Simplify, Then Add Lightness

"ttyymmnn" (ttyymmnn)
03/18/2015 at 10:48 • Filed to: planelopnik, planelopnik history, wingspan

Do you recognize this airplane? Probably not. Only two of them were ever built, and the program was canceled by the US Navy before production began. This is the Douglas XB2D Skypirate. It was designed by the brilliant Douglas engineer Ed Heinemann, who is known for creating some of our most successful warplanes, such as the TBD Dauntless dive bomber, the A-20 Havoc and the A-26 Invader, the A-3 Skywarrior, and the A-4 Skyhawk. And while you may not know the Skypirate, you will almost certainly know what it became.

As WWII raged in 1942, the Navy started looking for a dedicated torpedo bomber to replace the outdated Douglas TBD Devastator. Heinemann proposed the Devastator II, later called the Skypirate, a huge, heavy and complex plane by WWII-era carrier standards. The XB2D was powered by a Pratt & Whitney R-4360 Wasp Major driving contra-rotating propellers, and would have been armed with four torpedoes (the Devastator carried just one) or four 2000 pound bombs, along with two 20mm cannons or four .50 caliber machine guns in the wings and twin .50s in a powered dorsal turret for self defense. The Skypirate took its first flight in March of 1945. The Japanese would surrender just six months later, ending WWII. The Skypirate was canceled.

But the story of the Skypirate doesn’t end with the Navy’s cancellation of the project. Rather than relegate the design to the dustbin of aviation design history, Heinemann, along with fellow engineer Bob Donovan, took the Colin Chapman approach: Simplify, then add lightness.

Heinemann !!!error: Indecipherable SUB-paragraph formatting!!! that for every 100 pounds of weight savings they could find, the airplane’s takeoff distance would be decreased by 8 ft, the combat radius would be increased by 22 miles, and the rate of climb would increase by 18 ft/min. So they wielded their cutlasses and began slashing the Skypirate. They saved 270 pounds by simplifying the fuel system; they lopped off 200 pounds by eliminating the internal bomb bay and using wing mounted pylons for ordnance; they shaved off 70 pounds by using a fuselage-mounted dive brake; they found 100 pounds more weight savings by ditching the nose wheel; they removed the dorsal turret, and eliminated two crewmen. Then they swapped the Wasp Major and its contra-rotating propeller for a Wright R-3350, saving about 1000 pounds. In all, Heinemann and his team found over 1800 pounds of weight that could be trimmed from the Skypirate. The result was the XTB2D-1, which would come to be known as the A-1 Skyraider, one of the greatest combat aircraft ever produced.

The Skyraider was a prop-driven anachronism in a jet age, affectionately given the nickname “Spad” by its pilots after the WWI French fighter plane. Starting with a Wright R-3350 radial engine, and later upgraded with more powerful engines, the Skyraider’s straight wing design gave it excellent low-speed maneuverability over the battlefield, and enabled the Spad to carry 8000 pounds of ordnance, equal to a B-17G Flying Fortress. Its piston engine gave it an enormous range and excellent loiter time over the target. The Skyraider was beloved by the troops on the ground for its ability to deliver munitions accurately against the enemy, and it saw combat with devastating effectiveness in both Korea and Vietnam. It wasn’t until the introduction of the LTV A-7 Corsair II, a subsonic jet, in the 1970s that the Spad was eventually phased out.

DISCUSSION (14)

Jake Huitt - Two Alfas And A Nissan, Not A Single Running Car > ttyymmnn
03/18/2015 at 10:55

Love that plane.

ttyymmnn > Jake Huitt - Two Alfas And A Nissan, Not A Single Running Car
03/18/2015 at 10:56

It's one of my all-time favorites. I go to lots of air shows, and jets are great, but there's nothing like sound of that Spad beating up the field.

Jake Huitt - Two Alfas And A Nissan, Not A Single Running Car > ttyymmnn
03/18/2015 at 11:00

Yeah. I wish I could get to more airshows. I just need to get flying again. Do you fly?

Jcarr > ttyymmnn
03/18/2015 at 11:01

...eliminated two crewmen.

Poor fellas. They knew too much.

Ever see Rescue Dawn? Great film featuring the Skyraider.

ttyymmnn > Jake Huitt - Two Alfas And A Nissan, Not A Single Running Car
03/18/2015 at 11:02

Nope. As much as I love aviation, I don't think I would want to be a pilot. I have enormous respect for those who do it well, but I'm not sure I'm cut out for it.

Jake Huitt - Two Alfas And A Nissan, Not A Single Running Car > ttyymmnn
03/18/2015 at 11:05

I started when I was 10.....

My dad got me a flying lesson for my birthday and then I got a "job" doing work around the neighborhood to pay for my flying since. You in the Denver area?

ttyymmnn > Jcarr
03/18/2015 at 11:05

Heinemann wasn't screwing around.

I have not seen the film. That CG was....not great. Looks like an intense story, though. Hard to imagine what it would have been like for the guys who actually experienced that.

ttyymmnn > Jake Huitt - Two Alfas And A Nissan, Not A Single Running Car
03/18/2015 at 11:06

You started when you were too young to know that it was difficult. Best time.

No, I'm in Austin.

RamblinRover Luxury-Yacht > ttyymmnn
03/18/2015 at 11:09

It's worth noting that the Able Dog bagged two MiG-17s during Vietnam - surprisingly, no -15s during Korea, though the Corsair and Tigercat both had claims. No, the only thing an AD shot down over Korea was a "night witch" in a Polikarpov biplane.

Jake Huitt - Two Alfas And A Nissan, Not A Single Running Car > ttyymmnn
03/18/2015 at 11:11

Yeah.

Darn. You really should look in to a discovery flight.

A friend of mine got his certificate here.

http://aboveaviation.com/learn-to-fly/

For $130, I'd go take a "discovery flight" and see what ya get. It really is easier than people think. In many ways, driving is harder.

I may have a bias as I'v been flying 5 years longer than I've been driving, but I think my point is still valid. :)

Snuze: Needs another Swede > ttyymmnn
03/18/2015 at 11:25

and enabled the Spad to carry 8000 pounds of ordnance, equal to a B-17G Flying Fortress

This always blows my mind... a B-17 is a massive aircraft and it only carried 8,000lbs of bombs, and a plane like this, designed a few years later, can do the same thing.

ttyymmnn > Snuze: Needs another Swede
03/18/2015 at 11:38

The B-17G could carry more, but that was for a stripped down, heavy load of bombs and was not normal operations. The 8000 pound number was for a short flight. For longer flights, it could only mange 4000 pounds. But yes, it's an amazing statistic. Remember, though, that the B-17 was big not just to carry a load of bombs but also to provide defensive armament. There were 10 men inside, and that was 1200 pounds right there. But as I was writing this, I mused on the idea of 1000 Skypirates/Skyraiders over Germany, protected by a gaggle of Mustangs and Thunderbolts. The amount of ordnance dropped would have been the same.

Snuze: Needs another Swede > ttyymmnn
03/18/2015 at 12:42

You're absolutely right about the B-17 carrying it's own defensive armament. There's a reason it's the "Flying Fortress." I'm sure also the enormous airframes could carry a lot of fuel. I recall that early on, at least before the P51, the bombers had to fly unescorted over their targets due to the fighters limited range.

1000 Skypirates/Skyraiders escorted by Mustangs and Thunderbolts would have been quite a sight to see though.

ttyymmnn > Snuze: Needs another Swede
03/18/2015 at 13:02

The RAF actually managed 1000 bombers over Germany in a nighttime raid over Cologne in 1942. It wasn't all big bombers though, as they had to scrounge planes from all commands and all types, even using students and instructors. Like most bombing raids over cities, the industrial bits were damaged, but so were tens of thousands of civilian homes. But I can only imagine the sound of 1000 planes droning overhead. It may not have been much of a strategic success, but psychologically, it was likely successful.