The Blackbird
The Lockheed A-12 and YF-12A aircraft served as starting points for the development of the SR-71, also referred to as the “Blackbird” or long-range, advanced strategic reconnaissance aircraft. The 4200th (later 9th) Strategic Reconnaissance Wing at Beale Air Force Base, California, received the first SR-71 to begin service in January 1966 but the first SR-71 flight occurred on December 22, 1964. On January 26, 1990, the U.S. Air Force retired its SR-71 fleet.
For almost 24 years, the SR-71 held the record for being the fastest and highest-flying operational aircraft in the world. It could cover 100,000 square miles of the Earth’s surface per hour from 80,000 feet.
This article features the story of the engine fire that plagued Lockheed SR-71 Blackbird #975 during the sortie flown on Mar. 20, 1982, by Gil Bertelson and RSO Frank Stampf as written by Bertelson himself.
SR-71 Engine Fire
One of the more exciting and memorable missions we flew started out much like any other flight. We made a normal (typically spectacular) takeoff at Kadena at about 10:00 o’clock one sunny morning. We were ultimately heading for the Korean demilitarized zone that day, to be followed by a pass between China and Taiwan. We’d flown this particular mission track, or ones very similar to it, on numerous occasions. The mission called for an inflight refueling about fifteen minutes after takeoff. As we approached 25,000 feet, about two minutes after liftoff, I reached for the throttles to pull them out of afterburner. Just as my left hand touched the throttles, a red LEFT ENGINE FIRE WARNING light came on.
The procedure was one of those BOLD FACE check list items like I mentioned earlier. The first step was “THROTTLE: EFFECTED ENGINE IDLE”. The checklist continued, “IF FIRE WARNING LIGHT REMAINS ILLUMINATED: THROTTLE, AFFECTED ENGINE OFF.” I quickly performed those two steps and then told Frank what was happening. The remainder of the fire warning checklist consisted of steps that he’d read to me over the intercom. I confirmed with him as I completed each of those following checklist items.
The engine fire checklist was one of the longer procedures we had to deal with. Obviously, I’d made an immediate turn to head back to Kadena. Frankie got on the radio and declared an emergency with Kadena approach control. Declaring the emergency meant that we now had priority over any and all other airplanes in the vicinity.
The many checklist steps for an SR-71 Engine Fire
We continued to work through the many remaining checklist steps. One of those steps was that we were to “dump” any excess fuel in order to lighten the weight of the aircraft prior to landing. The airplane handles better with less weight aboard, and when you’re down to one engine that’s a good thing. The lighter weight also shortens the roll-out distance after landing and, should there be a fire after landing, there’s less fuel to feed the fire.
The left engine hydraulic system provided the power source for the normal landing gear extension system. Since the left engine was shut down, we’d have to rely on the “alternate gear extension” system to lower the landing gear. The alternate method called for me to grab hold of a yellow and black striped handle on the instrument panel just in front of, and basically between, my knees.
As Frank read the checklist step—“Alternate gear handle – pull”—I reached down and pulled on the handle that was attached to a cable. It just didn’t feel quite right as I pulled on it. I knew how it was supposed to feel because I had previously performed this procedure on maintenance test flights. I was supposed to feel three distinct “clicks” (for lack of a better word) as each of the three landing gear doors was unlocked and then came down due to gravity. Then the three landing gears themselves would follow the doors, again extending due to gravity.
Ejecting over the South China Sea
I hadn’t felt the three clicks, I quickly remembered a statement in the flight manual, known as “the dash one” (the numeric assigned to the aircrew member’s flight manual) that indicated that it might require 65 lbs. of force to activate the unlock system. I decided I hadn’t pulled hard enough, I gave it another tug, and the handle broke off in my hand. The handle was supposed to be attached to a cable that, when pulled, would initiate the emergency unlock, allowing everything to work. As the handle and the cable parted company, the cable then “ratcheted” back into the instrument panel and disappeared.
I now had an interesting dilemma. There I am, holding onto the handle that was supposed to extend the landing gear. The runway is now about eight to ten miles in front of us. We have little fuel left, and we have no landing gear. The “dash one” stated that an SR-71 should never be landed gear up. That’s a brilliant directive. I hope I don’t ever forget that one. That specific instruction, however, was directed exactly for a situation like Frankie and I were now facing.
Due to the composition of the materials that the airplane is made of, 90% titanium alloy, there is significant fire danger if a landing on the belly of the aircraft is attempted. In a no landing gear situation the recommendation is to try to find the best place possible and then eject from the airplane. In our circumstance, ejecting over the South China Sea, hopefully near a friendly boat, would likely be our best alternative.
Single-engine inflight refueling
When I think back on the circumstances, it’s amazing how things seemed to slow down at this point. As I was thinking about where to put the handle (there are no drawers or the like, and it wouldn’t be smart to put it on the floor where it might interfere with the flight control stick) a number of things came into focus. First, we need to “scramble” the ground alert tanker and get it airborne immediately (there was always one of those available and ready to takeoff anytime a Blackbird was airborne). Then we’re going to have to do a low altitude, single-engine inflight refueling which, as far as I know, is something no one had ever accomplished, practiced or anticipated.
That would get us some fuel which would keep us airborne for a while longer. Then we’d make a HF (high frequency) radio call back to California and get some Lockheed engineers out of bed. Those guys will recommend some things for us to try in an attempt to get the landing gear down. Given our particular circumstances, their well-intended suggestions probably wouldn’t work and at the end of the day; we’d need to try to find that friendly boat, and hopefully they’d be able to pick us up shortly after we ejected, and before we sank.
Circuit breakers reset
While all that was going through my mind I just instinctively reached down and back behind me (sort of under and behind my left arm) and reset a couple of circuit breakers (there were about seventy of them on that particular panel) that had been pulled as part of the checklist steps.
Then, for lack of anything better to do at that time, I cycled the normal landing gear handle to the down position. The particular c/b’s I’d pulled and had now reset had to do with positioning hydraulic solenoids into a position that would allow the alternate gear extension system to do its thing. By resetting the circuit breakers, the solenoids were returned to their original positions. I was just about ready to tell Frankie what I’d been thinking we needed to do when, out of the corner of my eye, I saw the green light for the left main landing gear illuminate, followed by a light for the nose gear and then the right main landing gear light.
We couldn’t be sure the landing gears were in the down and locked position, but at least it appeared they were down. The SR-71 guy in the tower looked us over with binoculars and told us he could see three landing gears in the down position. That was a quantum leap from where we’d been just a moment before.
A significant fire in the SR-71 left engine
The landing gears came down because even though the left engine was shut down, airflow through that engine was still causing the fan blades to slowly rotate—referred to as “wind milling” RPM. There happened to be just enough of the windmilling RPM to push sufficient hydraulic pressure through the lines to slowly activate the landing gear system.
It was pretty uneventful after that. I made my usual perfect landing, then stopped straight ahead on the runway and waited until the maintenance folks had installed the safety pins that would prevent any possibility of the landing gear collapsing during taxi. We then taxied to the hanger, turned the airplane over to maintenance, and our excitement for the day came to a successful ending.
It turns out that we’d actually experienced a significant fire in the left engine. Occasionally, a fire warning light might come on due to a wiring or sensing malfunction. That wasn’t the case this time. The fire was caused by a break in a 5500-psi fuel line near the afterburner. By the time we taxied to the hangar, maintenance was already pointing to a significant hole that had been burned in the side of the aircraft. In order to repair the airplane a whole new wing section had to be flown in from California. We were told that the damage amounted to more than $2 million.
Entire Blackbird fleet inspected
Because of the failure of our emergency landing gear handle and cable, the entire Blackbird fleet was inspected to look for a pending failure of that system in other airplanes. Several other aircraft had seriously frayed cables and could have experienced a failure under circumstances similar to ours.
The cause: For the pilots, getting in and out of the airplane was not a graceful maneuver. As we entered and exited the cockpit it was an easy and inadvertent thing to bump the emergency extension handle with our boots. Over time, with enough boots bumping the handle, one of the twenty or so strands of the cable could eventually break. After another period of time, another strand could break. And so on until the cable itself might fail. The odds, though, of another aircrew experiencing all of the same things that happened to us that day were pretty small.
The fix: Maintenance manufactured a bracket that covered the handle so it would no longer receive direct hits from the bumping of pilots’ boots as they entered and exited the aircraft. The cost of the manufactured part was about $5.
Check out Habubrats SR-71‘s Twitter profile, SR71Habubrats‘s Instagram profile, and Born into the Wilde Blue Yonder Habubrats‘s Facebook page for further Blackbird photos and stories.
Photo by U.S. Air Force