Sign in to follow this  
Gregdpw

Problem understanding sid on this kdtw to kbos route?

Recommended Posts

Help AVSIM continue to serve you!
Please donate today!

The first flight I pulled up off FlightAware had JHW as the first waypoint after the SID, so it seems reasonable enough.

 

Mike

Share this post


Link to post
Share on other sites

You have told routefinder you are going to be using a SID (you ticked the SID box).

 

So routefinder has given you a flightplan that has the first waypoint as the end of your SID. That is the way it works.

 

Altitude at JHW ?   I would hope you would be at cruise FL by then. There is no altitude requirement for JHW (except a minimum of 4000 feet on the leg from BEWEL).

Share this post


Link to post
Share on other sites

I see what your saying. I was a little confused when it said 4000 before Jamestown. Thanks guys! The pmdg is awesome just a tad bit of a learning curve but the payoff is sweet!

Share this post


Link to post
Share on other sites

 

 


first waypoint which is Jamestown is 188 miles away

 

How did you come up with a 188 miles? You might want to refigure it.

Share this post


Link to post
Share on other sites

Now how do I determin the speed? If Jamestown is my first waypoint do I just go 250 kts the whole way there?

Share this post


Link to post
Share on other sites

You would climb to the altitude assigned by ATC, or odd altitude + 500 ft. if VFR. Speed wise, if you are flying in the US you would be at 250kts till you are thru 10,000 feet

Share this post


Link to post
Share on other sites

Oh boy!. Gregdpw. You have to do a flightplan  and the first thing I suggest is understanding the MACH speeds. Once an airliner is near its Cruising altitude it will calculate its speed based on the percentage to the speed of sound. Or MACH.  For example most airlines will fly above 30000 FT and at a mach speed from .78 or .80 and anything in between. That is 78% of the speed of sound Or 80%. It is not measured by the airspeed in KTS because the air in higher altitudes is lighter so the true airspeed changes. 

 

 So to give you an example here is a route from BOS to DTW this morning

 

http://flightaware.com/live/flight/JBU1837/history/20140703/2340Z/KBOS/KDTW

 

 That is a the real world route from Jetblue 1837

 

 The route is using is 

HYLND3 HYLND SYR J547 BUF SPICA2

 

Based on the aircraft type E190 I know that it will be flying at .78 Mach. True airspeed of 299 but an average ground speed of 430 KTS. 

 

 I suggest you google some articles and I think you should do some tutorials from Payware aircraft that will help you understand the logic a bit better.

 

Reach out if I can be of any help.

Share this post


Link to post
Share on other sites

 

 


Based on the aircraft type E190 I know that it will be flying at .78 Mach. True airspeed of 299 but an average ground speed of 430 KTS.
Hmmm. That doesn't sound right. 299 true? It should be closer to 450. I see the link says 299, but that must be an average or something.

Share this post


Link to post
Share on other sites

I'm sure he meant indicated airspeed.  True airspeed of 299 at FL300 would mean an IAS of about 188, which is very slow.

 

Using the most recent example from flightaware - which cruised at FL400 - 0.78 mach would result in a TAS of 447 kts, and a touch under 250 indicated (assuming a std atmosphere).

 

jeff h.

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