Long before electronic computers tried to simplify things, slide rules, affectionately nicknamed "slip sticks", were used for everything from designing gigantic skyscrapers & huge, ocean-going ships to calculating weight & balance data for the proper loading of an airplane...





The Depot 41 Museum Collection's

Load Adjusters

In the early 80's, one of the perks of working for S.A.L. Instrument Co. (decades before, the West Coast's largest dealer in surplus aviation gauges) was the ability to wander around in awe through warehouse after warehouse, each still piled literally 'to the ceiling' with former military items of all shapes and sizes. You see, ol' Buck had once worked for Wunderlich at Kingman during the immediate post-War aircraft salvage operation (that period being the genesis of the greatest surplus phenomenon anyone will ever see) and he ended up with tens of thousands of instruments plus TONS of other items taken out of the fighters and bombers. Among the treasures acquired were most of the bomber's Load Adjusters, which for years he handed out as souvenirs to friends, potential customers, etc. Imagine my frustration when he once had me take a B-24 Load Adjuster to the owner of a neighboring business and present it to him!

In any event, after years of tense negotiations with Buck and then his family after his passing, I ultimately ended up with most of the Load Adjusters from the Kingman bombers, each bearing the tail number of the aircraft from which it was taken.


Around 1983, the very first Load Adjuster matched to its Bomber was

B-24M #44-50734,

the 446th Bomb Group's MY DEVOTION

Picking myself up off the floor, thus began an exciting era of discovery enriched with an unparalleled, tangible connection to history!


In addition to those from many other Kingman

A-20 Havocs, A-26 Invaders, B-17 Flying Fortresses, B-24 Liberators, B-25 Mitchells, B-26 Marauders and B-32 Dominators, the Depot 41 Museum Collection also contains the Load Adjusters from these bombers:


B-17G #44-6633, the 2nd Bomb Group's (name?)


B-24J #44-40670, the 11th Bomb Group's


B-17F #42-30620

of the 19th Bomb Group

This Stateside Trainer had GI painted on her tail & ENLIST IN THE AAF on her dorsal fin

Load Adjuster

and Bombsight DATA BOOK

from B-24L #44-41468 the 30th Bomb Group's


B-17G #43-37864

the 34th Bomb Group's PENNY JIVE

Prior to overseas deployment, her partially-disassembled tail is seen here during the 1944 BDV Tests

B-24J #44-10503

the 44th Bomb Group's



B-24L #44-41534, the 90th Bomb Group's


B-17G #43-38379, the 91st Bomb Group's Margie

Nestled in a custom mahogany box, her Load Adjuster was presented to the artist Tony Starcer in the early 80s, then returned to me after his passing.

B-17G #42-37735

transferred from the 482nd to the 92nd Bomb Group

...by the time this old girl arrived at Kingman, her basic weight was 35,826 lbs!

B-24J #42-50501, the 93rd Bomb Group's

Solid Comfort

B-17G #43-38183

the 94th Bomb Group's


Talk about a workhorse, this plane also served with the 379th & 457th Bomb Groups - after ground crews repaired the damage seen here from a wheels-up landing, she went back to the 'job' before returning Stateside and ending up at Kingman

B-17G #43-38281,

the 95th Bomb Group's*


assigned to Kingman 6 December 1945

*after having been transferred from the 92nd BG


B-17G #42-102978 of the 96th Bomb Group

The last G-60-BO Fortress off the Seattle line, once this gear malfunction damage was repaired, she returned to duty, eventually ending up at Kingman

B-17G #44-6537

the 97th Bomb Group's (name?)

B-17G #44-6694, of the 99th Bomb Group (name?)

Upper Turret fitted with APG-5 Ranging Radar, she's seen here coming in after losing a tail wheel and the Crew then having to jettison the Ball Turret to facilitate a safe landing

B-17G #43-39005, the 100th Bomb Group's


Shown right after the release of her six 1000 pound, M65 bombs; this Load Adjuster was traded for B-17 parts in the 90s . . .

B-17G #44-6370

the 301st Bomb Group's


B-17G #42-38050, the 303rd Bomb Group's famous


Feb 1989: I took her Load Adjuster with me on a trip to the National Air and Space Museum, seen here in front of Keith Ferris' spectacular painting of THUNDERBIRD!

B-17G #44-6009

the 305TH Bomb Group's


- My nomination for a Top 10 nose art list . . .

Far left: 6009 undergoing major engine repairs

B-17G #42-38148, the 306th Bomb Group's MAMU

This Bomber was assigned to Kingman on 12 March 1945

B-24L #44-41696

the 307th Bomb Group's

My Heart Belongs To Daddy

B-17F 42-29831, the 351ST Bomb Group's THE INVADER

One of their original & Kingman's oldest Fortresses,

according to information on the Load Adjuster's Card,

somewhere along the line she became a TB-17F,

indicating possible War Weary status

Load Adjuster & Manufacturer's Plate

from B-17G #44-6915 of the 379th Bomb Group (name?)

...and the Load Adjusters from:

B -24J #44-40434, the 380TH Bomb Group's

Flak Fled Flapper

B-17G #42-107018

the 381st Bomb Group's

Los Angeles City Limits

B-17G #42-39888

the 384th Bomb Group's "HOTNUTS"

B-17G #42-102614 of the 385th Bomb Group

'Square G' Group insignia was replaced in 1945 with the red / silver checkerboard, which is what she most likely sported upon her arrival at Kingman

B-17G #44-6102

the 388th Bomb Group's


Brand spanking new, on the Douglas, Long Beach flight line

B-24J #42-51451

THE CARRIER PIGEON of the 389th Bomb Group

B-17G #43-37836

the 390th Bomb Group's


War over, this ship was assigned

to Kingman on 8 November 1945

B-24J #42-51238

the 392nd Bomb Group's


B-17G #43-38775 of the 398th Bomb Group, code: K8-H

The name "MILLIE" was painted on the side of the Tail Gunner's position and "MURIEL" was below the Waist Gunner's window.

For some reason, her Chin Turret had been removed.

Further, the B-17 closest to K8-H's left is #43-38564, N8-X, also sent to Kingman for disposal, but no Load Adjuster for this ship in the DEPOT 41 Museum Collection.

B-17G #43-38077


of the 401st Bomb Group

B-24J #42-50609

SKYLINE DRIVE of the 445th Bomb Group

B-24J #42-51581, the 446th Bomb Group's

Naughty Nan

B-17G #42-31225

the 447th Bomb Group's

122 mission


Combat theater shot and post-War Stateside, in the field at Kingman, life rafts having been pilfered...

B-24J #42-51288, the 448th Bomb Group's


B-24J #44-10621, the 451st Bomb Group's


B-17G #43-37807

the 452nd Bomb Group's (name?)

- Delivered to the USAAF on 24 May 1944

- Assigned to the 452nd B.G. 20 June 1944

- Returned to the U.S. 6 July 1945

- Assigned to Kingman 8 December 1945

B-24J #44-10575, the 453rd Bomb Group's

Becoming Back

B-17G #43-37733

the 457th Bomb Group's


Nine of her twelve AN M64 500 pounders exiting the bomb bay, on their way to Today's Target


B-24J #42-50912, the 458th Bomb Group's

B-24J #42-51916 of the 460th Bomb Group

B-17G #42-97907, the 463rd Bomb Group's


B-24J #42-95617, the 466th Bomb Group's


B-24J #42-51282 of the 467th Bomb Group

B-17G #44-6616, the 486th Bomb Group's




B-17G #43-39249, the 487th Bomb Group's

Unfinished Business

Two shots of her at Kingman,

with a fitting post-War correction

B-17G #43-38729 of the 490th Bomb Group

TB-24J #44-40164, formerly the 491st Bomb Group's


B-24J 44-40159, the 492nd Bomb Group's


B-17G #43-38198, the 493rd Bomb Group's


B-24J #44-40707

BUGS BUGGY of the 494th Bomb Group

In addition to the 53 above, the Load Adjusters out of even more aircraft from some of these Bomb Groups, as well as others representing even more Bomb Groups plus some trainers & what were then brand new aircraft - literally thousands of Kingman bombers - still exist today...

Absolutely AMAZING !

Think of the countless lives that were touched by the airplanes at Kingman... from those who labored at defense plants designing & building them to male & female ferry pilots who delivered them to their initial Army Assignments; men who crewed them sometimes in training, but more often in combat (occasionally various bombers even having multiple crews); the lucky few who were able to climb aboard for that cherished post-War flight Stateside (avoiding the cramped, dank bowels of seaborn ships jam-packed beyond capacity); and coming full circle back again to scores of ferry pilots who guided them to their final destination in the Arizona desert, ultimately ending up in the hands of those who destroyed them...

Depot 41 Museum Collection's Load Adjusters are, in most cases, the final remnant of those historic bombers, embodying both the memory of the planes and all those who once touched them, many having shared the exhilarating experience of flight during a fantastic event that can never, ever be repeated.

The autographed Bomb Bay Door (details on the B-24 Page) may be one  of the single most important pieces in the Depot 41 Museum Collection, but collectively its cache of Load Adjusters far surpasses, in every conceivable aspect, even that amazing Artifact...

Conservatively, their monetary value has been estimated to be well into seven figures,

but their historical value is

unquestionably priceless.



Hopefully the following will answer a few questions as well as correct some mistakes regarding the LOAD ADJUSTER:

First off, new old stock, still-in-the-box LOAD ADJUSTERS still appear from time to time, but if it had actually been assigned to an airplane, the shipping carton would have been discarded long before, as those weren't carried onboard the airplane. An original carton would then indicate an UNUSED Load Adjuster, as would the presence of Instructions and a stainless steel mounting bracket - those were usually left attached to the airplane and will definitely have fastener scars if, in fact, it had been removed from an airplane.

More importantly, if a Load Adjuster was assigned to an aircraft, the paper card inside the window will bear the plane TYPE & MODEL, as well as its MILITARY SERIAL NUMBER, BASIC WEIGHT early on, then replaced later on with SEE CHART "C", plus an INDEX NUMBER, the latter being that particular plane's unique starting point for the Weight & Balance calculation.

Further, the gold-embossed number on the Sheath's LOOP originally corresponded with the 'end numbers' on both the Slide Rule BASE and SLIDE:


This arbitrary number was simply an effort to help prevent the Slide Rule's SLIDE & BASE from being separated & mixed-up with another type AND insure that the original Slide Rule stayed together with its original leather Sheath or Case.

As an extreme example, problems would arise if a B-24M Slide was mistakenly slipped into a B-17G Slide Rule Base (values for each model being totally different), the calculations derived from this mismatch would definitely be skewed bigtime.

The 'end numbers' matching isn't as important as the 'E' numbers on the Base & Slide matching; this 'E' number signifies the actual TYPE OF PLANE and if they don't match, you have parts from 2 different models and/or types of planes:

How could they possibly get switched, you might be wondering... Well, whenever substantial fixed equipment such as radios, radar, turrets, etc. was either added to or deleted from the aircraft, it required a recalculation of that aircraft's Basic Weight & Index Point so the Engineer had an up-to-date starting point for his daily load calculations. For this procedure, Load Adjusters were removed from planes to modify their Card's information (a B-24 Load Adjuster in the Depot 41 Museum Collection shows at least 5 changes to its information!). Further complicating matters, Base Air Depots were extremely hectic places, nearly always managing several different types of planes side by side at any given time.

After handling thousands of LOAD ADJUSTERS used in both trainer & combat aircraft, I can testify that Slide Rules were not always returned to their original Sheaths; THE PARAMOUNT CONCERN WAS THAT SLIDE RULE 'E' NUMBERS MATCHED, THAT IT'S MODEL COINCIDED WITH THE CARD INFORMATION . . . AND THE CORRECT LOAD ADJUSTER MADE IT BACK INTO ITS AIRPLANE.




I've seen more than one unsuspecting collector pay a lot of money for a phoney that some underhanded seller had taken an NOS Load Adjuster, filled-in the Card with bogus data, then made up an incredible story to make it more appealing.



photo credits this page:

William T. Larkins,

Pat McGinnis/Boeing,


Yankee Air Museum,

A VERY SPECIAL THANKS TO http://www.b24bestweb.com,

www.100thbg.com, www.301bg.com,

The Roger Freeman Collection via americanairmuseum.com,

Thanks to all who have relayed images from their famlies' albums,

Depot 41 Photo Archives


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