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The slowest SR-71 Blackbird fly-by

theaviationgeekclub.com

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Re: The slowest SR-71 Blackbird fly-by

#121

Post by warner25 »

fnord77 wrote: post #50

I find these stories hard to believe. An expensive top secret spy plane that is hard to fly, requires boatloads of fuel and maintenance allowed to make a detour for a joy ride flyby?

As a (recent) former military pilot, I think your intuition is generally correct for the modern era. Our planned routes and maneuvers and flight conditions were all annotated on a formal risk assessment which had to be briefed and approved by the appropriate command authority before we completed any other steps of the pre-flight routine. And crews did not deviate from that plan. Getting briefed and approved for something very different over the radio while in-flight, especially with sketchy weather conditions, probably would not happen. With that said, I've read several books about military aviation in the Vietnam era, and I compiled a long list of things that would "never happen" today. The difference shows up in the number of fatal mishaps over the years. The US Army lost more helicopters in Vietnam than it has today in its entire fleet.

Re: The slowest SR-71 Blackbird fly-by

#122

Post by aorth »

Excellent story and stunning pictures.

Side note: I randomly tried highlighting some text and right clicking on the website—I guess a lot of people do that while reading—and was annoyed at the "you're not allowed to view source" messages. I downloaded the entire site using wget and I'm going to do what I want with the pictures and content, thank you very much. For personal use of course. Jesus...

Re: The slowest SR-71 Blackbird fly-by

#123

Post by junon »

buryat wrote: post #36

SR-71 speed check One time we were going fast a small plane got on the radio and said "how fast am i going" the tower said "you are going fast" and then a bigger plane got on the radio and said "haha i think i am going faster how fast am i going" and the tower said "you are going a little faster" and then a jet fighter was going really fast and talked like a really cool guy and said "hey there, I sound like a cool gu…

GPT-3 is that you?

Re: The slowest SR-71 Blackbird fly-by

#124

Post by rocqua »

jacquesm wrote: post #119
odonnellryan wrote: post #88

Earlier quoted context omitted.

Boats are tough. I have to bring my sailboat under two draw bridges each winter. It is always a little too exciting, especially if you are unlucky enough to get stuck between the bridges which are really close together!

Fixed mast? Here in NL we have a type of mast that can be dropped under sail and re-set right after crossing under a bridge. This is a pretty exciting operation best practiced a large number of times without the presence of a bridge before you try it for real. Failures tend to be fairly spectacular. Here a demo on a very small boat, I've seen this done with a big Tjalk and that was most impressive (but I can't find a…

My uncle developed something similar for his boat but only the top. The idea was to have a 15-ish meter high mast fit under the Hollandse Brug (12.8 meter high bridge). He put a hinge in the mast and added a lot of stays to allow this to happen.

He is a maritime engineer, so he had it all calculated out to ensure it would hold up in rough weather. And knowing how racy he sails, I am pretty sure its been put to the test.

Re: The slowest SR-71 Blackbird fly-by

#125

Post by mnw21cam »

shostack wrote: post #114
mmaunder wrote: post #9

Stick and Rudder is the best read out there if you want an intuitive pilots understanding of what happened here. It unpacks angle of attack from a pilots perspective rather than using engineer speak. At that speed the control surfaces of the Blackbird would have had very little effect which is incredibly scary as you’re approaching a stall low and slow. They’d need big deflections to keep her straight and it would ha…

In the middle of this book now. So excellent. Is what you're referring to here called coffin corner? Or is that something else?

No, the coffin corner is something else, and it doesn't apply to the SR71 (or any aircraft capable of supersonic flight).

The coffin corner is where an aircraft is flying as slow as it possibly can, but that slow speed is also very close to its maximum mach speed. So the aircraft is both in severe danger of stalling and losing lift because the speed is too low, and in severe danger of getting supersonic airflow over the wings and losing lift because the speed is too high. This occurs at high altitudes where the air is thinner and the stall speed increases.

The problem with the coffin corner is that you need to maintain the exact air speed very accurately. If you let it increase or decrease by just a couple of knots, then one of the two failures happens, and you can pitch down, which will further increase your speed above supersonic, potentially making the pilot lose control or causing damage to the airframe.

See https://en.wikipedia.org/wiki/Coffin_corner_(aerodynamics)

Re: The slowest SR-71 Blackbird fly-by

#126

Post by usrusr »

ananonymoususer wrote: post #62
edge17 wrote: post #23

Earlier quoted context omitted.

SSFL?

Santa Susana Field Laboratory. It was picked up by Boeing when they acquired Rocketdyne and I had the pleasure(?) of visiting a few times. The building I visited was across the street from where the meltdown had occurred, but it had a separate history of some nuclear contamination. All of it had been allegedly cleaned up, except that we were all instructed to never use the running water for anything but flushing the…

https://en.m.wikipedia.org/wiki/Santa_Susana_Field_Laborator... reads like something straight out of 1970ies fatalistic scifi like Dark Star.

Re: The slowest SR-71 Blackbird fly-by

#127

Post by dan_hawkins »

mnw21cam wrote: post #125
shostack wrote: post #114

Earlier quoted context omitted.

In the middle of this book now. So excellent. Is what you're referring to here called coffin corner? Or is that something else?

No, the coffin corner is something else, and it doesn't apply to the SR71 (or any aircraft capable of supersonic flight). The coffin corner is where an aircraft is flying as slow as it possibly can, but that slow speed is also very close to its maximum mach speed. So the aircraft is both in severe danger of stalling and losing lift because the speed is too low, and in severe danger of getting supersonic airflow over…

Like Air France Flight 447?

Re: The slowest SR-71 Blackbird fly-by

#128

Post by _moof »

perl4ever wrote: post #113
Isamu wrote: post #112

Earlier quoted context omitted.

I find comments like this interesting - what is so implausible about this? It’s just a bit of radio chatter, nothing amazing happens, just a funny anecdote that a pilot tells when speaking to an audience. Maybe because it’s a polished story that he told over and over? Maybe one of the planes was an added embellishment to make the story longer? The last part is the most plausible- that they would do an unnecessary spe…

>what is so implausible about this That's an interesting question. I'm not a pilot, I haven't spent a lot of time listening to pilots talk, and I have no specific thing to point to that is definitively impossible. I have no reductionist explanation. There might indeed be a core that was embellished. If so, then I think it was overdone. Real things that happen can be unbelievable; I've had the experience of telling a…

I've spent many, many hours talking to ATC and other aircraft. I don't know if the original story is true, but it's more or less believable. First off: I absolutely, 100% believe that pilots would do this. These are precisely the kinds of shenanigans one gets up to in the air.

The detail that makes this story not quite work for me is that it has civilian and military aircraft on the same frequency. That's now how it works in real life. They will talk to the same facility, but civilian aircraft use VHF and military aircraft use UHF. Coming into a certain dual-use airport we would often hear the ATC side of a conversation (tower transmitting on all its freqs simultaneously, which is normal) but we'd never hear the F-15s, for example.

I suppose, though, that it's possible that the military aircraft in the story switched over to the VHF frequency after hearing the ATC side of a hilariously (to them) slow speed check. I know at least some military ships have VHF capability, having talked to a few myself. Whether it's typical for the particular aircraft in the story to have VHF radios though, I don't know.

Re: The slowest SR-71 Blackbird fly-by

#129

Post by _moof »

userbinator wrote: post #25
mmaunder wrote: post #9

Stick and Rudder is the best read out there if you want an intuitive pilots understanding of what happened here. It unpacks angle of attack from a pilots perspective rather than using engineer speak. At that speed the control surfaces of the Blackbird would have had very little effect which is incredibly scary as you’re approaching a stall low and slow. They’d need big deflections to keep her straight and it would ha…

A similar thing happens with boats --- the rudder only has an effect when water is moving past it, so it's more difficult to maneuver when moving slowly.

To complete the analogy, your boat would also have to sink.

Re: The slowest SR-71 Blackbird fly-by

#130

Post by aynyc »

NikolaeVarius wrote: post #92
aynyc wrote: post #75

Earlier quoted context omitted.

It's also on the Intrepid. The first time I saw it in person, my brain didn't understand how it could fly. It's massive. It looks like a space shuttle rather than a jet.

The aircraft on the Intrepid is not a SR-71 Blackbird, it is a A-12. They look similar, but are pretty different.

You are right! I never knew about the A-12. They both are amazing machines!
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