With the Red Book comes huge responsibility. It is about the ability as a true airman to do everything possible to ensure safe RPAS/drone operations.
A pilot uses superior judgement to avoid having to use superior skills.
In this document, we will be looking at general safety guidelines any drone pilot can follow to ensure safe drone flights and operations, regardless if you are a commercial certified RPAS pilot or simply flying a drone for your enjoyment.
Safety guidelines centre around:
- Flight modes and the pilot’s flying skills
- Limitations of the aircraft, environment and pilot
- Fail-safe mechanisms
- Orientation Recovery
- Battery Management
Which mode is the safest mode to fly in, ATTI mode or GPS mode?
Some would argue that GPS mode is the safest mode because of the minimum inputs required from the pilot for safe flight. GPS mode relies on the GPS receiver electronics on board the aircraft, the accuracy and processing capabilities of those electronics, the environmental conditions for receiving GPS signals, etc. In my opinion, ATTI mode is the safest mode to fly in for the simple reason that in ATTI mode the least can go wrong.
But, there is a saying that says:
A pilot is paid NOT for what he does, but for what he CAN do.
Therefore, for ATTI mode to be the safest mode, we need the pilot to be 100% competent.
My father loved playing golf. Being a senior, he could play from a 24 handicap. One day, he played with a scratch golfer. After the game, on the 19th, he asked the guy why he never went pro, being a scratch golf player?
The man asked him:
Uncle, is there a big difference between your golf and my golf?
My father answered:
One hell of a difference!
The guy then said:
Between my golf and Ernie Els’ game, there’s the same difference!
The point is, anyone can play golf but not everyone goes pro. Anybody can fly a drone, not every drone or RPAS pilot makes it in the industry. Your mindset should be to become a pro. In both flying skills in ATTI mode and knowledge about the industry you want to enter.
|Start with 18 golf handicap||The objective is to get your handicap as low as possible||And strive to become a professional golf player|
|Start Flying in GPS mode||The objective is to become as good and skilled as possible in ATTI mode||To be the best you can be in the RPAS industry you want to enter|
Gary Player once said:
The more you practice the luckier you get!
There are 3 major limitations you as the pilot should be taking into consideration:
- Safe maximum flight time
Know your aircraft’s maximum flight time. Remember, flying an aircraft until it goes into battery failsafe is a pilot error! Manage your flight time!
- Weather conditions
Besides rain and visibility, we want to make special reference to wind speed. Know your aircraft’s maximum allowable wind speed. Have an anemometer on site to measure wind speed. This is the only way for you to accurately confirm that you are within your aircraft’s maximum wind speed.
- You, the pilot
You need to always be honest with yourself and be sure that you always operate within your means. Know your skill level. If your skill level only allows 4m/s wind, although your aircraft can handle 10m/s wind, do NOT fly outside your envelope of expertise.
Always assess yourself: IMSAFE
Am I suffering from any illness or symptom of an illness which might affect me in flight?
Am I currently taking any drugs (prescription or over-the-counter) that can affect my sight, judgment and general coordination?
Am I overly worried about other factors in my life? The psychological pressures of everyday life can be a powerful distraction and consequently affect a pilot’s performance and judgment.
8 hours from bottle to throttle. Consider your alcohol consumption within the last 8 to 24 hours.
Have I had sufficient sleep and adequate nutrition?
Have I fully recovered from any extremely upsetting events such as the loss of a family member or relationship trouble?
You need to know exactly how to set the following fail-safes on the system you are using:
- Low Battery – Return to Launch (RTL) with correct return height set.
- RC Loss -RTL with correct return height set.
- Telemetry Loss – What do you want the aircraft to do when the telemetry link is lost?
- Geo-Fence – Set the maximum height and distance from the take-off point.
- Legal Flying Ceiling – Be aware and set the maximum flying height to local regulations.
Orientation Recovery Skill
This is a very important skill you need to have sorted in your mind:
- Step 1 – Leave the sticks centred.
- Step 2 – Determine the left and right movement. Yaw or rotate the aircraft until the aircraft move Left and Right when you apply the Left/Right stick. This ensures the aircraft is orientated tail-in (tail facing towards you).
- Step 3 – Pull the Forward/Backward stick towards you. Remember, because of optical illusion, the aircraft will initially seem to not come closer towards you, it will! Trust your Left/Right confirmation.
It is also very important to test and exercise the fail-safes to ensure they are working and doing what they are supposed to do.
Good LIPO Battery Management Principles
How you handle, store, charge and use your LIPO batteries will determine their lifespan.
- LIPO batteries are like red wine. They want to be kept cool. They don’t like extreme heat or extreme cold.
- Charge them just before you fly and keep them discharged at about 60% when you don’t fly.
Instead of using % to manage your batteries, look at the single cell voltages with the following rules:
- A fully charged LIPO battery’s single cell voltage will be 4.2V per cell.
- At storage level will have a single cell voltage of about 3.85V per cell.
- A battery that has been discharged to the 80/20 rule, will read about 3.75V per cell.
- There should never be a difference between cell voltages of more than 0.2V in the same battery.
The 80/20 rule is based and calculated on the battery’s mAh capacity and not the Voltages. For example:
On a 5000mAh battery, you should never use more than 4000mAh. Your single cell voltage should then never read below 3,75V per Cell. If it does, your flight time was too long and you will damage the battery and shorten its lifespan.
Consider the following table as a quick reference:
|# LIPO Cells||Fully Charged||Storage Level||Lowest Allowed (80/20 rule)|
It is very important to keep a Battery log. Even though the Smart batteries with DJI keeps an onboard log for you, it is insufficient.
The first rule of your Battery Logs is that it must tell you a story. It must show you that a battery is busy deteriorating. This deterioration is caused by IR (Internal Resistance), which builds up over time.
IR can be explained as follows: You have a plate of food on the table. Initially, all the food is available for you to eat. But over time more and more food falls on the floor for the dog to eat and you have less and less food available for yourself. This is exactly what IR does. As it builds up, less and less energy is available for the motors.
You will notice this IR by structuring you Battery Logs in such a way that you can monitor flight time versus end Voltage. Your target is not to go lower than 3.75V per cell. Initially, you might get, let’s say, 15 minutes flight time to before it reaches 3.75V. Over time, the battery starts giving you 12 minutes flight time before the 3.75V per cell level is reached. Later, only 10 minutes flight time. This tells you that IR is building up and the battery is busy deteriorating.
The main items that needs to be logged are:
- Battery unique number
- Begin Voltage (4.2V/cell)
- End Voltage (NOT lower than 3.75V/cell)
- Flight Time
Pilot Check List
Finally, as a good pilot always does, you can compile and use a checklist for yourself, the pilot.
|1||I fly very well in ATTI mode without any orientation problems, even in the wind.
I keep on practising my skills.
|2||I always check the flight plan NOT to exceed the aircraft’s Maximum Safe Flight Time.|
|3||I always have an Anemometer with me to confirm that I do not fly in conditions exceeding the aircraft’s or my own limitations.|
|4||I Always ensure IMSAFE.|
|5||I have checked and tested ALL the aircraft’s Failsafe Features. They do what they are supposed to do.|
|6||I have mastered the Orientation Recovery Skill.|
|7||I always check the battery for 4.2V per cell BEFORE I take off.|
|8||I never fly my batteries lower than 3.75V per cell.|
|9||I always store aircraft batteries at 3.85V per cell when I do not use them for a long time.|
|10||I have a Battery Logbook that monitors when a battery’s IR is increasing.|
To download this article in PDF format, for free, and many other RPAS related documents, check our library of documents.