Heinkel He-162 engine.

[DerAdlerIstGelandet]

I believe all jet engines of that time were not as reliable as they wanted them to be. The just lacked the materials. This was especially true though in the German engines and those of the Me-262.

[FLYBOYJ]

Originally Posted by DaveB.inVa

I've heard that before and certainly believe it. As Im sure you know many big bombers were able to handle better than smaller fighters and such at higher altitudes. There are many references of B-36's being able to turn inside faster jets... if the jets could even get to the B-36's altitude. Paul Tibbets in his book describes mock dogfighting a P-47 at high altitude in a B-29. He said every time the P-47 got near his tail he just had to bank hard into a turn. When the P-47 would try to follow, it would stall out and fall away! This is pretty much how the Lancaster survived with its corkscrew.

It always has suprised me just how manuverable those big bombers and transports really are!

The B-47 was extremely manevuable and there was one planned tactic to deliver nukes in a "lob," flying straight up and allowing the weapon to arc toward the target while the aircraft made its getaway. Eventually these types of maneverus put great stain on the wing attach structure and the -47 starting developing cracks in this area.

[me262]

Originally Posted by delcyros

I do agree that the Ho-IX isn´t the forefather of the B-2. Some conceptual similarities are there but both are indigenous projects.

i see the aproch like this:
the H0 IX/Go 229 was made with plywood and hence almost invisible to radar, at that time they did not imagine this concept, and the b-2 invisible to radar

[plan_D]

"...not really absorbes, just it do not bounce back the radar impulse..."

If the RADAR waves do not bounce back off the wood then the wood has absorbed the waves.

[CharlesBronson]

[evangilder]

Yes the B-49 did suffer from a few problems, and politics. The thought of a dogfight between a P-47 and a B-29 sounds funny, but the altitude makes all the difference for that. Somewhere I have a pic of a B-47 from my dad's days in the air force.

The B-2 has radar absorbing paint, as does the F-117. What does get reflected back is about what a small bird reflects.

[the lancaster kicks ass]

whilst in comparison most modern fighters have the radar cross section of a small house.........

[delcyros]

Charles, the He-162 with V-tail is the subtype He-162 A-6, not He-162 Z.
The A-8 subtype with Jumo-004 D engines would weight up to 3000 Kg fully equipped. The plus in poweroutput was thought to increase the top speed to 918 Km/h or 570 mp/h. The thrust to weight ratio would be decreased to 0.31 instead of 0.32-0.33 in case of BMW-003 E (overrewed), but the plane would be able to sustain it´s top speed for a much longer time. But this is still better than anything except for the Me-163 and Meteor MK IV.
To the turbines:
The alloys used were tinadur (15% chromium, 15% nickel, 5% titanium and steel) for Jumo-004 B1 and cromadur (without nickel but therefore traces of manganese) for Jumo-004 B4/D/E. The first was thought to be more heat resistant but worser to produce, so it was replaced by cromadur, which could be easily welded instead of deeply drwan for the hollow turbine blades. In the end the later was easier to cool and therefore much more heat resistant than tinadur.
The disadvantage of the Jumo´s in general, beside of the average lifetime was its prone to flameouts under 6.000 rpm. This is mostly because of the fuel regulation system at lower rpm (easy to burn out the turbine blades if too much fuel is injected at low rpm):
A gear driven pump that produced a linear amount of fuel proportion to the engines rpm, the pilots throttle was directly connected to a bypass valve that would recirculate unwanted fuel. Fuel then passed to a centrifugal speed governer that operated another bypass valve. However, if the engines rpm was under 6.000 rpm (set to idle), the speed governer did not take into effect and the throttle bypass was the only fuel flow regulation. The pilots throttle also was connected to a governor by a pressure spring and would regulate the governers rpm setpoint this way. At full throttle, for example, the rpm of a Jumo-004 B4 was at 8875 rpm. Under 6.000 rpm the pilot had to be very careful, because without the governeor it was easy to allow to much fuel entering the combustion chambers and thereby burn them out.
So there can be a dissimilarity between engines rpm and air flow. The BMW-003 had a similar layout but in addition a device that consisted of an aneorid capsule across the compressor stages. This "accelerator valve" regulated the fuel flow in correspondence to the air flow (by pressure) and the governeor had less importance. In the end the actual air flow and spool up time was taken into account, so that the BMW-003 throttle could be handled less gingerly. The Jumo-004 on the other hand had a more sophisticated system to regulate the exhaust nozzle, while the BMW-003 exhaust nozzle was manually controlled.
Further improvements have been under work (some ceramics and thermocuple to reduce fuel flow if temp limits are to be exceeded).
That´s why type testings means something close to zero, the most limiting factor of the lifetime of early jets have been careful handling in the start and spool up phase. That´s one reason why the Jumo-004 B-1 had around 10-25 hours lifetime while the -004 B-4 had around 25-50 and the BMW-003 around 200.

[DerAdlerIstGelandet]

Originally Posted by evangilder

The B-2 has radar absorbing paint, as does the F-117. What does get reflected back is about what a small bird reflects.

This I have heard to, but I have read that the B-2 was not as successfull in this in that it was actually seen as the size of a plane on radar. I do not know the truth in this though. Could you clarrify for me.

[plan_D]

I've read it has a small signature for the size of the plane but not small enough to avoid RADAR detection - but the shape of the plane allows to easily fly under RADAR.

[DerAdlerIstGelandet]

That is what I read thankyou for making more sense out of it.

[evangilder]

The best way to describe it is take a playing card and hold it out in front of you. If it is facing you, you see plenty of it. Now look at the edge, you see less. That is pretty much how it is with the B-2. It has a small profile, so if it is heading toward the radar, the cross-section is pretty small, and the radar absorbing paint helps with that. Now if the radar is pointing at a B-2 that is banking or climbing, the cross-section is quite a bit bigger.

[DerAdlerIstGelandet]

Nice way to put it.

[evangilder]

Thanks, I try to use a simple explanation. Easier to understand for everyone.

[FLYBOYJ]

Originally Posted by DerAdlerIstGelandet

This I have heard to, but I have read that the B-2 was not as successfull in this in that it was actually seen as the size of a plane on radar. I do not know the truth in this though. Could you clarrify for me.

This is correct about the B-2 but along with ECMs that are rarely discussed, the B-2 achieves an almost invisible RCS.

I've had the opportunity to work on both aircraft. In mt opinion the -117's RAM material and stealth "system" seemed a little more resilient when compared to the B-2. Also the B-2, being much larger is prone to much more RAM material damage and rework.

Many auto body and fender mechanics were employed by Northrop during the assembly of the aircraft. They were known as "surface prep mechanics."