Aircraft normally should take off into wind. This gives the best climb gradient over the shortest distance. As the aircraft gets higher, the wind is stronger. This gives a much better rate of climb over the distance, than an aircraft taking off with a tailwind. In a tailwind take off the distance is increased across the ground.
On average the wind is double the speed at 2000ft than the surface wind. The surface wind is slowed by friction. The wind may also be from another direction where it could have been deflected. Be very careful of valley winds during the day. They have caught some pilots outs.
Each aircraft has a best climb speed and this should always be used after take off until a safe height is reached. Pilots of aircraft should read the aircrafts handbook for best climb speeds. Only when at a safe height should you adopt the cruise climb. For pilots the climb gradient must be that shown in the SID charts as a minimum. Noise abatement also comes in to play here. Remember the higher you are the less noise.
Lets look at two aircraft taking off with the same airspeed and rate of climb. The first one takes off into wind, and the second one with a tailwind.
The aircraft taking off into wind will have traveled a much shorter ground distance to a height 2000 ft compared to the aircraft taking off with a tailwind. The climb angle would also be bettered by at least 3 degrees. We will assume the wind to be 20 knots on the ground. At 2000 ft it would be double. It is true the faster the aircraft fly's the more lift it has, but you also have to realize the more ground you will cover before you get to the same height.
Lets assume the wind is a 20 knots and you take off at 140 knots. This means your groundspeed is 140 - headwind speed = 120 knots
Now lets assume you take off with a tailwind of 20 knots at a climb out speed of 140 knots, your groundspeed now will be 160 knots 140 +20.Some airfields have minimum climb gradients published for pilots in chart form. This will tell the pilot the minimum climb for the VSI and airspeed allowed for safety at different speeds. Remember a hot day and a high altitude airfield will seriously affect your climb performance.
The best way to stay alive is to always make sure that your aircraft's climb gradient is quicker than the climb gradient of the hills around you. Early signs of this going wrong is the eyeballs getting bigger and the urge to go to the toilet. Have fun but be careful especially if going into cloud. It is essential that the aircraft manual is checked and the correct speed flown. Also watch your Vertical Speed Indicator.
Below is a table for you to work out how much you climb or descent rate should be per climb descent angle published in charts. This charts is for take off and landings climbs or descents on route
The assumption is is 1 degree =100 ft per nautical mile
Most ILS approaches are 3 degrees so 300ft per mile you are required to descend.
|Height/FT req to gain lose per NM||Ground||speed||Feet||per||
Charts should give you these details. But if the climb angle is greater than this you should be able to work the sequence out. Simcharts by Jeppesen are worth buying.
Example you need to climb out on a 3 degree path. Your climb groundspeed is 210 knots your vertical climb speed needs to be at least 1050 feet per minute. terrain and obstacles may make the climb or descent gradient differ from airfield to airfield.. It is important therefore to comply with the charts For example the London City climb gradient is 6 degrees.
This should help you make better approaches now once you know the ILS gradient on the charts. or safer in the climb out