Talk:Lockheed SR-71 Blackbird

Max. Range Speed, Subsonic cruise performance

Does anyone know which speed or mach number results in the maximum range? Is the range in subsonic cruise greater or smaller than supersonic? --Hbquax (talk) 02:08, 10 March 2013 (UTC)

There are numerous sources for Mach 3.2 as "the most efficient speed", so I'd guess subsonic performance would be inferior (without being any expert). The necessarily high angle of attack at low speed probably is a killer. Zac67 (talk) 12:30, 10 March 2013 (UTC)

Could you give me one reliable source? I don't want to guess, I want to know ;-) --Hbquax (talk) 12:56, 16 March 2013 (UTC)

• Start by looking at the Bibliography section of this article, e.g. Ben Rich's book and others. -Fnlayson (talk) 14:19, 16 March 2013 (UTC)

• At least two former SR-71 pilots have provided information during interviews that have pointed to the SR-71's top speed and altitude. Brian Shul gave a speech, during which he showed the audience photographs taken from 88,000 feet. Former pilot Richard Graham told an interviewer at the Frontiers of Flight Museum that he had taken the SR-71 to Mach 3.2 and a test pilot had taken it to Mach 3.4. The Air Force got very nervous about the airplane flying faster than that, due to problems with engine inlet temperatures and the danger that the airplane would come apart at the expansion joint at the border of the aft body if its angle of attack changed too quickly, causing a rapid pitch-up movement. It stands to reason that the Blackbird could sustain Mach 3.4 at 90,000 feet (and you could speculate perhaps as much as Mach 3.5); that is good enough so that if you took a Blackbird today (2013), updated its radar absorbent paint, you could fly it right over Moscow or Beijing or Pyongyang with impunity.

BTW, I thought I read that the SR-71, on its 1990 cross country flight, reached 2,242 mph between two of the radar gates in one of the news stories covering it. That's just about Mach 3.4 Raryel (talk) 04:32, 12 November 2013 (UTC)

Losses

The high rate of loss isn't addressed. Taking the statement that none were ever downed due to enemy action at face value, must presume they were mechanical failures due to stretching technology limits but maintenance issues are also suggested by their being bunched together. Glaring that there's no discussion of this. 76.180.168.166 (talk) 19:14, 1 September 2013 (UTC)

Loss Rate Comments

There were multiple causes of the SR-71's lost, and there are excellent HABU web sites that list the reasons for every one. Some were pitch up problems after refueling, some were system failures such as electrical generator failures ( example, the first B model crash ), and the last SR-71 loss tail number 974 ( a great aircraft that came back from Kadena Air Base with "Ichibon' and a big red number ! over a HABU ) had an inflight catastrophic system failure over the ocean near the Philippines; both crew members ejected and bailed out successfully. Hope you read the story on each loss; it's there in the internet.

David Dempster, SR-71 RSO 09:07, 22 January 2014 (UTC) — Preceding unsigned comment added by David Dempster (talk • contribs)

remove reference to thesis on Mach 6 inlets

Ref Col Graham in his book "SR-71 Revealed" the maximium temperature observed by the pilots with regard to limiting the flight speed was the compressor inlet temperature of 427degC because the engine was not certified beyond that temperature. The current wording in the article tends to suggest the intake itself was the cause of the limit with the thesis reference added for insight into how to increase it. I don't see any relevance to including this particular aspect of the aircraft's design as the whole airframe and all the systems would be redesigned for flight beyond the SR-71 design speed of Mach 3.2. This design speed is also quoted in Col Graham's book. I will reword the temperature limit statement.Pieter1963 (talk) 22:41, 20 May 2014 (UTC)

Fnlayson, you shouldn't have to correct sloppy work. Sorry about that. Why is ISBN-13: 978-0-7603-0122-7 not acceptable? ThanksPieter1963 (talk) 00:55, 21 May 2014 (UTC)

• The Wiki code will not link the ISBN number with the -13, e.g. ISBN-13 978-0-7603-0122-7 vs. ISBN 978-0-7603-0122-7. -Fnlayson (talk) 15:55, 2 June 2014 (UTC)

revise descriptions in inlet and engine sections

These sections contain incorrect/misleading terms and explanations, some obtained from references which are also not well informed. I will improve shortly, including credible references. I will delete the worst offending text first because while it remains I think it degrades the quality of the article and potentially harms the credibility of Wikipedia.Pieter1963 (talk) 23:33, 22 May 2014 (UTC)

remove sentences

"Ben Rich, who designed the inlets at Skunk Works, often referred to the engine compressors as "pumps to keep the inlets alive"; he sized the inlets for Mach 3.2 cruise, the aircraft's most efficient speed."

Ben Rich didn't design the inlet. He was the program manager for the propulsion system ref "Skunk Works" by Ben Rich. "pumps to keep the inlets alive" just raises more questions than it answers as it is an insightful comment for people "in-the-know" and I don't think is appropriate for this article. After all, what's the difference between an alive inlet and a dead one? I kept the Mach 3.2 comments but repositioned them.Pieter1963 (talk) 01:20, 2 June 2014 (UTC)

Removed "No other engine did this" Although it is very likely that this assertion is true I don't believe that it can be verified.Pieter1963 (talk) 12:36, 2 June 2014 (UTC)

Please provide sources here before removing cited text. -Fnlayson (talk) 15:50, 2 June 2014 (UTC)

It is not clear in which reference the statement "No other engine did this" originated because there are 3 references giving blanket coverage to several sentences. Since I cannot find the statement in any of the cited refs it could even be the contributor's personal opinion.

A more fundamental reason for deletion is that the statement infers certainty as a consequence of not being aware of something, that something being Soviet engine developments.

A safer statement, if one is required at all, might be "This mode of operation was thought to be unique, at least in the Western world."

There is no reference for this of course because I made it up. However, it's a better way of bringing attention to what is perceived to be a distinctly unique characteristic of the engine.Pieter1963 (talk) 18:20, 2 June 2014 (UTC)

• OK, but I was only asking for sources where cited text is to be removed as a general request. If it is not actually covered by the sources, then it is uncited and can be readily removed. -Fnlayson (talk) 18:53, 2 June 2014 (UTC)

What is "Please provide sources here" referring to? "Here" makes it sound specific to my latest edit, not a general request.Pieter1963 (talk) 22:05, 2 June 2014 (UTC)

• Here as in this talk page; just discuss the changes first. -Fnlayson (talk) 22:33, 2 June 2014 (UTC)

Dates are contradictory

Wow, the amount of contradictory information here is astounding. It was retired in 1990. It was retired in 1988. It was retired in 1998. It was retired in 1999. Just wow. Sloppy journalism, at best. My first question is: if this article is about a PRODUCT, an object (the SR-71), then what does "retirement" mean? Isn't it a specific reference to some owner/operator's USE of that object? (That is, it is a paper or conceptual distinction, not a physically meaningful one; wouldn't "last flight" be more meaningful?). I suggest you eliminate the "retirement" language, since its last USAF flight was in 1997, and for NASA in 1999. Some of the planes were "decommissioned" but continued to fly. So, perhaps you need to distinguish between mission flights and transportation flights? (And so, distinguish between its principle owner/operator's program(s) and its two separate times in service.) In the timeline, it is claimed that the 1989 explosion was the first in 17 years...this implies that during all or almost all of those 17 years, the plane was in active use...is this correct, and not misleading? Also, the "in service" dates are different than the dates the plane was actually flown. The program was reactivated in 1994 but the first flight was 1995, I think its not too difficult to be clear about whether you're talking about funding or about actual operation. Confounding Congressional funding decision dates (votes as well as effective dates), program dates, and operational dates is sloppy and simply unnecessary, imho.173.189.73.1 (talk) 16:02, 26 July 2014 (UTC)

Life support rubbish

The section contains the following:" Furthermore, an emergency ejection at Mach 3.2 would subject crews to an instant heat rise of about 450 °F (230 °C); thus, during a high altitude ejection scenario, an onboard oxygen supply would keep the suit pressurized during the descent.[citation needed]" Oh, my! First of all, it is absolute rubbish to claim someone is "subjected" to a "heat rise". This is high school science we're talking about! I don't know what the author intended to mean: did he mean a temperature rise of 450°F? I doubt it, but since there is no reference, there's no way to find out. Did he mean the friction would heat his clothing (and any exposed skin) by 450°F ? Probably, but no way to know... Finally, what possible connection is there to a "heat" rise after ejection and onboard oxygen supply?? It seems to imply that the ejected person remains tethered to the plane. (Perhaps the author meant to imply that ejection at that speed (and altitude, although the relationship between altitude and frictional heating isn't straightforward) was prohibited because of the friction...it would seem to me that the force of the wind, regardless of temperature/thermal effects, could cause serious injury, too?) But he didn't say that. Instead he created a mash-up of two distinct thoughts. It needs to be removed (without citation) or fixed.173.189.73.1 (talk) 16:18, 26 July 2014 (UTC)

Folks, I apologize for my sloppy editing here. However, my knowledge of how to properly edit a Wikipedia talk pages is minimal. However, I do have a serious point to make. The Wikipedia page says that only one pilot was lost. I am not sure if that is true or not. There were two well documented fatal accidents in the history of the program. The first was SR71 the MD21 Blackbird Accident. See "SR71 Sistership, The MD21 Blackbird Accident" (http://www.youtube.com/watch?v=GMyC2urCl_4). This was apparently in 1964. The second (and better known) accident was in 1966. See "Subject: Test Pilot Bill Weaver tells about a Mach 3.18 in-flight breakup of an SR-71 Blackbird" (http://webcache.googleusercontent.com/search?q=cache:_NPGmF1ql90J:www.barthworks.com/aviation/sr71breakup.htm+&cd=1&hl=en&ct=clnk&gl=us&client=firefox-a).

At least in my opinion, the SR-71 Wikipedia page should provide information on both accidents. Does anyone agree? Disagree?