Flying at high altitudes (>1500 m above mean sea level)

WingtraOne is capable of flying at altitudes up to 5000 m AMSL despite the thinner air. Read this article to learn what propellers are required and how flight behavior changes depending on the altitude.

When to use high-altitude propellers

For flights above 1500 m (4900 ft) AMSL, the use of high-altitude propellers is recommended.

With the normal propellers, you can take off up to 2500 m (8200 ft) AMSL. For flying higher, you need the high-altitude propellers, which allow taking off at altitudes up to 4800 m (15.700 ft) AMSL and flying at altitudes up to 5000 m (16400 ft) AMSL.

High-altitude propellers can only be used from a home location above 1500 m. Normal propellers can only be used from a home location below 2500 m. Between 1500 m and 2500 m, both types of propellers can be used. However, your flight time will be substantially higher with the high-altitude propellers.

Taking off with normal propellers above 2500 m AMSL is not possible.

If you fly regularly in altitudes above 1500 m AMSL, we recommend using the high-altitude propellers for optimal results in safety and coverage. In the following table, you can see a comparison between the estimated flight time and coverage when flying with the standard propellers and the high-altitude propellers (HAP).

flight_time_NP_HAP

What are high-altitude propellers?

High-altitude propellers are optimized for the thin air of high altitudes (1500 to 5000 m). They come in pairs and are mounted as replacements to normal propellers, using the same washers and nuts. For step-by-step instructions on how to replace the propellers, read the article Replace the propellers.

You can differentiate between normal and high-altitude propellers by the location of the color label.

For the normal propellers the label is on the top:

normal_prop

For the high altitude propellers it is on the side:

HAP_prop

How to fly at high altitudes

In WingtraPilot you will need to select the type of propellers you are using. 

WIP_props_select

Create the flight plan as it is explained in the article Create a new flight plan. If the home point is above 2500 m you have to mount your high-altitude propellers. For any home point higher than 1500 m, there will be a pop-up prompting you to select the type of propellers in use. For safety reasons, make sure the correct type is selected. 

High_altitude_propellers

The high-altitude propellers require specific flight control parameters. Provide the correct answer to the prompt. Flying with the normal propellers within the defined high-altitude parameters is not safe.

Low battery RTH and altitude above mean sea level

Automatic low-battery RTH ensures that WingtraOne always has enough battery capacity to land safely. For more information about which parameters influence the failsafe RTH feature, please follow the link to this article Failsafe scenarios.

Air density decreases as the altitude above mean sea level increases. Therefore, the automatic low-battery RTH is also impacted in higher altitudes, as lower air density means that WingtraOne motors need more power to generate the thrust required to fly. Increased engine power causes increased battery consumption.

When flying at high altitudes, you should expect the RTH to be triggered at higher percentages (up to 60% remaining battery). This percentage is highly dependent on the altitude itself, the transition height, and the distance between the home location and the mapped area.

To ensure maximal flight time at a given altitude please make sure of the following:

  • The Transition height is as low as possible (How transition height impacts flight time)
  • The survey is as close as possible to the take-off location both in distance to the survey area (visual line of sight) and vertical distance to the survey altitude (not more than 120m above take-off location)

Flight behavior and coverage

Due to the lower air density at higher altitudes, WingtraOne flies faster with the high-altitude propellers. Although the flight time will be reduced, the drone will still be able to cover large areas. More specifically, you should expect the following decrease in the coverage when flying at high altitudes:

  • 2000 m AMSL --> 85% of the area covered at 500 m or 40 minutes of flight time*
  • 3000 m AMSL --> 75% of the area covered at 500 m or 33 minutes of flight time*
  • 4000 m AMSL --> 60% of the area covered at 500 m or 25 minutes of flight time*
  • 5000 m AMSL --> 40% of the area covered at 500 m or 15 minutes of flight time*

* under optimal conditions

More information regarding coverage at 500 m can be found in the Technical specifications.

Another important note: due to the increased flight speed, there are some limitations to the best resolution that can be achieved. The maximum frontal overlap for a given GSD and survey altitude, which ensures that there will not be missing triggers in a flight, is decreasing. Therefore, the lowest resolution that can be achieved in order to successfully map an area increases. More specifically, the lowest resolution that can be achieved with the Sony RX1RII camera at altitudes above 2500 m is 1.0 cm(0.4 in)/ pixel, and with the Sony QX1 camera is 2.5 cm(1 in)/pixel, which correspond to flight height of 78 m (256 ft) and 88 m (289 ft) respectively.