Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Blackbird SR-71 Flight Manual (2010)

sr-71.org

Post reply on HN
Print view View original

71–80 of 156 posts

Re: Blackbird SR-71 Flight Manual (2010)

#71

Post by kryogen1c »

wolfgang42 wrote: post #54
ColinWright wrote: post #4

A comment[0] by ehnus[1] from last time this was submitted[2] said: > My favorite section is emergency procedures which contains gems like this: > "If both the A and B hydraulic systems fail as indicated by illumination of the A HYD and B HYD warning lights and confirmed by loss of A and B hydraulic pressure and deteriorating control effectiveness: > 1. Eject" ======== [0] https://news.ycombinator.com/item?id=1338777…

In a similar vein, page 3-135[0] describes what to do when e.g. under missile fire ("the pilot is authorized to use the tactical limits listed...to exit the hostile area by the most expeditious means... Subsequent reentry into situations which rely on use of these limits is NOT authorized.") on the same page as the procedure for defogging the cockpit. [0] https://www.sr-71.org/blackbird/manual/3/3-135.php

Nuclear propulsion manuals for the U.S. navy have similar wordings.

>By order of the commanding officer [actually a highranking person on carriers, compared to little ships where COs can be realtively junior and low ranking], this reactor limit may be ignored during tactical situations.

Legend has it that every CO (3, i think i heard) to invoke "when tactical" exceptions have been fired in the following review. The only thing worse than crashing a billion dollar boat is damaging the publics trust in naval nuclear power : )

Re: Blackbird SR-71 Flight Manual (2010)

#72

Post by saganus »

rwmj wrote: post #68
starpilot wrote: post #19

Earlier quoted context omitted.

No, everything about the aircraft is obsolete which is why no other country has attempted to develop anything similar. The J58's are really dated, though most of the thrust is generated by the inlets when supersonic.

> most of the thrust is generated by the inlets when supersonic I've often heard this (also about the bypass in Concorde's engines), but I've never heard a clear explanation about how some element of an engine which doesn't involve burning fuel can generate thrust. Can anyone explain it?

If I remember correctly, in the book Skunkworks they explain that it would increase the air pressure. The analogy made was that it was similar to putting a finger on a garden hose to partially block it, thus increasing the water pressure.

Obviously there must be some complex physics going on but that was the gist of it.

Probably someone with more knowledge can confirm or correct me :)

Re: Blackbird SR-71 Flight Manual (2010)

#73

Post by dylan604 »

Hydraulix989 wrote: post #24
chrisseaton wrote: post #22

Earlier quoted context omitted.

What other options would you have in such an extreme situation? It seems to make sense to me.

Right, you have no control over the lift surfaces in this scenario. This would be the equivalent of your steering wheel suddenly not turning the wheels.

Except, even if my steering does go out, I can typically hit the brakes and come to a stop. Airplanes do not have that as on option.

Re: Blackbird SR-71 Flight Manual (2010)

#75

Post by EForEndeavour »

Archsys wrote: post #48
chrisseaton wrote: post #32

Earlier quoted context omitted.

It's an emergency checklist - of course it's terse. I don't know what people expect.

Laughter is provoked by a discontinuation of what your brain expects. If you saw a dog walking a man on all fours, you would most likely laugh, because of the unexpectedness. In this case, the unexpected terseness causes laughter. You don't expect what follows to just be "Eject". In a technical context like a manual, you expect what follows to be a detailed list of steps and instructions. When this expectation is sha…

Speaking of humour, I can't tell what I find funnier: the fact that someone didn't see how these checklist items could possibly be construed as humorous, or your clinically precise explanation of the concept of humour itself, complete with a mechanistic explanation and example. Together, they're a beautiful example of the tone of HN.

Re: Blackbird SR-71 Flight Manual (2010)

#76

Post by russb »

rwmj wrote: post #68
starpilot wrote: post #19

Earlier quoted context omitted.

No, everything about the aircraft is obsolete which is why no other country has attempted to develop anything similar. The J58's are really dated, though most of the thrust is generated by the inlets when supersonic.

> most of the thrust is generated by the inlets when supersonic I've often heard this (also about the bypass in Concorde's engines), but I've never heard a clear explanation about how some element of an engine which doesn't involve burning fuel can generate thrust. Can anyone explain it?

Here's a great answer on avation.stackexchange.com that answers that exact question:

https://aviation.stackexchange.com/a/27024

Re: Blackbird SR-71 Flight Manual (2010)

#77

Post by chrisseaton »

EForEndeavour wrote: post #75
Archsys wrote: post #48

Earlier quoted context omitted.

Laughter is provoked by a discontinuation of what your brain expects. If you saw a dog walking a man on all fours, you would most likely laugh, because of the unexpectedness. In this case, the unexpected terseness causes laughter. You don't expect what follows to just be "Eject". In a technical context like a manual, you expect what follows to be a detailed list of steps and instructions. When this expectation is sha…

Speaking of humour, I can't tell what I find funnier: the fact that someone didn't see how these checklist items could possibly be construed as humorous, or your clinically precise explanation of the concept of humour itself, complete with a mechanistic explanation and example. Together, they're a beautiful example of the tone of HN.

Everyone says they're funny because they're unexpected, but simple direction and plain language is exactly what I'd expect from an aviation checklist, so I have no idea.

Re: Blackbird SR-71 Flight Manual (2010)

#78

Post by linsomniac »

nominatronic wrote: post #46
adolph wrote: post #25

No Blackbird post is complete without a link to the Speed Check story: https://www.thesr71blackbird.com/Aircraft/Stories/speed-chec... It all had lasted for just moments, but in that short, memorable sprint across the southwest, the Navy had been flamed, all mortal airplanes on freq were forced to bow before the King of Speed, and more importantly, Walter and I had crossed the threshold of being a crew.

Executive summary: Cessna: How fast. Tower: 6 Beechcraft: How fast Tower: 8 Hornet: Yo how fast bro Tower: Eh, 30 Sled: mfw Sled: How fast sir Tower: Like 9000 Sled: More like 9001 amirite. Tower: ayyyyy Sled: ayyyyy

Yes, but the telling is well worth listening to, as are his longer speeches. Including this gem: Navy pilots: "What did YOU do today?" Sled pilots: "Nebraska in 4.5 minutes, which is the best way to do Nebraska."

Re: Blackbird SR-71 Flight Manual (2010)

#80

Post by ThenAsNow »

rwmj wrote: post #68
starpilot wrote: post #19

Earlier quoted context omitted.

No, everything about the aircraft is obsolete which is why no other country has attempted to develop anything similar. The J58's are really dated, though most of the thrust is generated by the inlets when supersonic.

> most of the thrust is generated by the inlets when supersonic I've often heard this (also about the bypass in Concorde's engines), but I've never heard a clear explanation about how some element of an engine which doesn't involve burning fuel can generate thrust. Can anyone explain it?

Since the SR-71 is a perennial HN favorite:

https://news.ycombinator.com/item?id=13567554

I think the StackExchange answer linked below covers interesting aspects of supersonic inlet behavior, but doesn't do a great job answering your specific question.

Post reply on HN