Forum: Drones

Everyone remember the old D-21 drone that was carried on the back of the M-21 Blackbird variant? I have a book written by Bill Sweetman called "Aurora: The Pentagon's Secret Hypersonic Spyplane" and in it he makes a rather remarkable claim about the D-21's range:

Quote:

High speeds have tended to be associated with short range, but-as was seen with the small, 15,000 mile range D-21 drone-this is not necessarily true.

15,000 miles? Is that really possible? He goes on to describe how this range was obtainable:

Quote:

One reason for the D-21's great range is that it was a "point design," with a very narrow flight envelope. It did not need to fly below Mach 3, so its simple, fixed inlet and exhaust were designed to operate efficiently in its design flight regime. The inlet cone, for example, was gradually flared so that the air moving over it generated a series of relatively weak shocks at the D-21's cruising speed. The D-21 did not need fuel to climb to its cruising height, it had no landing gear or recovery gear, and it needed to be strong enough for only one flight, so its structure was very light.

It must have been remarkably efficient, as its small size would have precluded it from carrying much fuel. To think that this little, 42 foot-long drone had longer legs than a B-52 seems incredible to me.

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I would be very surprised to see something like the d-21 have a range of 15,000 miles. from what ive seen in person those drones just dont look like they can hold nearly enough fuel for a 1,000 mile trip let alone 15,000 miles.

It's greater than 3400 miles. How much greater than, is still subject to speculation. Habu and Parrothead should see this one and respond.

TC , really? Thats impressive. hmmm, 15,000 still seems a bit unreal though, but I could be wrong----> again.

According to one of my favorite books "Lockheed's Skunk Works, The Official History" (Updated Edition) by Jay Miller....

Here are "the official" D-21B stats

Construction: Titanium (Beta-120/Ti-13V-11Cr-3A1) monococque w/some super-high-temperature plastics
Length: 42 feet 10 inches
Wingspan: 19 feet 1/4 inch
Wing Area: (none given)
Height: 7 feet 1/4 inch
Empty Weight: (none given)
Max Gross Takeoff Weight: 11,000 pounds
Maximum Speed: Mach 3.35/Mach 3.25 cruise at 80,000 to 95,000 feet
Operational Ceiling: 95,000 feet
Maximum Unrefueled Range: 3,000 miles
Fixed Armament: none
Powerplant Data: Marquardt RJ-43-MA-11 ramjet rated @ 1,500 pounds thrust

I agree with the others; the D-21 wasn't large enough for that much range.

Interesting fact: The M-21 Blackbird could use the D-21's engine as extra thrust to accelerate into a target area. Prior to launch the D-21's tanks were topped off with JP7 transferred into it by the M-21. Shame the whole M-21/D-21 system didn't work as Kelly Johnson had hoped.

...and yes it is the M-21 according to Lockheed. (not M-12 as many internet sources show) The M-21 was the "Mother" and the D-21 was the "Daughter" The common misconception is the M-12 followed the A-12 and YF-12 designations. (Then again the SR-71 was originally the RS-71)

Marquardt RJ43-MA-7 was an awesome engine. In the Bomarc CIM-10B missile it made 12,000lbs of thrust at a had a thrust/weight ratio of about 40! Twisted Evil

Now that's how to deliver a 10 kT surprise 440 miles @ over Mach 2!

Keep 'em flyin' Thumb

TEG

I'm going to have to stick with TEG on this one. Of course, I'll do my best to confirm this in October when the next reunion rolls around Smile

Anybody read Ben Rich's "Skunk Works" and remember him mentioning a Russian guy giving him a piece of a D-21 they recovered? When I get home I'll post an article written by one of the Russians that got to do the study of the recovered D-21. Very interesting reading.

Here it is:

http://www.xmission.com/~sferrin/voron.pdf

sferrin, very interesting read! I had known about the soviet capture of a crashed D-21 but I did not know they were trying to develop it as well. Funny though is that they basically were making carbon copies of the d-21.....I swear russian aviation is just a tad bit boring...nothing original.

Whos! Sorry for the delay guys! I didn't see that this was new, my forum listing showed it ghosted out.
Anyway....15,000 eh? Theoretical. The sheer size of it couldn't hold enough fuel for that kind of range, it's not a Global Hawk. This of course was never actually done...that we know of. None of the flights were ever successful enough to test out the absolute range. It's part of the mystique that still surrounds the Black Jets. Much like what the 'real' top speed of the Blackbird was. Well, we may never know, it was CIT that maxed it out, not aerodynamics.

And yes, the mothership was in fact the M-21....but many have said that it was a modified A-12. This isn't the case, the two airframes were taken right from the A-12 production line, and made into M-21s right out of the factory. They were in fact purpose-built.

I hate to bring back such an old thread, but does anyone know where I can find "The Voron Project" article posted above? I’ve tried searching the net but can’t find mention of it anywhere.

Any help would be greatly appreciated Smile

Forum: Drones

D-21 Range