I have changed the way that I will be presenting some of the posts here on mikewinslade.com

They now come in the format of two briefs. A quick brief and a full brief.

The quick brief is intended for people who are simply looking to refresh their memory on a particular subject. This will be possible through the use of succinct bullet points that outline the main important facts of the topic.

The long brief section of the post will then go into greater detail to explain exactly what is happening and to give those of you who are not familar with the topic the ability to study it in more depth to develop a greater understanding.

Sometimes there may be a topic that is to technical to have a quick brief associated with it, however I will try to include quick briefs where I feel it will be useful.

If you have any feedback on this format please let me know.

Quick Brief:

• Most propellers rotate in a clockwise direction when viewed from the cockpit.
• Slipstream from the propeller not only flows rearward in a straight line, it also spirals rearwards around the fuselage.
• As this spiraling airflow strikes the rear of the aircraft on the tail it pushes the tail to the right.
• This is observed by the pilot as a yaw to the left.

Full Brief:

As we discussed previously the majority of propellers rotate in a clockwise direction when viewed from the cockpit.

Now we all know that the airflow from a propeller flows backwards behind the aircraft. This airflow however does not simply flow rearward behind the aircraft in a straight line. Due to the rotation of the propeller the airflow also spirals in a corkscrew like manner around the aircraft fuselage as it flows rearward.

This spiraling airflow strikes the rear of the aircraft on the vertical stabiliser resulting in the tail of the aircraft to be displaced to the right. Consequently we will notice that the nose of the aircraft will move in the opposite direction due to the fact that it is ahead of the centre of gravity (which acts like a pivot point). The nose therefore moves out to the left, which we call a yaw.

The slipstream is always present whilst the propeller is rotating. The force of the slipstream varies with the speed that the propeller is rotating. The faster the propeller is rotating the greater the force of this slipstream striking the tail.

To counteract this effect of slipstream from the propeller pilots in aircraft with a clockwise rotating propeller must apply right rudder to offset the yaw that is produced from the slipstream.

To help reduce the amount of rudder input required from the pilot to compensate for this slipstream and subsequent yaw, a rudder bias tab is fitted to many aircraft and it works in a similar manner to a trim tab. I will cover the aerodynamics behind rudder bias tabs and trim tabs in another post.

Quick Brief:

• Propeller torque acts in the opposite direction to the rotation of a propeller.
• If we are in an aircraft with a clockwise rotating propeller  the   torque will act in the opposite direction, (to the left / anticlockwise)
• This force will attempt to rotate the aircraft in that direction     placing a greater force on the left wheel.
• This extra force acts like a brake on the left wheel, yawing the   aircraft to the left.

Full Brief:

Propeller torque acts in the opposite direction to the rotation of the propeller. For this post I will only be considering propellers that turn in a clockwise direction when viewed from inside the cockpit. This is the direction that the majority of propellers turn.

With the propeller rotating in this clockwise direction, the aircraft will experience the effects of the engine torque acting in the opposite direction (an anticlockwise direction).

During the takeoff roll with full power applied (we are producing the most amount of torque) the torque force will try to rotate the entire aircraft in an anticlockwise direction. This results in the left wheel of the aircraft having a greater force applied to it.

The extra force that is placed on the left wheel results in the wheel acting as though the left brake has been applied. This in turn causes the aircraft to yaw to the left.

To counteract this effect during the take-off roll we should be using our rudder pedals as required to keep the aircraft on the centre line.

Following on from flight computer basics 3.1 I am going to cover how you use the wind side of the E6B flight computer to calculate the headwind/tailwind, crosswind components and how much of a heading change is required to ensure you remain on track allowing for any drift.

You will learn how to do the following:

• Find the headwind/tailwind component
• Find the crosswind component and how much of a heading change will be required to stay on track.

Let’s now have a look at the wind side of the E6B flight computer.

As you can see the wind side of the E6B flight computer is very different to the CR2. There is a large metal plate that slides in and out of the flight computer. There are two sides to this plate and for most applications for light aircraft we will use the side that is numbered 30 to 260 (If you require speeds greater than this then you would use the opposite side). You will notice that the circular disc is very similar to the CR2 in a sense that it has a ‘wind disc’ surface that you can rotate to adjust both the direction that the wind is coming from, or the track that you intend to fly.

To demonstrate that you will get roughly the same answer using either this flight computer or the CR2 I will use the same wind and aircraft details from the CR2 example.

We have a wind that is coming from 240°(M) at 20 knots. You have determined that you need to fly a track of 010°(M), and your aircraft has a TAS of 115 knots.

The Process:

1. Slide the metal plate into the computer making sure that it is the correct way up (numbers increasing from the bottom to the top).
2. Next you have to align the direction that the wind is coming from on the wind disc for this example we have a wind that is coming from 240°(M). So align the 240° directly underneath the true index.
   
3. Mark the velocity of the wind on the wind disc surface, I find that the best way to do this is to slide the metal sheet so that 100 appears directly underneath the circle in the centre of the disc. From here you can mark in the 20 knots from our example by measuring upwards to the 120 on the metal plate underneath.
   
4. Now that our wind is marked on correctly we need to rotate the wind disc so that our track is directly underneath the true index marker. So rotate the wind disc so that 010° is directly underneath the true index.
   
5. We are now able to start calculating our heading to ensure that we remain on track. Slide the metal plate so that your mark on the wind disc lines up with your TAS (115 knots). Reading the scale that is underneath our mark we can read off and find that we need to adjust our heading by about 8° to the left.
   
6. The final thing we need to do now is find out what our tailwind/headwind component is. The E6B makes it very easy for us to jump to our final ground speed, we can read that by looking at what is lined up underneath the centre circle mark on the wind disc. In this example you can see that 127 is underneath this mark, this is our ground speed. Giving us a tailwind component of 12 knots (127 – 115 = 12). (View the image above).
7. We can now combine what we have calculated to get our heading, since the wind is coming from our left we will need to alter our heading to the left, we know that our track was 010°(M) and to allow for drift we need to adjust our heading by 8° so our heading will be 010° – 8° giving us a heading of 002°(M). The E6B makes it simple to calculate our ground speed as it provides us with that right off the disc, as mentioned before our ground speed is 127 knots.

That there completes the operation of the wind side of the E6B flight computer. You probably noticed that whilst calculating the ground speed and wind component with the E6B we found our ground speed to be 127 knots instead of 128 knots from the CR2, there is no issue with this as practically it will make minimal difference to your navigation, a tolerance of +\- a few knots is certainly acceptable. The E6B does not give you the ability to calculate an ETAS.

In this post I am going to show you how to apply forecast winds to a flight plan so that you are able to accurately allow for drift and find a heading to steer to keep you on track.

To do this I am going to break it up into two post’s so that I can cover both the CR2 flight computer and the E6B model.

This post will cover how to use a CR2 flight computer.

You will learn how to do the following:

• Find the headwind/tailwind component
• Find the crosswind component and how much of a heading change will be required to stay on track.
• Find and allow for ETAS if needed.

Firstly lets have a look at the wind side of your flight computer.

Looks rather complicated right? Well I assure you that it’s actually not as complicated as it looks. There are three different surfaces on this side of the computer. An outer scale that has numbers that represent knots. An inner scale to calculate the drift that you need to allow for to stay on track, and finally another surface that is covered in lines similar to a graph which I will refer to as ‘the wind disc’, this is where we will calculate the tailwind/headwind and cross wind components.

For this example lets consider that we have a wind that is coming from 240°(M) at 20 knots. You have determined that you need to fly a track of 010°(M), and your aircraft has a TAS of 115 knots.

The Process:

1. On the inner scale you will find that there is an arrow with the word TAS underneath it, you need to align this arrow with your TAS on the outer column as demonstrated below. (Remembering that you need to place the decimal point where it is required. So we will align the TAS underneath 115.)
   
2. On the wind disc surface you need to line up the direction that the wind is coming from underneath the TAS (directly on top of the TC) So we need to set 240 over head the TC. Be careful to make sure that you have your flight computer orientated with TC at the top.
   
3. Now place a cross on the graph representing the strength of the wind that is coming in that direction. So for this example we will put a cross over the 20.
   
4. Rotate the wind disc so that you now have your track directly overhead the TC. (010 for this example)
   
5. Looking back at the cross we made before we can now find our crosswind component which when reading off the horizontal line is 15 knots from the left.
   
6. To calculate the heading change to allow for drift, ensure that your TAS on the inner scale is still lined up with 115 knots on the outer scale. Read off 15 knots from the outer scale to the number of degrees found on the inner scale, in the case we will have to allow for 7° or 8° (lets use 8°).
   
7. Now looking back again to the cross we marked before we can now read off our headwind/tailwind component. The cross is on the bottom half of the disc so we are looking at a tailwind, if you read off the position of the cross to the vertical line running down the disc you can see in this example we have a 13 knot tailwind.
   
8. We can now combine what we have found to give us our ground speed. Since we have a tail wind we will add 13 to 115 giving us a ground speed of 128 knots. To find our heading we need to subtract (due to the wind coming from our left) 8°  from our track which was 010°(M) giving us a heading of 002°(M).

ETAS

ETAS stands of effective true airspeed. ETAS is included in the calculation of our ground speed when we require more than a 10° change in heading. We have to apply ETAS to allow for the fact that we won’t be pointing our aircraft along our intended track which will result in the TAS along our track being reduced.

Let’s take a quick example to look at this. If we had a wind coming from 300°(M) at 30 knots, and we had a track of 350°(M). We would find that we have a crosswind component from the left of 24 knots which would require us to allow for 12° drift. Since this is greater than 10° we have to use the ETAS section at the top of the computer. You will notice that to the left of the TAS marker there is a highlighted section with varying increments in degrees beyond 10°. For this example we need to find our ETAS from the 12° mark on the inner scale, which will give us an ETAS of 113 knots.

Since our ETAS is 113 knots and we have a headwind component of 19 knots our ground speed is going to be  94 knots, and due to the allowance for drift we will have to steer a heading of 338°(M).

That covers the wind side of a CR2 flight computer, next week I will follow this up with a post on how to use the wind side of the E6B flight computers, it allows you to calculate most of the same things however there is a different method to it.

In the first part on how to use a flight computer we looked at some basic multiplication and division. In this second part I am going to show you how to use a flight computer to calculate how long it will take to travel a set distance based on the ground speed you are travelling. Also how to calculate how much fuel will be used over a given time period.

I will also show some variations of these calculations which will simply be a case of working backwards.

Calculating an Estimated Time Interval

The followings steps will let you calculate the ETI for a leg of a flight: (Use ground speed of 120 and a distance of 30 miles for this example).

1. Use the inner scale and align the number 60 against the number that corresponds to your ground speed on the outer scale. For our example align the 60 with the number 120 as shown.
   
2. Find the distance that you are going to travel on the outer scale, and read the number on the innerscale below it. This will give you an ETI in minutes. (For our example it is 15 minutes as shown).
   

That’s it as simple as that for calculating an ETI on the flight computer, essentially it is the same as multiplication. You can also work this calculation backwards to find your ground speed if you are given a distance and the time taken to travel that distance. Lets take the time to look at that now.

Calculating a Ground Speed:

The following steps will let you calculate a ground speed based off a distance traveled and the time taken to travel that distance. (For this example use a distance of 50 miles traveled in 30 minutes).

1. One the outer scale you want to find your distance traveled, and align this number against the time taken to complete the distance on the inner scale. (For this example align the number 50 on the outer scale with the number 30 on the inner scale).
2. Now looking at the inner scale read off the number 60 against the number on the outer scale. This will give you your ground speed. (For our example our ground speed is 100 knots as shown).

Calculating Fuel Required:

Calculating the fuel required for a leg is done in a very similar fashion, once you have an ETI. Except that we need to find the time required on the inner scale to then read the fuel required off of the outer scale.

For this example use a fuel flow of 40 litres an hour and a time period of 45 minutes.

1. Setup the number 60 on the inner scale against your fuel flow on the outerscale. (For this example setup your flight computer with the number 60 on the inner scale against the number 40 on the outer scale as shown)
2. Find your time interval on the inner scale and read off your fuel flow in the outer scale. (For this example you will find your fuel consumption to be 30 litres as shown.)

You can also calculate your fuel flow by working backwards like we did when we found our ground speed earlier. I will leave you to experiment doing this on your own. However if you need any help please feel free to leave a comment and ask.

In the next post I will cover how to find the crosswind and tailwind/headwind component and how you can find in which direction your aircraft will drift and how to allow for it.

It has been quite sometime since I have posted here. So I felt that an update is long overdue.

After training for 7 weeks I completed my flight instructor rating on Friday. I thoroughly enjoyed all of my training and it is amazing how much of a refinement it is to your own flying skills. I had always heard my instructors talk about how you don’t really learn how to fly until you do an instructor rating, and there is definitely some truth in that.

The completion of my flight instructor rating also completes my degree a Bachelor of Science in Aviation.

Looking towards the future I am now going to start looking for a job as a flight instructor, and now that I have some credibility behind me I am going to really start working on creating more content right here on mikewinslade.com

In this post I am going to look at some basic multiplication using a flight computer (or whizz wheel as it is often referred to). Now for sure you can use a digital calculator to do any of the calculations here, however, it is very important to be able to quickly use a flight computer. The functions of the flight computer that have not been easily replaced by a calculator are found on the wind side, which lets you easily and visually calculate tail wind and crosswind components to find out how much of a heading change is required to allow for drift and your ground speed.

For now I am going to just focus on basic multiplication and division, which is very helpful for calculating how much fuel is required for a certain flight or how long it is going to take to travel a certain distance from a ground speed.

There are two types of flight computers the E6B one pictured below where you slide the plate up and down for calculating wind components.

The other circular type just below eliminates the need to slide the wind component plate up and down, resulting in a more compact computer. Also from experience I prefer to use the smaller circular style of flight computer as opposed to the other one.

The content in this post can be used on both styles of flight computers.

Looking at the calculation side of the computer pictured below you will notice that the inner scale and the outer scale are the same. The inner scale can be rotated and this is how we will conduct basic calculations on the computer. It is important to note that on the flight computers you must determine the position of the decimal point yourself. Eg. the number 10 could be either 1, 10, 100, 1000 etc.

If we wanted to multiply 4 by 3. We would do the following.

1. Align the number 1 (which is actually a 10 on the whizz wheel) on the inner scale underneath the number 4 (40) on the outer scale.
2. Find the number 3 (30) on the inner scale and read the number sitting on the outer scale which is a 12. (In this example you did not need to worry about the decimal place but had this been 40 times 3 we would of read out the number 120 here instead.

It is as simple as that.

If we wanted to do the reverse and divide 12 by 4. We would follow the same procedures as above except, we would read the flight computer differently.

1. Align the number 1 on the inner scale underneath the number 4 on the outer scale.
2. Find the number 12 on the outer scale and read the number underneath it on the inner scale. Which would be a 3.

In the next post I will be showing you how to calculate the time it would take to travel a certain distance using the whizz wheel.

When training for your night VFR rating you have to become competent with two of the radio navigation aids. These being the automatic direction finder (ADF) and the very high frequency omni-range (VOR). I’m not going to go into how these instruments work in this post but talk about some of the simulators that are available on the internet to help you understand their usage and how to orientate yourself with these instruments.

The simulator that I used was the luizmonteiro ADF and VOR simulator. It is quite an advanced simulator that has more than you really need for just learning the intercept requirements for a night rating.

You can visit the luizmonteiro simulator here.

If you are after something that is a little bit less complicated to use then I recommend Tims Air Navigation Simulator.

If you spend the time learning how to master these instruments on the ground you can save yourself money by not having to learn how to orientate off them whilst in flight.

There is always a lot of people asking around what order should I complete my CPL exams in? Everybody has their own answer to this, when really there is no exact answer to this question, however below is the order that I think I completed them in (it has been a while), which I felt was quite effective. Of course this is merely one idea of the order to sit them in I know that a lot of people like the idea of starting off with the easiest exams first, being human factors and air law, but I went about things differently and actually left them as the last two exams.

Whilst the order of completing the exams might not be of huge importance the timing of when you start the exams is. I started my CPL exams when I started my conversion onto the aircraft that I was going to fly for CPL, which was a Mooney M20J. Remember that a lot of places will want you to of completed your exams before you start your CPL training, and let’s face it the last you want to be doing whilst doing your CPL training is finishing off the exams. So try and knock them off whilst you are building command time.

I started off sitting my CPL exams with the idea that doing aircraft general knowledge (AGK) first would be the obvious place to start and so I did. This turned out to be a very good move, because the AGK theory covers how the CSU operates very indepth and I found this to be a very good supplement to what my instructor had been teaching me about the CSU. So I think that starting with the AGK exam at about the same time you are moving onto a CSU retract aircraft is a good idea.

So I think the ideal order to complete them in is as follows:

1. Aircraft General Knowledge
2. Aerodynamics
3. Navigation
4. Performance
5. Meteorology
6. Human Factors
7. Air Law

Frequency To Sit Exams

Really the order does not matter a great deal what is important is that you start them and then keep working at them consistently. I found that starting the first exam by booking it in and having a deadline is a good way to start off. Then as soon as you get home from that exam with a pass book the next exam for another 3 weeks. This gives you one week to relax which helps to prevent you from burning out and then two to study hard for the exams.

The only exception to the three week rule is for the performance exam I found that I had to move the exam back an extra week. So allow four weeks from the previous exam (one to relax three to study).

Once you get the ball rolling you will find that once you have knocked off one, two etc things start to snowball and before you know it you will have five done, with the easier ones left to finish.

Best of luck with your exams.