Former SR-71 Engineer Talks NASA’s Blackbird Revival Program
When it comes to the future of Tail 844, the SR-71 Blackbird that mysteriously disappeared from NASA’s Armstrong Flight Research Center, few people have more insights than Tim Conners. When he worked at NASA in the 1990s, Conners was the lead propulsion engineer for the agency’s Blackbird program. He worked extensively on 844 and has an intimate knowledge of what made the iconic aircraft tick. Now, he brings an insider perspective on NASA’s secretive work to get the Blackbird back in the air and speculates on what it would take to do so, as well as the famed jet’s possible flight test role for the agency after 27 years of dormancy.
Late last month, we wrote about how satellite imagery taken over Armstrong showed that Tail 844 had been missing since at least May. The revelation was first made by Steve Trimble, Aviation Week‘s defense editor and friend of TWZ. It came after NASA Administrator Jared Isaacman cryptically teased plans for a new high- and fast-flying X-plane with a silhouette of an aircraft that immediately drew comparisons to the Blackbird. Trimble reported just this week that NASA had been talking to ex-SR-71 program personnel about coming back to work on the aircraft. This confluence of events has led to rampant speculation about whether NASA was planning to resurrect the Blackbird and for what purpose?
In an exclusive interview with TWZ, Conners, now technical director for advanced weapons systems at Tiberius Aerospace, gave us his take on NASA’s Blackbird revelations and insights into what NASA is working on and how far along they are in the process.
Some of the questions and answers have been slightly edited for clarity.
Tim Conners
Q: Tell me about your background with the SR-71 program. How did it begin? How long did it last? And what did you do?
A: So that basically fell in my lap when I was an engineer at NASA’s Dryden [Flight Research Center] back in the early ’90s when NASA took delivery of three of the airframes when the Air Force was retiring the fleet. So NASA got two A models and a trainer. Obviously, tail number 844, which is NASA’s designation, is the one that’s getting all of the attention right now. But those came to Dryden in the early ’90s.
By luck of the draw, I was in the propulsion group. We were short-staffed for a number of reasons, and they needed an engineer on Blackbird. And I had been with NASA for about three or four years at that point, and I got tapped to prepare the NASA side of the mission for the upcoming research flights. So I had a few years to get familiar. That was a part-time job, by the way. I also owned the F-15 fleet at NASA as a propulsion engineer, and that was occupying a lot of my time, but it did give me an adequate amount of time to get familiar with the way that the airplane operated, at least from the propulsion standpoint. And then we began doing research missions in ’96. I left NASA in ’98, but I was able to support the program through two years of flight testing and all the years of preparation for those two years.
Q: Tell me more about your role with the Blackbirds.
A: I was lead propulsion engineer on the NASA side. So what NASA would do is they would assign disciplinary leads across from their industry and government counterparts. So Dryden’s disciplinary leads, their job was basically to make sure that any experimental packages were integrated safely with the airframe, and that we could execute the proposed test missions safely and successfully. I owned propulsion and I also owned performance. So if you recall the Lockheed Linear Aerospike rocket engine activity, that package weighed 20,000 to 25,000 pounds and was mounted externally on the back of the SR-71. That was a drag issue, obviously. So part of my role was to make sure that we could actually accelerate through the transonic drag rise with that package and get out to the target test conditions.
SR-71 tail number 844 during its service with NASA. This picture was taken on October 31, 1997, during a flight in support of the NASA/Rocketdyne/Lockheed Martin Linear Aerospike SR-71 Experiment (LASRE). NASA
Q: There is a tremendous amount of interest in seeing the Blackbird fly again. The biggest question seems to be why? What kinds of experiments or research would an SR-71 provide that couldn’t be done more effectively with a modern aircraft, rocket or unmanned vehicle? Can you walk us through some of the reasons NASA would like to see it in the skies again?
A: Yeah, that’s a question that everybody’s been asking. Why? I’m speculating, although I do have a good feel for where this is going. So bear with me.
They probably are not going to do this for — or trying to do this — for aerodynamic reasons. You can do CFD [computational fluid dynamics]-based modeling in this speed regime all day long and very accurately in this day and age. It does not take a lot of time or money to do that. What you cannot do is an accurate representation of a new type of engine integrated into a high-speed airframe. You can do the conceptual modeling of it. Of course, it’s difficult to get the final installed answer, especially if it involves an engine that operates at long duration. That is where I think they’re going with this. I believe that they’re developing basically a high-speed engine test bed. That would make the most sense to me.
Q: That’s something you couldn’t do with a more modern aircraft or rocket or unmanned vehicle?
A: That’s a good question. But you know, probably two-thirds of that battle is just developing the airframe. It does depend on the size of the engine that you’re after.
Obviously, if this were a Williams engine or that size class, you could get by with probably a bespoke drone to do your testing. That wouldn’t be that expensive. If your goal is to test something that’s man-rated or very large, like a J58-s
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