Aldin Skinner
Museum Volunteer – Collections
No, that wasn’t a typo… I meant Tail.
Our SR-71 is designated 971 by the Air Force and 832 by NASA, but what do the markings on its tail mean?
Recently, a visitor asked what the crosses in the red band on her rudders meant. The red band containing four crosses is the 9th Strategic Reconnaissance Wing emblem.
In addition to the red band marking applied later in life, its tail number has also changed. The initial markings designated it as AF 17 971. However, the Air Force changed the marking rules to make the first two numbers represent the fiscal year the aircraft was ordered. The revised designation became AF 61 971, as it was ordered in fiscal year 1961. The BB marking indicates it was based out of Beale Air Force Base.
While we’re on the subject of tails, the SR-71’s rudders operate differently than many of our other aircraft in that the entire rudder rotates around a post, rather than having a movable control surface attached to the trailing edge of a fixed vertical stabilizer. This design is similar to the “Tail Feathers” on the F-117 Nighthawk. This post is located towards the front of the rudder, roughly in line with the leading edge of the aforementioned red bands. A hydraulic actuator rotates the post/rudder assembly for yaw control.
Another difference in the tail is that rather than having an elevator, it has four “elevons” across its trailing edge. These blend the roles of both the elevator and ailerons.
Click here to check out this YouTube segment on the mixer illustrates how elevons work.
The video was produced by Animagraffs with the help of our friends at the Air Zoo (Aerospace & Science Museum) in Kalamazoo Michigan. You will surely want to take a deeper dive into the inner workings of the SR-71 by watching the entire video , which explains the Blackbird’s construction, propulsion, and subsystems in detail.
Be sure to come out to see our amazing SR-71 Blackbird!
