Bendix Central Air Data Computer

[VM325]

Ken Shirriffs blog

Determining the airspeed and altitude of a fighter plane is harder than you'd expect. At slower speeds, pressure measurements can give the altitude, air speed, and other "air data". But as planes approach the speed of sound, complicated equations are needed to accurately compute these values. The Bendix Central Air Data Computer (CADC) solved this problem for military planes such as the F-101 and the F-111 fighters, and the B-58 bomber.1 This electromechanical marvel was crammed full of 1955 technology: gears, cams, synchros, and magnetic amplifiers. In this blog post I look inside the CADC, describe the calculations it performed, and explain how it performed these calculations mechanically.

Cant help thinking it's easier these days with silicon..

[ORAC]

Now all done on a single chip….

Tatjana van Vark ~ The Inertial Navigator Platform.

Tatjana van Vark ~ Navigation and Bombing System NBS

https://timeandnavigation.si.edu/mul...on-system-sins

[Asturias56]

the odd thing is that contraption worked - after a fashion..................

[falcon900]

When there’s a will ( and limitless budget), there’s a way!

[Jhieminga]

There are also a couple of video's that accompany this blog post, one is linked:

You Tube

The other one is here:

You Tube

If you're into this stuff, keep an eye on CuriousMarc's Youtube channel. These guys also got an Apollo Guidance Computer back to working order.

[sandozer]

Glenn`s Computer Museum

A really comprehensive site for early and later military aircraft "black boxes", well worth a look.

Home ? Glenn's Computer Museum

[LowObservable]

Someone on the Internet used to have recordings of the original Nagging Nora, the Nortronics voice alert system from the B-58, but the last time I looked for it it had 404d...

[sangiovese.]

Suitable system of levers and gears…..wow

[tdracer]

You should see the inside of a pre-FADEC hydromechanical engine control - similar idea but with Jet A doing all the work...

[57mm]

I remember the CADC from my RAF F4 days. Gave us KCAS in the cockpit and was IIRC, pretty reliable. I believe it was mounted near the boiler....

[happybiker]

Originally Posted by Asturias56

the odd thing is that contraption worked - after a fashion..................

The analogue electro mechanical computers were fascinating bits of kit in their day but their reliability was always a problem. GEC Marconi were successful in the early 1980s when they produced a digital Standard Central Air Data Computer (SCADC) system for retrofit in a wide range of USAF and USN aircraft with far greater reliability.

Standard Central Air Data Computer [SCADC, 1982] :: Rochester Avionic Archives

[Asturias56]

Having vistied Cap e Kennedy just before Covid I was stunned by the back end of the Saturn 5.

It was all pipes that looked like our local plumber had been at work (clearly not him as a Saturn 5 actually worked) but it was very 1950's tech.

[Timelord]

Someone who knew more about the subject than I do described the Vulcan’s Ground Position Indicator (GPI) 6 as the high point of analogue computing. About the size of a carry on suitcase stuffed full of electro mechanical wonders. Accurate to a couple of miles per hour as well.

[tucumseh]

This reminds me of how very lucky I was having two watchmakers in the Instrument Shop. They always got these jobs.