Questions & Answers
Describe what kind of mentors you had in flying
Phil: I had a number of mentors during my Air Force flying career. They were usually my flight commanders or instructor pilots or instructor weapon system officers (WSOs). I entered the Air Force in 1973 and started out flying the F-4 Phantom. At that time early everyone in my initial training and operational squadrons were Vietnam war veterans, with extensive real world combat experience. When I was flying the SR-71 my mentor and in many ways “hero”, was an RSO named LtCol Joe Vida, he was the most experienced RSO and had the most flying time of any SR-71 crew member. He was the RSO flying with Major Ed Yielding on the record flight from Los Angeles to Washington DC of 1 hour and 4 minutes.
Did flying with elevons feel different to you?
Phil: Unlike other Air Force two place aircraft, the SR-71 did not have flight controls in the rear cockpit. So as a Reconnaissance Systems Officer (RSO), I can’t say from personal experience, but the pilots said it flew like other similar size and weight aircraft.
I have heard that the SR-71 got longer in flight. Was this apparent to you as the pilot in any manner?
Phil: It did grow in length due to aerodynamic heating. The average surface temperature is 600 degrees F. I’ve heard that it grows 4”, I’ve also heard that that it grows 7”. You can’t though see any specific evidence of this expansion while flying.
What’s the best thing about your job?
Phil: This was a great aircraft to fly and I was so fortunate to have been a small part of this amazing program. I was part of the flight test team flying out of Palmdale California. We had two very experienced test pilots at Palmdale and they were both great to fly with. As a Flight Test Engineer and an RSO I got to fly and test the newest and most advanced systems and sensors being incorporated into the aircraft.
Can you give us a good explanation of what an Unstart is? Did you and your pilot ever experience one? What years did you fly the Blackbird?
Phil: An unstart is when the normal shock wave, that must be established inside the engine inlet, becomes unstable and is ejected. When this happens a very loud bang occurs and the propulsion systems loses a significant amount of thrust. This causes the aircraft to yaw in the direction of the unstarted engine inlet. The adverse yaw causes the aircraft to then roll. Of course this is all happening at 3 times the speed of sound. If corrective action isn’t taken the nose will pitch-up and loss of control can occur. While an unstart can certainly startle the crew, it’s not dangerous if properly handled. At Palmdale California we were testing the new Digital Automatic Inlet and Flight Control Inlet System (DAFICS). Much of test program required us to fly the aircraft to the full limits of the flight operating envelope. This resulted in several unstarts, which provided data for Lockheed and Honeywell engineers to make software changes and improve the system’s performance. Once the system was fully tested and introduced into the fleet the number of unstarts diminished significantly. I flew the aircraft during 1985-1987.
Over what part of the world did you enjoy flying the most? How large of an area could be captured in an image?
Phil: The sensors varied in the areas that they could image. The Optical Bar Camera (OBC) camera, carried in the nose, could capture 100,000 square miles of imagery per hour. Other sensors had resolutions as good as 1 foot, but they captured imagery over a much smaller area. Because I was assigned to a flight test organization my flying was mostly limited to test flights in the US.
Could you elaborate on the handling qualities of the SR-71 at subsonic speeds? Did you ever practice stalls?
Phil: The aircraft had good handling qualities. It was not a fighter and wasn’t capable of doing rolls or loops. At Mach 3 and 80,000’ turns could be made at 45 degrees or bank. The G limit at altitude and speed was 1.5g. At subsonic flight conditions and with lower fuel loads the G limit was 3.5g, so it was pretty maneuverable under those conditions.
Did you ever meet any of the engineers from Lewis Research Center? They helped solve the un-start problem. Can you explain that?
Phil: No I did not. The unstart problem was significantly improved over the history of the program. The biggest improvement came when the analog inlet control system was replaced with a triple redundant digital computer system called DAFICS (Digital Automatic Flight and Inlet Control System). This was a Honeywell system, which may have had inputs and research provided by NASA Lewis.
Can you give us examples of emergency scenarios pilots trained on and how realistic were simulators back then?
Phil: Crews were trained in the simulator to handle any and all likely emergencies. The simulator was not motion based, not did it have a visual system, but it had a very high fidelity when it came to aircraft systems and their associated malfunctions. Engine failures, engine fires, loss of cabin pressurization, various inlet malfunctions and hydraulic failures were typical emergencies that crews trained to handle. Many training scenarios involved multiple emergences at one time, which could be a huge challenge.
Would love to hear about what training is required to stay proficient in this type of aircraft
Phil: The simulator was also a used extensively for initial training and for crews to maintain proficiency. The SR-71 program also had dedicated T-38 trainer aircraft assigned to the unit. The pilots flew the T-38 aircraft about once per week to maintain basic flying proficiency, while the RSOs flew the T-38s a couple of times per month. The program also had a “B” model aircraft which had a rear raised cockpit with flight controls. This aircraft was used to train new pilots coming into the program or pilots needing recurrency training.
What was the most scary thing that happened to you in the SR-71?
Phil: While we on occasion had various minor emergencies the unstarts definitely got your attention. The unstart if handled properly was not a serious problem. I also had the opportunity to fly a damaged SR-71 back from Milenhall, England. The aircraft had been over G’d resulting in major structural damage. The Lockheed engineers had assessed the structural integrity and made some fixes to clear the aircraft for a one time flight back to the depot facility in California for further analysis and repair. During the work-up to the flight the engineers briefed the test pilot, Tom Tilden, and myself that the aircraft was cleared for the flight, but some uncertainty still existed. The flight was limited to Mach 2.8 to reduce aerodynamic hearting. The highest risk of the mission was assessed to be at rotation of the nose on takeoff, where some low probability existed that the aircraft could break in half. I can assure you that we were very attentive during the takeoff sequence. Everything worked fine and we flew the aircraft non-stop back to California. The damage was such that after further assessment the aircraft never flew again.
Is there a simulator for the SR71 and how often did you have to do recurrent training?
Phil: Yes there was a simulator for the program. It was at the main SR-71 base, Beale Air Force Base in northern California. The simulator was an integral part of the program and was used extensively during the initial training of pilots and RSOs. Once a crew was fully trained and not deployed overseas they typically had a simulation session every 2-3 weeks. That simulator is now at the Frontiers of Flight Museum in Dallas TX.
