# Is it possible to fly horizontally using augmented fly pack?

#### Tabaristiio

Assume there is a wingless augmented flight pack such as a jetpack attached to a person's body. Assuming that there is sufficient amount of power.
will it be possible according to the laws of physics to fly in a horizontal position instead of a vertical position?

What are the requirements for someone to be able to fly horizontally using a wingless augmented flight pack?

This question ignores irrelevant factors such as health risks and etc. It's just asking if it's possible within the laws of physics to fly horizontally using a wingless flight pack.

Related General Engineering News on Phys.org

#### FactChecker

Gold Member
2018 Award
The thrust would have two components -- one part vertical and one part horizontal. As long as the vertical part is equal to the force of gravity, the flight would be horizontal. That is a lot easier if the jetpack exhaust is pointing down. If it was pointing more horizontally, it would have to be a huge jet to have a downward component great enough to oppose gravity. Then the horizontal component and resulting horizontal speed of flight would be like a rocket.

#### cosmik debris

In skydiving (ski-jumping too) it is possible to shape one's body in the general shape of an aerofoil and gain considerable lift, one can even notice stall. Whether there is sufficient lift at non-injurious speeds I'm not sure.

Cheers

#### Tabaristiio

The thrust would have two components -- one part vertical and one part horizontal. As long as the vertical part is equal to the force of gravity, the flight would be horizontal. That is a lot easier if the jetpack exhaust is pointing down. If it was pointing more horizontally, it would have to be a huge jet to have a downward component great enough to oppose gravity. Then the horizontal component and resulting horizontal speed of flight would be like a rocket.
Yes, I was referring to flying horizontally with the body in a horizontal position during flight. So does everything else you wrote still apply?

#### jbriggs444

Homework Helper
Yes, I was referring to flying horizontally with the body in a horizontal position during flight. So does everything else you wrote still apply?
So the jet pack is horizontal -- purely horizontal thrust. And the person's body is horizontal. No lift from the person's body. No wings allowed. So there is no vertical thrust of any sort. Then the jet pack and human will fall like a rock and hit the ground. Possibly miles ahead if the launch was from the top of a cliff.

The only way out would be to reach orbital velocity. Move horizontally fast enough and the ground curves downward beneath you as fast as you fall. That would burn you to a cinder if it didn't tear you apart first. But we are told to ignore such issues.

#### FactChecker

Gold Member
2018 Award
Yes, I was referring to flying horizontally with the body in a horizontal position during flight. So does everything else you wrote still apply?
The jet exhaust would have to tilt down. It needs a vertical component large enough to counteract gravity. It seems impractical to me. Wings are very important for horizontal flight.

#### Tabaristiio

The jet exhaust would have to tilt down. It needs a vertical component large enough to counteract gravity. It seems impractical to me. Wings are very important for horizontal flight.
What do you mean by a vertical component? Could you provide an example of something like that please?

#### Tabaristiio

So the jet pack is horizontal -- purely horizontal thrust. And the person's body is horizontal. No lift from the person's body. No wings allowed. So there is no vertical thrust of any sort. Then the jet pack and human will fall like a rock and hit the ground. Possibly miles ahead if the launch was from the top of a cliff.

The only way out would be to reach orbital velocity. Move horizontally fast enough and the ground curves downward beneath you as fast as you fall. That would burn you to a cinder if it didn't tear you apart first. But we are told to ignore such issues.
The only rule is that the person's body is horizontal during flight and no wings are allowed. The jetpack itself can be arranged in anyway required in order to accomplish this and accommodate the body. If possible, it's allowed for the jetpack to be arranged in a way where it can do enable the horizontal fight. This includes enabling vertical thrust.

How do other wingless aircrafts fly horizontally? Assuming enough power exists, can't human augmented jet packs / flight packs also fly like that? Or is it mandatory for the aircraft to have to travel at orbital speeds in order to accomplish this?

#### CWatters

Homework Helper
Gold Member
The only rule is that the person's body is horizontal during flight and no wings are allowed. The jetpack itself can be arranged in anyway required in order to accomplish this and accommodate the body. If possible, it's allowed for the jetpack to be arranged in a way where it can do enable the horizontal fight. This includes enabling vertical thrust.,
Sure that would work. Point the jets down at some angle and some of the thrust stops him falling and some pushes him along horizontally. Take a look at the Harrier jump jet and it's vectored thrust. Yes it has wings but at slow speeds these have no lifting effect.

#### FactChecker

Gold Member
2018 Award
What do you mean by a vertical component? Could you provide an example of something like that please?
Any force can be divided into parts of force in different directions. The force of a jetpack can be divided into the force upward and the forces sideways (horizontally). You can call those the components of the total force.

"Is it possible to fly horizontally using augmented fly pack?"

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving