Quote:
Originally Posted by captainphil  This is an embarrasing thing to ask at this point in my training,but i'm going to ask it anyway. After 4 cross country flights I am still having trouble with some of my flight planning on my Nav Log. Here is what I have questions on :
1) When I plan the night before the flight and the weather changes the day of my flight , do I still fly with the same information I put on my Nav log?
2) How do I find My True airspeed and RPM setting in the POH, I know how to interpolate but I mean taking the temperature from the metars and using the ISA which I don't understand.
3) When I use my flight computer to determine my Ground speed do I set the minature hole over 100 and than slide the mark I make with the pencil to my true airspeed?
Thanks for any help. |
1: If winds change then you should change your plan. Depending on the change your flight plan could change dramatically - headings, GS etc. I made an excel flight plan that was easy to alter after the fact. Plan the route the night before - plug the numbers next morning.
2: All this info is in the cruise performance section of the POH. Use the winds aloft for your temp and then calc if this is standard, above or below (15 degrees at Sea level , drop of 2 degrees per 1,000 feet), then see performance section for impact.
3: Yes, set hole over 100. Rotate wind direction to under the true index - mark wind speed - rotate true course to under true index and move the slide to put your mark over your TAS - GS will be under the hole. This also gives you your wind correction angle, then correct for magnetic variance and compass deviation and you have your magnetic course.
Remember - for a given route in a given aircraft, the only variable for Mag Heading is the WCA. Hence I just plugged the new/current WCA on the excel sheet mentioned above (Var and Dev already calculated)
Also, winds may not be as advertised therefore you will have to adjust your plan enroute as necessary- therefore having easily indentifiable route and frequent checkpoints will keep you on course.
AOPA give you a free jepp flight planner that links to DUAT and calculates wind for you - might be a good way to check your work (not an easy out!)
DUAT also has a flight plan tool that calcs magnetic course if you link to the WX.
Good luck.