Jump to content
Sign in to follow this  
hawker111

Help Reading F-106 Delta Dart Performance Charts Contained in the F-106 manual

Recommended Posts

Hello,

 

I have been studying a couple of charts from the F-106 Delta Dart flight manual, and the speeds shown are in mach.

 

Since mach changes at different altitudes, I was curious to know if the charts in the manuals showing mach numbers use static mach numbers (1Mach = 661.47knots).

 

Or, do the mach numbers on the charts need to be converted to knots with an aviation calculator such as the one on this page:

 


 

If you would like to see the charts in the F-106 manual, you can download the manual here:

 


 

The manual I downloaded is:

 

T.O. 1F-106A-1 (1969, rev.1972)

 

Please take a look at pages 6-8 to 6-18.

 

I appreciate the help very much!

Share this post


Link to post
Share on other sites

Mach 1.0 is Mach 1.0, regardless of altitude. The airspeed indicator always reads indicated airspeed, which varies with altitude. Only certain aircraft types (the F-4 Phantom being one of them), had a ground-speed readout in addition to the airspeed indicator.

Share this post


Link to post
Share on other sites

Thank you, Sir.

 

The reason why I asked is because I read this yesterday:

 

"The speed of sound (otherwise known as Mach 1) varies with temperature. At sea level on a “standard day,” the temperature is 59°F, and Mach 1 is approximately 761 mph. As the altitude increases, the temperature and speed of sound both decrease until about 36,000 feet, after which the temperature remains steady until about 60,000 feet. Within that 36,000–60,000 foot range, Mach 1 is about 661 mph. Because of the variation, it is possible for an airplane flying supersonic at high altitude to be slower than a subsonic flight at sea level."

 

But according to the USAF flight manuals, when a chart says . . .

 

MACH .2 at 5,000 ft.

and says

MACH 2.0 at 35,000 ft.

 

. . . what I need do to get the speed in "true airspeed knots" is to . . .

 

multiply .2 x 661.47 = 132 knots

multiply 2.0 x 661.47 = 1,323 knots

 

?

 

I wasn't sure if I should multiply the mach numbers by different numbers because each mach number is for a different altitude.

Share this post


Link to post
Share on other sites

That is correct, it is temperature that causes a variation in Mach, not pressure.  I found it a bit hard to understand at first, until I saw this chart.  I hope it helps you, as well:

 

Mach.jpg

 

 

 

 

Share this post


Link to post
Share on other sites

Therefore, I can't simply use this formula to convert the mach numbers on the F-106 charts to true airspeed knots?

 

multiply .2 (which is at 5,000 ft) x 661.47 = 132 knots

 

multiply 2.0 (which is at 35,000 ft) x 661.47 = 1,323 knots

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×

Important Information

By using this site, you agree to our Terms of Use, Privacy Policy, and We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue..