Brian Abraham
November 06, 2010, 11:59:00 GMT
permalink Post: 6043219

Quote:

Yes I think the Mercure had a HUD if i'm not mistaken

Was the first HUD installation on a commercial airframe (Thomson/Sextant). Certified to CATIIIb.

Subjects (links are to this post in the relevant subject page so that this post can be seen in context): HUD (Head Up Display)

Brian Abraham
November 09, 2010, 05:04:00 GMT
permalink Post: 6048926

The SR-71 tech notes describe it as having a delta wing (Ogee applies to an S shaped wing) where the outboard portion has negative conical camber to move the centre of lift inboard to relieve loading on the nacelle carry through structure. Also improves the max lift characteristics of the outboard wing at high angles of attack and enhances crosswind landing capability.

The chines improve directional stability at increasing angles of attack at all speeds, but their primary purpose is to provide a substantial proportion of the total lift at high supersonic speeds and eliminate the need for canards or special nose up (drag producing) trimming devices.

Subjects (links are to this post in the relevant subject page so that this post can be seen in context): SR-71

Brian Abraham
November 09, 2010, 08:48:00 GMT
permalink Post: 6049170

Quote:

Also, the concorde was only just supersonic (as in ALL airflow supersonic) so at times keeping the wing surface subsonic in cruise would be advantageous.

With all due respect, I don't think you have any understanding.

Subjects: None

Brian Abraham
December 19, 2010, 22:57:00 GMT
permalink Post: 6132313

Quote:

Throttles opened for take -0ff
At 500 ft switch off reheats
At 1000ft select Climb Rating with the switches on the overhead panel
At M0.95 select reheats in pairs
At M1.7 switch off reheats
At 50,000ft select Cruise Rating on the switches on the overhead panel

Why the switches for climb and cruise ratings. What was being accomplished that modulation of the throttles couldn't. Which brings the question, why switches for the reheats rather than throttle aka military style?

When this thread is finished I think we should have the info necessary to retire to the back shed and knock one up. Keep it up Gents.

Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Afterburner/Re-heat

Brian Abraham
December 20, 2010, 05:11:00 GMT
permalink Post: 6132575

Quote:

the limiting speed factor of the SR-71 was the wing leading edge temperature of 734 degrees

As with any aircraft the 71 was subject to any number of limitations, but airframe temperature was not one of them. The crew had no info on skin temp in any event. However compressor inlet temperature was the major limiting item (427\xb0C).

Thread on the Concorde inlets here http://www.pprune.org/tech-log/42690...ke-thrust.html

Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Intakes SR-71

Brian Abraham
February 08, 2011, 01:10:00 GMT
permalink Post: 6230706

Quote:

was constantly undermined \x96 indeed sabotaged by the bloody-minded working practices of those dinosaurs

Great story Adverse Jaw, and there are threads on here pondering why the demise of British aircraft manufacturing.

Quote:

they all had families to support and I was in danger of causing the suspension of overtime

Law of unintended consequences?

Subjects: None

Brian Abraham
April 12, 2011, 04:47:00 GMT
permalink Post: 6364687

Quote:

Basically, a relatively small failure within the intake/spike structure of the SR71 engine, was enough to simply tear the airframe apart within seconds of onset.

Not quite the case, although the potential for a very rough ride was always there. Bill Weavers accident was the only one that involved an unstart, and was due in no small part to the test nature of the flight - CG out the back door. In Bills own words,

Quote:

Jim Zwayer, Lockheed flight-test specialist, and I were evaluating systems on an SR-71 Blackbird test from Edwards. We also were investigating procedures designed to reduce trim drag and improve high-Mach cruise performance. The latter involved flying with the center-of-gravity (CG) located further aft than normal, reducing the Blackbird's longitudinal stability.

On the planned test profile, we entered a programmed 35-deg. bank turn to the right. An immediate unstart occurred on the right engine, forcing the aircraft to roll further right and start to pitch up. I jammed the control stick as far left and forward as it would go.

No response. I instantly knew we were in for a wild ride.

The cumulative effects of system malfunctions, reduced longitudinal stability, increased angle-of-attack in the turn, supersonic speed, high altitude and other factors imposed forces on the airframe that exceeded flight control authority and the Stability Augmentation System's ability to restore control.

The next day, our flight profile was duplicated on the SR-71 flight simulator at Beale AFB, Calif. The outcome was identical. Steps were immediately taken to prevent a recurrence of our accident. Testing at a CG aft of normal limits was discontinued, and trim-drag issues were subsequently resolved via aerodynamic means. The inlet control system was continuously improved and, with subsequent development of the Digital Automatic Flight and Inlet Control System, inlet unstarts became rare.

Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Air France 4590 C of G Intakes SR-71 Simulator

Brian Abraham
October 11, 2013, 06:52:00 GMT
permalink Post: 8093152

You say it better than I PJ2. Was fortunate to be at the Oshkosh show when the aircraft was in attendance and giving flights to those who could afford the price. The big memory was standing at the barrier on the runways edge (insanely close it seemed to the runway) and happened to be standing at the point of rotation. A memory not to be forgotten, nor the noise and visceral vibrations within the body.

Subjects: None

Brian Abraham November 06, 2010, 11:59:00 GMT permalink Post: 6043219	Quote: Yes I think the Mercure had a HUD if i'm not mistaken Was the first HUD installation on a commercial airframe (Thomson/Sextant). Certified to CATIIIb. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): HUD (Head Up Display)
Brian Abraham November 09, 2010, 05:04:00 GMT permalink Post: 6048926	The SR-71 tech notes describe it as having a delta wing (Ogee applies to an S shaped wing) where the outboard portion has negative conical camber to move the centre of lift inboard to relieve loading on the nacelle carry through structure. Also improves the max lift characteristics of the outboard wing at high angles of attack and enhances crosswind landing capability. The chines improve directional stability at increasing angles of attack at all speeds, but their primary purpose is to provide a substantial proportion of the total lift at high supersonic speeds and eliminate the need for canards or special nose up (drag producing) trimming devices. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): SR-71
Brian Abraham November 09, 2010, 08:48:00 GMT permalink Post: 6049170	Quote: Also, the concorde was only just supersonic (as in ALL airflow supersonic) so at times keeping the wing surface subsonic in cruise would be advantageous. With all due respect, I don't think you have any understanding. Subjects: None
Brian Abraham December 19, 2010, 22:57:00 GMT permalink Post: 6132313	Quote: Throttles opened for take -0ff At 500 ft switch off reheats At 1000ft select Climb Rating with the switches on the overhead panel At M0.95 select reheats in pairs At M1.7 switch off reheats At 50,000ft select Cruise Rating on the switches on the overhead panel Why the switches for climb and cruise ratings. What was being accomplished that modulation of the throttles couldn't. Which brings the question, why switches for the reheats rather than throttle aka military style? When this thread is finished I think we should have the info necessary to retire to the back shed and knock one up. Keep it up Gents. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Afterburner/Re-heat
Brian Abraham December 20, 2010, 05:11:00 GMT permalink Post: 6132575	Quote: the limiting speed factor of the SR-71 was the wing leading edge temperature of 734 degrees As with any aircraft the 71 was subject to any number of limitations, but airframe temperature was not one of them. The crew had no info on skin temp in any event. However compressor inlet temperature was the major limiting item (427\xb0C). Thread on the Concorde inlets here http://www.pprune.org/tech-log/42690...ke-thrust.html Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Intakes SR-71
Brian Abraham February 08, 2011, 01:10:00 GMT permalink Post: 6230706	Quote: was constantly undermined \x96 indeed sabotaged by the bloody-minded working practices of those dinosaurs Great story Adverse Jaw, and there are threads on here pondering why the demise of British aircraft manufacturing. Quote: they all had families to support and I was in danger of causing the suspension of overtime Law of unintended consequences? Subjects: None
Brian Abraham April 12, 2011, 04:47:00 GMT permalink Post: 6364687	Quote: Basically, a relatively small failure within the intake/spike structure of the SR71 engine, was enough to simply tear the airframe apart within seconds of onset. Not quite the case, although the potential for a very rough ride was always there. Bill Weavers accident was the only one that involved an unstart, and was due in no small part to the test nature of the flight - CG out the back door. In Bills own words, Quote: Jim Zwayer, Lockheed flight-test specialist, and I were evaluating systems on an SR-71 Blackbird test from Edwards. We also were investigating procedures designed to reduce trim drag and improve high-Mach cruise performance. The latter involved flying with the center-of-gravity (CG) located further aft than normal, reducing the Blackbird's longitudinal stability. On the planned test profile, we entered a programmed 35-deg. bank turn to the right. An immediate unstart occurred on the right engine, forcing the aircraft to roll further right and start to pitch up. I jammed the control stick as far left and forward as it would go. No response. I instantly knew we were in for a wild ride. The cumulative effects of system malfunctions, reduced longitudinal stability, increased angle-of-attack in the turn, supersonic speed, high altitude and other factors imposed forces on the airframe that exceeded flight control authority and the Stability Augmentation System's ability to restore control. The next day, our flight profile was duplicated on the SR-71 flight simulator at Beale AFB, Calif. The outcome was identical. Steps were immediately taken to prevent a recurrence of our accident. Testing at a CG aft of normal limits was discontinued, and trim-drag issues were subsequently resolved via aerodynamic means. The inlet control system was continuously improved and, with subsequent development of the Digital Automatic Flight and Inlet Control System, inlet unstarts became rare. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Air France 4590 C of G Intakes SR-71 Simulator
Brian Abraham October 11, 2013, 06:52:00 GMT permalink Post: 8093152	You say it better than I PJ2. Was fortunate to be at the Oshkosh show when the aircraft was in attendance and giving flights to those who could afford the price. The big memory was standing at the barrier on the runways edge (insanely close it seemed to the runway) and happened to be standing at the point of rotation. A memory not to be forgotten, nor the noise and visceral vibrations within the body. Subjects: None

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