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Cross Country Navigation For Private Pilots Planning Stage Once the
student pilot has completed phase one of his training , which included all
circuit training and emergency procedures, it is then time for the pilot to
learn how navigate across country to other airfields. The Student pilot must be
able to do this without using radio navigation beacons. It is therefore
important that the student pilot learns to fly on an accurate heading and
allowing for wind. The student pilot also has to keep to the correct safety
height and speed. Basically the pilot will draw lines between the departure and arrival airport .The pilot will then measure this on the map and work out the bearing and distance. The pilot will then have to add the Magnetic Variation to the chart. Pilots then obtain the wind from weather charts for different heights normally 2000 and 5000 ft for the area concerned. The pilot then uses a slide rule compass Computer and plots the wind onto this circular slide rule. After this is done the pilot turns the slide rule compass around until the required track is shown at the top. The pencil mark made for the wind will then have moved around. It will show like a graph chart underneath the pencil mark. From this the groundspeed and drift can be read. (It will then show the drift angle and ground speed allowing for the forecast wind.) Once this is known the pilot makes a Flight Plan Log showing the distance ,track, and the drift corrected heading to fly. The pilot should then using the other side of the slide rule and set up the groundspeed obtained. Then around the side of it the pilot should go to the distance he has worked the track out to be between the two airports. This is shown on the outer circle of the slide rule. On the inner circle
of the flight computer this will give the
pilot the time it should take to fly the track between the airports. This
then gets entered in the log. The pilot can then work out how much fuel is
required allowing for 45 minutes holding and a diversion etc. A normal light
aircraft will burn 3 to 4 gallons and hour. A gallon weighs about 7.0
pounds. Weight
The pilot will check this
for departure and landing phases working out the fuel burn weight to
subtract. Both weights are plotted onto the chart. If both points are within the envelope
then the flight is safe. If not then the whole weight and fuel plan will
have to be revised. (Leave the wife/husband behind with the children and
luggage if going on a tour with a light aircraft) the less weight the further
you can get away from them . It is important also that you load any luggage in the correct place on the aircraft as if the luggage is not put exactly where the manual states it could make the aircraft go out of balance in the air. (Especially as fuel is burned the centre of gravity will change in the aircraft and could cause the pilot to lose control on some aircraft.) It is to be noted that on a hot day or a high altitude airport then the correct weight and balance chart should be used as performance in lift will vary dramatically engine performance is also affected.. It is better to work out your take off distance whilst having a cup of tea at the planning stage, than when the hedge at the far end of the runway is fast filling the windscreen. You then find out you are too heavy for take off or to clear that hill just after take off. You therefore under go a rapid character change ,and it can ruin a good day. Weather It is important that you check the weather for the flight and the forecast. If the wind is slight and the temperature and dew point are the same in winter then fog could form . Remember you as a private pilot without instrument training are not allowed to fly in cloud or low visibility. In Summer hot days around midday can trigger thunderstorms if conditions are right. You can get weather either on the internet or listen to VOLMET broadcasts. Or use the old fashioned method phone the tower of the destination airfield. It is good practice to do this and tell them your intentions then if you was overdue they could send that search and rescue helicopter to find you. You would have to do this if you was going to fly into an aerodrome traffic control zone where you would enter the zone before being able to give a warning on the radio. An example of this would be flying from Biggin Hill to Southend where almost immediately on take off you would be in the London City Airport Control Zone. It would be better to get your Special VFR clearance over the phone less to worry about then on take off and setting course. You would still have to call them when airborne. But they wont get annoyed and tell you to go away and you then have to do a 50 mile detour.
Safety Height You should check
your planned track and look for the highest obstacle within 10 miles either side
of the track. You need to add 1000ft to this height and that will be your safety
height for the flight. Controlled Airspace
or Control Zones Example Flight Plan 2000 ft Wind 330/20 knots Flying an indicated airspeed 110 The Take off time is 12:00 hours Make the Plan like this
Distance over Groundspeed = Time So if the aircraft burns 4 gallons an hour your trip fuel would be .75 of that about 3 gallons. add a little bit extra for taxi and take off then add your contingency fuel and diversion so about 8 would be about right 8 gallons weighs about 56 lbs in weight this is from the table above.
It is well
worth buying a slide rule flight computer they are reasonable in price. All your
figures can be worked out in seconds. They are not that expensive. You can buy
one from your local flying club or flight shop. When I did my pilot
training I found my tracks and times very accurate. The flight times are
within seconds after using it. Not bad for a novice. I was very impressed with
this simple tool . You will need a local area chart and ruler and protractor as
well for your VFR flight kit . I use the 1 in 500,000 charts The next lesson will be what happens in the air on route and applying other flight rules and Air Law requirements.
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