Several modelers have asked me for information on the full scale Blackbirds versus the various kits available and I wrote the following as a response.
The SR-71 is like many other military aircraft in that the overall appearance varied considerably depending on the time and particular airframe. When they first came out of the paint barn, new or after IRAN/Phase inspections, they were as black as a lump of coal, uniform in color, with no visible panel lines and flat reflectivity. The paint had iron ferrite particles mixed in it and was a unique Lockheed paint with NO particular FS #. As each airframe started adding flight hours, the paint faded a small amount to a very dark gray which varied depending on how hot that particular part of the plane became during high mach flight. The nose cones were interchangeable, depending on what sensor was carried, ie OBC or Optical Bar Camera, early SLR or Side Looking Radar, the later high resolution SLR or just a ballast nose. Depending on how many flight hours a particular nose had, it could be the same shade as the rest of the fuselage, darker or lighter. Sometimes individual panels had a different hue to them than their immediate neighbors and sometimes not. Panel lines were miniscule on the full scale and sometimes they were noticeable and sometimes not.
Some details very seldom seen on Blackbird models are:
- There were air data sensors that looked like small 90 degree pitot tubes located on the top of the nacelles a little outboard of the center and centered on the bottom. These were used to measure pressure differential of the air entering the nacelle and this data was primary in determining the position of the air inlet spikes.
- The tips of those spikes were left unpainted, usually polished and the center of each spike was canted down and in rather than dead center in the nacelle.
- There were two red, rotating beacon lights, one top and one bottom mid-way back on the fuselage that were retractable. They were extended for flight at lower altitudes were other aircraft flew and the SR-71 was under ATC control. Two UHF blade antennas were on the underside and were also retractable during high speed flight. Both the lights and antennas had to be retractable to avoid damage from the high speed heat and to lower the overall RCS.
- The nose pitot tube was angled down 7 1/2 degrees, not straight in line with the airframe centerline. The fuselage was designed to fly at a 7 1/2 degree angle of attack while the engines, pitot tubes and cameras were angled such that they remained parallel to the ground and line of flight. After a few test flights, the Lockheed engineers determined that 6 degrees of AOA worked better, but by then, it was too late to change the design.
- The flame holders at the back end of the engines were located about 6-7 feet in front of the aft bypass doors with the intervening distance taken up by the afterburner. Nearly all of the models have this aft face of the engine barely in front of the bypass doors. There is an aftermarket resin set that does a superb job of correcting this for the 48th scale birds, but you have to improvise for the 72nd scale.
- The nose landing gear had two lights on it, one centered and one off center and slightly lower to the right. Most models have only the center one.
- The1/72 Monogram, (later Revell), kit has a rectangular shaped area embossed proud of the surrounding surface on the outside of the rudders and towards the front. The full scale had a panel that shape in that location, but it was flush with the surrounding area.
- The Testors/Italeri kit has camera windows located in the chine bays a little ways ahead of the wing. The windows are in the center of each equipment bay and should be at the very aft end of each bay. The Technical Objective Camera or TEOC framing camera in the forward bay had a square window, slight larger than the rectangular window for the Operational Objective Camera or OOC panoramic camera in the aft bay. The starboard TEOC bay was frequently filled with ELINT and ECM gear on operational flights, so eliminating that window would also be correct. There are several pictures that show the belly of the plane and there is a white square clearly visible in the center of each camera bay. This is not the camera window, but rather a ground crew warning instruction that reads, "Heavy equipment may be mounted on the inside of this panel. Remove with care".
- The Terrain Objective Camera or TROC or tracker camera is a framing camera located in the C bay just in front of the nose landing gear. There is no indication of this camera on any SR-71 model that I have seen.
- Those pie shaped, radar defuser panels on the SR-71 are located on the wing leading edge between the fuselage and inboard side of the engine nacelle and on the outer edge of the wing from the nacelle, around the wing tip and across trailing edges/control surfaces. They are NOT on the chine between the air inlet and the outer wing LE. A couple of the early A-12s had them all along the fuselage chines, but they were later removed and replaced with standard panels.
- The lower, rear fuselage between the main landing gear and the tail has a distinct bulge to it, but it is not nearly as pronounced as some of the models kits have it. I don't know of any feasible way to correct this.
-Every Blackbird built has "In Flight Refueling" capability. The IFR hatch was hydraulicly operated and was open on the ground and of course during IFR. It was closed during other phases of flight. The A-12, YF-12 and SR-71 each have this hatch located in a slightly different location. The SR-71 hatch is furthest aft, with the A-12s hatch being about a half hatch length further forward. The YF-12 hatch is a full hatch length forward of the SR-71.
- You have to be a little careful when using museum displayed aircraft as your reference. There have been at least three SR-71s on display where the museum staff painted them with HIGH GLOSS black paint. That NEVER happened during their operational time. A-12 # 06937 on display at the Southern Museum of Flight in Birmingham, Alabama, has the main gear wheels painted silver. They should be either bright red or green. That plane also has two of the CIA pilots names on the canopy rails, which weren't there originally. It is a very appropriate honor for them, but modelers beware. The same name thing is on the A-12 # 06938 at the USS Alabama Battleship Museum.
I hope this information is of interest and helpful to those wishing to model a "Titanium Wonder Bird"!