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buznee

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Posts posted by buznee

  3. Posted

    Yup.

    You may want to check the math on that. Regardless, you'll hit VnE long before you run out of Q or temperature because TAS is higher than IAS at high altitude.

    Why does the aircraft care about TAS? Your VNE is derived from IAS, it is usually an airspeed limit set for structural limitations directly related to load factor and ultimately dynamic pressure. IAS has a relationship directly proportional to dynamic pressure (keeping density as a constant, standard sea level density). Here is the relationship used to derive your true airspeed and indicated airspeed from your dynamic pressure which is derived off of the total pressure port and static pressure port in the pitot static system. For true airspeed you will need a static temp sensor as well to derive your air density.

    Pdynamic = PTotal - Pstatic =.5*airdensitySSL*IAS^2 = .5*airdensity*TAS^2

    From what I remember reading, the reason aircraft use indicated airspeed instead of true airspeed is because it allows you to have a constant set of markers that the pilot can refer to regardless of altitude. If the stall speed on a fixed wing is 60 KIAS at sea level, then at altitude it will still be 60 KIAS, even though your true airspeed may be much higher.

    VH on the other hand is the airspeed in which the aircraft can't physically go any faster. Depending on the aircraft and condition VH might be higher or lower than VNE.

  6. Posted

    I figured I'd create a post and post bugs as I find them.

    Feel free to post here as well.

    -Cruise ship at the dock near the city is half submerged in the water.

    -When trying to land on ships the aircraft starts to bouce heavily sometimes causing the ship to submerge. This includes large frigates.

    -Tail Rotor and Main Rotor spin at the same RPM. This should be between 4:1 to 6:1 ratio, not 1:1.

    -Walking into a tail rotor should kill you.

    -Game slow down and crash. After a while game begins to lock up a bit and eventually crashes.

  8. Posted

    Thanks for the replys.

    Out of curiousity what do you have set for the joystick sensitivities and deadzones for the collective, cyclic, pedals. I am using the Saitek X52.

    Also the only controllability difference I see in Trainee as compared to Expert is the auto trim. Is this what you are refering to that makes the aircraft feel different or are there things that you can't select within the difficulty options that make the Trainee mode different than Expert?

    Do you use the manual trim engage / release ?

  10. Posted

    Did some flying last night with the beta and just wanted to give my first impressions.

    For a beta I believe this is a great start. I have played the ARMA series of games and the menu screens and interface definately show the roots. Although there seems to be lots of left over stuff from ARMA that should be removed to avoid confusion. Too many control assignments that seem redundant and can add confusion to the player.

    There are some issues I believe should be addressed though with regards to aircraft handling.

    Helicopters by nature require active input by the pilot to keep the aircraft in a controlled manner. Because of their unstable nature they are designed with good controllability for precision flying. This is what we call direct stick to head control. You input a deflection into the cyclic control and you see the result right in front of your eyes. Similar to a bicycle, it should feel very intuitive and instant.

    The aircraft in the beta seem to have control sluggishness and delay/lag which is extremely aggrevating in an aircraft that is naturally unstable. I understand that the joystick axis sensitivity and deadzone can be adjusted, but this does not fix the issue. I beg the TOH development team to address this very issue because it is a deal killer for this sim. For some reason the pedal controls do not seem to have nearly as much of this sluggishness / delay as the cyclic and collective.

    Collective should also be instant since the pilot is controlling blade angle directly. The only thing that should be delayed if any is rotorspeed response based on engine fadec control dynamic engine response and FADEC controlled engine limiters for the more expensive twin engine helicopters. Also because the collective is instant, that means the torque on the rotor should change instantly with a change in collective. This does not seem to be true in the sim.

    With regards to aircraft performance

    The power required may be off as well, especially for hover. Most helicopters hover at around 60-100% torque depending on many things such as weight, altitude, and temperature. Most pilots are therefore looking at the torque gauge especially during hover because of the great deal of an incredible amount of power required. Sometimes an aircraft is loaded so heavy that it has to do a HIGE (hover in ground effect) and then transition into bucket speed in order to have enough excess power to climb out. There should be a considerable amount of collective/torque required to hover as compared to bucket speed in trimmed level flight (Vy, best rate of climb speed or best endurance speed) of ~60 kts for an MD500. At Vy the torque should be minimum. It should then increase rapidly as you approach Vne (Never exceed speed.) This should all ofcourse vary with aircraft weight and operating altitude but the relation is the same.

    Engine power available should also vary with density which can be derived from temperature and pressure altitude. Anotherwords, as you go higher the engine gets less oxygen and produces less power. This means that you may not get to 100% torque at high altitudes and start drooping the rotor speed sooner.

    These are all very real effects that I believe should be included because it effects pilot operations. Just like how you guys are trying to implement pre-flight walk around to make sure you don't have a bird's nest in the engine compartment, you should also have the pilot do a quick check of the aircraft center of gravity plot and weight to make sure you can actually fly safely and have the capability as well as have enough fuel to go and do what you want to do. This can all be simplified and integrated in a userfriendly interface so it is a little less of a hassle.

    Overall I think the team is heading in the right direction but I plead on getting the helicopter feel to be more direct. Pilot should feel like he one with the helicopter, remove all sluggishness and lags. If you need something to compare to, go take an intro flight in a real Robinson R22 or download the Dodosim Bell 206 for FSX and you will see what I mean. It is very sensitive and instant but yet highly controllable. Not sluggish / lagged / muffled.

    Other issues.

    I tried doing the single missions and there definately needs to be some work done with the scripting and triggers as well as the briefing. Landing in one helipad vs the other will trigger or not trigger the waypoint to go talk to the guys who are waiting for you. If that is the case it needs to be clear in the briefing or through the radio that you need to land in the north or south helipad etc. Also when the mercenary guy tells you to follow the road it would be nice to know if you turn left onto the road or right onto the road as well as what speed and altitude he wants you to target. Having him tell you headings to fly or being more clear without you having to turn on the waypoints would be great. Also at the end when you go to drop the guys off at the shooting range there definately is issues with triggers for them to disembark.

    Missions need to be well briefed and clear in what needs to be done or it will add frustration. I hope for a polished release and if not initially I hope that the team strives to continue to support the development because this sim has tons of potential if done properly.

    I wanted to thank you guys at BI for Take on Helicopters. Lets get this right!

  11. Posted

    Agreed.

    First of all I wanted to congratulate Bohemia Interactive in releasing what can be potentially the best immersed helicopter simulator out. I understand this is a beta and still needs tons of work but I would like to provide some feedback that will help make this sim top notch.

    The flight model in general is workable but it definately has a long way to go.

    A good place to compare how a helicopter should fly is to fly the dodosim Bell 206 for Flight Simulator X. Very well put together. Tons of work trying to match the same performance charts of the aircraft and getting feedback from many 206 pilots with regards to handling qualities.

    What bothers me is that the aircraft in TOH are actually more unstable and difficult to fly then the dodosim bell 206, x-plane, fsx and dcs blackshark aircraft.

    Pedal control feels about right. Has good damping and good controllability.

    The problem lies in the cyclic and collective. There is not sufficient roll and pitch damping and too much inertia in the longitudinal and lateral directions.

    The lateral and longitudinal inertias for the aircraft seem too high. When you put in a control input in a helicopter you should see it immediately in the aircraft response. It seems there is quite a sluggish feel between input and output feedback. Which means that when you fly you have to push the control, hold it, to overcome inertia, wait for aircraft response and anticipate wayyyyy ahead of time the aircraft behavior so that you can put in a correction to stop the roll/pitch rates. This should not be so. Stick to head should feel direct. This makes the aircraft very frustrating to fly with precision. The pilot should be working on putting the aircraft over a point on the ground much more than trying to hold a pitch/roll attitude. If the pilot has a hard enough time holding attitude it is quite frustrating even attempting to hold a point over the ground.

    In level flight above 60 kts the aircraft should begin tracking easily in both pitch and roll since the tail surfaces are now weathervaning in the wind. This should make it quite easy to hold an airspeed and altitude. Does not seem to be that way with this current flight model.

    Most light twin and medium twin helicopters come with SAS (stability augmentation system) as standard equipment. I highly recommend including this feature in the light twin and medium twin helos in TOH. Usually these size helicopters are considerably easier to fly than the lighter smaller helis. You should be able to hit the trim release and release the controls and the aircraft should hold a perfect track while in level flight. In hover you should be able to hold a pitch/roll attitude by trimming and just work the cyclic to stay over a position on the ground.

    Is aircraft steady state power required modeled? It should take quite a bit of power to hover as compared to flying at best rate of climb speed (Vy) it should then require a great deal of power/torque to get anywhere near Vne. Ofcourse this will depend on aircraft gross weight. Is variable weight based on fuel burn modeled?

    Collective rigging and torque indications do not seem accurate.

    It should take more than 50% collective to get light on wheels in hover. Most helicopters will require pilot at ~75% collective to be in stabilized hover out of ground effect, ofcourse depending on weight this value will vary.

    Torque should be instantly changing with collective input. No delay. This is not a power available (engine) variable, the torque is simply measuring the drag on the rotor system. so increasing blade angle is instant, therefore torque measurement is instant. Power available should come in with regards to how quickly the rotor speed catches up to a quick collective change. If the engine response is fast than the rotorspeed should catch up quick. If engine response is slow or you are at the torque limiter or engine limiter, the rotor speed should droop.

    Drag coefficient needs to be increased as well. It seems way too easy to get up to speed and overspeed the aircraft in level flight without even getting close to the torque limit.

    Not sure if this is related to the flight model or not but why does the aircraft cockpit view randomly buffet / shake in flight. Does not seem realistic. If this is supposed to be simulating turbulence or helicopter vibrations its not very convincing. I would remove this for now until you can make this look more believable. It is quite aggrevating.

    All in all though. Thanks so much for putting something like this out there! I am very excited to be able to fly at tree top level and have wonderful scenery to look at as well as being able to walk out of the aircraft.

    On another note, the current options menu for controls etc seem to have lots of leftovers from ARMA. I would try to seperate this game as much as possible from that. There are too many control assignments, half of which are not very useful. I would recommend consolidating all of the view controls between vehicles and infantry etc into one easy to understand set of assignments. Try to tweak the model with the default control settings for a standard usb joystick and have those settings as your default. It is a bit frustrating to have to mess with sensitivities, dead zones, etc to make the aircraft flyable.

    If you guys get the flight model right and work out the bugs with regards to the mission/scripting/triggers, I think you will have a great product that will appeal to a wide range of audience.

    Thanks for listening.

  13. Posted

    So far I have been really impressed with the handling characteristics of the ARMA helicopters.

    There are a couple little things that bother me that are easy fixes.

    First off, The collective takes a bit too long to respond, especially from takeoff. Almost all helicopters both turbine and piston are designed to operate at constant main rotor speed. Lift production is controlled by feathering (changing the pitch of the main rotor). Doing this is very fast therefore a change in climb rate should be more responsive than it currently is (even though ofcourse it is dependent upon mass since everything has inertia).

    Also I see that no matter what, when on the ground, the dust blows around when the main rotor is turning. In reality in a collective pitch helicopter, this only occurs when the rotor is producing lift. Anotherwords it should kick more dust as the collective is pulled up higher. This would give a very cool experience in arma, you can tell when the pilot is starting lift off when you see the dust begin to kick. If possible you can even make the dust particle size and velocity proportional to the collective setting, just as it is currently dependent upon altitude, since downwash effects "dustkicking" increasingly at lower altitudes and ultimately goes away at higher altitudes.

    Also there should be a saturation point in which too much collective is added and the rpm governer cannot hold the rpm therefore the tq goes to redline and the rpm begins to drop. This causes the pilot to input lots of rudder to counteract the torque from the main rotor. I know this is not supposed to be a helicopter sim but just things that would definately give the wow factor. A simple thing such as when you turn the engines on, you have to have the collective at the low setting if not the heli will not reach operating rpm and if you stay in the red line for tq you will overheat the engine and it will fail. This is something that definately can happen in a helicopter, it would be as simple as a tq dial showing green and red arcs, as long as you dont pull the collective to max, keep it in the 80-90% range then your engine will be fine. If you hit red, you'll start to shake, rpms will drop and if you dont bring it back down soon enough your engine will fail and you will have to autorotate.

    One last thing in the flying characteristics is rudder becomes almost useless at moderate to high forward speeds. Eventhough a helicopter has a vertical tail it still has significantly more rudder control at forward speeds than what is currently modeled. This would allow fishtailing approaches in which the fuselage can be used as an "airbrake" for much better decelerations and you can use the cyclic in the side to side direction to slow the helicopter down and touch one skid at a time.

    Being able to autorotate after tail rotor failure would be very cool too.

    Another thing that helicopters have is translational lift. This is the main reason helicopters have wheels. At forwards speeds not too far from hover, the helicopter requires significantly less power to fly than in hover. Therefore allowing it to carry more loads. So if loads can be modeled in ARMA, you can overload your helicopter and still be able to takeoff by doing a rolling takeoff on the ground, and then land either a bit hard or do a rolling landing.

    There are many more little things that can be improved but by just improving these items, it would definately make the helicopter experience much more enjoyable.

    On a side note, for the harrier, adjustable nozzle control and linear power for any aircraft for that matter would be much better. It feels that currently most aircraft dont have very linear power with throttle control. Seems you add poewr and it goes from 0% to 100% and then it sorta moves around if you try to find a happy medium. It cant be that hard to just make it linear power. Then just change thrust output to downward, maybe helicopter flying characteristics when the nozzles are pointed downward and you can use throttle to control decent rate. This would be much more realistic. You could also keep the autohover for people that perfer that.

    If you guys have any other things for improvements in realism post!

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