Engines 05 - SR 71 vs SR 72

OPENING QUESTION: Write down quick bits that you know about our baby, the SR-71 as quickly as you can in the next 2 minutes. Go!

LEARNING GOAL FOR TODAY: I will be able to compare and contrast scramjet and ramjet engines during today's class.


  • Thurst ("forward pushing force")
  • Air Friction ("resists forward motion")
  • Lift ("Lower pressure, upward pull")
  • Weight ("downward pull")
  • Propeller ("Pulls Air")
  • TurboProp
  • Jet Engine ("Pulls and Pushes Air")
  • Ram Jet Engine ("SLAMS Air")
  • ScramJet Engine










Work O' The Day

Although some people think the SR-71 was replaced by another high performance aircraft called the "Aurora", there is very little evidence to suggest that plane was ever built, let alone evidence to support the claim that it was put into production.

With that in mind...

Let's make a list of the benefits of the Blackbird... in otherwords, what did it do well.


No let's make a list of items where the Blackbird didn't do so well.



Shall we get those on the board?



What about engines?



Now we'll do a bit of a web quest next. But before we do that, let's imagine we were the designers at the legendary "Skunk Works" plant run by the Lockheed Martin Corporation in Southern California


What are key specifications that the SR-72 MUST meet?


Now let's go and see if we can find how they are going to meet those.


Here are a few links:

Aviation Week & Space Technology Article. This is an excellent source, but not so easy to read. May I suggest the "wolgemuthian skim" method.... let's discuss.

Here's an article from WIRED magazine... it's a wee bit shorter