Petrel U42W Review – a Beginner Quadcopter with Altitude Hold

Petrel U42W Review

More and more toy grade drones are attempting to include altitude hold, but some work  better than others, and some don’t work very well at all.

The Petrel U42W is a quadcopter with a well-working altitude hold and has FPV capabilities by using your smartphone as a monitor. In this review, we’ll take a look at the plentiful features this drone offers.

Let’s take a closer look!

Flight Performance

The U42W has two different flight rates. I’ve found both to be extremely smooth and precise, perfect for filming video from the air. Some may say that this quadcopter is on the slower side, and that is true, but this is a quadcopter designed for filming, not for racing. Stability trumps speed here.

The yaw rate is a bit on the slower side. I’d like it to be a little more maneuverable to help it fight light winds which is something the U42W tends to struggle with. Otherwise, the flight characteristics of this drone, while not very sporty, get the job done for filming. The amazingly accurate altitude hold feature certainly helps with flight performance as well.

Petrel U42W FPV quadcopter with altitude hold

Altitude Hold Works PERFECTLY

Altitude hold is becoming more and more popular in toy quadcopters every day. The U42W implements this altitude hold feature very well.

The throttle stick on the included transmitter is automatically centered anytime you let go. Once in the air, this causes the quadcopter to hover at whatever altitude it was when you let go of the throttle stick. Pushing the throttle stick up or down will cause the quadcopter to increase or decrease in altitude respectively. This is different from the standard transmitter throttle stick, where letting go of the stick would simply cause the quadcopter to descend slowly as it loses power. The U42W just stays in place!

The U42W holds its altitude near perfectly. This is not something I can confidently say for every toy quadcopter with this feature, so that’s a major plus.

Remember, even when using altitude hold, you still need to use the pitch/yaw stick to control your quadcopters direction. Even so, not having to worry about throttle management is certainly helpful when filming video or even just for beginners learning to fly quadcopters for the first time.

Flyingsee App & Drawing a Path for your Drone

The app that lets you control your quadcopter/fly in FPV is called Flyingsee. It has many different functions, such as the ability to use your phone as a transmitter, independently from the traditional transmitter.

I really like that they included a physical transmitter for those who prefer not to use their smartphone as a transmitter, such as myself. I feel that the controls are just a bit too clunky to fly using a touch screen and the (very) slight delay is enough for me to not even bother.

It does have two additional flight methods. One of which allows you to use your phone’s accelerometer to control the direction the quadcopter flies. The other lets you actually draw a path that you wish your U42W to fly in. This is a really neat feature, something we see on higher end drones like the DJI Phantom series, and it’s a welcome improvement to the U42W.

Although I’d consider these modes novelties, I still really enjoy them, and they are rather unique, so i’m glad they were added, as they make flying this quadcopter a whole lot more interesting.

You can also control all of your standard controls straight from the app such as trims, and you can choose to save your settings for next time or reset it if you choose.

You Can Draw Your Own Flight Path with the Petrel U42W

Camera and FPV

One of the neat features of such a budget quad is the ability to fly in FPV using the Flyingsee app as a display monitor. Now, there is a slight delay, and i’ve noticed sometimes the connection to get very choppy. This is likely caused by some external interference in my local area, but I’ve flown in multiple different locations each with the same result.

Despite the fact that sometimes the FPV can be unresponsive and unreliable, when it works it can be very fun. Because the connection is done via WiFi, I wouldn’t fly completely in FPV, as there is a slight delay regardless of how stable the connection is.

Instead, it’s very useful to simply see what the camera is seeing, and line up your video/still images accordingly. Overall, I’d say the camera is about average considering the price.

Petrel U42W Transmitter and FPV Smartphone MountTransmitter & Setup

The included transmitter is pretty standard for a quadcopter of this price. The main differences being the centered throttle stick for altitude hold and the included smartphone mount that clips right on top.

It fits nicely in hand and has separate buttons for:

  1. Switching between flight rates
  2. Headless mode
  3. One-button takeoffs/landings
  4. Flips

Binding the quadcopter is as simple as turning on the transmitter and holding the throttle stick down. Once you let go, turn on the quadcopter and it should bind automatically.

Arming and disarming the quadcopter is just as easy. Simply place both sticks down and inwards at the same time to arm it. To disarm, just hold down on the throttle stick until the motors power down.

Alternatively, you can use the one-button takeoff/landing buttons on the transmitter. Both are simple and intuitive methods.

Tip: In the Flyingsee app there is also an “Emergency Stop” button which kills the motors immediately. This will cause the quadcopter to drop out of the sky but is useful if you expect a hard crash, as turning off the motors during a crash helps protect them from damage.



The U42W comes with 2x 500 mAh batteries. Usually, quadcopters only come with one battery so the included spare is a nice addition. They take about 70 minutes each to charge and offer 7-10 minute flight times. Any attached accessories (prop guard, landing legs, camera) will drain the battery quicker.

There is a battery bay that is covered by a flap, and a little snug once pushing the battery and its wires all the way in. There is a convenient on/off switch underneath the quadcopter so you don’t waste battery when it’s not in use.

One of the neatest features about the U42W is it’s low battery warning. Not only do the lights on the quadcopter flash, but the transmitter itself begins to loudly beep, letting you know that the quadcopter’s batteries are running low. This is helpful since the flashing lights on the quadcopter are not always visible from afar or during the day. I love this feature and it’s something I think every quadcopter should have.

Petrel U42W Package ContentsWhat’s in the Package?

  • Petrel U42W Quadcopter
  • Transmitter
  • Smartphone FPV mount
  • FPV mount sun-visor
  • 4x Spare propellers (2 clockwise, 2 counter-clockwise)
  • 4x Propeller Guards
  • 2x 500 mAh batteries
  • USB Battery charger
  • 1x Screwdriver
  • Instruction manual

The Final Verdict

The Petrel U42W is a beginner’s camera quadcopter. It’s not the fastest, but it has features such as the ability to draw your flight path on your smartphone, as well as an amazing altitude hold that distinct it from other beginner quadcopters on the market. If you’re looking for one of your first few drones and have a couple of extra dollars to spend, the Petrel U42W is worth considering.

We hope this Petrel U42W review was helpful. Let me know what you think about this drone. If you have any questions, feel free to ask in the comments below and i’ll be glad to answer!
– Drone Trove


  1. Anthony
  2. Robert H Miller

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