Geli SR-71 Blackbird - Page 5

**Rata** · #41 09-04-2018, 05:28 PM

Aviation engineering at it's very best. I remember reading years ago that at top speed control sensitivity was a thing so pumping the fuel load for or aft was used to change flight trim. Don't know how true but it makes good reading!

**Ckendzierski** · #42 09-04-2018, 05:42 PM

Is that not the plane that when filling it up you would walk under from one side of the wings and have taken a shower in jet fuel

And as soon as it got in the air they had to refuel

Was told every thing made a bit on loose side so when it got up their the pressure would seal everything off

**Rata** · #43 09-04-2018, 06:19 PM

Yep. Friction heat would expand everything and help seal up the tanks too. Only quoting from memory here (and will happily stand corrected): because of heat expansion the plane was about 10 inches longer at the end of a flight than when it took off. Would shrink back as it cooled. Plus the special tyres were filled with (I think) liquid nitrogen to resist the heat. Truly amazing plane especially when you consider when it was designed. Must have cost a fortune per hour to operate!

**Rubenandres77** · #44 09-04-2018, 06:21 PM

BigGiraffe:

This is looking really nice!

Surely your dedication to this model will show once it is finished. You're doing it great.

Quote:

Originally Posted by Rata

Aviation engineering at it's very best...!

In the times of paper, pen, and sliding rulers, the design was flawless.
There's a short article at: https://frontlinevideos.com/blogs/vi...r-minds-blown/
Since it provides no sources or references, it may well be a modern myth. Fake or not, what it says is still enchanting:

Quote:

What’s even more incredible is that in the 2000s this design was ran through a sophisticated computer program used to design planes. You’re talking about thousands of rivets, angles of the fuselage and about a million other factors that this computer checks for.

The end result? The computer wouldn’t do anything different. The design is as efficient as it could be. It was perfect.

In any case, beautiful and well-designed as it was, and despite fulfilling its purpose,
the SR-71 was the most dangerous plane ever built: 20 out of 50 of the Blackbirds
(counting all the variants) crashed or disintegrated on flight for different reasons
Never because of being hit by enemy fire.
And that's an unacceptable loss rate.
https://www.sr-71.org/blackbird/losses.php

Quote:

Originally Posted by Ckendzierski

Is that not the plane that when filling it up you would walk under from one side of the wings and have taken a shower in jet fuel And as soon as it got in the air they had to refuel
Was told every thing made a bit on loose side so when it got up their the pressure would seal everything off

More or less.
The gaps in the body were purposely made so that the metal dilation because of extreme heat at the high speeds it reached would seal it properly.
Also, because of that, the engine's oil was so thick it was solid at ambient temperature, and the engines had to be started with the help of an external cart.

Interesting plane

**MichaelS** · #45 09-05-2018, 03:26 PM

That's the great thing about this site. Great builds and history lessons thrown in for free!!

**BigGiraffe** · #46 09-09-2018, 04:44 PM

It is kind of fun learning about the airplane (or other models) as we go along.

This kit came with clear plastic film for the windshields. I used Aleene's "Jewel-It" bead glue, something I learned about when doing JSC's Queen Mary 2 ocean liner with its plastic sheet railings. First I glued the plastic into place on the window frame, then glued the frame assembly to the model. Alignment of the black parts was difficult for my tired old eyes.

The engines are next. The first section (for each side) was straight-forward, just a cylinder with cardboard bulkheads at each end. But the air intake isn't so obvious. There is an outer skin and inner skin, but it's not readily evident whether the seam for each "ring" should be lined up the other, or opposite the other. It looks like I'll have to assemble the air intake cone so I can dry-fit parts and figure it out.

I hope everyone has a good week,
Kurt

**Dlazarus6660** · #47 09-28-2018, 05:10 PM

OK boy's and girl's, time for me to chime in!

Check out this article on the SR-71 blackbird.

https://www.planeandpilotmag.com/art...6t9_lRdLM:eek:

**Mike1158** · #48 09-29-2018, 05:08 AM

Nice Blackbird, thank you very much for the story link. A story like this reaches the little boy deep inside.

**BigGiraffe** · #49 09-30-2018, 10:15 AM

Interesting story about the fly-by!

Continuing with the engines, the main section is assembled, and the nose spike. I decided not to attach the spike until the whole engine was finished, so I could set it on the front end while glue dried on parts at the rear.

**BigGiraffe** · #50 09-30-2018, 10:17 AM

The exhaust cylinder section on the very back of the engines consists of outer skin, inner skin, and three small cardboard rings. The rings are somewhat of a pain to cut out, but not bad with a sharp knife blade. First I did most of the inner cut, leaving some so that the center stayed in place so it would hold the round shape while I did the outer cut. That worked pretty well.

The engine was impressively long, once all the parts were attached to each other. I like the way they did the exhaust section, those air gaps actually open to the outside (as the last photo, looking inside the exhaust, tries to show).

Take care,
Kurt