How the heck do you auto rotate, lets say the bell jetranger
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#1: How the heck do you auto rotate, lets say the bell jetranger Author: jg300-Deputy_Dale, Location: Orlando PostPosted: Thu Sep 13, 2007 11:04 pm
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I cannot remember how to auto rotate any helo. I think turkey or booray tried to show me once and i plum forgot. Anyone? I'm tired of flattening my fuselage.
#2: I found this at hovercontrol Author: jg300-Deputy_Dale, Location: Orlando PostPosted: Thu Sep 13, 2007 11:25 pm
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Hovering Autorotations

This maneuver is performed if you lose power while in a low hover, but will be somewhat difficult to perform in the simulator because of the coordination required to cut the mixture with the mouse and control the aircraft with the sticks. Start by facing into the wind at an altitude of 3 to 10 feet, and maintain a stable hover.

In a real aircraft, a practice autorotation would be entered by cutting the throttle, but in the simulator it is essential to cut the mixture (the red sliders adjacent to the throttle control). The mixture must be cut because in the simulator the throttle is typically correlated with the collective position, so as you raise the collective you will be re-engaging the engine.

It is important to keep the engine from providing any power to the rotor. To begin the maneuver, cut the mixture with the mouse. Immediately apply right pedal to arrest the left yaw, and apply cyclic to stay over your spot. A little forward motion is acceptable, but sideward and rearward motions are to be avoided.

As the aircraft begins to settle to the ground, slowly apply up collective to cushion your landing.

Entering the Autorotation From Altitude

Begin the maneuver by cutting the mixture with the mouse. If you take no other action, two other effects will become immediately obvious: the aircraft will yaw to the left and the rotor speed will drop. Therefore your first reactions should be to lower the collective and apply right pedal.

Several years ago there was a fatal accident where an aircraft lost engine power and the pilot apparently never lowered collective. The wreckage was contained on a small roof with almost no forward motion, and witnesses described the rotors as barely turning. Ultimately the accident was traced to contaminated fuel, but poor pilot reaction to the situation resulted in the loss of 4 lives and one aircraft. Once rotor speed has fallen below 70%, recovery will most likely be impossible.

Check the trim of the aircraft by monitoring the slip-skid ball, and adjust pedal as necessary. Note the rotor speed and work to keep it in the high end of the green area by adjusting the collective. Also check cyclic control so you are flying in the direction desired and heading toward an airspeed of about 65 kts. In time, the coordination of controls on entering an autorotation should be almost simultaneous. Once you are in trim at a stable airspeed and rotor speed, you have successfully initiated the autorotation.

Unlike regular flight, higher rotor speeds may be acceptable during autorotation on some aircraft. For instance, the Enstrom F-28 allows rotor speeds of up to 120%. If collective is all the way down, the rotor speed may climb to an unacceptably high level, so you should be prepared to raise it a bit to keep the rotor speed in check. I have flown aircraft where the blades have been set so as not to require addition of collective to check rotor speed in autorotation. While this may appear to reduce workload, it also can lead to dangerous bad habits when you fly aircraft that are not rigged in this fashion. Also, acceleration of rotor speed may be slightly reduced.

It is also important to note that in a real piston powered aircraft you should add full carburetor heat whenever collective is lowered with an intent to descend. This is true for normal descents as well as practice autorotations. Adding carburetor heat when practicing autorotations is one piece of insurance that the engine will be available should you choose to terminate the maneuver. In a real aircraft, it is also wise to crosscheck the engine speed after cutting the throttle to ensure that you will only be practicing the maneuver and not performing a real autorotation. Failure to add carburetor heat at the appropriate time is one cause of engine failure that can lead to the need to perform an autorotation. Obviously you should follow the explicit instructions for application of carburetor heat for the aircraft you are flying.

Maintaining the Autorotation

Now that collective and pedal have been set, and you are attempting some semblance of control over airspeed, continuation of the autorotation should be fairly easy. Select a landing spot into the wind and maneuver the aircraft to accomplish this. You may have to turn 180 degrees. You may have to turn 180 degrees, fly past your landing point, and then turn back another 180 degrees (remember, in a real aircraft your life depends on selecting an appropriate spot, with considerations of its size and the wind direction). As you maneuver the aircraft to your spot, you should also be adjusting airspeed to slightly above the best endurance airspeed (nominally 65 kts).

For the most part, that is about it. No adjustment of pedal or collective is required, and your airspeed is also constant. The best endurance airspeed offers your least rate of descent, so you can take advantage of this to mentally prepare for the landing.

You should develop some idea of the glide capability of your aircraft in autorotation. For the R-22, best glide is about three fourths of a mile for each 1000 feet of height (about 4.5:1). The POH lists the conditions for best glide as 65 kts and 90% rotor speed.

Completing the Autorotation

As you continue descending toward your selected spot you will need to assess how close you will come to it. If you think you will be a little short (oh look…I must clear those trees), you can increase airspeed to the best range speed (nominally 80 kts) and increase collective a little. You will descend a little faster, but you will gain more distance over that altitude loss. It is acceptable to take a small loss of rotor rpm here, as you can regain it by lowering collective and slowing back to 65 kts when you think your spot is made. Similarly, if you think you will overshoot (oh look…I am going to land in the base of those trees at the far side of the clearing), you can momentarily slow down, but try to stay above 40 kts. You will again descend a little faster, but you will not gain as much distance. Again, restore airspeed if there is time once you are sure you will make your spot.

Now for the fun part. As you cross 40 feet height (use your radar altimeter, or in a real aircraft use the height of ground features such as trees or buildings, but try to keep your eyes outside the cockpit and looking in front of you), the ground will appear to rush up toward you. Begin to slow the aircraft to bleed off airspeed and vertical speed by applying aft cyclic. There is no need to adjust pedal, as you will not be changing power. Losing vertical speed is far more important here as you can always slide on the ground a bit. The goal is to have minimal vertical speed at about 5 feet above the ground. If you still have some forward speed here, you can pull back a bit more, but try to avoid any climb (and definitely avoid planting the tail in the ground or planting the rotor in the tail boom). Slowly move the cyclic forward so the aircraft is level, and as the aircraft begins to settle to the ground, slowly raise collective to cushion your landing.

Full autorotations to the ground are rarely performed for practice in real helicopters because of the risk of damage to the aircraft. Rather, once you have stopped forward and vertical motion, apply collective (remember, your engine should still be working) and enter a hover.
#3: So do i release the clutch or not? (Shift .) Author: jg300-Deputy_Dale, Location: Orlando PostPosted: Thu Sep 13, 2007 11:29 pm
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So i am attempting to translate this to keystrokes and joystick action. I get mixture down then struggle a bit with collective (what i use for aircraft throttle)
#4: Re: How the heck do you auto rotate, lets say the bell jetranger Author: JG300-fr8ycat, Location: Los Angeles PostPosted: Thu Sep 13, 2007 11:53 pm
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unfortunately FS9/10 don't really replicate autos too well with much reality but it is possible to do them to the best of FS's ability.

I get in in level flight around 1000 AGL 80kts into the wind. For a little more realism I cut off the motor, drop your collective all the way down and then bring it up a hair. For some reason if you leave it all the way down your rotor speed bleeds off and you lose it (one of the unrealistic things). now you wanna adjust your attitude to maintain about 60kts. since you already had forward speed entering the auto this will only require a slight nose down position. Somwhere around 75 feet AGL you wanna start your flare to reduce your forward airspeed to around 20kts then nose over to a level attitude and slowly pull collective to cushion the landing.

I've found for practice that viewing the 2d panel is good for the start and entering of an auto and as you get down to the ground switching to spot for your flare and set down. once you get the hang of it you can do it all the way down in VC mode.

I think there might even be a video with instructions over at HC. I'll see if I can find the link.

Last edited by JG300-fr8ycat on Fri Sep 14, 2007 2:37 pm; edited 1 time in total
#5: Re: How the heck do you auto rotate, lets say the bell jetranger Author: JG300-fr8ycat, Location: Los Angeles PostPosted: Fri Sep 14, 2007 2:36 pm
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Also, the throttle on your joystick operates the collective. For helicopters in FS there is no control over the the throttle/rotor RPM so to speak. It maintains a constant 100% in flight.

Ctrl+Shift+F4 to turn on motor
Ctrl+Shift+F1 to turn off motor

sorry I had them reversed.
#6: I don't wanna die Author: jg300-Deputy_Dale, Location: Orlando PostPosted: Sun Sep 16, 2007 3:22 pm
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Thanks Fr8ycat see video below http://www.youtube.com/watch?v=4dyzug2fzis (b)
#7: Re: How the heck do you auto rotate, lets say the bell jetranger Author: JG300-fr8ycat, Location: Los Angeles PostPosted: Sun Sep 16, 2007 6:26 pm
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Nice job. I made a quick video Friday I was gonna post to help ya out but didn't have time to upload it before leaving town. Auto's in FS are a nice challenge and fun stuff.

I think your auto was smoother than the one I did in the video I was going to post for you. Laughing I'll see if I still can't get it uploaded.
#8: Re: How the heck do you auto rotate, lets say the bell jetranger Author: JG300-fr8ycat, Location: Los Angeles PostPosted: Sun Sep 16, 2007 7:14 pm
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OK, we'll see if this works. This was the vid I made for ya.

mysite.verizon.net/rfr...s/auto.mpg
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