The SR-71 ( and all along that line however denoted ) have unique engine characteristics.
- fuel is a special high grade kero with a catalyst in the mix. Without the tetraethyl borane not much interesting happens.
- a variable intake spike which modulates the bow shock position for the supersonic external -> subsonic internal transition.
- best efficiency is at the top end of both altitude and speed.
So paradoxically you slow down and go low to refuel which is less efficient than if you'd stayed high. Alas no supersonic refuelers ....
Cheers, Mike.
( edit ) A brief research indicates that the JP-9 fuel used by the SR-71 is quite similiar to that used for the air launched variety of cruise missiles. Methyl cyclohexane seems to be the key stuff here. The main desired property is low melting point ( so it doesn't freeze at high altitude ) and high volatility ( to enable starts/restarts at high altitude/velocity ). You don't really want to come down during a mission if flameout happens. This is a long way in performance and price from your bog standard commercial flight fuels.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
As I recall it was a Saturday at MCAS Futema on Okinawa. Around 1300 on a clear, sunny day. I quickly crouched to avoid being hit. When I looked up the shadow that triggered my reaction had moved on. It was an SR71 inbound to Kadena. The only thing missing was a pair of pearl handles. Ominous.
It was ~1971 MCAS El Toro, California. The Blue Angels were in town for an airshow. They practiced for about 4 days prior to the show. Their aircraft of choice: F4s in angel Blue. That aircraft had a certain "cry" when the engines were throttled back - cry of a Banshee. One maneuver: solo plane flying the runway heading. Enters a perfect 360 loop. At 12:30 o'clock throttles back engines. Silence. Oh crap what is wrong? Falls in a perfect arc to 5 o'clock. Throttles up. Burner 1 .... and gone. "Most impressive".
As I recall it was a Saturday at MCAS Futema on Okinawa. Around 1300 on a clear, sunny day. I quickly crouched to avoid being hit. When I looked up the shadow that triggered my reaction had moved on. It was an SR71 inbound to Kadena. The only thing missing was a pair of pearl handles. Ominous.
It was ~1971 MCAS El Toro, California. The Blue Angels were in town for an airshow. They practiced for about 4 days prior to the show. Their aircraft of choice: F4s in angel Blue. That aircraft had a certain "cry" when the engines were throttled back - cry of a Banshee. One maneuver: solo plane flying the runway heading. Enters a perfect 360 loop. At 12:30 o'clock throttles back engines. Silence. Oh crap what is wrong? Falls in a perfect arc to 5 o'clock. Throttles up. Burner 1 .... and gone. "Most impressive".
Happy birthday Mike.
I also was at MCAS Futenma on Okinawa in 85 and 86. We would get a call at the barracks saying the tanker just took off and we would hot foot it down to Kadena where about a half hour later the SR71 would take off. The tanker had to take off that much earlier so he was far enough ahead of the SR71 so he could refuel just a few minutes after takeoff. The SR71 could not take off fully loaded, so they took off with a small fuel load, caught up with the tanker a few minutes after take off, then would throttle up and be gone.
As I recall it was a Saturday at MCAS Futema on Okinawa. Around 1300 on a clear, sunny day. I quickly crouched to avoid being hit. When I looked up the shadow that triggered my reaction had moved on. It was an SR71 inbound to Kadena. The only thing missing was a pair of pearl handles. Ominous.
It was ~1971 MCAS El Toro, California. The Blue Angels were in town for an airshow. They practiced for about 4 days prior to the show. Their aircraft of choice: F4s in angel Blue. That aircraft had a certain "cry" when the engines were throttled back - cry of a Banshee. One maneuver: solo plane flying the runway heading. Enters a perfect 360 loop. At 12:30 o'clock throttles back engines. Silence. Oh crap what is wrong? Falls in a perfect arc to 5 o'clock. Throttles up. Burner 1 .... and gone. "Most impressive".
Happy birthday Mike.
I also was at MCAS Futenma on Okinawa in 85 and 86. We would get a call at the barracks saying the tanker just took off and we would hot foot it down to Kadena where about a half hour later the SR71 would take off. The tanker had to take off that much earlier so he was far enough ahead of the SR71 so he could refuel just a few minutes after takeoff. The SR71 could not take off fully loaded, so they took off with a small fuel load, caught up with the tanker a few minutes after take off, then would throttle up and be gone.
Cool stuff.
Happy Bday Mike.
Phil
Another way was to watch a hill at the end of Kadena's main runway. When it was covered with Japanese photographers you knew a launch was imminent. I was on Kadena one day during a launch. It rolled to about the 1/2 way point on the runway, then went vertical. Gone. And you are right about the tankers.
Some of you will be interested in a particular item on today's launch. Or maybe you heard already. It seems to be the only thing making the launch newsworthy in the US media.
David
Miserable old git
Patiently waiting for the asteroid with my name on it.
9 minutes after launch the 1st stage is scheduled to touch down on the floating pad. Seas are good as of "now" and the platform has received some upgrades so lets do this!!!!
Some of you will be interested in a particular item on today's launch. Or maybe you heard already. It seems to be the only thing making the launch newsworthy in the US media.
It looks pretty good/tasty. Heck I have made a lot worse. Besides it can't be worse than instant.
Thanks for that information
)
Thanks for that information Peter. :-)
The SR-71 ( and all along that line however denoted ) have unique engine characteristics.
- fuel is a special high grade kero with a catalyst in the mix. Without the tetraethyl borane not much interesting happens.
- a variable intake spike which modulates the bow shock position for the supersonic external -> subsonic internal transition.
- best efficiency is at the top end of both altitude and speed.
So paradoxically you slow down and go low to refuel which is less efficient than if you'd stayed high. Alas no supersonic refuelers ....
Cheers, Mike.
( edit ) A brief research indicates that the JP-9 fuel used by the SR-71 is quite similiar to that used for the air launched variety of cruise missiles. Methyl cyclohexane seems to be the key stuff here. The main desired property is low melting point ( so it doesn't freeze at high altitude ) and high volatility ( to enable starts/restarts at high altitude/velocity ). You don't really want to come down during a mission if flameout happens. This is a long way in performance and price from your bog standard commercial flight fuels.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
As I recall it was a Saturday
)
As I recall it was a Saturday at MCAS Futema on Okinawa. Around 1300 on a clear, sunny day. I quickly crouched to avoid being hit. When I looked up the shadow that triggered my reaction had moved on. It was an SR71 inbound to Kadena. The only thing missing was a pair of pearl handles. Ominous.
It was ~1971 MCAS El Toro, California. The Blue Angels were in town for an airshow. They practiced for about 4 days prior to the show. Their aircraft of choice: F4s in angel Blue. That aircraft had a certain "cry" when the engines were throttled back - cry of a Banshee. One maneuver: solo plane flying the runway heading. Enters a perfect 360 loop. At 12:30 o'clock throttles back engines. Silence. Oh crap what is wrong? Falls in a perfect arc to 5 o'clock. Throttles up. Burner 1 .... and gone. "Most impressive".
Happy birthday Mike.
RE: As I recall it was a
)
I also was at MCAS Futenma on Okinawa in 85 and 86. We would get a call at the barracks saying the tanker just took off and we would hot foot it down to Kadena where about a half hour later the SR71 would take off. The tanker had to take off that much earlier so he was far enough ahead of the SR71 so he could refuel just a few minutes after takeoff. The SR71 could not take off fully loaded, so they took off with a small fuel load, caught up with the tanker a few minutes after take off, then would throttle up and be gone.
Cool stuff.
Happy Bday Mike.
Phil
I thought I was wrong once, but I was mistaken.
HAPPY BIRTHDAY MIKE ! Bill
)
HAPPY BIRTHDAY MIKE !
Bill
RE: RE: As I recall it
)
Another way was to watch a hill at the end of Kadena's main runway. When it was covered with Japanese photographers you knew a launch was imminent. I was on Kadena one day during a launch. It rolled to about the 1/2 way point on the runway, then went vertical. Gone. And you are right about the tankers.
Semper Fi.
Some of you will be
)
Some of you will be interested in a particular item on today's launch. Or maybe you heard already. It seems to be the only thing making the launch newsworthy in the US media.
David
Miserable old git
Patiently waiting for the asteroid with my name on it.
9 minutes after launch the
)
9 minutes after launch the 1st stage is scheduled to touch down on the floating pad. Seas are good as of "now" and the platform has received some upgrades so lets do this!!!!
RE: Some of you will be
)
It looks pretty good/tasty. Heck I have made a lot worse. Besides it can't be worse than instant.
Launch aborted at t-3:07 -
)
Launch aborted at t-3:07 - weather violation.
Re-scheduled for 1610 tomorrow EDT.
Scrubbed for today for
)
Scrubbed for today for violation of the anvil cloud distance rule.
This means next attempt may be just about 24 hours from now.
The abort call came at just over 3 minutes before launch.