SR71 for FS2004(FS9) Operation GuideOptimized for Flight Simulator and this model based on the real world SR71 Pilot Manual.Paul R. Varn
SR71 for FS2004(FS9) Operation Guide
The book "Lockheed SR-71" by Jay Miller provided a wealth of information I didn't have access to before. Thanks to Gary Hall for loaning it to me. Also thanks to Gary Hall for finding the unclassified pilot manual online. This provided massive amounts of information. IMPORTANT!!! USE AT YOUR OWN RISK!
THIS AUTHOR WILL NOT ASSUME ANY RESPONSIBILITY FOR ANY FAILURE
WHATSOEVER, IN HARDWARE or SOFTWARE. Added REAL after-burner (shift-4.) You will read many references to weight and weather in provided documentation.
These two variables affect the performance of the model dramatically. Especially
at high altitude 40K to 50K feet higher than typical airliners fly.
You cannot fly at maximum altitude, at max weight in very high or low
air pressure where the temperature is excessively cold. Stable flight is a careful
balance of flight path planning, altitude, speed, and fuel load.
Considering the aircraft has no flaps or spoilers, it has a 200+ knots
air speed range of stability at Mach cruise. The Panel is a collection of gauges from other planes which fit the general theme of grey-black high performance aircraft. Some gauges are not accurate. In some cases where accuracy was abosolutely necessary, I constructed primitive text-based XML gauges so the pilot could fly the plane to real-world procedures and specifications. It's not pretty, but functional. As my elementary gauge making skill improves, I'll replace more of the gauges and add more realisitic ones. I invite gauge artists who enjoy high performance aircraft to pariticipate in creating a freeware panel that does justice to this amazing aircraft. SR71-FS2004 Weather environment: As AS creates weather around the world, it will set the top layer to different altitudes and temperatures. Because of this, you will never have the same flight conditions twice. Sometimes you will get weather near or colder than the operating limits. Sometimes much warmer. As in the real world, pilots flying the Concorde and SR71 had to ride a range of altitudes and speeds to continually optimise the conditions for maximum range and speed. I call it "Threading the Amospheric Needle." In the sim, the most important indicators are the Exhaust Gas Temperature (EGT) Air Speed Indicator (ASI) and Fuel Flow (FF.) To prevent structural damage or stalls, the aircraft has to be flown between a 200 knot speed band (300 - 500 KIAS.) To prevent engine failure, the combination of Compressor Inlet Temperature (CIT) and EGT must be kept within their limits which are strongly influenced by the Static Air Temperature (SAT) Engine RPM and air speed. The tools you will use to juggle the temperature and structural limts are Altitude and Mach speed.By keeping the mach setting so the ASI is kept as close to 400 KIAS as possible you will fly right in the middle of the structural limit range between failure and stall. By adjusting the altitude of your flight between 72K and 92K feet to keep the EGT as close to 800C as possible, you manage the temperture of the air to prevent engine damage. The last of the three legs of the flight management is Fuel Flow (FF.) By keeping the fuel rate under 20K lbs/hr per engine, you will get the maximum range the flight model is designed for. As you read further into this guide, you will see many references to speed and altitude limits. I hope this explanation will give you the background to understand why these limits are there and to assure you they are indeed real world. Pilots had to plan and fly their plan to cooperate with these limits. Unlike airliner flight where you set a altitude and speed and keep them for the whole cruise flight, the SR71 "Habu" pilot can rarely enjoy that kind of leasure. Most flights will be realtively calm and uneventful. Some will have you changing speeds and altitude frequently to stay ahead of the changing weather situation. Configuation for AS and the most trouble-free flight is covered in the flight prep portion of this document. The following graphic from NASA illustrates the effect of altitude and pressure:
![]() Since I first started working on this model I recently added several reality gauges which reflect some true real world limitations of the aircraft. As exceptional as it is, it's not a space shuttle. Real world pilots had limitations placed on what they could do. In addition, there were physical limitations to the airframe and engines. These are discussed again later in this document within relevant sections: CITEGT:
Annunciator:
Drag Chute: TEB: Below the engine throttles are two TEB chemical counters, one for each engine. The counters are maintained separately for each engine. Each time an engine is successfully started or the AB is enabled, the TEB count for the cycled engine will lower by one. You start out with 16 "shots" of TEB. When the count reaches zero, the affected engine cannot again be restarted or its AB enabled. The TEB count is only lowered if the engine start is successful or the throttle position is 70% or more for engaging afterburners. An engine which is fully functioning will remain working if the counter reaches zero until another failure occurs. Spike: ABThrottle: This gauge is an enhancement to the main panel throttle. The SR71 has a combined throttle AB control (like most reheat jets.) To activate the AB the throttle is moved to a hardware stop, then the handle is pulled out-away from the base on a spring and the throttle lifted over the stop into the minimum AB setting. As you all well know, faults of any kind are not a normal part of FS simulations. The built-in random failure system is so unlikely and unrealistic no one wants to use it. These faults take some getting used to, but are an attempt to help wannabe "Habus" appreciate the skill and technical complexity associated with this unique aircraft. Although Airliner pilots are known to sleep at the stick from boredom, Habus could not!. Go to sleep in this aircraft and you'll find yourself in a reset in short order. These faults are not random. The pilot has to fail to react to out of limit flight perameters for them to happen. In a normal flight, you will not have any faults. |
Specifications: | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Fuselage: Length: 103' 10" Height: 18' 6" Wing Span: 57' 7" Wing Area: 1,605 sq' (some sources claim 1,800 ft sq) V Stab Area: 70.2 sq' Gross Weight (MTOW): 172,000lbs Zero Fuel Weight: 80,000 lbs | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Engines: Weight(2): 13,000 lbs (6,500 lbs ea) 20' long, 4',5" wide (2) P+W JT11D-20B (J-58) Turbo Ramjet. 32,500lbs static thrust @ sea level (45,000 lbs with after-burner) Single Rotor, 9 stage 8:8:1 ratio compressor. ![]() Starting RPM: 3,200 Idle RPM: 4,000 Max RPM: 7460? Min RPM above M 2.5: 6100 Typical Cruise RPM: 7100 Overspeed RPM: 7450 < 300C CIT, 7300 > 300C CIT Cruise Inlet/Engine power ratio: 80%/20% Core airflow: 450 lb/s Max inlet spike movement = 26 inches. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Fuel Load (JP-7) at 100,000 lbs Gross Weight: 11,570 lbs Fuel Capacity: (real world) 83,302 lbs JP-7 (12,200 US gal @6.9 lbs/gal) Fuel Capacity: (this model) 80,653 lbs FS "JetA" (12,038 US gal @6.7 lbs/gal) Unusable: 32.4 Gal (217 lbs) Standard temperatures and pressures: Rated Cruise: Mach 3.20 @80,000ft Fuel Rate at Ground Idle: 4800 - 6300 lbs/hr Fuel Rate MAX Take Off Full AB: 65K lbs (40,000+ simulated) Fuel Rate at refuel speed and alt: 12K lbs/hr Fuel Rate (rated cruise): 36-41,000lbs/hr Fuel Rate (Average Climb): 22,500 lbs/hr Fuel Rate (Average Descent): 16,500 lbs/hr Full Fuel: Min Take off Runway length: 9,000ft. (with after-burner) 10K lbs fuel or less: Min land Runway length: 7000ft Typical Runway Take off Roll (45K lbs fuel): 4800ft Max Crosswind landing: 25 knots dry, 20 knots wet. Max Ground Tire Speed: 238 KAES, 239 KIAS, 275 MPH Tire Cooling: 9 minutes for every 14,000ft or 2.75 miles of taxi distance at 70 deg F. Tire Pressure: 400 Psi Max initial breaking speed 10K lbs fuel: 209 KIAS @70 deg F Min Ejection Altitude: 15,000ft Touch Down Vertical Speed: Typical- 50 to 100 fps, Max- 600 fps | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
V Speeds (45K lbs fuel): V1 = 156KIAS Vr = 180 KIAS V2 = 210 KIAS Vr(full weight) = 205KIAS | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Max Speed: Mach 3.45/510 KIAS ![]() Recommended Operational Ceiling: 85,000ft (model tested stable to 95K ft) Normal Cruise Altitude: 81K ft westbound, 80K ft Eastbound. Range: 3,250 miles un-refueled (rated cruise using Active Sky temperatures) Minimum Single Engine Approach = 200 KIAS 25,000 lbs fuel. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Temperatures: From 600 to 900+ degrees Fahrenheit on the airframe. Temperatures on the J-58 engine exhaust reach 3200 degrees. Min Operating temperature = -75 deg C Sub-Mach Max Climb Speed (no turbulence) = 400 KIAS | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Typical AOA at the above speeds and weights are 10 to 12 degrees, not to excede 14 degrees (tail strike.) AOA Flight: Drag Chute deploy: Max Sub-Mach Climb to Cruise: Active Sky Weather Simulation: Max Safe Altitude (Active Sky) = 85Kft (without special auth.) Max Rated Altitude = 92K ft (can go higher when weather permits.) Max Pitch at cruise = 7 deg (Speed loss/Stall Instability @ 6.0 deg) Min IAS at cruise (above M3) = 310 KIAS (real world) 280 KIAS (simulated) No Power Glide (80K ft Mach 3.2): Refueling: Max Deceleration above M 1.8 = 1 mach per 3 minutes
MLW: Not Limited (suggested 40K lbs fuel max)
![]() EGT: ![]() COG: Mach 3 Environment Temps: Oil Pressure: Hydraulic Pressure: Electical: --------------------- FLIGHT PROCEDURES: ---------------------- This general overview of technique for flying this aircraft in FS2004 is not real-world but based on manipulating the sim to obtain consistent results. Active Sky weather is assumed. FS and SB3 weather should not be used as the data doesn't support altitudes over 45K ft. o PRE START PREPARATION- FLIGHT PLAN loaded into GPS or another navigator that performs turn prediction. FS2004 GPS turns about 2.8 miles prior to the waypoint at high speed. This is JUST enough to maintain control during turns. At cruise, waypoints should be 500 miles apart or more if they have moderate turns, No-turn waypoints can be as close as 100 miles. When flying over water to your destination (ATC hate mach speed in their space) a careful flight Plan will include a way point close to the coast (assuming your destination is somewhat inland) for use as a descent calculation target. This is explained in the descent profile later. Fuel Loading:
![]() Note: The rear tanks (Center2 and L/R Tips) typically contain 30% less fuel to conform with max take-off COG of 22%. Typical practice is to fill all front tanks to 70% and the rear tanks (Center2 and L/R tips) which when set to 40% will provide 22.1% COG and apprx 45.5K lbs fuel on take-off. Easy Rule of thumb:
In order as they appear in FS fuel dialog:
Fuel distribution is as follows (rough):
END FUEL PREP. WEATHER PREP:: The SR71 is sensitive to pressure more than wind speed and temperature because of the high altitude. Near the flight limits large pressure changes can throw the flight model well beyond its operational limits. If forecast pressure areas over the course of your flight have the potential to be below 29.45 you should use the Active Sky Enhanced Version feature "Force Constant Pressure" while preloading Flight Plan or descend to a safe altitude near the problem area. Pressures over 30.10 are problematic because they force you to fly very high (which can be fun, but increasingly risky.) You can expect to fly 92K ft or higher to barely maintain M 3.20 safely with a pressure of 30.35. Check for strength and direction of prevailing winds. Typically, in the northern hemisphere, you will have mostly head winds traveling West and tail winds heading East. I add 1000 lbs when going West and subtract 1000 from the estimate going East. The exception would be flights more N/S than E/W where I don't modify the estimate. 81,000ft should be used for flights East and 80,000 for west. Although the model supports flights up to 92K ft, unstable weather over coastal transition boundaries (300 - 500 miles from land crossing over large bodies of water) may cause highly unstable flight. AS does not support temperature layers above 82,000ft. As you climb above this, temps actually INCREASE rather than decrease. This can cause failures of the type where sudden weather changes can cause an extreme engine efficiency change with consequential overspeed or stall. FSUIPC and Active Sky optimization:Active Sky- ![]() Note: 170 miles suppression, 5 min update interval settings. Your flight setup procedure should include use of the "New Route" button at the main screen. When clicked, set the cruise speed to 1750 and "Import" an FS flight plan of your flight route. This will cause AS to pre-scan all the weather along your route and create some optimizations including "Virtual" stations between large gaps in real world stations. With "Constant Pressure" selected both real world and virtual station data will be modified slightly to reduce the severity of pressure changes. Sometimes even with a flight plan pre-loaded and pressure smoothing, the condtions can still be totally unfavorable to flying the SR. The options are to change your flight to another part of the world, or not pre-loading a flight plan and letting the AS program create a more dynamic "load as you go" environment (which is AS's default condition.) Virtual stations will still be created (based on the suppression and update intervals you entered.) This dynamic environment may cause more disruptions in your flight, but you have an equal potential of getting an acceptable high altitude condition at any given time as a bad one. Instead of a bad condition the whole flight, you may get periods of acceptable condtions. Weatherset: A useful tool for checking the quality of the weather generation is a free program which comes packaged with FSUIPC called Weatherset. FS2004 and X users should use Weatherset2. This program displays all the weather data being sent to FSUIPC by the weather program in a numerical display (rather than the FS weather dialog tabed graphical display. This lets you see all the current weather settings at a glance without scrolling or tabbing. Take a look at the temperatures above 50K ft and the current pressure. If you pre-loaded a flight plan with force constant pressure, the current pressure shown will only deviate slightly through the flight. Another useful tool comes with the online multiplayer connection program FSINN. Along with a large package of tools in the main FS menu is the "Pressure" indicator. This places a current pressure display in the sim so you can see what the current pressure is at all times. This is helpful because above 18K ft, setting the altimeter in FS forces a constant 29.92 which is standard practice for airliners. However, the SR71 is a military jet not an airliner and compesating the altimeter was not standard practice. For this reason, I elected to provide a non-compensated altitude reading in the main panel "Triple" gauge. You can use this to compare the compensated display in the main altimeter to the non-compensated in the triple display to tell if you are flying in higher or lower than normal pressure. As you get more experienced, you will come to expect certain IAS readings at certain altitudes. Higher or lower than normal air speeds at Mach 3.2 are an indication you are flying in unusually low or high pressure. FSUIPC-The following settings in the WINDS section of FSUIPC are necessary to smooth the wind for Mach speed flight. If you are using the free version, you cannot set this resulting in less than satisfying weather conditions in all aircraft: CHECK "Smooth Changes" Knots or degrees/second = 0 OR for this many seconds for each 1 degree = 2 After weather clear delay smoothing by seconds = 0 CHECK "smooth only when airborne." NOTE on PRESSURE: In practice using AS weather, pressures during M3+ flight OVER
1024.4 (30.25mb) or UNDER 997.3 (29.45mb) are problematic. You can expect to have to
climb very high (90K+) to obtain M3 or descend very low (72K) to avoid stall near
these pressures. Avoid IAS over 460 or under 380 at cruise. I cannot stress enough
that the most maintenance-free flights will have cruise speeds near 400KIAS (the middle
of the model's stability range.) PRESET THE AUTOPILOT to have AutoThrottle ENABLED, set initial altitude +10,000 AGL, 250 knots IAS (for low alt restriction) and 3500 ft/min climb rate. When not conserving fuel, higher climb rates can be used. Switch NavGPS switch to GPS (note: GPS mode disables ILS approach so you need to turn
the switch back to ILS during automated approach.) o Start-up- o Taxi- o Take-off: Smoothly advance the throttle to 70% (full military.) Release the breaks and
engage the Afterburner (shift-F4.) Smoothly advance the throttle to 100%. The TEB counter will drop another number to ignite the ABs. Be prepared to pull the throttle back soon to avoid EGT limits in hot weather or conform to any area speed restriction which might be in place. Crossing 156 knots reduce throttle to apprx 85% to prevent over-shooting
terminal area speed restriction of 250 KIAS. Note: Clicking the speed hold with the mouse has a different effect than
using the key combo Control-R. At this point the plane will be under stable autopilot control in trimmed flight. As the speed reaches 250KIAS increase normal climb to 3500 ft.min. Max climb off the runway can initially be as high as 10,000 ft/min on full throttle/AB. Sustainable climb using 7000 ft/min is possible up to 24K ft. o Terminal maneuvers: Above 10K ft AGL, lower climb rate to 3000 ft/min and advance autopilot IAS bug to
obtain 400 KIAS climb to next altitude target. Crossing 250KIAS engage Yaw Damper.
Crossing 18K ft, reset altimeter to 29.92. o Refueling: Dipsy Doodle (modified for FS9): o Mach Climb: COG: As speed increase stops or begins to drop, advance IAS bug to hold 400+ KIAS. When using Max Climb, keep the 440 KIAS bug setting until Mach hold is engaged. The goal is to hold as close to 400+ in the speed gauge as practical to avoid too-high pitch, yet avoid potential overspeed in high pressure and cold temps. Typical max bug setting on normal climb is 440 KIAS to avoid O-Speed. ----------------------- WARNINGS AND PROCEDURES: -----------------------!!!! PITCH WARNING !!!! PITCH TOO LOW PROCEDURE: Climb moderately and or slow to lower mach speed. Loss of control roll procedure (overspeed): - Immediately Disengage AB and idle throttle by disengaging MACH hold. - Attempt to climb. Try to avoid uncontrolled dive which will make the problem worse. If the negative pitch is caught early enough by slowing quickly, the plane will recover itself. STALL PROCEDURE: - Reduce climb rate, level off, or descend as conditions require. Maintain highest safe mach. Do not exceed M3.35. When pitch drops to stable condition, maintain profile (no matter how long it takes) until a typical pitch of .2 to 4.8 degrees is obtained. Only then can climb be re-engaged. Note: Sometimes conditions combine to limit engine power AND provide excessive pitch. This will seem like a no-win as the temperature limits the engine so you cannot increase speed and lower the pitch. Descend or maintain altitude until stable flight is obtained. !!!! ENGINE POWER WARNING !!!! !!!! Engine Overheat Warning !!!! !!!! OVERSPEED WARNING !!!! !!!! Electrical Power loss and Dead Stick Landing !!!! 440 IAS in the AP speed bug is the maximum SAFE that should be used in the
mach climb so a smooth mach mode switch-over can be obtained without over-speed. Switch back and forth between IAS and Mach mode and increase-decrease IAS bug numbers
until the mach indication reads .20 (typically while crossing Mach 3.01 on the IAS gauge.
This will hold Mach 3.2. Use the same procedure to change Mach speed. Switch back and forth between IAS and MACH and change the bug while in IAS mode.
At max fuel load, climb rate is slowly decreased as follows (note: These are guides.
Actual operation may vary depending on weight and weather conditions. This table is for
conserve fuel usage.) Alternatively for conservative climbs, use the Concorde style "Cruise Climb" at 100ft/min above 60K ft. Note: FS9 setting for max climb is Auto-Throttle set to 440 IAS, then manage the climb rate to keep the IAS gauge above 400 IAS as possible. Engine Spike: o Cruise: Cruise Climb: o Descent:
At 14k ft AGL, slow to 300 KIAS by setting AIS bug to 290. At 12K ft AGL, slow to 250 KIAS by setting IAS bug to 240. Within 40 miles of landing slow to 220 KIAS minimum turn speed. o Terminal maneuvers and approach: Normal landing weight is 10K lbs and base turn should be made @20 miles and 220 KIAS. When lined up reduce speed to 17k KIAS. At max weight, decel to threshold speed should be made at least 9 miles out. 10K lbs fuel can decelerate in @7.5 miles. 8 degree pitch is typical on the landing descent, 10 degrees on the AH over the threshold. Use shift-enter key sequence to lower the view to see the runway. shift-backspace to pitch up or SPACE key to recenter view to default. The Approach Auto-pilot will hold a steady glideslope with fuel weights up to 22,000 lbs. In the current panel, target AOA is apprx 12 degrees on the gauge (which is actually
close to the real AOA of 10 degrees. HI limit will be near 10 degrees on the AH.
- Set decision height on the radar altimeter to 350 ft. Real world tanker descent (assumes M3.2 80Kft): PROCEDURE SECTION COMPLETE Some interesting facts: 50 Blackbird airframes of various designations were built. The SR-71's fly at 33+ miles per minute (1,980 MPH/1,722+ knts) or 3,000 feet per second or faster than a 30-06 bullet. Each SR-71 cost 33 million to build and $1 million/mission to launch. Aircraft skin temperature can reach 800 deg F. Full AB thrust test stand exhaust flame apprx 30ft long producing 311 deg F temp and 150 knot winds 100 yards behind the engine. Another jet engine is used to push hot, super sonic air into the intake. The cameras can photograph a golf ball on the green from 80,000 feet. They can survey 110,000 square miles of the Earth's surface per hour. In 1981 Kelly Johnson announced that the SR-71 had over 1,000 missile launches against it, but none successful. Pilots in a pressure suit can lose up to 5 pounds in a four hour flight. The SR71 nickname Habu is the name of a Cobra snake in Okinawa, Japan. Apparently it's not normally aggressive to humans but has a nasty bite. Because of the sleek "hooded" appearance of the Blackbird caused by the chine, the Okinawan's claimed it looked like a Habu snake. Thus the nickname. Additionally, SR-71 Crew members are called Habu's. The SR-71 flew for 17 straight years (1972-1989) without a loss of plane or crew.
Of the 50 variants produced, 19 crashed with no loss of US Air Force crew. 478 total people have flown the Blackbirds.
More people have climbed to the top of Mount Everest.
Last flight of a military SR71 into Beale AFB for display: 1997
http://www.wvi.com/%7Esr71webmaster/sract%7E1.htm
NASA used one of its two SR aircraft for research on the LASRE aerospike engine project
as late as 1998: Program Info:(as of Jan 1990) Source: http://www.blackbirds.net/ * Total Flight Hours:...........53,490 EGUN Mildenhall England (main base) RODN Kadena Okinawa Japan (main base) KBAB Beale Air Force Base California USA (main base) KEDW Edwards Air Force Base California USA (Dryden) (also near Lockheed Martin Skunkworks) in Palmdale KPMD KSKA Fairchild AFB Spokane WA USA (training) Note: Most flights out of Palmdale were operated by CIA and had differing procedures from the USAF. |