XB-70 Photo Archive
It probably flew better with dropped wing tips due to the compression lift, I read where it had the greatest lift efficiency of any fast / large aircraft.
Posted on 08/15/2008 3:31:20 PM PDT by valkyry1
I have been wanting to get this topic on airplanes going for awhile. I hope some of you find an interest also.
//It probably flew better with dropped wing tips due to the compression lift//
That was the theory, but in practice the dropping of the wingtips the airplane gained more by shifting the center of pressure forward, so much less elevator trim(drag) was required to keep the airplane level. At least thats how I understand it.
Compression lift did not meet its hype other than drag reduction I would guess. Ben Rich had some good words on it.
The LA Biker B70 website, we used to have some email correspondence!
Did you see the news today where America has agreed to pay Libya for the damages caused by Reagan’s raid?
No kidding. What’s this country coming to?
http://www.freerepublic.com/focus/f-news/2062736/posts
They should have finished the third bird, not scrapped it.
The miniature in the Smithsonian is the wind tunnel model for the third one, with the canards set farther back than the first two.
Actually it had, IIRC, 6 tanks. And some of the fuel was also used for cooling of some components and engine hydraulics.
But hey, whatever works.
I think it would have been far more effective than they gave it credit for also.
With ECM, HARMS, SRAM type weapons, plus Mach 3.5, it would have been formidable.
Think of what scores of Jap Me-262’s could have done in the Pacific...
IMO the Germans had a lot of fantastic design ideas that their manufacturing capabilities could not meet.
Strategic bombing proved itself by taking that away.
I've never seen as much quality as I did when looking at a German machined stainless steel U-boat torpedo housing. but the same when for small arms...that's why we have the MP-5 and G3 of today.
I always liked the FW-190D ‘Dora’. Saw it at Wright Patt museum.
They had to fly it with a wood prop.
ping #40
Basically short sighted mission parameters.
The SR-71 was designed to haul ass, make it back home, and do so repeatedly.
Differences in the mindsets of the commanders, mission, designers and production.
That, and the P&W J58 was really a remarkable engine for a remarkable bird.
Here's an excerpt of an excerpt from the book "Sled Driver" you might enjoy. They're flying a mission over Libya in preparation of Reagan's attack on Tripoli...
With the Libyan coast fast approaching now, Walt asks me for the third time if I think the jet will get to the speed and altitude we want in time. I tell him yes. I know he is concerned. He is dealing with the data; that’s what engineers do, and I am glad he is. But I have my hands on the stick and throttles and can feel the heart of a thoroughbred, running now with the power and perfection she was designed to possess. I also talk to her. Like the combat veteran she is, the jet senses the target area and seems to prepare herself. For the first time in two days, the inlet door closes flush and all vibration is gone. We’ve become so used to the constant buzzing that the jet sounds quiet now in comparison. The Mach correspondingly increases slightly and the jet is flying in that confidently smooth and steady style we have so often seen at these speeds. We reach our target altitude and speed, with five miles to spare.
Entering the target area, in response to the jet’s new-found vitality, Walt says, ‘That’s amazing’ and with my left hand pushing two throttles farther forward, I think to myself that there is much they don’t teach in engineering school.
Out my left window, Libya looks like one huge sandbox. A featureless brown terrain stretches all the way to the horizon. There is no sign of any activity. Then Walt tells me that he is getting lots of electronic signals, and they are not the friendly kind.
The jet is performing perfectly now, flying better than she has in weeks. She seems to know where she is. She likes the high Mach, as we penetrate deeper into Libyan airspace. Leaving the footprint of our sonic boom across Benghazi, I sit motionless, with stilled hands on throttles and the pitch control, my eyes glued to the gauges.
Only the Mach indicator is moving, steadily increasing in hundredths, in a rhythmic consistency similar to the long distance runner who has caught his second wind and picked up the pace. The jet was made for this kind of performance and she wasn’t about to let an errant inlet door make her miss the show. With the power of forty locomotives, we puncture the quiet African sky and continue farther south across a bleak landscape.
Walt continues to update me with numerous reactions he sees on the DEF panel. He is receiving missile tracking signals. With each mile we traverse, every two seconds, I become more uncomfortable driving deeper into this barren and hostile land.
I am glad the DEF panel is not in the front seat. It would be a big distraction now, seeing the lights flashing. In contrast, my cockpit is ‘quiet’ as the jet purrs and relishes her new-found strength, continuing to slowly accelerate. The spikes are full aft now, tucked twenty-six inches deep into the nacelles. With all inlet doors tightly shut, at 3.24 Mach, the J-58s are more like ramjets now, gulping 100,000 cubic feet of air per second. We are a roaring express now, and as we roll through the enemy’s backyard, I hope our speed continues to defeat the missile radars below.
We are approaching a turn, and this is good. It will only make it more difficult for any launched missile to solve the solution for hitting our aircraft. I push the speed up at Walt’s request. The jet does not skip a beat, nothing fluctuates, and the cameras have a rock steady platform.
Walt received missile launch signals. Before he can say anything else, my left hand instinctively moves the throttles yet farther forward. My eyes are glued to temperature gauges now, as I know the jet will willingly go to speeds that can harm her. The temps are relatively cool and from all the warm temps we’ve encountered thus far, this surprises me but then, it really doesn’t surprise me.
Mach 3.31 and Walt are quiet for the moment.
I move my gloved finder across the small silver wheel on the autopilot panel which controls the aircraft’s pitch. With the deft feel known to Swiss watchmakers, surgeons, and ‘dinosaurs’ (old-time pilots who not only fly an airplane but ‘feel it’) I rotate the pitch wheel somewhere between one-sixteenth and one-eighth inch, location a position which yields the 500-foot-per-minute climb I desire. The jet raises her nose one-sixth of a degree and knows I’ll push her higher as she goes faster. The Mach continues to rise, but during this segment of our route, I am in no mood to pull throttles back.
Walt’s voice pierces the quiet of my cockpit with the news of more missile launch signals. The gravity of Walter’s voice tells me that he believes the signals to be a more valid threat than the others.
Within seconds he tells me to ‘push it up’ and I firmly press both throttles against their stops. For the next few second I will let the jet go as fast as she wants.
A final turn is coming up and we both know that if we can hit that turn at this speed, we most likely will defeat any missiles. We are not there yet, though, and I’m wondering if Walt will call for a defensive turn off our course. With no words spoken, I sense Walter is thinking in concert with me about maintaining our programmed course.
To keep from worrying, I glance outside, wondering if I’ll be able to visually pick up a missile aimed at us. Odd are the thoughts that wander through one’s mind in times like these. I found myself recalling the words of former SR-71 pilots who were fired upon while flying missions over North Vietnam. They said the few errant missile detonations they were able to observe from the cockpit looked like implosions rather than explosions. This was due to the great speed at which the jet was hurling away from the exploding missile. I see nothing outside except the endless expanse of a steel blue sky and the broad patch of tan earth far below.
I have only had my eyes out of the cockpit for seconds, but it seems like many minutes since I have last checked the gauges inside.
Returning my attention inward, I glance first at the miles counter telling me how many more to go until we can start our turn. Then I note the Mach, and passing beyond 3.45, I realize that Walter and I have attained new personal records. The Mach continues to increase.
The ride is incredibly smooth.
There seems to be a confirmed trust now, between me and the jet; she will not hesitate to deliver whatever speed we need, and I can count on no problems with the inlets. Walt and I are ultimately depending on the jet now - more so than normal - and she seems to know it. The cooler outside temperatures have awakened the spirit born into her years ago, when men dedicated to excellence took the time and care to build her well. With spikes and doors as tight as they can get we are racing against the time it could take a missile to reach our altitude. It is a race this jet will not let us lose. The Mach eases to 3.5 as we crest 80,000 feet. We are a bullet now - except faster.
We hit the turn, and I feel some relief as our nose swings away from a country we have seen quite enough of. Screaming past Tripoli, our phenomenal speed continues to rise, and the screaming Sled pummels the enemy one more time, laying down a parting sonic boom.
In seconds, we can see nothing but the expansive blue of the Mediterranean .I realize that I still have my left hand full-forward and we’re continuing to rocket along in maximum afterburner. The TDI now shows us Mach numbers not only new to our experience but flat out scary. Walt says the DEF panel is now quiet and I know it is time to reduce our incredible speed. I pull the throttles to the min ‘burner range and the jet still doesn’t want to slow down. Normally, the Mach would be affected immediately when making such a large throttle movement. But for just a few moments, old 960 just sat out there at the high Mach she seemed to love and, like the proud Sled she was, only began to slow when we were well out of danger.
I loved that jet.
For some reason, the name Michelle Obama comes to mind.
Even parked, nice porn.
WoW - great photo!
I totally hear you on the airplanes.
Above Mach 2.75 or so, the jet engines start to transition or ‘cycle’ into ramjets all on their own. If the engine cant cope with that, it becomes extremely sensitive to throttle movements and ultimately overspeeds and maybe over heats.
Removing all other factors, the J-58 had air bypass by air withdrawal from the 4th stage of compression (which fed directly into the after burner). This allowed the engine to cycle into much more of a ramjet, and the compressor could be spooled down while still supplying power to the accessory gearbox case to power all of the fuel pumps etc.
The J58 was genius in simplicity, it was the metallurgy that made the engine work.
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