fourlocks Loc: Londonderry, NH

I had read this anecdote but pilot Brian Shul delivers it with the timing and skill of a stand-up comedian. Just try not to laugh when you hear it! Thanks for giving me this link; I belong to a radio control airplane club (with many "real" pilots) and I'll send this to them.

Shellback Loc: North of Cheyenne Bottoms Wetlands - Kansas

Thanks for the info - I had not heard the term unstart before this thread... Would have loved to ride in one...

DaveC1 Loc: South East US

The Apollo moon program and the 747 were also slide rule designs. I have about 3 or 4 of them including a Pickett N4-ES and an Aristo-Multilog 0970. The Pickett supposedly came from the widow of one of the engineers that worked on Apollo, a guy by the name of Don Norman.

sr71 Loc: In Col. Juan Seguin Land

Thanks for the link, just increased my data base some I knew some I didn't......

Bushpilot Loc: Minnesota

A beautiful aircraft in every way!

Earnest Botello Loc: Hockley, Texas

Thanks for SR-71 facts Mac, very interesting read.

DaveC1 Loc: South East US

One of my acquaintance's father taught in the electrical engineering department in one of the state colleges and was quite proficient on slide rule math. His favorite trick was to put a lengthy problem on the board and race students to a correct solution with them using calculators and him using a slide rule. That used to drive students crazy.

47greyfox Loc: on the edge of the Colorado front range

About 3 years ago, my wife and I flew into Dulles to attend a Maryland wedding. We had a couple days to kill before returning home and an even flight so we decided to fill the time by visiting the Smithsonian Udvar-Hazy Center. For those who have visited the center, they have a SR-71 parked almost in the middle of the museum. We joined the free tour the museum group and eventually got to the SR-71, where the grouper leader stopped. Unknowing to us, there was a former SR-71 pilot in our group and the tour guide immediately turned the tour over to him. He proceeded to take us on a joy ride that we'll not soon forget including a surprise flight one day where he discovered that a certain countries had improved the range of their surface to air missiles or a hot shot flight across the country before the plane was retired. It was an amazing hour listening to this guy, whose name has long escaped me. Here's also an interesting website I ran into this morning about SR-71 losses including pilots:
https://www.sr-71.org/blackbird/losses.php

47greyfox Loc: on the edge of the Colorado front range

Still have my old yellow aluminum Pickett and leather case Post Versa Logs. Amazing what those engineers got out of "antique" calculating devices! A typical handheld slide rule is what, 3-4 significant digits, max? That's okay, the Apollo program was written in a somewhat advanced "basic" language. A visit to the Johnson Space Center will reveal some interesting antiques that guided and returned astronauts.

PhotoPhred Loc: Cheyney, Pa

When I was in college you could always tell who were engineering/math students by the slide rule sticking out of a book. There was one guy in my class, I started in 1968, that had a Bowmar Brain. Anybody remember them? they were only a 4 function machine, not even square root or % keys. They were 100 bucks, so he still had to carry a slide rule. I remember about a year later Texas Instruments introduced a programmable calculator that you could store a couple formulas on little strips of 1/4 inch tape. I seem to remember thy cost around $400.00. Now look what you can get at Staples for 30 or 40 bucks.

wrangler5 Loc: Missouri

I lived with 'em for 4 years at Beale AFB in '68-'72. Saw my first one as I was driving onto the base to report for active duty, on a road that was in line with and slightly offset from the departure end of the runway, when one took off. If you've heard the sound those engines make at a mile or two you can imagine what it was like at a few thousand feet underneath one, coming from a Bat plane I had no idea even existed. I almost drove off the road. Welcome to the USAF.

I am still in awe of the things. Got a great thrill sitting in the seat of one at the Museum of Flight in Seattle last month - they have a cockpit people can climb into - although there were no rudder pedals, there was a kiddie seat (wooden box) to get your butt up to where a real pilot's would be with his flight suit and gear on, and all of the switches and dials were behind plexiglas. Only the stick moved. Still, it was a thrill, even after all these years. (If you want to see what it looked like for real, this is a good image http://www.nmusafvirtualtour.com/media/068/SR-71A%20Front%20Cockpit.html that you can look around in.)

For those of you who are mechanically inclined (or just curious) here's a description of what actually goes on inside those engines at various airspeeds. https://aviation.stackexchange.com/questions/27003/why-does-the-j58-engine-of-the-sr-71-have-a-diffuser-after-the-inlet-spike . Kelly Johnson was famously described as being able to "see air" when he was designing airframes. Somebody at P&W must have had the same talent when they came up with the airflow patterns that let the J58 operate from 0 to Mach 3+.

The retirement of the SR-71 is usually attributed to the increasing quality of satellite imagery and the enormous cost of maintaining the worldwide tanker support that the SR needed. They took off only partially fueled and needed to fill up immediately, and then every couple of hours or so during missions (i.e. every 4-5000 miles.) These were dedicated tankers that carried the JP-7 fuel that was used only by the SR-71 (and U-2, although I don't think those planes did aerial refueling) and so were unavailable to refuel other AF aircraft between SR-71 missions. I suspect it was also driven by the perpetual need of USAF brass to come up with new money to spend on new equipment.

DaveC1 Loc: South East US

The problem with the satellite technology explanation is that with a bit of work its predictable. My personal opinion is it has to do with the advancements in surface to air missile technology. At this point in time I have to believe the SR71 replacement (and yeah I believe there is one) is a hyper sonic drone with the pilot sitting somewhere in an air conditioned room looking at computer screens.

wrangler5 Loc: Missouri

You may be right about the SAM situation - that would certainly be true today, when supposedly we have missiles that can down satellites, although I'm not sure how real that risk was in 1998.

An interesting speculation on the subject is here http://456fis.org/WHY_THE_SR-71_WAS_RETIRED.htm , especially under why it was REALLY retired. Probably all of those factors played a part.

donb17

When I was in 9th grade (1960), one of the other kids in my algebra class brought a plastic slide rule to class. His father had given it to him. The only thing he knew how to do with it was to use it as a straight edge to draw lines. I mentioned it to my dad who got me a simple one. I immediately learned how to do multiplication, division, powers and roots. (That was before I learned abought logs, etc.) My dad knew then that I’d become an engineer, and he was right. Before I graduated (in math) from Georgia Tech in 1963, I had a number of slide rules, including bamboo (encased in plastic) and metal circular slide rules.

I didn't get my first electronic calculator (a TI) until around 1972.

Tom G Loc: Atlanta, GA

Back in the late 50's, this was a cheer chanted at the football games by a group of Engineering Students (Who else?)

‘E to the U du dx, / E to the X dx. / Cosine, secant, tangent, sine, 3.14159. / SlipStick, SlapStick, BTU / SlipRule, SlideRule, / YAY PURDUE

P.S. When the lights go out, better have a Slide Rule handy.