Why nose pitched up during take off?

[russatfirstoff]

Is it a requirement for the nose on an gyro to pitch up during take off? Why cant a Gyro be designed with the main wheels moved back to stop the nose pitch-up and take off with a level air-frame attitude? Seems to me that over pitching during take off causes accidents.

 

[Abid]

Is it a requirement for the nose on an gyro to pitch up during take off? Why cant a Gyro be designed with the main wheels moved back to stop the nose pitch-up and take off with a level air-frame attitude? Seems to me that over pitching during take off causes accidents.

Any aircraft I have flown usually brings its nose up first before it leaves the ground on mains. That's pretty normal.

 

[russatfirstoff]

Hmmmm. I understand why a fixed wing air craft pitches up. But why a Gyro? On a Gyro the rotor tilts back, relative to the air frame, and is capable take-off lift with the air frame level. Is it a case of "its just always been done that way"?

 

[MikeBoyette]

This is a common misconception of aero dynamics of a gyro. First off in a gyro the main thing you are flying is the rotor disk. You control it and it drags the airframe with it. The nose wheel coming up and balancing is something that is ,although similar in looks as a fixed wing, not the same thing. The closest thing I can compare it to is when the tail comes up on a tail dragger.

It is also just part of how a gyro flys. They are different than fixed wings. To change a fundamental flying characteristic of a Gyro just because you’re used to an airplane, requires a change in your thinking not to change in the characteristics of the machine. My machine was set up so I had over 120’ on the nose wheel with the pilot on board. On the take off roll this meant as long as your RRPM’s on the tach was jiving with what the machine was feeling like and telling you. Once the nose wheel levitated you could proceed with full power and you were up and accelerating in ground affect up to your best airspeed for climb out.

This is one of quite a few things that makes an airplane driver harder to train than a completely green rookie whom has never flown anything. Muscle memory of a fixed wing pilot is very hard to quell while PIC in a gyro. No different than flying a helicopter requires different skills. The problem I have found is that gyros are kinda viewed as not really an aircraft like a helicopter and shouldn’t have its own method for taking off, flying, or landing. To most who are ignorant it’s a toy it should be easier than a real airplane.

This is the reason tail draggers were all but extinct until a recent resurgence. In an effort to draw less skilled people manufactures like Cessna and Piper changed to a nose wheel and took one of the things that made those early airplanes better to fly IMHO.

 

[russatfirstoff]

Hey Mike, Thanks for the reply. The fact that a FW is different than a gyro is kinda my point. Let me ask you this....can you take off in a gyro without lifting the nose wheel? Or with a very small amount of lift. This is design/function question.....not a challenge of your skills and abilities.

 

[WaspAir]

The A&S 18A lifts off level. The McCulloch J-2 can be lifted of at 45mph with essentially no time rolling with the nosewheel up.

 

[Aerofoam]

Since you are holding full aft stick to allow more air flow through the rotor and to make sure the rotor RPMs are rising, the nose wheel will lift before the aircraft is ready to fly. If you held a lower angle in the initial acceleration, you would risk flapping a blade.
The 2 aircraft in the prior post can pre rotate well beyond flight RPMs with depitched blades and are capable of jump take offs.

 

[Abid]

Hmmmm. I understand why a fixed wing air craft pitches up. But why a Gyro? On a Gyro the rotor tilts back, relative to the air frame, and is capable take-off lift with the air frame level. Is it a case of "its just always been done that way"?

You need to talk to your gyroplane instructor. This is not how it works.

 

[MikeBoyette]

Hey Mike, Thanks for the reply. The fact that a FW is different than a gyro is kinda my point. Let me ask you this....can you take off in a gyro without lifting the nose wheel? Or with a very small amount of lift. This is design/function question.....not a challenge of your skills and abilities.

In my experience you can but, it’s going to extend your take off roll. The nose wheel height should be wherever the balance point between the tail wheel and nose wheel is. Once you have trained and trained it becomes automatic and not something you even think about.

 

[Gyro-nut]

IMO, I would never want to take off 'level' in the gyro's current configuration. I see your point in trying to prevent the flapping condition, however, I believe you would be introducing another potentially even more dangerous situation.

If you did not take off perfectly level and the mains came off the ground before the nose wheel, any skidding/side to side movement of the nosewheel on the pavement could produce a yawing scenario that could be unrecoverable. Would proper training overcome this; probably.... just like taking off correctly

 

[loftus]

I think possibly your question is asked with the thought that it may be safer to take off with the nose wheel flat, it's certainly possible but just not the most efficient or safest way to do so. It's possible to keep the nose flat as one takes off but this will increase ground speed and increase the risk of a flap as well as lengthen the takeoff roll. A gyro is at it's most unstable when on the ground, so keeping the takeoff and landing roll to the minimum necessary enhances safety. Control of the nosewheel is the key component of landing and taking off in a gyro; the initial lightening of the nosewheel is the first indicator to the pilot that the gyro is about ready to fly. It's up to the skilled pilot to control the nosewheel, neither pushing it down nor allowing it to lift uncontrollably before the rotor has generated enough lift to fly. This is the reason why so many emphasize the skill of balancing on the mains during training. The nose lightening and then controlling it is your sign the gyro is about to be ready to fly, and then retaining control of nosewheel position is key to lifting off safely and avoiding getting behind the power curve after takeoff.

 

[Vance]

Is it a requirement for the nose on an gyro to pitch up during take off? Why cant a Gyro be designed with the main wheels moved back to stop the nose pitch-up and take off with a level air-frame attitude? Seems to me that over pitching during take off causes accidents.

All of the pilot operating handbooks I have read suggest a near level takeoff attitude is best.

Allowing the nose to come up too far often allows the gyroplane to lift off prematurely below an appropriate climb out airspeed.

I feel that a nose high takeoff in a gyroplane is evidence of limited pilot skills and a misunderstanding of the flight controls.

Lately I have started to spend some time with my clients watching things on YouTube and explaining why what they see may be poor pilot technique.

 

[Vance]

Since you are holding full aft stick to allow more air flow through the rotor and to make sure the rotor RPMs are rising, the nose wheel will lift before the aircraft is ready to fly. If you held a lower angle in the initial acceleration, you would risk flapping a blade.
The 2 aircraft in the prior post can pre rotate well beyond flight RPMs with depitched blades and are capable of jump take offs.

In my opinion holding full aft cyclic during takeoff is poor piloting technique.

I feel there is value in a gyroplane pilot learning to anticipate the nose wheel lifting and adjusting the cyclic in a timely way.

 

[MikeBoyette]

I agree with Vance. I was taught to bring the stick to rear stop and push it off or it just a little bit. This is because it allows you to feel the blades as they are starting to hit the flap stops. If it’s all the way back you don’t feel it and can flap them without even realizing it.

 

[russatfirstoff]

Hey Mike, Abid, WaspAir, Areofoam, Gyro-nut, Luftus and Vance, thank you all for taking the time to reply. With all of your input, I understand completely variables and the logic of nose-lift/no nose-lift during take off. I see that all of your points are valid.
Thanks again. Russ.

 

[Sv.grainne]

I was taught to prerotate per POH. My Genesis go to 120rrpm, stick full back and spin up to 150rrpm. I release the brake and start my takeoff roll watching as rrpm climbs then drop prerotator and throttle up. When nose wheel comes up use the stick to manage nosewheel slightly off the runway increase speed and lift off. Accelerate and as air speed climbs fly away.

 

[loftus]

When one thinks about it, and distills thing down to basics, controlling the nose (wheel) is probably the key to safely taking off and landing any aircraft, and controlling climb or descent in all phases of flight. It's also like the goldilocks story, not too hot, not too cold, but just right. Fixed wings also take off with lifting and control of the nosewheel - neither too high nor too low, but just right. I think it's fair to say that in any phase of flight, it's all about what the nose is doing, the rest follows. Pitch and power being the two main variables.

 

[AviomaniaTexas]

IMO, I would never want to take off 'level' in the gyro's current configuration. I see your point in trying to prevent the flapping condition, however, I believe you would be introducing another potentially even more dangerous situation.

If you did not take off perfectly level and the mains came off the ground before the nose wheel, any skidding/side to side movement of the nosewheel on the pavement could produce a yawing scenario that could be unrecoverable. Would proper training overcome this; probably.... just like taking off correctly

In fact, a single place gyroplane with the mains too far back and with a hang test that is near the limit for a nose down set up, the mains can and will come off the ground first resulting in the gyro cartwheeling down the runway and potentially rolling over. Especially after reducing the throttle to abort the takeoff relieving the propeller induced drag that is keeping the back of the machine from lifting up.

 

[Rowdyflyer1903!]

The A&S 18A lifts off level. The McCulloch J-2 can be lifted of at 45mph with essentially no time rolling with the nosewheel up.

Ron Herron's "Little Wing" whose gear looks similar to a tail dragger ie conventional landing gear, departs the runway from a three point stance with no apparent rotation. The rotor finds its sweet spot and lifts the fuselage accordingly.

 

[Aerofoam]

Ron Herron's "Little Wing" whose gear looks similar to a tail dragger ie conventional landing gear, departs the runway from a three point stance with no apparent rotation. The rotor finds its sweet spot and lifts the fuselage accordingly.

I think most tail draggers will do this, or even slightly lift the tail first (don't know this for a fact with full scale) due to the higher AOA of the disk because of the nose high stance.
My RC gyro would lift the tail slightly before take of if you were deliberate with a gentle acceleration, so I guess there was a sort of rotation when the elevator was given a bit of up pressure for climb. This was a fixed head aircraft.