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About Airplanes & Rockets

Kirt Blattenberger, Webmaster - Airplanes and Rockets

Kirt Blattenberger


My Engineering Web: RF Cafe

Carpe Diem! (Seize the Day!)

Even during the busiest times of my life I have endeavored to maintain some form of model building activity. This site has been created to help me chronicle my journey through a lifelong involvement in model aviation, which all began in Mayo, MD ...

Airplanes And Rockets Copyright 1996 - 2026

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the Airplanes and Rockets website are hereby acknowledged.

My Main Modeling Websites

Academy of Model Aeronautics (AMA) - Airplanes and RocketsAcademy of Model Aeronautics

Tower Hobbies logo - Airplanes and Rockets

Tower Hobbies

Horizon Hobby logo - Airplanes and Rockets

Horizon Hobby

Sig Manufacturing - Airplanes and Rockets

Sig Mfg

Brodak Manufacturing - Airplanes and Rockets

Brodak Mfg

Estes Altiscope / AltiTrak

Estes AltiscopeEstes AltiscopeThis is the vintage Estes AltiTrak. The one I had back in the 1970s was made of wood that went by the name Altiscope (see below). The AltiTrak one is a newer incarnation made of plastic and is held like a pistol.

Both models work on the right triangle completion principle. You stand off a predetermined distance from where you expect the rocket to be at apogee (its high point of flight), and then follow it up with your instrument. At the highest point, you lock the angle indicator on the protractor. You can see the concept in the picture to the left (click for a larger version).

The base of the right angle angle is the side adjacent to the measured angle (θ), which makes the vertical line to the apogee the side opposite the measured angle. Since the tangent of an angle is equal to the quotient of the side opposite divided by the side adjacent (which you determined at the beginning), that leaves the altitude being:

Altitude = Base * tan (θ)

Estes Altiscope - Airplanes and RocketsNow, when I was a teenager trying to use my Altiscope, I didn't know a tangent from a schmangent. Fortunately, Estes provided a table of values. Yes, teachers had attempted to learn me about trigonometry, but I wasn't having any of it. As they did with many other rocket-related topics, Estes produced a very nice pamphlet entitled "Estes Industries Technical Report TR−3, Altitude Tracking," Cat. No. 651−TR−3. NASA has a do-it-yourself Altitude Tracking plan for building a simpler type of  (here it is on in case NASA disappears due to being too White for them these days)

The Altiscope images below came from an eBay listing. I sure wish I had gotten it!

Estes Altiscope kit contents (Cat. No. 651-A-1) - Airplanes and RocketsEstes Altiscope kit (Cat. No. 651-A-1) - Airplanes and Rockets

Estes Altiscope Kit  (Cat. No. 651-A-1)

Here is a list of my other rocket models.



Posted March 20, 2023