Predator/Reaper, why they went with a V-tail design?

[RandomGuy88]

I have some questions about these two aircraft.

Does anyone know why they went with a V-tail design?

My understanding is that the Reaper is a more advanced version of the Predator. Why is the tail of the Predator point downwards but not the tail of the Reaper? I have heard that the Predator's tail was upside down because of the coupling between yaw and roll that the V-tail creates. If an upside down V-Tail tries to yaw the aircraft to port then the aircraft will roll to port, but if the V-Tail is right side up and it yaws the aircraft to port then it will create a rolling moment to starboard. Was this an actual reason for this tail config, or are the rolling moments from the V-tail to small to worry about? And if so what was the reason? It seems like a downwards pointing V-tail could have ground clearance issues.

The Reaper also has a vertical stabilizer in addition to the V-tail. Why is that?

 

[Cyrus]

I have some questions about these two aircraft.

Does anyone know why they went with a V-tail design?

My understanding is that the Reaper is a more advanced version of the Predator.

The MQ-9 is much larger than the predator, and flies a bit faster. For the MQ-9, its a Y tail, not a V tail.

Why is the tail of the Predator point downwards but not the tail of the Reaper?

It was an issue of ground clearance for the landing gear.

I have heard that the Predator's tail was upside down because of the coupling between yaw and roll that the V-tail creates. If an upside down V-Tail tries to yaw the aircraft to port then the aircraft will roll to port, but if the V-Tail is right side up and it yaws the aircraft to port then it will create a rolling moment to starboard. Was this an actual reason for this tail config, or are the rolling moments from the V-tail to small to worry about? And if so what was the reason? It seems like a downwards pointing V-tail could have ground clearance issues.

Yep.

The Reaper also has a vertical stabilizer in addition to the V-tail. Why is that?

For more weathercock stability.

 

[NatSusan]

Hi there,

The decision to use a V-tail design for these aircraft was likely based on a combination of factors, including aerodynamic performance, stability, and maneuverability. The V-tail design can provide better control and maneuverability compared to a traditional tail design, as it combines both horizontal and vertical control surfaces into one. This allows for more precise control of the aircraft in different flight conditions.

As for the difference between the Predator and Reaper's V-tail configurations, it's important to note that the Reaper is a newer and more advanced version of the Predator. The Predator was originally designed for surveillance and reconnaissance missions, while the Reaper was designed for both surveillance and combat operations. The Reaper's tail is not pointed downwards because it has a different mission and requires more advanced control and maneuverability capabilities.

Regarding the issue of coupling between yaw and roll, it is possible that this was a consideration in the design of the Predator's inverted V-tail. However, as you mentioned, the rolling moments from the V-tail are likely small compared to the overall control of the aircraft. The Predator's inverted V-tail may have also been chosen for other reasons, such as reducing the overall size and weight of the aircraft.

As for the vertical stabilizer on the Reaper, this is likely to provide additional stability and control in flight. The vertical stabilizer helps to keep the aircraft flying straight and level, especially during turns and other maneuvers.

Overall, the decision to use a V-tail design for these aircraft is likely a combination of various factors and considerations. I hope this helps answer your questions.