Great SR-71 Story - How slow could it fly?

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garndawg

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Feb 29, 2008
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They also tended to have to restart those engines pretty often didn't they? That was only after it was in ram jet mode though if I remember correctly.

Not quite, the 'unstart' event was an automatic recovery in ramjet. If the spike didn't translate correctly and the shock got inside the inlet, there would be a subsonic flow region inside the engine and a massive high pressure associated with it. A great loss of thrust, which is quickly overcome by supersonic flow and a massive restoration to supersonic flow and power. Hence the 'unstart', which wound up translating to the pilot as a massive blow to the side of the head as the aircraft 'lurched' to whichever side the unstart occured.

Pilot's always knew which side had burbed, as that was the same side their head hurt...
 

jlee

Lifer
Sep 12, 2001
48,517
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Remember a story from when I was stationed at ellsworth AFB some time ago about radio chatter between an SR-71 and the control tower. The Sr-71 radioed requesting clearance for 80,000 feet. The response back from the tower was "sure if you can climb that high" or words to that effect.

The SR-71 radioed back "descending to 80,000".

Not sure if apocryphal or not but found it funny at the time. Sr-71 was (is) an amazing piece of technology.

SR71 be like
50ed828c41160.jpg
 

Markbnj

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Interesting story. I was surprised he lost track of the airspeed to that extent while flying low and in a banked attitude.
 

garndawg

Member
Feb 29, 2008
88
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Holy christ, so 152 knots while in a "banked" turn? I'm surprised they didn't crash the plane.

70k lbs of thrust will get you out of a lot of problems. Will also get you into a lot more in a hurry...


As impressive as it was, I appreciate the XB-70 Valkyrie's method for high altitude lift production more :awe:

Look closely at the SR-71's leading edge..especially out at the wingtips outboard the engine nacelles. Notice anything...unusual...about their shape?
 

Blitzvogel

Platinum Member
Oct 17, 2010
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70k lbs of thrust will get you out of a lot of problems. Will also get you into a lot more in a hurry...

Look closely at the SR-71's leading edge..especially out at the wingtips outboard the engine nacelles. Notice anything...unusual...about their shape?

The LERX on the outboard side of the nacelles? I'm well aware of them, unless you're trying to get at something else :p
 

Aikouka

Lifer
Nov 27, 2001
30,383
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I have a couple A-12 stories (One from 1963) and know where one A-12 plowed into the ground but someone cleaned up most pieces parts before I could ride my motorcycle to the crash site without getting arrested or shot. They say the RS-71 (yeah that's one of the names it was called before Johnson's feud with Goldwater) holds the speed record but the A-12 flew faster and higher. If I could find it I have a photo of the tarmac at the ranch with A-12s and SR-71s lined up. I had it along with an early same view picture of a bunch of U-2s. Sure glad all that is declassified and I took them home when Lockheed Martin closed our office and told me to work from home.

They've got a few A-12s around Alabama. They're really rather purdy planes, but I'll admit that I thought it was an SR-71 before I got close enough. :oops:
 

cabri

Diamond Member
Nov 3, 2012
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Interesting story. I was surprised he lost track of the airspeed to that extent while flying low and in a banked attitude.
Feel of the aircraft will allow you to know when something is not correct
 

cabri

Diamond Member
Nov 3, 2012
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They've got a few A-12s around Alabama. They're really rather purdy planes, but I'll admit that I thought it was an SR-71 before I got close enough. :oops:

I saw what I thought was a '71 on the 72A between Madison and Huntsville back in 2007. Maybe it was the '12 instead.

Either way, it looked like a sewing needle with two engines bolted on.
 

destrekor

Lifer
Nov 18, 2005
28,799
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I hate stories like this.

Words only do so much, man! I want to see it and feel it. See it from the ground, and see it from the cockpit. That would be something spectacular to see.
 

K7SN

Senior member
Jun 21, 2015
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They've got a few A-12s around Alabama. They're really rather purdy planes, but I'll admit that I thought it was an SR-71 before I got close enough. :oops:

Basically an SR-71 without a backseat :) A-12 was to be a fighter interceptor to replace F-104 but at Mach 3.5 it would take a couple states (or countries) to turn around if you had to go back for something missed. Anyway that's what I was told.

BTW: My 1963 A-12 story was a friend of mine who worked for Nevada Department of Wildlife (NDOW) was doing a deer count from a Cessna in a mountain range just north and west of the ranch. He's flying along and an A-12 at subsonic flew past him. He happened to be at a meeting (NDOW has an interest in wildlife on the patrolled side of the fence) a few months later. He related the incident and described the strange plane (This is still 1963 remember) to a Colonel who was representing the Groom facility and he said the Colonel's face got ashen and in a concerned voice whispered, "Please don't tell anyone about that!" :)

You see a lot of interesting things exploring on the BLM side of the fence, I once saw a B-1 (not a B-1B) playing tag with an Aardvark riding in a canyon east of the range that includes the ranch. This was 1975 and I didn't figure out what I had seen until a year or so later when "future design was announced. I was in this canyon and had rode up on a little knoll maybe 300 feet above the valley floor. I was looking around and heard the noise and actually was looking out and down as they flew by. One never knows what you'll see out there.
 

Markbnj

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Feel of the aircraft will allow you to know when something is not correct

Well yeah, but enough people stall airplanes and die, including military airplanes, that "not always" seems a reasonable answer to that point. Flying an SR-71 low and slow would seem to be a good time to be hyper-attentive to airspeed.
 

JEDIYoda

Lifer
Jul 13, 2005
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I have a couple A-12 stories (One from 1963) and know where one A-12 plowed into the ground but someone cleaned up most pieces parts before I could ride my motorcycle to the crash site without getting arrested or shot. They say the RS-71 (yeah that's one of the names it was called before Johnson's feud with Goldwater) holds the speed record but the A-12 flew faster and higher. If I could find it I have a photo of the tarmac at the ranch with A-12s and SR-71s lined up. I had it along with an early same view picture of a bunch of U-2s. Sure glad all that is declassified and I took them home when Lockheed Martin closed our office and told me to work from home.
http://roadrunnersinternationale.com/a-12s.html

The a12 was 32,000 lbs lighter when fully fueled......or 16 tons lighter......and even then it weas not all that much faster. The sr-71 could go 1,000 miles further than the a12 unrefueled!!


Empty as in no fuel the sr-71 was 7,500 lbs heavier....
 
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twinrider1

Diamond Member
Sep 28, 2003
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I'm only half-joking when I say that I think Kelly Johnson is the closest thing we have to proof of alien life.
 

IndyColtsFan

Lifer
Sep 22, 2007
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687
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One of the pics I took last weekend at the USAF museum - the SR-71 with the B-2 bomber behind it.

19927786756_9550d638e7_b.jpg


Front of the SR-71 (had to sharpen it more; it was very dark in the hangar and tough to take photos):

19765967338_a5fe424acc_b.jpg
 

Ichinisan

Lifer
Oct 9, 2002
28,298
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Remember a story from when I was stationed at ellsworth AFB some time ago about radio chatter between an SR-71 and the control tower. The Sr-71 radioed requesting clearance for 80,000 feet. The response back from the tower was "sure if you can climb that high" or words to that effect.

The SR-71 radioed back "descending to 80,000".

Not sure if apocryphal or not but found it funny at the time. Sr-71 was (is) an amazing piece of technology.

:awe:
 

Markbnj

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Sep 16, 2005
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The pilot is lucky that he didn't fly that Aircraft into the ground. It is real dangerous flying a aircraft not meant to be flown low and slow and doing a low altitude pass like that.

https://en.wikipedia.org/wiki/1994_Fairchild_Air_Force_Base_B-52_crash

https://www.youtube.com/watch?v=sjFIB1L3BPU

In that incident the extremely aggressive angle of bank was a major factor. I think it was around 60 degrees. The guy was a showboater and he was pissed off about being ordered to do a go-around, or something along those lines. Plane crashed right in front of their families :(.
 

BUTCH1

Lifer
Jul 15, 2000
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One of the pics I took last weekend at the USAF museum - the SR-71 with the B-2 bomber behind it.

19927786756_9550d638e7_b.jpg


Front of the SR-71 (had to sharpen it more; it was very dark in the hangar and tough to take photos):

19765967338_a5fe424acc_b.jpg


Nice pics, what's amazing was these planes were designed without any help from any computer, that's engineering my friend..