SR-71 Dash 1

[squorch2]

Someone put an old copy of the Dash 1 for the Blackbird online, complete with weird EPs like Inlet Unstart and Cockpit Too Cold.

 

[helolumpy]

Great book entitled "Skunkworks: My years at Lockheed" by Ben Rich. He worked on the SR-71 under Kelly Johnson and then took over after Johnson retired and led the development of the F-117. He discusses some of the engineering that went into both aircraft. My favorite tidbit about the SR-71 was that the decision to paint it black was for heat dissipation, it had nothing to do with the actual mission.

 

[squorch2]

Yeah, they talk about that in the beginning description of the aircraft - that and how the fuel (JP-7) is also used in the engine hydraulics.

 

[nittany03]

"Inlet Unstart" was actually a very very bad thing IIRC. Apparently, it resulted from the inlet cone malfunctioning, causing the shock wave at the inlet to be jettisoned and snuffing the engine. Jet engines can't run on supersonic air, so most designs use a fixed or variable system to trap shockwaves and slow the air to subsonic speed before the first compressor stage. Since the engines on the SR were so far apart, lose one at Mach 3 and bad things happen. Read several articles about it over the years quoting former drivers.

 

[ryan1234]

Thanks for the link... that's pretty interesting.... lots of interesting limitations on symmetrical vs. rolling flight at high mach as well as CG limitations at different airspeeds. The switch from KIAS to KEAS is also interesting. Max "usable" airspeed: 1925KTAS @ 427c CIT

Max altitude is 80k unless higher is "authorized"

Fuel flow during Mach 3.2 cruise @ 100,000GW: 18,600lb/hr per engine specific range 49.4nm/1000lb fuel

 

[statesman]

Someone put an old copy of the Dash 1 for the Blackbird

Is the Dash 1 the AF equivalent of NATOPS? Never seen that terminology before.

 

[squorch2]

Indeed it is the equivalent.

 

[Dan VA46]

Great book entitled "Skunkworks: My years at Lockheed" by Ben Rich. He worked on the SR-71 under Kelly Johnson and then took over after Johnson retired and led the development of the F-117. He discusses some of the engineering that went into both aircraft. My favorite tidbit about the SR-71 was that the decision to paint it black was for heat dissipation, it had nothing to do with the actual mission.

Another tidbit,
The J-58 (we call them JT-11 at P&W) afterburners could not be lit off with conventional ignitors, so a chemical system was used (TEB).
Fuel is commonly used in engine hydraulics on modern jet engines.

 

[yak52driver]

"Inlet Unstart" was actually a very very bad thing IIRC. Apparently, it resulted from the inlet cone malfunctioning, causing the shock wave at the inlet to be jettisoned and snuffing the engine. Jet engines can't run on supersonic air, so most designs use a fixed or variable system to trap shockwaves and slow the air to subsonic speed before the first compressor stage. Since the engines on the SR were so far apart, lose one at Mach 3 and bad things happen. Read several articles about it over the years quoting former drivers.

Years ago I bought a Aviation Week video about the SR-71, if I remember correctly a few aircraft were lost due to inlet unstarts. Violent yawing if memory serves.

 

[Rocketman]

Occasionally seeing a Habu on short final to Kadena AFB always made my liberty trips down to Naha that much better.

 

[Swanee]

"Inlet Unstart" was actually a very very bad thing IIRC. Apparently, it resulted from the inlet cone malfunctioning, causing the shock wave at the inlet to be jettisoned and snuffing the engine. Jet engines can't run on supersonic air, so most designs use a fixed or variable system to trap shockwaves and slow the air to subsonic speed before the first compressor stage. Since the engines on the SR were so far apart, lose one at Mach 3 and bad things happen. Read several articles about it over the years quoting former drivers.

I think I remember a guy who flew them tell me that (at least at one point) the cones were manually adjusted by the pilot with a couple levers in the cockpit, and that once at altitude you spent a lot of your concentration on getting those settings exact, only to have to readjust them constantly for climbing and banking and what not.

 

[yak52driver]

After having read parts of the OP's link to the manual, it's pretty amazing the aircraft they were able to build with slide rules and drafting on paper. Even some of the performance charts look like they were drawn on regular old graph paper from back in the day.