Quantcast Head or Tail Wind Computation

 

Click here to make tpub.com your Home Page

Page Title: Head or Tail Wind Computation
Back | Up | Next

Click here for thousands of PDF manuals

Google


Web
www.tpub.com

Home

   
Information Categories
.... Administration
Advancement
Aerographer
Automotive
Aviation
Construction
Diving
Draftsman
Engineering
Electronics
Food and Cooking
Logistics
Math
Medical
Music
Nuclear Fundamentals
Photography
Religion
   
   

 



STUDENT GUIDE
VISUAL NAVIGATION
What is the crosswind?
In this case, by doubling both the error and time interval we have 1
NM of error over 6 minutes of time. Using the equations previously described, this equates to 10
kts of crosswind.
EXAMPLE 7-2: After eight minutes of flight, a fix reveals the aircraft is 1 NM left of course.
What is the crosswind?
In this case, by halving both the error and time interval we have
NM of error over 4 minutes of time. Using the equations previously described, this equates to
7 kts of crosswind, which is typically rounded to either to 5 or 10 kts.
7.7.2. Head or Tail Wind Computation:
7.7.2.1. Head or tail wind components are nothing more than the difference between the ground
speed and the true airspeed. Rather than use a ground speed derived from a TACAN DME
reading, take the difference between the planned and actual time of arrival, and convert it into a
distance. This distance divided by the time flown equals the head or tailwind component. Again,
from Unit 5 of the T-34 VNAV text, the equation is:
Planned Aircraft Convert to
Speed (NM/sec)  NM/hr
Time gained or lost (sec)
X
NM
X
60 min
= Head/Tailwind (kts)
approx. time flown (min) since
sec
hr
last compensation update
7.7.2.2. In the above equation, planned airspeed is a factor, and changes the equation for T-1
usage. Reducing terms and applying an airspeed of 300 kts, the equation becomes:
Time gained or lost (sec)
X
1NM
X
60 min
= Head/Tailwind (kts)
approx. time flown (min) since
12 sec
hr
last compensation update
Or:
X
5NM =
Head/Tailwind (kts)
Time gained or lost (sec)
approx. time flown (min) since
min
last compensation update
7.7.2.3. For a time interval of 5 minutes, this equation becomes:
Time gained or lost (sec) =
Head/Tailwind (kts)
7.7.2.4. As with cross wind computations, this "Five minute rule" may be used with time
intervals between 4 and 6 minutes. (Additionally, this equation could also be used to compute
7-6


Privacy Statement - Press Release - Copyright Information. - Contact Us

Integrated Publishing, Inc.
6230 Stone Rd, Unit Q Port Richey, FL 34668

Phone For Parts Inquiries: (727) 493-0744
Google +