Sign in to follow this  
Guest tonyc

ATR first test flight comments

Recommended Posts

Nice plane with nice handling characteristic, especially during takeoff.In landing,however, the flaps extension appears to have too great(and too sudden) of a lift relative to the yoke's ability to counter that force.Also, with full flaps, the plane simply does not want to descend unless the yoke is pushed all the way forward.The trim alone will not do the trick of keeping the nose down. I am interested to hear from others on this.In order to counter a very sensitive yaw and elevator, I've reduced the sensitivity settings of the joystick, in the joystick calibration options. These are preliminary tests and not conclusive. tony

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

Hello. I'd like to add my test results as well!I agree the flaps extension have too much of an effect on the lift, and most especially the pitch of the aircraft. It's an instant nose pitch up and baloon the second the flaps go down. I'm not sure if this is realistic behavior, and I don't know if the ATR has a reputation with pilots for being difficult to fly, but I noted this as creating a challenge for flying approaches.I have the same behavior as you with full flaps down. Simply cannot get it to decend without pushing the yoke all the way into the panel.Another thing I noticed was very sensitive ground handling. I found it quite hard to keep it on the centerline since a tiny adjustment would put me off line.Last gripe, when landing without landing gear down, the plane will coast along the runway forever. There is no drag even if you're dragging the plane along the ground and pushing the nose down. I'm not sure how this could be fixed but I just thought I'd mention it.To summarize:The flight model seems very nice; however, the trim is not effective enough (Or it moves too slowly), the flaps cause significant and possibly incorrect pitch attitude changes, and excessive balooning effect, and both effects occur too quickly. The flaps provide too much lift at low speeds.The ground handling should be de-sensitized significantly to allow for easier taxiing and runway handling.The airplane is not capable of belly landings due to a minor glitch, there is no friction between the ground and belly of the plane and as such it will slide forever on a wheels up landing.Please take this as constructive criticism! I really like this plane! I hope that we can all help it achieve perfection. It's already close to it, just needs a small ironing out.

Share this post


Link to post
Share on other sites

Yes, the ground handling is very sensitive , too. But this is true with most FLY2 aircrafts. I intend to play with the values in the whl file. Given the scope of the project, I am sure that ROTW will appreciate all constructive comments that help them tweak the flight model to perfection. The flaps, too, can be tweaked as well in the wng file. I am building two new aircrafts, and clearly the flight model tweaking is the the most challenging part, given all the many variables that affect its behavior. There's a great article written by Rober Young on the subject. In fact I think it should uploaded on a web site for the tweakers.tony

Share this post


Link to post
Share on other sites

we knew these points. The real pilot had noticed an assett instability during the approach.When I ask to Jean if he can fix it, he said: "it's very difficult because these parameters need to reconfigure the PA also and I need at least a month to do that". Then we decided to upload the ATR "as is" because the delay. I hope Jean, who is on another great project, will take time to fix this in a future version.Thanks to continue giving your comments.

Share this post


Link to post
Share on other sites

Hi, Rene. What is the "PA"? This interesting to me, since ,as you know, I am working on two aircrafts....tony

Share this post


Link to post
Share on other sites

Donny AKA ShalomarFly 2 ROCKS!!!My experiences were a bit different. The ballooning and mushing when applying/retracting 15 degrees flaps seems to occur too suddenly, but if anticipated it can be compensated for with the stick. The Ballooning is much less pronounced in a 30 degree turn, though the mushing is more. "Full flaps" is an emergency setting, and I found it to require 1/4 to 1/3 forward sick to counteract. At 30 degrees, the stick stays about neutral. But the recomended setting is 15 degrees for most aproaches and landings. Also a power setting of 44 percent N1. It took me a period of trial and error to determine which guage Jan called N1, but I finally settled on the second one down as the most likely candidate. This reads "prop RPM" when you put the mouse over it. To my delight, the plane settled down to 113 knots with the gear down and a descent rate of 500 FPM and on the initial aproach seemed to mantain the glideslope almost by itself. But NEVER reduce power below 44% on the aproach! If you are high, pitch down. I was a slow learner, thinking I could "get away" with reducing power below 44 percent for breif periods, but speed can bleed off very rapidly and make the aproach hard to salvage. You must make apropriate pitch/power corrections, ocasionally exceeding 44 N1 especially near decision height. Airspeed management is essential, as I heard it is on aproach in all aircraft that cruise faster than 250 knots. But once I got used to it, 15 degrees was the easiest to use and I even did a successfull no flaps landing! Though it does seem to get trickier at any flaps setting right near decision height. Lost count, did over a dozen aproaches. I think my usual policy of always having my first flight in anything with higher performance than a PA-28 at a runway with an ILS and STAYING in the pattern till familiar with it really paid off with the ATR. Actually I chose the new "community", though the surrounding terrain made it more challenging. I had to get up to 6500 on the downwind before the GPWS would shut up, resulting in a long final but I think that helped. Don't consider myself ready for "Xcountry" yet.BTW, except for making sure it was in the takeoff range, I NEVER TOUCHED THE TRIM!!!I did an autostart so I could watch where everything was but I noticed the props weren't spinning in exterior view. When I advanced the throttles, the props began spinning. Also the EFIS would flash on and off occasionally, but when I did a manual start the props spun in exterior view and nothing flashed. I did get ocasional Air conditioning and engine EP warnings in flight though. Taxiing with condition levers at 100% seems to result in always winding up too fast or too slow, which I assume is realistic behavior. 40% works fine.The last thing I noticed when parking at the "comercial area" behind runway 16 is that when I tried to apply differential braking, the plane would stop.Well, off to bed.Best Regards, Donny:-wave

Share this post


Link to post
Share on other sites

Donny AKA ShalomarFly 2 ROCKS!!!My second session in the ATR didn't go as well. I followed procedures for a manual start using external power. Last night I had noticed the plane stopped when left braking was applied, but tonight noticed when right differential braking is applied nothing happens. I lost hydraulics then. The failure manager was all green, but I noticed the auxillary pump which I had turned on was off. It read off, not fault. Even if it had failed, for the auxillary pump to cause you to lose hydraulics pretty much would negate efforts at redunduncy. I thought somehow the pump had been switched off with my attempt at differential braking, which seemed to be confirmed by an attempt to do it again, so I taxied back to runway 16 and took off. But the aux pump shut down again before I could get the gear and flaps up. Once again, the whole system failed. To make a long story short, it switched off several more times including once on rollout, and though I was able to stop safely I had reason to hope for a while that one of the ROTW developers had good insurance on his house... The pump shut off again three more times on the way back to parking. I had reentered in Persistent world, and thinking that to be the problem I switched to a TRI default aircraft and exited. Oh, yeah, every time I panned up to the overhead I heard a "click, click, click" like I used to hear in the 707. I still heard it after I had rebooted and everything, so I exited and deleted all my .hst files. When I reentered, I found that the clicking sound was still there but went away when I cycled the batery switch. Before I hadn't bothered with that switch cuz I was on external power. Going thru the checklist I found "fault" when I tried to activate the AC alternators after engine start. DC was fine. As a test I went back to external power and the AC system worked once I switched the alternators back off. Also, my auxillary hydraulics pump would switch off occasionally still and take the whole system with it. But the hydraulics system would suddenly start functioning again when I activated external AC power. Very strange. I would love to find out I just missed something on the preflight but I can find nothing in the manual that can explain this behavior. For now this beautiful bird seems grounded. Just to be sure, I tried a manual start using battery power. Same result, haven't tried Hotel yet. I don't know why I hadn't noticed it before, but on this session I noticed the LP fuel valve buttons were inop.Anybody else, or is it just me?Best Regards, Donny:-wave

Share this post


Link to post
Share on other sites

HelloSorry for not answering earlier but I was aways this week.1)- I did not make extensive tests on differential brake on ground and that may explain the poor performance you experiment. But anyway, there is no direct relation with hydraulic power. There is no way in Fly! to adjust the brake behaviour in real time. We can adjust it once for all in the WHL file. The auxilary pump is to be used if both main pumps (blue and green) are down (as you could experiment when total hydraulic failure is simulated). It will operate 20 or so seconds then shut down (this is so in the real ATR). This gives you enough time to activate the gear or flaps.To activate main hydraulic power, you need to have AC power to operate the pumps. During start-up alternators will supply power when some RPM are reached, so something like 10 % of gaz is required and the 'fault' lights will extinguish. Hydraulic power will then build up and reach the required PSI in about 15 or so seconds.2) The clic-clic is a problem I spent many time on it, without finding the cause. Seems that FLY! tries to activate the battery switch and probably I should find if it is a fixed name or whatever. Anyway, as you did, it goes away as soon as the battery switch is clicked.3) Hotel mode is just a ground procedure to provide DC and AC power with engine 2. It replaces the classical APU.4) LP valves are linked to the conditioners lever. They shut down when levers are all the way down and open when levers are on the FTR position.5) I have read the reports about the aircrft behaviour with flaps. I think I will rework the flight model in the next future for a new release. However, due to the time I spent on this aircraft, I need some relief and I currently work on another plane. So the new release will be a little time aways.Jean

Share this post


Link to post
Share on other sites

I confirm there is a bug on the differential brakeThe left will act on both wheels and the right is inactive. Although I don't see the cause, I will try to fix this.Jean

Share this post


Link to post
Share on other sites

Great job, Sabatier. Take your time....I know how much work goes into making a plane as complex as the ATR.tony

Share this post


Link to post
Share on other sites

yesterday I have to go to Paris in plane: I flew in an... Airliner ATR42-500 (yes, it's not a joke) and captain accept I was in the cockpit during the flight.Then, I observed and asked for some explanations (not too much because they are very busy during this short flight).to be short:- In the ATR, they always use the "hotel mode" to start engines- in this company, they always stop left engine between runway and park after landing.- some switches and lights on the top panel have their actions to be modifiedBut I hav'nt see major problems with Jean's ATR (other theses reported above) and his cockpit panels and views are full realistic.Note: this aircraft is very wind sensible during landing.

Share this post


Link to post
Share on other sites

Donny AKA ShalomarFly 2 ROCKS!!!I knew the first time it happened in midair that the hydraulics shutdown had nothing to do with the brakes, but I felt I needed to explain why I took off after hydraulics shut down twice on the ground...I figured out what was wrong. I did another start but after a minute I still had fault indicators on AC system. I happened to switch to exterior view and saw the props were not spinning. When I advanced the throttles slightly they began spinning and remained spinning at idle power. I was then able to power up the AC and hydraulics with no further malfunctions. I tested my joystick and it seems to be calibrated, but I'll recalibrate just to be sure. Also the hydraulics system functioned with just the "blue and green" pumps on, had an LP on the aux system which was off but on the previous flight before I turned on the aux I had nothing and when the aux system would switch off- not register fault- I lost the whole hydraulics system.I don't know how many people use persistent world, but that's where I noticed this. Maybe it's because I switched from certain aircraft I noticed some of these things. Also when I come back after a shutdown still in the ATR-42 I am told I ripped off the power cables...None of these things are major problems, just posting this so if someone else experiences them they'll know what to do. That instrument panel checklist really comes in handy. I am enjoying this aircraft immensely, thank you Jean!Best Regards, Donny:-wave

Share this post


Link to post
Share on other sites

Donny AKA ShalomarFly 2 ROCKS!!!Jean's version taxis very well on one engine. You can even go into sharp turns into the operating engine from a dead stop. That's something you can't do in many other prop planes for FLY II. About the only thing Jean left out that I really miss is a stewardess to bring me foi de gras. But not even PMDG gives you that.Best Regards, Donny:-wave

Share this post


Link to post
Share on other sites

Sorry Donny, ther is never "Foie gras" on short commuter, even in France! :-lol Today, another ATR pilot come home to work about the flight model and the "hotel mode". Informations this week-end

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this