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This New York Times article on the B-52 mentions old fashioned
navigation with stopwatch, slide rule, and protractor when the computer
complex temporarily goes down. Part of the navigator instrument panel is
shown.

http://www.nytimes.com/2015/12/06/us/b-52s-us-air-force-bombers.html?_r=0

You enter a B-52 through a belly hatch. Take one step forward and a
vertical ladder to your right goes through a square hole in the ceiling
to the upper deck where the EWO (Electronic Warfare Officer), tail
gunner, and pilots sit. Before I retired from the USAF (my entire career
was in bomber avionics maintenance), the gunner was deleted from the
crew and the gun removed. However, the last time I looked the control
panels were still there.

In the lower deck forward of the ladder are seats for the radar
navigator (senior navigator, on the left) and navigator. There's enough
space between them for a man to stand. At the rear of the compartment
are racks for electronics, a urinal, and toilet.

Once upon a time the computer crash mentioned in the article would have
been my job to troubleshoot after flight. Back then, the OAS (Offensive
Avionics System) had three identical IBM AP-101 general purpose
processors for nav and weapon delivery. An instructor told me these were
also the main processors of the space shuttle.

The panel on the left third of the photo controls the processors. In 30+
years it hasn't changed. The DTU (Data Transfer Unit, not shown) has
four slots for removable tape cartridges. In this case, the top row of
status lights shows two tapes are installed. Below that you see the
status of the three processors, then knobs to load them. You select the
DTU slot that contains the software, the processor to load, and which
program (1 - 4) to load. The button in the lower left starts the load,
and the PROC SYNC button puts all loaded processors on line. Digits in
the RES PGM readout (overexposed and hard to read) show what software is
resident in each processor.

Unfortunately the article has much bias and misinformation and should be
taken with a grain of salt, or maybe a whole salt shaker. For instance,
the B-70 never "spewed highly toxic exhaust." The exotic high energy
"zip fuel" project was abandoned years before the B-70's first flight
due to insuperable problems with toxicity and deleterious effects on
engine components.

However, what the article says about the B-52 processor complex taking
"several minutes" to reboot is probably accurate. I remember reloading
two or three processors was irritatingly slow. You had to wait for the
tape to rewind after each one. Do they still use tape cartridges? I
don't know.

The middle third of the photo is munitions stuff. Note the guards over
the switches. You must flip the guard up to throw a switch. Furthermore,
each guard can be secured with copper wire. It takes a hard pull on the
guard to break the wire.

(Speaking of switch guards, in the early 1980s a B-52 crew chief at
Griffiss AFB in New York, proud of "his" airplane, did some detailing in
the cockpit. Among other things, he installed new guards on the landing
gear emergency switches at the pilot station. Unfortunately, the new
guards held the switches to the retract position. On its next mission
the bomber slid on its belly off the end of the runway when the gear
retracted on the takeoff roll. Though nobody got hurt, the plane was
severely damaged. A co-worker who was stationed there at the time told
me, "They wanted to hang the guy but couldn't do a thing to him because
nobody could find any official guidance on switch guard installation!")

In the right third of the photo are old school instruments. The small
gauge is the outside air temperature indicator.

Part of the radar presentation panel is visible at the bottom right
corner. STC = sensitivity time control. This produces a variable
receiver gain (with respect to time) to help equalize the intensity of
near and far terrain on the scope. The small triangular "BW" knob
coaxial with the STC knob varies the antenna beamwidth. Just out of
sight are the marker intensity (e.g., for the range rings on a PPI
display) and video gain knobs. Between them is a button to toggle
between logarithmic and linear receiver response. LOG is selected.

The photo shows only a small part of a panel which spans the full width
of the lower compartment in front of the navigation team. There's also a
panel on each side and an overhead panel. They are all packed with
stuff. It's impressive. Not all the available space is occupied,
however. There are metal plates to cover the empty areas. In some planes
I saw the plates removed and HO 249 and the Almanac stuffed into the
openings! I've also seen those publications in the storage bin behind
the nav seat.

Each navigator has a table which slides out from the console. There's a
reasonable amount of space to plot on a chart. In case of ejection,
pyrotechnic actuators automatically retract the tables before the seats
fire. In the B-1 there's only one navigator and the table is small. And
if you need a table in the B-2 there's only the lid of the storage
compartment between the seats.

Before the B-52 tail gunner was deleted he usually operated the sextant
and the navigator reduced the sights. I suppose manual celestial on
bombers is history now. As far as I know the B-1 never had any such
provision.

My first encounter with the B-2 was at the plant in Palmdale. Standing
in a partly completed cockpit, I noticed a circular port in the ceiling,
on the center line. A sextant port for emergency nav, I thought. Wrong.
The hole was for an air refueling lead-in light!

The B-2 does have an AINS (astro inertial navigation system), and
eventually I had a chance to track stars in daylight. But that's another
story.

   

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