THE 456th FIGHTER INTERCEPTOR SQUADRON

THE PROTECTORS OF  S. A. C.

 

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Blackbird Maintenance

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SR-71 Maintenance

(July 1984 - December 1989):

By Christopher W. Bennett
 

 

Let's start with a brief tour of the aircraft.

When I arrived, I was most interested to see the cockpit of the SR, and knew it had to be an assortment of high tech. instrumentation and screens. What I saw was not even close, and amazed me. Although the Forward Cockpit (FCP) was filled with more instrumentation than other Air Force (AF) aircraft, it was the same old 60's technology. Actually, it was quite similar to that found in the old "bent-wing" F-4s. The Aft Cockpit (ACP) is a bit better, with mostly navigation and sensor control panels. No Star Wars technology here, as all the really neat stuff lies inside the many mission bays, out of view from prying eyes. Both cockpits are very spacious compared to that of fighters, and are equipped with ejection seats. The engine throttles are located on the left console, and tons of circuit breakers line both consoles. Only the front seater has a control stick to fly the aircraft. Map projectors were installed before flight in both cockpits. These were just scrolling imagery films, put together so that the entire mission route could be seen and tracked by both crew members. An optical view sight was installed in the ACP to allow the Reconnaissance System Officer (RSO) to view the target areas. Later, a video viewsight replaced the ancient optical one. Both the map projectors and view sights are not incorporated in todays SR-71s. Later on, a Peripheral Vision Display (PVD) was installed in the FCP. It is a laser, that projects a horizon line across the entire instrument panel, assisting the Pilot in flying. It also makes for a great light show on those winter evenings when the California fog rolls into the hangers. One cute little device found in the cockpits is what we call a "dingy stabber". This is just a six inch long flat piece of metal with a pointed end, and used for puncturing life rafts should they inflate accidentally in flight. For some reason, these became highly sought souvenirs during the program closure.

The airframe is primarily titanium alloy, covered by metal skin with plastic (honeycomb construction with asbestos) and metal panels. Many louvered panels surround each nacelle which allow for inlet inflows and outflows. The entire fuselage aft of the cockpits are fuel tanks. They number one through five from front to back. The inboard wings also house fuel cells, which incorporate part of tank three and two sections of tank six. The outboard wings are hinged near the top of the nacelle, and fold inward to allow access to the Pratt & Whitney J-58 engines. All electronic, communication, and mission bays are located on both sides of the lower fuselage beneath chine panels, and start just in front of the FCP extending aft to the 715 splitline, which is where the wings start. There is one other bay in the forward section of the Nose Landing Gear (NLG) wheel well which houses more circuit breakers, and is currently used to house the data-link system. The nose section is changeable according to each mission. Atop the aircraft behind the ACP and above tank one is the Astro Navigation System (ANS). This is the avionics package that navigates the SR-71 by the position of stars, weather day or night. We do have a hard time getting it to operate inside the hanger though. A mission tape is also loaded into this system, and is interfaced with the Auto Pilot system and various sensors for automatic operation. Just aft of the ANS package is the In-Flight Refueling (IFR) receptacle. Also atop just aft of the Main Landing Gear (MLG) wheel wells is the drag chute compartment. All landing gear struts are titanium, and nitrogen filled. There are two tires on the NLG, and three on each MLG.

Many internal systems are worth mentioning. There are three ten liter Liquid Oxygen (LOX) storage converters located under the left chine panels below the FCP. System one supplies the FCP, two supplies the ACP, and the standby system supplies both. Of course, these systems are used to sustain aircrew breathing at high altitude. Three Liquid Nitrogen (LN2) storage dewers are required to pressurize the fuel system. Two are located in the aft section of the NLG wheel well, with the other under the left chine panels just forward of the LOX system. Four hydraulic systems (L, A, B, and R) are incorporated, with engine driven pumps. The fluid was specifically designed for the high temperatures of the SR-71 and is clear in color. L and A reservoirs are located in the left MLG wheel well, with B and R in the right. L and R are used to control the inlet systems, NLG steering, MLG brakes, and the IFR receptacle. A and B are used to control all flight control surfaces, and assist in NLG steering through rudder movement. R is a backup system for L, with B a backup for A. The primary and backup systems are driven by different engines to facilitate safe flight in the event of an engine failure. The heart of the aircraft's electrical system is the "load center" located in the electronics bay beneath the chine panels on the left side. It is powered by ground equipment, or in-flight by a pair of engine driven generators, Constant Speed Drives (CSD), and an Accessory Drive System (ADS). Due to the many sensors and systems operated, the SR-71 electrical system can adequately power a small city. JP-7 is the fuel used, and is specifically designed for high altitude flight and high temperatures. All fuel system tanks are filled to a specific amount for each mission profile. In flight, they are usually filled to capacity, and an auto-sequencing system controls the flow to ensure a proper Center of Gravity (CG). Fuel is also re-circulated through the system to be cooled, and also provides some cooling to the engines and generators. Two engine driven oil systems are used to lubricate the J-58s, and are located on each engine. This oil is also clear in color, and was specifically designed for the high temperatures encountered. This oil must be heated to seventy degrees Fahrenheit prior to each engine start. Below this temperature, it is as thick as molasses. The environmental systems "heat-sinc packages" are located in the lower inboard section of both nacelles. They are fuel cooled, and provide engine bleed air to the air-conditioning package located in the ANS compartment. This package primarily provides cooled air for the pressurization and cooling of the cockpits, nose, mission bays, and ANS bay. Triethylborane (TEB) is used in place of igniter plugs to start each engine due to the high flash point of JP-7. TEB is a volatile fluid that ignites when it comes in contact with air. It is serviced prior to each flight and is stored in a sealed tank mounted atop each engine. With engine rotation, TEB is released by placing the throttle over the hump to the idle position, then again when placed into the After Burner (AB) position.

The inlet system is the heart and soul of mach three flight, and is controlled by many factors. There are three Digital Automated Flight Control System (DAFCS) computers, A, B and M, and are also located in the electronics bay. There are three, a primary and two backups, because the inlet system is critical for aircraft safety at high speeds. These computers receive there inputs from the alpha and beta probes on the pitot tube through the Pressure Transducer Assembly (PTA) located just aft of the nose assembly. The computers then send a signal to the Differential Pressure Transducers (DPRTs or "hot boxes") located on both lower inboard nacelles. These units send signals to the flight control servos, and actuate the inlet control systems, such as the spikes and forward and aft bypass doors. The spikes are the pointed conical sections which extend from the front of the inlet of each nacelle. These spikes can travel as much as twenty-one inches aft, and are used to position the super-sonic shock wave inside the inlet. Combined with the back pressure from the face of the engine, the supersonic airflow enters the forward bypass doors. This ensures that supersonic air will not enter the engine, with some being bled overboard, and the rest bypassed around the engine, and dumped into the aft engine sections for greater thrust. The aft bypass doors perform similar functions. In fact, about 75% of the actual thrust is generated by this bypassing air, and allows the engine to operate economically, not using much more fuel at cruise speeds than it does on the ground.

You've probably heard the SR-71 is a severe leaker, and I'll try to put this into perspective. Once LN2 is serviced a few hours prior to launch, the fuel system becomes pressurized, and that's when the real leaks start. Normally, about five or six steady fuel leaks (about the width of a drinking straw) show up coming from both inboard wings, falling about six feet to the ground. The entire bottom of the fuselage becomes wet, and starts dripping onto the hanger floor. Some puddling starts to accumulate on top of the inboard wings, and at times runs off the wing onto the floor. In some bad leakers, fountains can be seen spraying upward from the top of the inboard wings, ranging anywhere from two inches to three feet in height. Usually, the really bad leaks occur when the aircraft is getting close to being sent to the Depot for an overhaul. How much fuel is actually lost prior to flight? It was a common practice to refuel the aircraft about four or five hours prior to flight. It was also standard to place about four to seven hundred pounds of JP-7 extra in the tanks to allow for this leakage. That's a loss of about one hundred pounds or sixteen gallons per hour. And folks, that's just for a standard fuel load. At times, due to lack of tankers, we would put considerably more fuel onboard, and launch her on a "rocket ride". When we did this, you could basically double the amount of leaks I've described. Why all the leaks? High temperature fuel sealant was especially designed for the SR-71, and there's no other substance known in existence to replace it. Once the aircraft is as cruise speeds, it tends to seal itself. The leaks I've spoken of do not jeopardize the safety of the aircraft, due to the high flash point of JP-7. In fact, a lit match thrown into it would just go out. Up until the late 80's, the fuel leaked was simply washed out of the hanger after the launch, and went into the ground. Due to environmental laws towards the end of the program, we started to catch the fuel in drip pans, dispose of it properly, and vacuum the residual from the floor. You could always pick out the guys who had participated in a launch. They smelled like JP-7, there hair was sticky looking, and fuel stains covered their uniforms. Many guys wore rain suits to eliminate this problem. Believe it or not, a half can of Coke added to the wash removed all the stains and smells from the clothing.

We had two methods to start the powerful J-58 engines. The first and oldest method was to use the start carts. These were twin Buick 455 v-8 engines, dressed out with racing cams and headers. They were coupled together to a rotating shaft that connected to the starter shaft of the engine. It took some serious rpms to start the J-58s, and it wasn't uncommon to see one break apart throwing piston rods through the engine block. In the late 80s, the Buick engines were replaced by built up Chevy 454s. That pretty much eliminated our rod throwing problem. The other method to start the engines was through the use of pneumatic air. The hangers at BAFB were equipped with these systems in the early 80s, and it quickly became the preferred method. A removable turbine was attached to the engine starter shaft, and was fed by two four inch diameter hoses connected to the system on the hanger wall. The Crew Chief operated the valve from the wall location. We would still use the start carts periodically to keep personnel current, as we had to use them on the trim pad, and when at Temporary Duty (TDY) locations at times. We did use the pneumatic system off station at times, but this was quite cumbersome. It required four ground air units (-60s) to start a single engine. These four units are manifold together, then connected to the two entry points on the starter turbines. This is the method now currently used by Detachment (Det) 2 at Edwards Air Force Base (EAFB).

Performing engine runs was the best part of the job. To perform this task, an engine run school had to be accomplished, and was limited to those at the rank of Staff Sergeant (SSgt) and above. There's nothing like the feeling of true power you get just sitting in that front seat with engines running. We were permitted to perform engine runs slightly below Military (MIL) power inside the hangers, and could also accomplish MIL runs on the ramp next to the shelters. Usually, the jet engine mechanics performed the trim runs in full AB, but at times, even us lowly Crew Chiefs got our chance. To get to the trim pad at BAFB, it was about a mile and a half tow south down the taxiway from the hangers. When a trim run is performed, the aircraft is held in place by huge steel bars connected from the nacelles to a ground attach point well behind the aircraft. The NLG is also anchored by cables. The SR-71 is probably the easiest aircraft in the world to start. Once engine rotation has begun by the ground starting unit, you simply move the throttle to the idle position and watch the gages. Rpm increases, TEB lights the fuel, oil, hydraulic and fuel flow pressures build up, the engine starts and Exhaust Gas Temperatures (EGT) begin to climb, all stabilize, and that's it! Different from other AF aircraft are the engine speed gage ( which is measured by rpm, not percentage), and the fuel quantity gauge (measured in pounds, not gallons). Once you're running, it takes about thirty minutes for the entire trim procedure, and we're kept quite busy recording numerous readings. There are more checks during this engine run than on any other aircraft I've encountered. When you're sitting there in idle, you can clearly see the crew entrance stand off your left side. When you take her to the MIL power setting, the nose of the aircraft drives down, and the stand appears to have raised two feet. When you take her to minimum AB, the nose drives down even further, and the stand all but disappears from view. Once in AB, the aircraft feels like it flying as it moves rapidly from side to side. When you nudge her to maximum AB, you can barely hear through the communications gear worn for contact with ground personnel, and the flame coming from the back grows from five to about twenty feet. Once it's all over, you slowly bring her back to MIL, then idle, and the nose comes back up, and it seems quite calm. After giving the J-58s a five minute cool down period, you shut them down.

TEB servicing was quite interesting. Early on, there was a special TEB shop to perform this task. Then in the late 80s, the Crew Chiefs took over this function. Any time this operation was performed, the Fire Department would be on the scene in case of trouble. Two mechanics were required, and both wore complete fire suits. One manned the TEB servicing cart on the ground, with the other atop the wings at the servicing point. Once servicing was under way, the mechanic on the wing carefully monitored the process for leaks. Leaks were frequent, and usually quickly corrected. At times, larger leaks occurred, and the mechanic would simply take a wet rag and rap it around the leak to smother it until the process was complete. I've seen leaks so bad, that the mechanic would pull his gloved hand from within the servicing panel, and it would be completely engulfed in flames. He would simply put his glove into a bucket of water, cool it off a bit, then press on. Sometimes the TEB servicing cart would also have small fires, and they were also quickly fixed by wrapping a wet rag around them. The BAFB Fire Department was usually well trained on how to deal with these fires. We always briefed them before we started, and they knew they should not respond unless we instructed them to. Well, sometimes you get a new guy, and on one such occasion, he got a bit anxious of a small fire, and unleashed a spray of water towards the wing and the mechanic performing the task. Unfortunately, the mechanic was blown off the wing, and broke his arm. The other mechanic quickly took care of the fire. There were rare occasions when the fire would drop on to the wing. In those cases, the Fire Department would spray it off the wing, and we'd let it burn itself out. Even if you kept it wet, once the hose was turned off, the fire would start again. It was also interesting to watch the TEB shop perform standard maintenance on the servicing cart. When lines were disconnected to change the filters, the filter elements would be extracted on fire. As you can imagine, every time we went off station with the SR-71, the local Fire Departments usually freaked out a bit when we told them of the operation we needed to perform.

Refueling the aircraft is a bit archaic, and four mechanics are required. One is the ground supervisor, one the fire guard, one monitors the fuel source, and the other performs the operation from the FCP. We usually refueled from ground servicing hydrants, and this was connected to our Single Point Refueling (SPR) receptacle on the right side of the fuselage just aft of the NLG. The mechanic in the FCP controlled the refuel box which was connected to a port in the NLG wheel well. This box controls the primary and secondary refuel shutoff valves in each tank. He would monitor the fuel tank quantities on the instrument panel, and turn off each tank as it neared the desired level. Many times, some fuel would go where it wasn't supposed to, and when that happened we would simply transfer the fuel between tanks. This could be accomplished by two methods. Without extra equipment, we could transfer fuel forward into tank one or aft into tank five. We accomplished this by switching on either the aft or forward fuel transfer switch on the FCP instrument panel, and applying boost pump pressure to the tank that fuel would be removed from. When fuel was needed in any other tanks, we would hook up what we called a "run-around" hose between the SPR receptacle and the de-fuel receptacle, which was located on the same side near the 715 splitline area. Then, using boost pump pressure and the refuel box, fuel was transferred. De-fueling was easily accomplished by boost pump pressure through the de-fuel receptacle. Weather refueling or de-fueling, it was a real pain to remove all the fuel from tank six. To accomplish this, the MLG struts had to be deflated, and the NLG strut fully extended. This gave us a nose up attitude, and allowed the fuel in tank six to reach the boost pump area. Since JP-7 has a high flash point, we were able to perform maintenance on the aircraft during fueling operations, which is usually not permitted on other AF aircraft. There was one very real safety concern to watch for during fueling operations. Sometimes a small amount of TEB would seep into one of the engines. This didn't happen often, but when it did, you definitely knew it. TEB has a distinctive odor, and that was the first sign. Next, smoke would appear coming from the affected nacelle. Usually it would burn itself out, and all was well. If it persisted, we would have to motor the engine to either blow it out, or eject it out the back of the engine. This only happened to me five or six times, and I only had to motor the engine twice. I found it quite interesting that every time it did happen, the fuel mechanic monitoring the hydrant would quickly disappear.

Let me say a little bit about the work force. The experience level and pride of our mechanics was without a doubt the best I had ever seen in the AF. This was due to the love for the aircraft, and a program called "code 42". Once a mechanic had been on station for a couple of years, he could apply for this code, which would keep him in the program for at least five additional years. Most mechanics I knew did exactly that, and in fact, it wasn't too uncommon to see folks hang around for more than ten years. Some spent their whole career on the SR-71. This made us very rank heavy, and very few new trainees were brought in. You've always got a few bad apples, but for the most part, everyone knew what they were doing. Integrity was extremely high, and very few mishaps occurred. This was one big family folks! Early on, we Crew Chief types worked a three shift operation, and each aircraft had it's own head Crew Chief. The rest of the personnel were in a floating pool and were assigned daily. There were also two "BPO/Lube" teams which took care of all after flight inspections and periodic lubrications. These functions will be discussed later. Towards the late 80s, we changed our maintenance concept. All Crew Chief mechanics were divided evenly and assigned to a specific aircraft. From then on, each aircraft had an Aircraft Manager (a fancy name for Crew Chief) and about ten mechanics permanently assigned. This worked out extremely well, and we basically worked our shifts around the missions. The only time we did not work on our own aircraft was when others needed help, and of course about once every six weeks on a rotating weekend duty schedule. Almost without exception, a weekend duty consisted of at least 24 hours of work.

Many inspections and periodic maintenance were required to maintain the SR-71. A Pre-flight (PR) inspection was performed within 24 hours prior to each flight. This inspection took roughly four hours, and required four mechanics. During the launch, a Crew Chief would perform what we called the "launch supervisory" inspection. This was usually a Technical Sergeant (TSgt) or above, and he generally made sure all went well, and identified any problems. He also accompanied the aircraft to the End Of Runway (EOR) to perform the last chance inspection. During all aircraft recovery operations, a Crew Chief would perform the "recovery supervisory" inspection. During this, he generally checks the condition of the aircraft, and searches for leaks and problem areas. After each flight, a Basic Post-flight (BPO) inspection is performed. Itís a bit more in depth than the PR, but involves the same amount of people and time. Due to the high temperatures the aircraft encounters, a Hourly Post-flight (HPO) inspection is required every 25 flying hours. At BAFB, this was usually after every sixth or seventh flight. This inspection consists of some in depth examinations and a complete aircraft lubrication. Additional inspections are performed every 50 hours. Each 25 hour HPO took about 24 to 36 hours, and each 50 hour HPO took about 48 to 72 hours. This inspection process continued until the aircraft reached the 400 hour HPO. This was a full blown Phased inspection where the entire aircraft and systems were thoroughly inspected. It usually took anywhere from six to nine weeks to accomplish this inspection. Every 800 hours, the aircraft would be sent south to Palmdale California for the Periodic Depot-level Maintenance (PDM) inspection performed by the Lockheed Skunk Works. This six month long inspection is where the aircraft is basically taken apart, inspected, modified, upgraded, put back together, and flight tested.

In the AF, there are several aircraft in the inventory that have become known as "pigs". That's a bad way to say they're maintenance intensive, or in other words, break a lot and are hard to maintain. In the fighter world, it was the F-4 and the F-111. Most of us SR-71 Crew Chiefs came from the fighter world, and completely understand that concept. The SR-71 makes the Phantom and Aardvark look like dream aircraft to work on. I have never worked so hard in my life to keep just one flying. It may sound like a contradiction, but while loving the aircraft, we also cursed it a lot! But let just one person try to call my SR a "pig", and a fight would probably result. While other Crew Chiefs hope for Code-1 (no problems) sorties, we were elated when it landed Code-2 (minor problems). But usually, Code-3 (broke) was the norm. Even on those rare occasions where she did fly good, many times the Digital Mission Recording System (DMRS) tapes would show problems that needed to be corrected, especially on Friday nights it seemed. There were some consistent problems that really stand out. First and foremost, DAFCS. Those inlets were hard to maintain, and as good as those technicians were, we continually had problems. I can't really single out one specific area of that system of concern, but it's something we learned to live with, and spent many hours getting to know the DAFCS folks. Another big problem was heat related engine and electrical problems. I say "heat related" because these problems usually only occurred at speeds above mach three, and then went away once it slowed down below 2.8. How do you troubleshoot those problems? There's no was to duplicate that condition on the ground. We would end up simply changing the most likely component (shot-gunning) that could cause the problem. Really, there was nothing much more we could do than that. Due to the stress of mach three flight, we would always find many structural defects after each flight. I'm generally talking about popped rivets, cracked panels, and delaminations. It wasn't uncommon to have twenty or thirty discrepancies found on each BPO inspection. Another problem occurred when trying to pin-point leaks. With oil, fuel, and hydraulic fluids being the same color, it was difficult to actually see what was leaking. Lets face it, as leaky as she is, there's already a little bit of fuel everywhere.

By Christopher W. Bennett
 

 

Introduction

This article is written from a maintenance guy's prospective, and is designed to give a better idea of what it was actually like to work in the Recce world. All comments and statements made here are from my own experiences and perceptions, and in no way reflects the official view of any agency or organization. It's simply how a Blackbird Crew Chief saw it!

I was assigned to the 9th Reconnaissance Wing (9RW) at Beale Air Force Base (BAFB) California for about twelve and a half years. I spent the first six years on the SR-71 as a Crew Chief, Expediter, and Shift Chief. The next four years were spent on the U-2 as an Expediter, Production Supervisor, and Production Superintendent. Then a year and a half as the SR-71 Maintenance Superintendent for the Reactivation and finished up the last year as the Chief Operations Group Inspector for Quality Assurance (QA). I will not discuss the SR-71 Reactivation here, as I've written a specific article on that subject, and is also available on this site for viewing. Over 90% of this article deals with the SR-71, with just a few reflections on the U-2 program. For more information on my assignments, a brief biography is also available here.

 

A Typical SR-71 Maintenance Process

What follows is the typical maintenance sequence of events each SR-71 must go through to fly a routine 1989 photo reconnaissance mission. Some acronyms may not be familiar, but youíll get the jest of how much work is actually involved to get one of these off the ground. Also included are many of the recovery functions performed after each flight. These tasks can and are performed at a greatly accelerated pace when less advanced notice is given, and especially during aircraft generation exercises. Keep in mind, this is based on AF maintenance personnel, not civilian contract maintenance.

0900 MISSION NOTIFICATION: TAKE OFF 0415 HRS.

0900 - 0930 TEB serviced.

0930 - 1000 LOX system serviced.

1000 - 1400 APG PR inspection performed.

1030 - 1100 IFF Mode 4 is keyed for flight.

1100 - 1300 Photo shop uploads and checks OBC and TEOC cameras.

1200 - 1600 EWS shop uploads and checks DEF systems.

1300 - 1330 DMRS is checked and pre flighted.

1400 - 1600 PR discrepancies are repaired, and the aircraft is paneled up.

1400 - 1430 Aircraft drag chute is installed and checked.

1600 - 1700 The aircraft fuel system is serviced for flight.

1700 - 1730 Aircraft landing gear struts are set for flight.

1700 - 1730 Weight and balance is computed and the RHSO and Mode Select are set.

1700 - 1730 ANS configuration is performed.

1730 - 1830 DAFCS/Auto Pilot pre flight is accomplished.

1830 - 1900 Batteries are installed, and electrical system pre flight is accomplished.

1900 - 2000 Aircraft wheel brake check is accomplished.

2000 - 2100 Aircraft's hydraulic system and accumulators are serviced.

2000 - 2030 Mission map projectors are installed.

2030 - 2100 Autopilot/SLR/INS interface performed.

2100 - 2200 Aircraft tires are serviced for flight.

2200 Electrical power applied to maintain temperature for TEOCs.

2300 - 2345 Communications system pre flight is performed.

0005 - 0200 Aircraft panel inspection is performed.

0005 - 0325 Heat is applied to engines if the temperature is below 70F.

0115 - 0145 Crew Brief: The crew chief meets with the aircrew to review the aircraft forms, verify weight and balance requirements and settings, verify mission equipment uploads, and to review the aircraft's previous maintenance history.

0115 - 0215 LN2 system purge and environmental pre flight performed.

0200 - 0230 Cockpit seat packs are installed.

0230 - 0300 Final cockpit inspection performed, and canopies and windscreen cleaned.

0230 - 0300 Final tire servicing check is accomplished.

0230 - 0315 LN2 is serviced.

0245 - 0300 NLG is lubricated.

0300 - 0315 Circuit breakers in C Bay are set, and bay is closed.

0300 - 0315 Aircraft covers are removed.

0300 - 0330 Engine inlets are inspected.

0315 - 0330 All maintenance tools are inventoried.

0315 - 0330 Aircraft forms are reviewed and the Exceptional Release is signed.

0315 - 0330 Mobile aircrew arrives, and sets up the cockpits for flight.

0315 - 0330 All camera covers (except OBC) are removed.

0325 - 0330 The aircrew arrives and enters the cockpits.

0330 - 0400 LAUNCH SEQUENCE BEGINS;

0400 - 0405 AIRCRAFT TAXIS TO HAMMERHEAD.

0404 - 0412 END OF RUNWAY CHECKS PERFORMED;

0412 - 0414 AIRCRAFT TAXIS TO RUNWAY.

0415 ONE BLACKBIRD IN THE SKY!

1030 AIRCRAFT LANDS.

1030 - 1038 Aircraft taxis to hanger.

1038 - 1040 Aircraft is marshaled into hanger.

1040 - 1050 AIRCRAFT RECOVERY CHECKS BEGIN;

1050 - 1055 Aircrew exits the cockpits.

1055 - 1100 Aircrew performs a preliminary debriefing of the aircraft's status.

1100 - 1130 Seat packs are removed.

1100 - 1200 All mission equipment is removed from the aircraft for data retrieval.

1100 - 1130 Engine JOAP samples are taken.

1100 - 1130 Aircraft ADS's are serviced.

1130 - 1200 Engine oil systems are serviced.

1130 - 1200 DMRS tapes are downloaded.

1130 - 1200 Mission map projectors are removed.

1130 - 1200 ANS/INS system post flight inspection is accomplished.

1130 - 1200 Formal debriefing is accomplished.

1200 - 1225 Aircraft is towed into correct hangering position.

1225 - 1230 Aircraft tires are inspected.

1230 - 1330 Aircraft circuit breakers are set for ground power application.

1230 - 1330 Aircraft is de-paneled for post flight inspections.

1330 - 1730 APG BPO inspection is accomplished.

1330 - 1530 Engine post flight inspections are accomplished.

1330 - 1400 Aircraft batteries are removed.

1330 - 1400 DAFCS post flight inspection is accomplished.

1730 - ???? Aircraft discrepancies and maintenance problems are in work.

 

Sr-71 Deactivation  (January - December 1990)

These were some very sad days indeed! Even when the program closure was announced, I never really believed it would actually happen. I had a hard time accepting that anyone in their right mind would retire the world's fastest and premier reconnaissance aircraft. I figured they would come to their senses, and do the right thing. The politics played out here was a hard pill for many of us to swallow.

On the very day it was announced, our Aerospace Ground Equipment (AGE) shop came out to the flight-line, and started removing all our support equipment. This was quickly stopped, as we were still going to maintain flying operations for the next several months. From that point on, anytime we needed any support, such as specialists to work maintenance problems, fuel, parts, or equipment, we took a back seat to the U-2 operation across the ramp. This was a dramatic change in our operation as we were used to being the highest priority on base. This loss of status is something we had to endure for the entire year.

Then something happened that left a bitter taste in all our mouths that lasts to this very day. AF man-power teams were sent to Detachment 1, Detachment 4, and BAFB to provide a selection of future assignments for all personnel. These included going to such programs as the F-117, F-15, F-16, and many other weapons systems. After the team completed it's business with the Detachments, they came to the 9RW. They were met by a few folks from our squadron supervision, and were told that we all wanted to be absorbed into the U-2 program. We were never told they were coming, nor when on base, and we wouldn't find that out until three months later after it was finalized and too late. How's that for gratitude and proper treatment? I'm here to tell you that about 80% of our personnel would have opted for an assignment to another airframe.

Shortly after that, nearly half of all our personnel were moved to the U-2 side. That was to be expected, but they forgot one important thing. Our flying tempo stayed the same. Now we had to support all sorties with half the people. If that wasn't enough, the flying schedule slightly increased so our Pilots could get in many more hot flights before it was too late. This created nothing but tension, and we ended up working twelve hour shifts to support our Pilots. So, here we are busting our butts to support an aircraft that's being retired! Talk about some very angry Crew Chiefs!

The program was also given forty million dollars to close it down. Many plans were made, such as more speed records, and a six ship formation fly-by as a send off. Well, the Strategic Air Command (SAC) took care of that, as they pulled thirty million dollars of it back for their use. Not only that, but the 9RW was instructed never to fly supersonic again, with the exception of the upcoming retirement ceremony. Keep in mind, what we call supersonic is a speed above mach 2.6. So for the rest of our flying, the Pilots simply flew around the local area a lot. It was really sad to see the returning Detachment aircraft. The normal four hour flights from Detachment 1 were accomplished in six and a half. One of their returning aircraft depicted the mood in an accurate fashion. A drawing of a head stone with RIP inscribed had been placed on both rudders.

The retirement ceremony was also a very sad day. Many media and local personalities were on hand, and the base was opened up for all to see. We started it out in dramatic fashion, as we opened all the SR-71 shelters simultaneously for all to view. All twelve shelters had an SR-71 in them. Aircraft 971 was flown that day, piloted by the 1st Strategic Reconnaissance Squadron (1SRS) Commander Lieutenant Colonel (Lt Col) Rod Dykman. He took her to speed and did a high pass over the base while dumping fuel. This was the best way to depict the speed on the SR-71, as all could look above at an aircraft at 80,000 feet, and see the swift contrail produced by the fuel hitting the cold air. In just a few seconds, it was out of sight. Shortly thereafter, he performed a few fly-bys, landed, and taxied her to the place of honor in front of the stage setup for the ceremony. During the ceremony, Rod's face told the story as he was nearly in tears. General Chain, the SAC Commander, seemed most happy with himself to announce that the SR-71 was now officially retired. There was no applause what so ever. Later, there was a banquet, also chaired by the General, and again with negative responses to his speech. Out of all this, how appropriate it was to see 971 as the first aircraft re-activated!

It was now time to start sending the aircraft to Palmdale and museums. All remaining personnel got their chance to go on one of these trips. All aircraft were flown subsonic to these locations. Once there, they were de-commissioned. We simply drained all fluids, removed the pyrotechnics from the ejection seats, and removed a few classified components. No components or systems were properly preserved, to include the engines. I was part of the team that took 976 to the AF Museum at Wright Patterson Air Force Base in Ohio. This was the last flight of any SR-71 by the Air Force. This is also where reality finally set in for me. After we decommissioned her, I helped the museum folks clean her up a bit, and tow it across the field to the main building. It would remain outside for all to view for two weeks, then would be placed inside the museum. Once we got her in place, it started to rain. I just sat there in amazement. My SR-71 had never been left out in the rain! I just stared at it for a couple of hours, realizing that this was its final destiny. I can't begin to describe how that felt inside. If there was any silver lining to this trip, it was the special tour we were given of the XB-70's cockpit. All and all, that was the worst trip I ever went on!

Upon returning to BAFB, most of the remaining personnel migrated over to the U-2 side. I wasn't going to go without a fight. Myself and four other Crew Chiefs were all that remained assigned to the SR-71. We were placed in charge of the turn-in of equipment, and assisted other museums prepare two non-flyable SR-71s for shipment. We had three such aircraft left which had been stored at BAFB since 1976. They were non-flyable because we had taken parts off of these for use on mission aircraft over the years. SR-71C 981 was cut into three pieces, and placed on a C-5 and sent to the Hill Air Force Base Museum. The cuts were made on both inboard wings just six inches outboard of the MLG trunions. The main section of that aircraft was towed onto the C-5. 961 was dismantled and sent to a museum in Minnesota, I believe. We put 963 back together, sealed the cockpits, and prepared it for static display at BAFB. Base Civil Engineering folks poured some concrete and asphalt per our specifications next to the control tower. This was done in the shape of the SR-71 three plus diamond patch, and we painted it as such. We then towed 963 into place, and it sits there today. All equipment was turned in by Christmas, and it was now time to be absorbed into the U-2 organization

 

The SR-71 vs. The U-2

This topic is always controversial, and should get the juices flowing! The first argument that comes to mind is the cost to operate and maintain these aircraft. This was the supposed logic behind the de-activation of the SR-71. If you park both Blackbirds side by side, you would likely choose the U-2 as the most cost efficient of the two. If you consider merely the aircraft and the fuel it requires for a mission, you're absolutely correct. The SR-71 uses at least ten times more than the U-2 for an average sortie. The SR-71 is also much more maintenance intensive to keep flying. Ok, now let's add the cost of KC-135 tanker aircraft that deliver the fuel in-flight to the SR-71, and it's support personnel. Now we see the SR-71 is about fifteen times more expensive to operate. Now, lets consider the rest of the story.

The SR-71 was primarily operated at three locations worldwide, while the U-2 has always maintained a few more. More program personnel, equipment, and supplies were required to maintain these locations. In the late 1980s, there were twice as many U-2s in service, with over twice the number of aircrew members flying. More funds were also being utilized for U-2 sensor upgrades. Lets say for the sake of argument, that after all this, the SR-71 is still five times more expensive to operate.

Now, lets look at reconnaissance commitment. The SR-71 maintained world-wide coverage from it's three locations. The U-2 had limited coverage, and often needed to deploy closer to hot spots, which created airlift expenses. Due to this movement, it could take days to get into position for coverage of a particular area. Due to the SR-71's speed and range, it could be over any hot spot in the world within five or six hours. Again, for the sake of argument, lets now say the SR-71 is still four times more expensive to operate.

The capabilities of a reconnaissance aircraft are measured by it's product. In the late 1980s, both the U-2 and SR-71 supported similar systems with very good quality products. There was, however, one significant difference. Due to the speed and range of the SR-71, it could cover over ten times as much surface area as the U-2. That equates to at least ten U-2 sorties to cover the same area as one SR-71 flight. Iíd venture to say that now the expense for operations is now about equal.

Lets look at Operation Desert Storm / Shield. The U-2, as well as many other AF aircraft had to deploy to the region to facilitate adequate coverage. Even with the U-2 in place, the SR-71 was requested. Although there was not enough time to re-activate the SR-71 then, I find this request very enlightening. This was by no means a major war, nor great force to contend with. And still, prior to US air superiority in the region, the U-2 was unable to provide reconnaissance of key hot spots. Why? As proven many years before, the U-2 is vulnerable to missile fire. Without "de-activating" these sites, no over-flights of particular areas could be attempted. Even after air superiority was achieved, more defensive measures had to be utilized. In fact, it was speculated that if the SR-71 still existed at the time, it could have launched from England, covered five times the area of the U-2 in Iraq, and landed back at base a few hours before the U-2 could have (remembering that the U-2 was in place in the region). It was also speculated that the SR-71 could have been deployed to areas like Egypt or Turkey. From either of those locations, the SR-71 would not have needed tanker aircraft support. One flight could have obtained five times as much coverage, and landed back at base before the U-2 even got into the area. The same basic scenarios applied to Bosnia as well.

Over-flight for the SR-71 is not a problem. Over the years, many have attempted to shoot her down, and I think the closest they ever came was within about a mile. In fact, we used to fly training sorties against our Navy. We would give them the following facts: Our launch time, route, altitude, and speed. If that wasn't enough, we would fly with transmitting beacons which would alert ground stations and aircraft to our exact location. Then, the Navy F-14 Tomcats would attempt to achieve a missile lock on the SR-71. At our speed and altitude, they have about 2 1/2 seconds to achieve a lock. We did this for several years, and to my knowledge, they never got us. No other aircraft in the world has had greater success in this area than our F-14s!

I didn't speak much to the issue of UAVs and satellites here, and for good reasons. They are just not practical solutions to reconnaissance in a hostile environment. The UAVís just crash or get shot down a lot, and satellites are predictable, and simply too hard to move into position.

You can decide for yourself which was more economical to operate. In 1990, politics canceled the SR-71 program. At that time, it was the most capable of all reconnaissance platforms in existence. One major reason it was canceled was to provide funds for the UAV programs. Congress was promised a replacement within five years. Obviously that never happened, and Congress directed the re-activation of the SR-71. The AF still favors the U-2 and UAVs, and continues to do everything to prevent it's comeback. Over the past six years, the U-2 has had many advancements, and is now the best. While the SR-71 is capable of returning as the world's premier reconnaissance platform, lack of funding is preventing this. All advancements planned for the SR-71 fall short of current U-2 capabilities, and that's the plan that's been directed from the top by the limited funding available. A data-link system that sends "real time" information from the platform to a ground station is where reconnaissance is at! The SR-71 is making an attempt to get there, but due to funds, had to settle for an aged system that really never worked well on the U-2.

I think its quite obvious which was more important for national defense! It was thought with the fall of the USSR, that the SR-71 would no longer be needed. Iraq and Bosnia proved this to be a falsehood. Who's next? I fear a world crisis is the only way the SR-71 will get another chance to prove itself. Lets hope I wrong!


By Christopher W. Bennett
 

 

 

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