A VCE is undoubtedly the best choice. Turbojets are bad because to fly at mach 3 continuously it will need a very low pressure ratio so that the turbine blades don't melt. What's wrong with a low pressure ratio? Terrible fuel efficiency at low altitudes and/or subsonic speeds. Even a supersonic bomber or interceptor is going to spend a significantly number of time flying at subsonic speeds when its landing/taking off/refueling/etc so a VCE, which can give you much better subsonic efficiency compared to a turbojet, is a much better choice. And a mach 3 turbojet like a J93 isn't much simpler than a VCE and most certainly is not "lighter" (I'm guessing you're referring to T/W). VCE devices will add at most a few pounds to the engine and the presence of the fan and the much higher pressure ratio will give you a significant T/W advantage over a conventional single-spool turbojet.

What's a significant amount of time to you? Surely a lot more than 10% of total flight time? Optimizing an aircraft to save fuel for such a small portion of mission time is just silly. If this were an aircraft that would be required to operate at speeds from mach 1 to mach 3 in a combat context, then a variable cycle engine may be worth considering. But, that isn't what this appears to be and nor should it be either.

Varying cycle doesn't work like a turbocharger, it's merely a way to have an engine perform better over a wider range of air speeds. Employing this technology will not produce any greater efficiency nor thrust than a properly optimized turbojet engine at Mach 3 speeds. So the extra weight, which is going to be a lot more than few pounds, will be effectively dead weight at Mach 3 travel. Dead weight is not desirable on any aircraft.

I didnt vote for Trump wrote:Before deciding on a variable intake, decide on an engine first. You're only focusing on using the intake to limit the airflow into the engine to be no more than the maximum of what the engine will require, therefore you need to know whether that's an issue first. If you don't need variable intakes, you don't want them. The more weight you can save on items like this, the greater the payload and range.

My advice would be to flesh out the background behind this aircraft first instead of going through the shopping list of what you may or may not need on it.

That's not the primary job of the intake. The intake has to decelerate the Mach 3 free-stream air to subsonic speeds before it can be ingested by the compressor. Since the supersonic shock angle is a function of mach number as you go faster you need to change the geometry to ensure that the compressor isn't getting hit with supersonic cshocks which would cause it to stall. This is what a VG or "variable-geometry" inlet is for and it's most certainly required to get to mach 3+ speeds. Limiting airflow to the engine is done to minimize splillage drag and is handled by a set of suction and bleed doors in the intake.[/quote]
I was more referring to variable geometry intakes in a much more external sense, but yes this is correct.

The Technocratic Syndicalists wrote:
Gallia- wrote:The obvious problem is maintaining a rapid turnaround with high landing temperatures.

The whole "when it landed it was too hot to touch" is a myth. I have the sanitized SR-71 flight manual and it never mentions the plane being too hot to touch when it lands. When the pilot begins the deceleration from 85,000 feet the plane is kept at a constant 365 KEAS descent until you level off at 30,000 feet and then begin the final landing approach. The plane is flying subsonic through cold air (-60 F at 30k feet) long enough so that when it finally lands the plane has mostly cooled to ambient temperature. The part of the aircraft that was "too hot to touch" after landing was the landing gear. After the SR-71 landed large fans would be placed in front or behind the landing gears to cool the gear and brakes.

The internal components of engines will be very hot. They won't be cooled as effectively as what they were at flying altitude. I presume this is what galla is referring to.

by **Pavelania** » Sat Jan 07, 2017 8:18 pm

The Technocratic Syndicalists wrote:
Pavelania wrote:
Whats F-Pole?

Range between the launch aircraft and target at the time of missile intercept. It's the primary number you look at when discussing the BVR capability of a specific aircraft/missile combination. For example with a stealth fighter you want the F-pole range of your missile to be greater than the detection range of your fighter versus the target's radar so that the target gets hit before he detects you. Essentially faster aircraft plus faster missile = greater f-pole range.

Ah ok.

Ok finished some revisions.

The original layout

Layout #2, with the engines being moved closer.

Layout #3, with the engines next to the fuselage.

Layout #4, with the engines blended with the fuselage.

by **Gallia-** » Sat Jan 07, 2017 8:43 pm

The Technocratic Syndicalists wrote:The whole "when it landed it was too hot to touch" is a myth.

If by "ambient" you mean "probably around 80 C", then yes. If you wanted to turn it around "quickly", you'd need a couple hours from touchdown and a sturdy pair of asbestos gloves.

It wasn't a big deal for the SR-71 because its missions weren't exactly ad hoc. It would be a big deal for a supersonic or hypersonic bomber or fighter, though.

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