I must agree, they have a D-21, but also an A-12, an SR-71, and the only surviving XB-70 Valkyrie, not to mention all the other stuff from early Wright built planes to an F-22 and YF-23.
Some advice though: Leave the wife and kids at home because they won't be nearly as fascinated as you are and want to read every single placard about the history etc. of every plane there. I'd probably still be there if they hadn't drug me out and it was 2 years ago when we went 😁
I've seen both in person at the US Air Force Museum in Dayton OH. Pretty incredible. Stored in the same hanger as the XB-70 Valkyrie which is just INSANELY massive.
Makes you wonder how it would perform on modern tech, and how much smaller they could make it. Probably could run the same computations on an Arduino, and faster, too.
@@musewolfman i guess there isn't much of a use case now when we have high resolution satellite imaging. Though virtually the same tech must be developed for the guidance on ICBMs
@@graham1034 I guess today similar ones are prepared to deliver an actual strike at hypersonic speeds, with up-to-date electronics and a big ass warhead.
@@graham1034Well the SR-72 and hypersonic jet aircraft are becoming a closer possibility everyday simply because satellite paths are well know and already can be taken down with interception programs even if they increase space junk. Returning back to the modus operandi of the SR-71 and other spy planes, fast, unpredictable and hard to detect is likely to be the future.
The museum of flight in Seattle has the only m21, with a d21 on top of it. In the Chinese Aviation Museum, they have the wreckage of the D21 which crashed in China. I might have a picture of myself standing next to it. I recommend both museums. The China Aviation Museum has lots of things you won’t see elsewhere. It’s in a retired Cold War Chinese Air Force base, so lots of the exhibits are in the tunnel under the hill. Just be prepared for Korean War MIGs with rows of stars representing combat kills.
Hello. I live in Washington state. The city I live in is - Federal Way ; which is a little south of Seattle. I have had the great fortune to have had a membership to the Boeing Museum Of Flight for several years. Seeing that M-21 / D-21 is always inspiring. I always consider myself lucky to be able to go to the Boeing MoF when I can get the time for it :).
I remember when the D-21 was brought into the public knowledge. The government didn’t release the photos,they were taken by an IPMS member (International Plastic Modelers Society)who was taking a tour of the Boneyard at Davis Monthan AFB when he saw a strange aircraft whose tarpolin cover had come loose and blown off. He shared the pictures with his fellow IPMS members and with a modeling magazine. The cat was out of the bag at that point. The rest is history.
I'm an IPMS member, and have heard that story, but I do believe it's legend. At least the part about the pics first being released in the IPMS journal before anywhere else. I do believe the photographer just happened to be an IPMS member.
They sent a Destroyer to recover a fragile film cannister and were surprised when the cannister was destroyed. Well, what did they expect would happen? It's right in the name, destroyer. It's obviously going to destroy anything around it. Destroy destroy destroy. You ever hear a word so many times that it stops making sense all together? Yeah, me neither. I wonder if you can restroy something or unstroy? What the hell is this jibberish! My mind is broken now, Tom!
yeah but this time of history always amazes me. how the americans came up with ways to spy on the soviets, first with ultra light high flying planes, then with ultra fast planes. sending sattelites into the orbit, and recovering their data through dropping it out of space and catching it in the air with planes. souds so awesome
Love the subject diversity and quality of your channels, Simon. Thanks to you and your team for great viewing information and pleasure. Happy New Year!
here in the UK we use a mash of absolutely all kinds of measurements from imperial and metric, we use pounds and kilos, cm and inches and so on but speed, distances and altitude are ALWAYS miles and feet and temperature is always Celsius
Steve we don’t use Celsius, it’s usually called Centigrade in the UK. Besides that’s a fairly recent change in itself and most people over 55 still use Fahrenheit. Go watch a TV weather forecast from the 1980s...
@@neilturner6749 we do use Celsius, we also use the name centigrade like you suggested, they are the same thing and centigrade is just the old name for Celsius. Your right about a large number of older people using Fahrenheit. My 70 year dad does but my mum who's in her 60's works in Celsius / centigrade .
Your channels totally seem like mass produced WatchMojo clickbaity stuff, but you really know your stuff. These videos are incredibly entertaining and the facts are almost always spot on. Definitely getting some merch to support your endeavors.
The PIMA AIR & SPACE MUSEUM has a LOCKHEED D-21B along with their LOCKHEED SR-71A BLACKBIRD. I was a member there when I lived in Arizona. Remarkable museum. Literally across the street from Davis-Monthan AFB in Tucson, Az (also the location of "The Bone Yard"). The Titan Missile Museum in Green Valley Arizona, about a half hour drive south of Tucson is also a very worthwhile museum to visit. There were many Titan Silos there once. This is the only one that still exists, as a museum. The missile that is in the silo came from Sheppard AFB as a training missile. I was stationed at Sheppard in 1972. It has been used in several movies and has a large square cut-out of the warhead so that the "Soviets" could see it in the silo from space to verify U.S. compliance with a treaty. There's nothing else like it. Thanks for posting this excellent and educational video.
Wonderful video. The Surviving M-21 / D-21 set is on display at the Boeing Museum Of Flight right out side of Downtown Seattle. The original Boeing headquarters is also a part of the MoF - the Red Barn. I have been to the Boeing MoF more times then I can remember ; seeing the M-21 / D-21 pair is always awe inspiring. Also there is a recovered cockpit from a SR-71 that crashed - you can sit in that cockpit.
Another excellent video, thanks Simon. If you're keen to do another video on an amazing aircraft, have a look at the Miles M.52. If you haven't heard about it, it was a late WW2 British secret project to build the first supersonic manned aircraft. It differed from the Bell X-1 in that it was powered by a Whittle jet engine with a huge afterburner system that was the precursor to the SR-71's bypass afterburner system, and it would have taken-off from the ground under its own power as well. Eric Brown was earmarked to fly it as he was a short chap and could fit into the small cockpit. In 1946 with the change of government, the project was cancelled with no official reason given.
Nice. I've wondered about this as the static display SR-71 at March AFB's museum which I visited about 5 years ago, had one of these exhibited with it without much to say about it.
Business Blaze Mega Projects Side Projects Top Tenz Today I Found Out Biographics Geographics Highlight History Xplrd Visual Politik EN The Simon Whistler Show I may have missed one. Visual Politk EN is now hosted by someone else. The Simon Whistler Show hasn't had updated content for a while. His new podcast not included.
How about a video on the Douglas DC-3? The plane helped win a war, kickstarted an entire industry, is one of the most beautiful ever designed and is the only aircraft ever to have no expiration date.
The one pictured at 6:42 is at the Boeing Air and Space Museum in Seattle. They also have an SR-71 cockpit section that you can sit in and a start cart (2 Buick Wildcat V8 engines) used to start the engines.
If you ever played Metal Gear Solid 3: Snake Eater you've recognize this. It's how Naked Snake infiltrated Russia. PS: it's also the inspiration for a GI JOE Cobra vehicle called the Night Raven.👍😉
@Old school Pete ...Running back and forth...? Which "others" are you talking about here? The only one that has 'running back and forth' is MGS2, unless you count MGS5...
Recently saw one of these at the Castle Air Museum. It was at the restoration hanger where they're restoring an F-117. I kinda knew it was a drone of some sort when I first saw it since it had the same shapes and color as the blackbird (they have one btw). Never knew they existed till that day.
Not that you'd need any help researching, but the book Skunk Works by Ben Rich (former director of said organisation) is a really good read and incredibly interesting if you haven't already read it. And thanks for another great video!
Growing up in the 80s its interesting how many SR-71 toys had this drone affixed to them. Matter of fact, im not sure i ever saw a die cast toy or model of the Blackbird that DIDN'T have the drone attached back then
My grandfather worked in the Skunk works program for quite sometime in a joint project with Pratt & Whitney & others. Only thing he ever talked about was his involvement with the F-14 Afterburner project to launch from carriers. He was involved in much more from what my dad has said and hope that one day he will tell me.
We have a D-21 Drone at the "Southern Museum of Flight" in Birmingham, Alabama....along with an A-12 Blackbird (Oxcart), the Faster, Yes FASTER, single seat model !
My dad was a Skunk Works employee 1964 - 1980. I know he was on the A-12 / SR-71 contract, and a couple of follow - on / support deals afterwards. Wonder if he did any of the machine or fab work on the D-21.
Simon, I've stood next to that drone at the US Air Force Museum. If you are ever in the greater Dayton Ohio area, they have an awesome museum!
Was there last winter, it is indeed impressive.
I must agree, they have a D-21, but also an A-12, an SR-71, and the only surviving XB-70 Valkyrie, not to mention all the other stuff from early Wright built planes to an F-22 and YF-23.
Some advice though: Leave the wife and kids at home because they won't be nearly as fascinated as you are and want to read every single placard about the history etc. of every plane there. I'd probably still be there if they hadn't drug me out and it was 2 years ago when we went 😁
Same. That XB-70 they parked it UNDER is MASSIVE.
@@jamesburleson1916 Holy hell, that one crazy collection of birds!
Well, I guess it's their stuff and their museum so I get it makes sense...
Simon: "I have a new TH-cam channel..."
Me (checks watch): "Is it Thursday already...?"
Simon: "I have a new TH-cam channel..."
Me (checks channel): "It already has 100K+ subs...?"
I wish he would start my channel
Simon needs a day drinking show . I personally would watch that .
Public drinking while going through a Wikipedia chain of links, maybe he eventually get to Kevin Bacon
Mate it's Tuesday
"Due to a damaged nut"
Always check your nuts, gentlemen.
When he said that, in my head I told myself "I'm a damaged nut."
I've seen both in person at the US Air Force Museum in Dayton OH. Pretty incredible. Stored in the same hanger as the XB-70 Valkyrie which is just INSANELY massive.
Simon's channels can be a megaproject.
Naw, he has help with them so its a micro project
Do a mega projects on Simon's house! 😎
I second this.
No, better do Megaprojects : Simon channels
@@rakaadizaputra9650 even better!
I see what you did there...
@@rakaadizaputra9650 to do this he'd need to make a new channel called Gigaprojects
Simon with his 1 million sideprojects.
and side channels
It's all about the side hustle. 🤑
He needs a channel about his channels.
Simon, Babbish, and Sean Evans gettin me through the pandemic. Thank you, gentlemen.
:) yw
Turns out that making a drone with 60s computer tech is hard.
Makes you wonder how it would perform on modern tech, and how much smaller they could make it. Probably could run the same computations on an Arduino, and faster, too.
@@musewolfman i guess there isn't much of a use case now when we have high resolution satellite imaging. Though virtually the same tech must be developed for the guidance on ICBMs
Same computers that got us to the moon....
@@graham1034 I guess today similar ones are prepared to deliver an actual strike at hypersonic speeds, with up-to-date electronics and a big ass warhead.
@@graham1034Well the SR-72 and hypersonic jet aircraft are becoming a closer possibility everyday simply because satellite paths are well know and already can be taken down with interception programs even if they increase space junk. Returning back to the modus operandi of the SR-71 and other spy planes, fast, unpredictable and hard to detect is likely to be the future.
The museum of flight in Seattle has the only m21, with a d21 on top of it. In the Chinese Aviation Museum, they have the wreckage of the D21 which crashed in China. I might have a picture of myself standing next to it. I recommend both museums. The China Aviation Museum has lots of things you won’t see elsewhere. It’s in a retired Cold War Chinese Air Force base, so lots of the exhibits are in the tunnel under the hill. Just be prepared for Korean War MIGs with rows of stars representing combat kills.
Hello. I live in Washington state. The city I live in is - Federal Way ; which is a little south of Seattle. I have had the great fortune to have had a membership to the Boeing Museum Of Flight for several years. Seeing that M-21 / D-21 is always inspiring. I always consider myself lucky to be able to go to the Boeing MoF when I can get the time for it :).
I remember when the D-21 was brought into the public knowledge. The government didn’t release the photos,they were taken by an IPMS member (International Plastic Modelers Society)who was taking a tour of the Boneyard at Davis Monthan AFB when he saw a strange aircraft whose tarpolin cover had come loose and blown off. He shared the pictures with his fellow IPMS members and with a modeling magazine. The cat was out of the bag at that point. The rest is history.
That's probably how I ended up with a model of this back in the day. It was part of an SR-71 kit.
Wow great history!! I also bought that revell model , D-21 was so cool
@@jimcappa6815 if my memory serves me wright that was an Italeri kit from the 90’s. The SR-71 and A-12 were both released back in those days.
I didn’t know that! Thanks for that little nugget of history.
I'm an IPMS member, and have heard that story, but I do believe it's legend. At least the part about the pics first being released in the IPMS journal before anywhere else. I do believe the photographer just happened to be an IPMS member.
Everytime Simon promotes "Sideprojects" I genuinly think first he started yet another one
its insane to me how he managed a few channels at once, yet he still uploads everyday here
@@nitsu2947 Simon basically reads the script, nothing more. That's how it works.
@@Cps1402 Someone have to write it.
He did; XPLRD. I actually thought that was the one he was going to mention.
They sent a Destroyer to recover a fragile film cannister and were surprised when the cannister was destroyed. Well, what did they expect would happen? It's right in the name, destroyer. It's obviously going to destroy anything around it.
Destroy destroy destroy. You ever hear a word so many times that it stops making sense all together? Yeah, me neither. I wonder if you can restroy something or unstroy? What the hell is this jibberish! My mind is broken now, Tom!
...you mean "restore" ?
yeah but this time of history always amazes me. how the americans came up with ways to spy on the soviets, first with ultra light high flying planes, then with ultra fast planes. sending sattelites into the orbit, and recovering their data through dropping it out of space and catching it in the air with planes. souds so awesome
That one went on top of my G.I. JOE SR-71! A classic!
Remember when they stashed Naked Snake into one of these in Metal Gear Solid 3? Good times.
The Boii with the Blaze was strong in this one. Almost sounded like you started to say Perchthemech
Simon: ...disappeared just as quickly as it appeared...
Me: it broke a Blackbird
Technically an Archangel, but... yeah.
How about a megaprojects about the German baureihe 52, the kriegslok or War locomotive
Now this is a megaproject.
When the Soviet’s find a crashed D-21 with photos of china’s nuclear test site
“It’s free reconnaissance”
Love the subject diversity and quality of your channels, Simon. Thanks to you and your team for great viewing information and pleasure. Happy New Year!
I remember the GI Joe toy it was a Cobra plane called the Night Raven and it basically was a SR-71 that had a drone piggyback.
TH-cam: "How many channels do you have?"
Simon: "Yes"
Simon: All of them
Thanks for another great project, Simon!
here in the UK we use a mash of absolutely all kinds of measurements from imperial and metric, we use pounds and kilos, cm and inches and so on but speed, distances and altitude are ALWAYS miles and feet and temperature is always Celsius
Don't forget stones. How many pounds are in stone again?
Oof ouch.
@@eoinkenny3188 lol yeah, we weigh ourselves in stones don't we, there's 14lbs BTW :)
Steve we don’t use Celsius, it’s usually called Centigrade in the UK. Besides that’s a fairly recent change in itself and most people over 55 still use Fahrenheit. Go watch a TV weather forecast from the 1980s...
@@neilturner6749 we do use Celsius, we also use the name centigrade like you suggested, they are the same thing and centigrade is just the old name for Celsius. Your right about a large number of older people using Fahrenheit. My 70 year dad does but my mum who's in her 60's works in Celsius / centigrade .
Thank you for this D-21 Drone Video!
Once again thank you for your mega projects channel, and thank you for doing such a good job with it, not many channels impress me at all !!!
Derpface D-21 is something I didn't know I needed
We all know Simon almost said "Purch the merch" at 0:31. Don't worry, Simon, we are all Business Blaze fans.
Legends
@@megaprojects9649 allegendly
I once spoke with an older man, who worked on this drone.
It was in the Tucson Pima Air & Space Museum
Really amazing!
Simon thanks for another super video bud.
Great as usual. Thanks
Imagine living in the Soviet Union or China and having one of those crash in your backyard. I’d prolly think it was a UFO at first
Or that the expected US attack had finally arrived.
~ laughs ~
Love the content of these videos.
Do a Megaprojects video on the massive amount of effort that goes into the work and life of Simon Whistler.
Unfathomable
New channel: MegaBiographic Projects - larger than life stories about real people doing ludicrously impossible things
Probably a 5 story mansion in prague
He did vlogs on his own channel every day for a year several years ago, but he seems to have deleted them all. Yeah... he's a super workaholic.
Best presentation of 2021 ... yet! ;-)
13:30 omfg i just cant.
Your channels totally seem like mass produced WatchMojo clickbaity stuff, but you really know your stuff. These videos are incredibly entertaining and the facts are almost always spot on. Definitely getting some merch to support your endeavors.
I've been waiting for this one!!
But also, you should do the Seawolf submarine class. Lots and lots of interesting unclassified history!
Simon: skunks works. I haven’t read it but it’s coming up. Super cool 😂😂😂
The PIMA AIR & SPACE MUSEUM has a LOCKHEED D-21B along with their LOCKHEED SR-71A BLACKBIRD. I was a member there when I lived in Arizona. Remarkable museum. Literally across the street from Davis-Monthan AFB in Tucson, Az (also the location of "The Bone Yard"). The Titan Missile Museum in Green Valley Arizona, about a half hour drive south of Tucson is also a very worthwhile museum to visit. There were many Titan Silos there once. This is the only one that still exists, as a museum. The missile that is in the silo came from Sheppard AFB as a training missile. I was stationed at Sheppard in 1972. It has been used in several movies and has a large square cut-out of the warhead so that the "Soviets" could see it in the silo from space to verify U.S. compliance with a treaty. There's nothing else like it. Thanks for posting this excellent and educational video.
I want to see Simon's mansion he paid for with all these TH-cam videos
On his private island, with parking for his yacht and helicopter.
@@tncorgi92 And inside an extinct volcano.
There's a reason he lives in Eastern Europe.
Its a singlewide trailer out in the middle of bumfuck, so the screams of Danny and the others can seldom be heard.
He lives in London right? Maybe he's got two rooms instead of the normal one.
Wonderful video. The Surviving M-21 / D-21 set is on display at the Boeing Museum Of Flight right out side of Downtown Seattle. The original Boeing headquarters is also a part of the MoF - the Red Barn. I have been to the Boeing MoF more times then I can remember ; seeing the M-21 / D-21 pair is always awe inspiring. Also there is a recovered cockpit from a SR-71 that crashed - you can sit in that cockpit.
Always a good video.
As always great job and looking forward to SkunkWorks video!
The Black Bird had many versions, including a prototype super high altitude bomber capable of carrying even the largest nuclear weapons.
Keep 'em comin' 🤜🤛
It didn’t slam into him Simon,it exploded close to his plane!cmon Simon jeez 😂
You should do a video on SLAM aka "the flying crowbar" the most terrifying weapon, thankfully, never built
Holy shit, that thing's intimidating! Thanks for mentioning it.
For what was probably the most horrible weapon ever conceived, the SLAM development program actually laid the ground work for MRI medical imaging.
@@rickc2102 an out of control/accidentally launched one could be a terrifying basis for a movie, or a really entertaining popcorn movie
Project Pluto. God of the Underworld dropping Hell bombs, spewing a Hell exhaust plume, and blasting a hypersonic shockwave Hell at treetop level.
@@texasbeast239 I think it's the ultimate weapon of mutually assured destruction; so terrifying it was never built.
Never knew about this drone and looking forward to the skunk works!
Another excellent video, thanks Simon.
If you're keen to do another video on an amazing aircraft, have a look at the Miles M.52. If you haven't heard about it, it was a late WW2 British secret project to build the first supersonic manned aircraft. It differed from the Bell X-1 in that it was powered by a Whittle jet engine with a huge afterburner system that was the precursor to the SR-71's bypass afterburner system, and it would have taken-off from the ground under its own power as well. Eric Brown was earmarked to fly it as he was a short chap and could fit into the small cockpit. In 1946 with the change of government, the project was cancelled with no official reason given.
The Museum of Flight in Seattle has one, mated with a M-21 "mother ship". I was fortunate to be able to see this last March.
I saw that last month!! Was amazing to see
Brilliant as ever Simon, thank you. A video on the US Air Force 'Quail' decoy drone might be interesting for either of your 'project' channels.
Nice. I've wondered about this as the static display SR-71 at March AFB's museum which I visited about 5 years ago, had one of these exhibited with it without much to say about it.
One of ma favourite drones 👍🏽
Love the content and other channels
Business Blaze
Mega Projects
Side Projects
Top Tenz
Today I Found Out
Biographics
Geographics
Highlight History
Xplrd
Visual Politik EN
The Simon Whistler Show
I may have missed one.
Visual Politk EN is now hosted by someone else. The Simon Whistler Show hasn't had updated content for a while. His new podcast not included.
Thank you
Exceptional! 👍😀👍
some craft i dint had any knowleage about, thats good, i dont need to know more , thank you.
How about a video on the Douglas DC-3? The plane helped win a war, kickstarted an entire industry, is one of the most beautiful ever designed and is the only aircraft ever to have no expiration date.
Love that design. Will live on in the SR-72.
This isa megaproject.
Excellent
Knowledge before work, well played.
Bro are there enough hours in the day for all your channels? You have to be the busiest dude on TH-cam. Respect!
The one pictured at 6:42 is at the Boeing Air and Space Museum in Seattle. They also have an SR-71 cockpit section that you can sit in and a start cart (2 Buick Wildcat V8 engines) used to start the engines.
well done
I love the dichotomy between No Fudging Around Simon on Megaprojects and WTFBBQ Simon on Business Blaze
megaproject for spacex's starship, a truly incredible feat of engineering
Never heard of this one. It's crazy to think that they attempted such a high speed drone so many decades ago.
Can you please update you playlist with all your videos. I love to put it on and listen to it through out the day.
If you ever played Metal Gear Solid 3: Snake Eater you've recognize this. It's how Naked Snake infiltrated Russia.
PS: it's also the inspiration for a GI JOE Cobra vehicle called the Night Raven.👍😉
When I saw it, I knew I recognized it from somewhere...
@Old school Pete ...Running back and forth...? Which "others" are you talking about here? The only one that has 'running back and forth' is MGS2, unless you count MGS5...
Recently saw one of these at the Castle Air Museum. It was at the restoration hanger where they're restoring an F-117. I kinda knew it was a drone of some sort when I first saw it since it had the same shapes and color as the blackbird (they have one btw). Never knew they existed till that day.
Awesome machine👍
Cool saw one at Blackbird park out by the Skunkworks few years back
Almost plugged the Business Blaze merch store at the beginning there. I like it.
Luv u Simon
Good video 👍
Didn't even know this variant existed, cool!
I swear i been watching this man since 2018 in 100 different TH-cam accounts
I love that Simon brings out the nerd in me
Fun fact, there is one housed in the Mcminville Aircraft Museum... when it was open in Oregon. The thing is HUGE.
Love all your content, just how many channels do u have?
Not that you'd need any help researching, but the book Skunk Works by Ben Rich (former director of said organisation) is a really good read and incredibly interesting if you haven't already read it.
And thanks for another great video!
The funny face on the D-21 cracked me up. Very funny.
So glad you did this and that you are going to be doing skunk works...
The D-21 has a menacing look that wouldn't be out of place in a sci-fi film.
12:01 imagine being the captain of the ship who just sailed over and destroyed the camera.
A megaproject video on the NHS
Growing up in the 80s its interesting how many SR-71 toys had this drone affixed to them. Matter of fact, im not sure i ever saw a die cast toy or model of the Blackbird that DIDN'T have the drone attached back then
D-21. Coolest looking thing EVER!
The craziest jet they made at skunkworks is the SR-71 because it's late 50s tech. 50s tech 🤯
Please do one on the Newport News ship building
OH MAN that would be nice. I got one better. the Virginia colony
That’s would be really cool too
I believe there is one at the Air Park in Palmdale CA (on Ave. P). There is also an SR 71 along many other aircraft.
I'd like an in-depth video of the inspiration for R2-D2! The astro-computer which kind of worked as an auto pilot for the SR-71!
My grandfather worked in the Skunk works program for quite sometime in a joint project with Pratt & Whitney & others. Only thing he ever talked about was his involvement with the F-14 Afterburner project to launch from carriers. He was involved in much more from what my dad has said and hope that one day he will tell me.
F-14, one of my favourite aircraft and pride of the Iranian Air Force.🇮🇷
He gets so happy doesn’t he, bless him😂
Awesome engineering concept. Seems it was more of a test program than actual operational hardware.
There is one at the BlackBird Park out at the Palmdale CA site near the SkunkWorks...
We have a D-21 Drone at the "Southern Museum of Flight" in Birmingham, Alabama....along with an A-12 Blackbird (Oxcart), the Faster, Yes FASTER, single seat model !
My dad was a Skunk Works employee 1964 - 1980. I know he was on the A-12 / SR-71 contract, and a couple of follow - on / support deals afterwards. Wonder if he did any of the machine or fab work on the D-21.