# Martin XB-51 Panther



## johnbr (Jan 4, 2019)



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## johnbr (Jan 4, 2019)



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## johnbr (Jan 4, 2019)



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## johnbr (Jan 4, 2019)



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## Wurger (Jan 4, 2019)




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## johnbr (Jan 4, 2019)



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## Wurger (Jan 4, 2019)



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## johnbr (Jan 4, 2019)



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## Wurger (Jan 4, 2019)




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## johnbr (Jan 4, 2019)



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## Wurger (Jan 4, 2019)




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## johnbr (Jan 4, 2019)



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## johnbr (Jan 4, 2019)



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## Wurger (Jan 4, 2019)




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## johnbr (Jan 4, 2019)

American Aircraft Fan Club - Cesare Brizio - XB-51 pictures from GLMMAM

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## Wurger (Jan 4, 2019)




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## johnbr (Jan 4, 2019)



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## Wurger (Jan 4, 2019)




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## johnbr (Jan 4, 2019)

The cockpit.

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## johnbr (Jan 4, 2019)



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## johnbr (Jan 4, 2019)



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## johnbr (Jan 4, 2019)




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## johnbr (Jan 4, 2019)

Tail

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## Wurger (Jan 4, 2019)




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## johnbr (Jan 4, 2019)




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## johnbr (Jan 4, 2019)




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## johnbr (Jan 4, 2019)




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## Wurger (Jan 4, 2019)




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## johnbr (Jan 4, 2019)



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## Wurger (Jan 4, 2019)




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## johnbr (Jan 4, 2019)

pdf xp-51

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## johnbr (Jan 4, 2019)




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## johnbr (Jan 4, 2019)

Alerts


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## Wurger (Jan 4, 2019)




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## johnbr (Jan 4, 2019)




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## johnbr (Jan 4, 2019)

The wheels and landing






.

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## johnbr (Jan 4, 2019)




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## Wurger (Jan 4, 2019)




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## johnbr (Jan 4, 2019)




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## johnbr (Jan 4, 2019)

*History*
*Key Dates:* Nov 1944 USAAF issues requirement for new attack aircraft. Feb 1946 Martin XA-45 selected as winner of competition. 23 May 1946 Two prototypes ordered under new designation of XB-51. Spring 1946 USAAF issues revised requirements for faster and lighter aircraft. 31 March 1947 USAAF approves new design for XB-51. 4 Sept 1949 XB-51 first prototype officially rolled out. 28 Oct 1949 First flight of first prototype. 4 April 1950 USAF flight testing begins. 17 April 1950 Second prototype makes first flight. Sept 1950 B-26 Night Intruder replacement requirement issued. 26 Feb 1951 Competitive fly-off between XB-51 and Canberra. 6 March 1951 Canberra selected by USAF. 14 June 1951 USAF issues RBL-X requirement for daylight tactical bomber. 29 Nov 1951 Douglas B-66 selected to meet RBL-X. Nov 1951 XB-51 production plans cancelled. 8 Dec 1951 XB-51 officially enters USAF service. 28 Feb 1952 First prototype damaged in landing accident. 9 May 1952 Second prototype lost when maneuvering at low altitude. 28 Feb 1953 First prototype returned to service for bomb delivery testing. 1955 XB-51 appears in the movie ‘Towards the Unknown’. 25 March 1956 First prototype lost in take-off accident.
*Development History:* XA-45 Initial design. 6 crew medium bomber with straight wing, 2 turboprop and 2 jet engines. XB-51 Revised design. Much smaller 2-seater with three jet engines and swept-wing. 2 prototypes built – initially without fin/tailplane bullet fairing. XB-51 Proposed version with tandem crew seating under single canopy. XB-51 Proposed seaplane version with boat hull, hydroskis or hydro-sled landing gear.
The bomber was manned by a crew of two. The pilot sat beneath a fighter style “bubble” canopy. The second crew member, the navigator/radio-operator, sat behind the pilot. The navigator could only view the sky through a small observation window on the left side of the fuselage. The cockpit was pressurized and temperature conditioned. The XB-51 would have a payload capability of 10,400lbs of ordnance in its internal bomb bay. It was also equipped with eight powerful 20-mm cannons located in the nose of the aircraft. The cannons could fire 1,280 rounds of ammunition before they needed to be reloaded. Operational ceiling for the new aircraft was an amazing 41,400 ft. Another impressive characteristic of the XB-51 was its un-refuelled ferry range of nearly 1,600 miles.

On the morning of the 28th October 1949, the XB-51 first prototype, tail number 46685, took to the air for the first time at Baltimore, Maryland. The plane flew as anticipated by Martin. The Air Force was so impressed with the flight testing of the XB-51 that it ordered Martin to finish work on the other test plane, serialled 46686. As it turned out, they would be the only two B-51s ever to be built. The situation in the Korean Peninsula had taken a turn for the worse in 1950 when Communist North Korean troops invaded the South. The US needed to quickly get into service a modern close-support aircraft for the theater and the only proven design available was that of the English Electric Canberra. The Canberra was chosen by the Air Force on March 1951, and this decision meant the end of Martin’s XB-51 close-support bomber.
The two XB-51 prototypes cost the US government the sum of 12.5 million dollars. Much of their subsequent career was spent at Edwards AFB perfecting the rotary bomb door and performing bomb delivery trials, before piloting accidents ended the lives of both aircraft. Martin, who had to “eat” much of the development cost for aircraft, quickly bounced back with the development and production contracts for the B-57 bomber – the Canberra fitted with the XB-51s rotary bomb door – which went on to become a very successful aircraft. The Panther, the name that the Air Force may have given to the XB-51, was an aircraft born ahead of its time. Many of the remarkable features incorporated in today’s bombers, came directly from the XB-51 program.

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## johnbr (Jan 4, 2019)



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## johnbr (Jan 4, 2019)



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## johnbr (Jan 4, 2019)

*General characteristics:* 

Crew: 2 

 
 Length: 25.9 meters (85.1 feet) 
 
 Wingspan: 16.1 meters (53.1 feet) 
 
 Height: 5.2 meters (17.3 feet) 
 
 Empty weight: 30,906 lbs (14,018 kg) 
 
 Loaded weight: 31,500 lbs (14,288 kg) 
 
 Max. takeoff weight: 62,542 lbs (28,368 kg) 
 
 Max. landing weight: 57,067 lbs (25,882 kg) 
 Powerplant: 3 x General Electric J47-GE-13 (5,200 lbf/2,358 kgf thrust min. each, 6,000 lbf/2,721 kgf thrust max. each) 
 Optional: 4 x RATO rocket pots for 14 seconds, 954 lbf each (432 kgf each) 
 
*Performance:* 

Maximum speed: 1,037 kph (560 knots, 644 mph) at SL (sea level) 

 
 Stall speed: 244 kph (132 knots, 151.9 mph) 
 
 Max. rate of climb at SL: 39.37 m/s (129.1 ft/s) 
 
 Service ceiling: 12,920 meters (42,400 feet) 
 
 Wing loading: 105.6 lbm/sq ft (515.58 kg/m2) 
 
 Thrust/weight ratio: 0.28 
 *Armament:* 

Guns: 8 x 20mm M24 cannons (160 rounds per gun, 1280 rounds in total) 

Rockets: 8 x High Velocity Aerial Rockets (HVAR) (in Bomb bay) 

Bombs (10,400 lbs in total): 
1 x 4000 lbs (Type: L.C.) 

 
 2 x 2000 lbs (internal) (Type: G.P.) 
 
 2 x 2000 lbs (external) (Type: G.P.) 
 
 4 x 1600 lbs (internal) (Type: A.P.) 
 
 2 x 1600 lbs (external) (Type: A.P.) 
 
 4 x 1000 lbs (Type: G.P.) 
 
 9 x 500 lbs (Type: G.P.)

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## johnbr (Jan 4, 2019)



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## johnbr (Jan 4, 2019)



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## johnbr (Jan 4, 2019)



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## Wurger (Jan 4, 2019)




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## special ed (Jan 4, 2019)

Fantastic collection of photos. The extra detail of the jato bottles shown in flight and the P4M in one photo along with the many different views, have made my day. Cockpit views indicate a busy pilot.

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## Dimlee (Jan 9, 2019)

Soviet spies have managed to steal XB-51 blueprints but girls in the copy department were sleepy and they placed prints of different parts in wrong order and...
Tu-22 was born.

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## Gnomey (Jan 9, 2019)

Nice shots!


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## johnbr (Jan 9, 2019)

net

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## nuuumannn (Jan 9, 2019)

The XB-51 looks like a spaceship from a science fiction movie.


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## TheRealMrEd (Jan 12, 2019)

Outstanding photos! Thank you SO MUCH for sharing!

Ed


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## swampyankee (Jan 13, 2019)

Dimlee said:


> Soviet spies have managed to steal XB-51 blueprints but girls in the copy department were sleepy and they placed prints of different parts in wrong order and...
> Tu-22 was born.



I had thought the KGB had sent some professional girls with vodka, hence the rather odd configuration...

Bicycle landing gear, weirdly placed engines, variable incidence wing, and what else?

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## TheRealMrEd (Jan 13, 2019)

Don't forget the rotary bomb bay, later used on Martin's B-57's...

Ed

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## special ed (Jan 13, 2019)

Look up Martin's Middle river Stump jumper, I think it was. It was a B-26 Marauder with bicycle L/G and the aviation press thought it was silly.


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## FLYBOYJ (Jan 13, 2019)

Excellent stuff! That photo where an XB-51 was designated Gilbert XF-120 was from the movie “Toward the Unknown.”

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## Wurger (Jan 13, 2019)




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## daveT (Jan 17, 2019)

*Martin XB-51 s/n 46-686 Accident*
The number two XB-51 (46-686) made its first flight on 17 April 1950. It was accepted by the Air Force on 8 December 1951. Most of its initial 64 hours and 13 minutes of flight testing for Martin was flown by F.E. "Chris" Christopherson. Further Air Force flights were conducted by such noteworthy pilots as Guy Townsend, Chuck Yeager, and Russ Schleeh. By the end of its career, 686 had logged about 151 flight hours. The aircraft was used for gun, rocket, and bomb tests. It also performed high-speed flight trials.

On 9 May 1952, Major Neil H. Lathrop (chief of Flight Test Operations at Edwards) took 686 up on a functional test flight. He took off from Edwards AFB at 0753, escorted by a F-86 chase aircraft. After approximately 20 minutes, the chase was relieved of his duties, and returned to base. Lathrop continued his test mission for about 10 more minutes. He then called the tower and requested permission to make some low-altitude, high-speed flybys over the South Base Runway for the benefit of a motion picture crew that was filming activities at the Air Force Flight Test Center.
Permission was granted, and Lathrop made his first pass from west to east. After two more passes were completed, he reversed course. Lathrop initiated a pass from east to west, at a slightly lower speed. His altitude was approximately equal to the height of the control tower. As the aircraft passed the western end of the ramp area, the pilot raised the nose of the XB-51 slightly, and initiated an aileron roll to the right. The roll appeared normal until the aircraft became inverted. At this point, the XB-51 appeared to "dish out" of the roll, striking the ground in a left-wing-low, slightly nose-down attitude. The crash was followed by an explosion and fire, completely destroying the aircraft and killing Major Lathrop. The cause of the accident was attributed to pilot error.

I have visited the XB-51 crash site several times as recently as late 2018. Debris is scattered over a wide area. There is no discernible crater. The jet left only a trail of structural fragments, aluminum skin, engine turbine blades, and cockpit debris adjacent to the Edwards South Base complex. Parts remain to this day.
Another great X plane destroyed, but not forgotten because of web sites like this. 

I have a copy of the official accident report. It is about a 40 meg pdf file, 154 pages long
Pictures below:

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## daveT (Jan 17, 2019)

Photos of XB-51 in flight!!!

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## daveT (Jan 17, 2019)

*Martin XB-51 s/n* *46-685 Accident at El Paso Texas *

While on its way to Eglin AFB, Florida, the aircraft made a brief stop in El Paso, Texas. Immediately after takeoff from El Paso Municipal Airport on 25 March 1956, the aircraft stalled and crashed. The XB-51 crashed through the airport boundary fence, tumbled through sand dunes, and burned. It had logged approximately 435 flight hours. The airplane's crew chief, SSgt. Wilbur R. Savage, was killed instantly. The pilot, Maj. James Rudolph, was severely burned and died from his injuries a few days later.

I have visited this crash. Only a few parts were found at the site.

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## daveT (Jan 17, 2019)

The *XB-51 Ground Support Jet Bomber *from Flying Magazine story by William Bullock
enjoy

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## Gnomey (Jan 19, 2019)

Good shots!


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## johnbr (Jul 7, 2019)

* Rotary Launcher* Spotlighted Photos | Code One Magazine




A Martin technician inspects the six 750-pound bombs loaded on the innovative rotary launcher used on the XB-51 medium bomber prototype, circa 1949. The bombs, rockets, or other weapons would be loaded on to the door itself. Once hoisted up into the aircraft, the wheels would be removed and the weapon/door combination would be attached to a spindle at each end of the bomb bay. Near the target, the door and weapons would be rotated 180 degrees. The weapons would be released or fired and the now-empty door would rotate back into place. The system allowed for accurate bombing at relatively high speeds. Two XB-51s were built, but the Air Force's medium bomber competition went to the English Electra Canberra design, which Martin later built under license.

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## johnbr (Jul 7, 2019)

*Tri-Jet Bomber same site



* 
The Martin XB-51 was designed in response to a 1946 Army Air Forces competition for a new ground support aircraft to succeed the A-26 Invader. The XB-51 featured three engines—two in nacelles and one in the tail— along with innovations such as a rotary weapons bay. Although the XB-51 program was cancelled in 1952, the two XB-51s continued as flight research aircraft, and one appeared in the 1956 Warner Brothers movie _Toward The Unknown _as the “Gilbert XF-120.” Both aircraft were eventually lost in accidents.

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## Gnomey (Jul 8, 2019)

Nice shots!


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## Vahe Demirjian (Dec 15, 2019)

Below is an artist's conception of the original XA-45 design:

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## FLYBOYJ (Dec 15, 2019)

Vahe Demirjian said:


> Below is an artist's conception of the original XA-45 design:
> 
> View attachment 564090


What does that have to do with the XB-51?


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## Vahe Demirjian (Dec 15, 2019)

FLYBOYJ said:


> What does that have to do with the XB-51?


This was the original design for what would become the XB-51, featuring two turboprops and one J33 turbojet. Only when the Army Air Force dropped the A-for-Attack category and started classifying attack aircraft as bombers was the Model 234 transformed into a light bomber solely using turbojet propulsion.


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## Zipper730 (Dec 27, 2019)

Vahe Demirjian said:


> This was the original design for what would become the XB-51, featuring two turboprops and one J33 turbojet. Only when the Army Air Force dropped the A-for-Attack category and started classifying attack aircraft as bombers was the Model 234 transformed into a light bomber solely using turbojet propulsion.


Fascinating, I'd have figured that, with the XA-43 being all jet, that all the other attack designs would have immediately gone all jet too...


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## John Matthews Art (Dec 31, 2019)

johnbr said:


> View attachment 524109



The image in Johnbr's original post was a study I was doing a few years ago to see what the XB-51 might have looked like with something approaching a SEA camouflage paint scheme. When I made the texture for the 3D models I made, I patterned the camo from SEA camouflaged B-57 Canberras, which I thought was kind of appropriate since that was the plane which won the contract over Martin. The tail codes and numbers are fictitious, but the nose art wasn't. Both "Sylvia" and "The Wench" were flown by the 13th bomb squadron of Whiteman AFB in Missouri. The nose art was originally on A-26 Invaders, which was one of the prop-driven attack planes the XB-51 was designed to replace. Here's another rendering I did of a camouflaged B-51:

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## John Matthews Art (Dec 31, 2019)

Here's one piece I did featuring the XB-51:





Shame neither one exists today. But, the design was so fascinating I wanted to make some artwork that featured them.

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## Snowman (Jan 1, 2020)

Absolutely perfect!


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## John Matthews Art (Jan 1, 2020)

Snowman said:


> Absolutely perfect!


Thank you very much!


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## Gnomey (Jan 1, 2020)

Good shots!


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## Zipper730 (Jan 2, 2020)

If the SAC sheets are right, it has a far lower stall speed than I'd have expected. That's good, because it means it will maneuver well.

That said, it was far too weak.


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## John Matthews Art (Jan 5, 2020)

Gnomey said:


> Good shots!



Thanks Gnomey. This is the most recent artwork I've done featuring the XB-51:

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## John Matthews Art (Jan 5, 2020)

Zipper730 said:


> If the SAC sheets are right, it has a far lower stall speed than I'd have expected. That's good, because it means it will maneuver well.
> 
> That said, it was far too weak.



That's interesting. The design was definitely a product of its time. I'd say the jets used to propel it were weak (underpowered, dreadfully slow to spool-up, etc.). The remainder of the design though: eight 20mm cannons, over 10,000 pound ordinance carried internally, variable incidence wing, top speed over 600 MPH... Had it been further developed provisions for in-flight refueling would have been added, in addition to uprated engines. It would have been a stronger contender at that point.


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## XBe02Drvr (Jan 5, 2020)

Looks like the perfect runway FOD vacuum sweeper to me. A flying Zamboni! Or maybe a winged Electrolux?
Cheers,
Wes


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## John Matthews Art (Jan 5, 2020)

XBe02Drvr said:


> Looks like the perfect runway FOD vacuum sweeper to me. A flying Zamboni! Or maybe a winged Electrolux?
> Cheers,
> Wes


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## J_P_C (Aug 10, 2022)

i've visited Middle River many times, XB-51 posters are still occupying walls in the engineering room, interesting design and bomb bay design was truly masterpiece....

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## nuuumannn (Aug 11, 2022)

Such a stunning looking aircraft, but those low hanging engines are FOD hoovers in the making. It would look so great in the experimental hangar at the USAF Museum alongside the YF-12A, XB-70 and so forth...

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## Zipper730 (Aug 12, 2022)

The XB-51 honestly had a lot of potential if it had a sturdier airframe and bigger wings.


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## GTX (Aug 12, 2022)

Some whatif operational schemes/variations done by some friends
years ago:

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