Hover/Side slip Control Tips?

[ESzczesniak]

I was wondering if anyone from the group could share any tips for controlling the harrier in the hover. Particularly in regards to avoiding or negating side slip.

 

It seems that it is very easy to get unstable and just oscillate rocking from side-to-side. I haven't been able to find much reading if rudder, aileron, or both are best used.

 

I've learned for the controlled sideslip on to the ship during landing, aileron and rudding in opposite directions is the most controlled...as I should have realized and known given the sideslip landing techniques of the same name in GA aircraft.

[NeilWillis]

The first route is to look well ahead when hovering in anything. Keep the horizon level, and you'll reduce sideslip tendency much more effectively than "chasing the ball".

 

The key is anticipation and not just trying to react to what's already happening.

 

It is however an art that takes a lot of practice. It is one reason Harrier pilots in the UK start their course by flying helicopters long before they're let loose in the Harrier.

[Eagle7907]

+1 on the looking ahead part. When I do the crossover I look at the bow of the deck and adjust to the tram line very carefully. Small corrections is key, and to keep the nose parallel to the tram line.

 

 

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[Badyk]

I found that fighting the oscillation results in over-correction and it just gets worse. If you minimise stick input it should dampen itself out

[Mars Exulte]

Yep, what Badyk said. Say you're drifting right, you roll left a bit to compensate. If you wait until you start moving left, you've already waited too long.

 

If you are drifting right, roll left to compensate, then immediately level back out. You're just waiting too long and fighting yourself. Same principal with helicopters, even in something as simplistic as Arma.

 

Don't overthink stuff, relax, and let the aircraft fly itself, you just need to guide it. Small corrections with a light hand.

[Eldur]

I also still have my issues with that, getting better tough, but I expect it get get a lot easier as soon as the AFC is implemented:

 

2.16.2.1 AFC Mode -- AFC Switch Only Engaged

 

When the AFC switch is engaged and the ALT HOLD switch is in the off position, the AFC mode provides pitch attitude hold, roll attitude hold and heading hold. At airspeeds above 50 knots, the AFC will capture and hold pitch attitudes in the ±30° range and roll attitudes within ±60° which are outside of the ±5° range about wings level. Heading hold is provided inside the ±5° roll attitude range for airspeeds above 140 knots if gear and flaps are up or above 0.3 Mach if the gear is down or if STOL flaps are selected (but not both). Heading hold is inhibited at all airspeeds if both the gear is down and STOL flaps are selected. With heading hold inhibited, roll attitudes within ±5° are rolled to wings level. Neither pitch nor roll attitude capture will occur for attitudes which exceed one or both of the ±30° pitch attitude or the ±60° roll attitude ranges. The AFC switch will remain engaged, however, the pilot must control the aircraft in both pitch and roll as in the SAS mode until the attitudes are within both limits. No cockpit indication is given to the pilot when he has maneuvered the aircraft outside the attitude capture limits. With the AFC engaged, mild stick vibration or chatter in pitch may occur during landing approach due to abrupt movement of the forward reaction control valve caused by flight control computer noise. This is normal and should be disregarded.

 

At airspeeds below 50 knots, the roll attitude range is restricted to ±20° and the roll to wings level action extends to the full ±20° range. The pitch attitude capture and hold action is restricted to the +3° to +12° range. Pitch attitudes outside this range but within -15° to +20° will be driven to the nearest of the +3° to +12° range boundaries. The AFC switch will disengage and reversion to the SAS mode will occur if either the ±20° roll attitude range or the -15° to +20° pitch attitude range is exceeded. If the true angle of attack exceeds +15° with the airspeed greater than 60 knots, the AFC mode will be disengaged and reversion to the SAS mode will occur.

 

Automatic pitch and roll trim are provided the AFC mode. The automatic trim tracks the aircraft pitch and rollchanges to keep the series servo actuators close to their neutral positions an effort to minimize disengage transients. On aircraft with departure resistance, the lateral stick to aileron interconnect may prevent the roll auto trim from keeping the aileron series servos near the center of the±6°range. The automatic trim rates correspond to approximately 0.25° per second stabilator and aileron surface rates and cause the control stick to move in the direction the trim change.

 

I just wonder how the roll reaction control nozzles are aligned. As we all know we hover with 82° nozzle angle and keep the witches hat on the horizon, at least that's what we should (since it's down ~6° at the moment, it gets a bit different). Now the waterline is 8° up. If we roll, that's where our roll axis goes though. At least when rolling with the ailerons this should be correct. But how is it when the whole roll movement is done by the RCS? Are those little nozzles angled 90° or 82°? The latter would make it a lot easier, but the simulation definately brings the first case at the moment which adds some unnatural feelin to it. When you roll left, the witches hat wanders off to the right and intuitively at least I try to counteract that which basically leads to the "problem" this thread is about. If the roll axis would go through the witches hat in hover instead of the waterline, it would be a lot more intuitive and since the hover stop angle for the main nozzles is 82° I highly suspect the roll RCS nozzles in the wingtips have that exact angle as well IRL. I just couldn't find any details on this yet (Disclaimer: reading the NATOPS takes ages, maybe it's just in there and I didn't stumble across it yet)