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Landing issue - strange behaviour
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eker View Drop Down
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Joined: 27 Feb 2015
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    Posted: 27 Feb 2015 at 4:15pm
Purchased yesterday (P3D 2.5) - and do some manual landing pattern to learn the aircraft.

Setup: Reduced fuel and weight to less than 50% MGW.

Approach selecting flaps down to 10 is fine.

At flap 22 or more it is suddenly ballooning straight up with pitch level. Push stick max forward, but nose will not drop. Max throttle does help it balloons straight up until speed drops below 100 with stall warning. It then falls down in flat stall unable to increase speed with motor power or to pitch down.

Have tried different airspeeds around 160 to 120, but no difference.

A different issue is instrument lightning. Primary instruments are too dark. (Have tried all? light switches - even those not mentioned in the manual (Left glareshield). But after dark the standard lights are on, I can fly in dusk and dawn for now.
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ftwd View Drop Down
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Joined: 26 Dec 2012
Location: Australia
Points: 56 		Post Options Post Options   Thanks (1) Thanks(1)   Quote ftwd Quote  Post ReplyReply Direct Link To This Post Posted: 28 Feb 2015 at 10:26am
Landing the Tristar is different to other aircraft as Lockheed developed a system called Direct Lift Control or DLC for short. When in the landing configuration, the DLC uses the spoilers to decrease or increase the rate of descent rather than pitch. This means that the aircraft will maintain its pitch giving the pilots better visibility during the approach and touchdown. The best description I found on the forum about DLC is by 'Peter HKG" and as follows:

Originally posted by Peter HKG Peter HKG wrote:

Flying with DLC is a new experience and the system will try to hold the plane stable during approach. I´m not a real pilot, can not decide what´s wrong or not. Before I flow the Captain Sim L1011. The approach is similar. The only difference I saw was the "Alpha" information at speed-window when I set Flaps 33 in Captain Sim. So I first expected to see "Alpha" here again, but it´s not shown. The approach speed I used from the table left in the cockpit depending on Weight of the airplane. Which can be easy found at the fuel panel, where actual fuel and weight are shown. If the speed is reasonable before setting flaps 33, there is no problem to fly manually. If the speed is too high, the plane will try to decrease the speed for flaps 33 setting with the spoilers I think. If thrust decrease at the same time, it losts altitude and if the pilot try to pitch up, it wouldn´t work because this would decrease the speed of the plane again.
Flying manually the L1011 the pilot must know during approach, pitch changes speed, thrust changes altitude. Uncorrect speed and thrust during approach leads to loss of altitude and speed when flaps 33 are set. The plane doesn´t know the distance to the runway, the system tries only to get a smooth glide path down. Maybe flying online ATC wants the pilot to fly minimum 170 knots until outer marker. Then I wait with flaps 33 until I reach outer marker. Otherwise the plane slows down and would be a obstacle for following airplanes. Maybe I´m wrong, but this way I have no problems to control the approach manually.

Functional the DLC works fine. Question is, should there be the "Alpha" announcment in the speed window or not? In the Captain Sim this was the information for me, NOW! DLC will correct my inputs.

Another question is the Altitude. With FMS flying, when I change the altitude after TOD, the airplane directly starts descent. Do not know this is correct. I expected first I had to set V/S to begin with descent. With other planes I do this:
Get from ATC "When ready to descent ... Altitude" I set the altitude at MCP. I know. this is the next altitude I´m allowed to fly. I calculate the TOD and V/S, later I set it and start descent.
Now I notice the new altitude on a paper and wait until optimum point of descent to set the new altitude on MCP. It´s not bad because when the workload is high, it´s faster to follow ATC instructions when a direct descent is needed. I need only to change the altitude at MCP and the descent begins.

Maybe there are different versions of L1011. For example the CS has no Autobrakes, which JF have.
The JF-Pro-Version is much better than the old version before. Good work!


I hope that this helps you some, keep up the practice.

Cheers,

Nathan
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eker View Drop Down
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Joined: 27 Feb 2015
Points: 16 		Post Options Post Options   Thanks (0) Thanks(0)   Quote eker Quote  Post ReplyReply Direct Link To This Post Posted: 28 Feb 2015 at 11:52am
Thank you for extensive reply. I makes sense and no doubt will address my problem

I can perform some pretty good landings at flap 22 now. I moved CG further back. Watching replay I do have high pitch - but probably will end up in that config for airspeed approx. 140 and rate of descend at -500 -1000.

I will try flap 33 when established at correct rate of descend and lined up.

Today I will do some VOR to VOR training with autothrottle and autopilot.

Thanks again Nathan!!
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eker View Drop Down
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Points: 16 		Post Options Post Options   Thanks (1) Thanks(1)   Quote eker Quote  Post ReplyReply Direct Link To This Post Posted: 28 Feb 2015 at 2:19pm
To ease the learning curve, you must try flap 33 while flying normal at approx. 6000` If out of control: select less flap and add power.

Coming in too high (above GS or all white papi) at flap 33 and you are doomed.

Select flap 33 when flying into GS (or 2 red papi) and sink rate between 0 and -500`. Be prepared to catch a ballooning effect by trim down.

Now the aircraft is extremely slow to react on sink rate change. Be very patient, and wait for the response.

Coming over the fence with a sink rate of -1000 can easily be corrected in other aircraft by flare. But not Tristar. You must start to decrease sink rate much earlier in a kind of semi flare.

Checking the wing view in replay, you can see the spoilers are slightly up after selecting flap 33. No doubt the DLC is working and to fight if you want some major changes in sink rate.

Edit:
In short - If in doubt, land at flap 22.
Perfectly setup for approach and want a challenge: select flap 33.
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ftwd View Drop Down
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Joined: 26 Dec 2012
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Points: 56 		Post Options Post Options   Thanks (0) Thanks(0)   Quote ftwd Quote  Post ReplyReply Direct Link To This Post Posted: 01 Mar 2015 at 1:04am
Pleased to see that things are getting better. Great reporting on how to fly the approach too

Nathan
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stretch1365 View Drop Down
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Points: 29 		Post Options Post Options   Thanks (0) Thanks(0)   Quote stretch1365 Quote  Post ReplyReply Direct Link To This Post Posted: 01 Mar 2015 at 8:22pm
Hi all,

I have today been trying to fly the Tristar Pro around Edwards Air Force Base KEDW, I thought I would try somewhere with plenty of space.............My first flight in the Tristar Pro last week went very well until I tried to land, where upon I got down to 150 with flaps 22 and turned off the autopilot to perform the landing manually, and woo, the plane went almost vertical and crashed into the ground nose up! 

I noticed the post here and was encouraged by what I read, today I followed the directions for the tutorial in the manual, fuel reduced to 50% in all tanks and firstly flew up to 15000ft and slowed down to the speeds mentioned in the manual, 200 at flaps 4, 180 at flaps 18, 160 at flaps 22 and then 150 at flaps 33. I found that the aircraft started to roll gently from side to side at both flaps 22 and flaps 33, which I thought wouldn't help with landing much!

So I then approached KEDW runway 21, slowed down fine to the point of flaps 18, the aircraft was stable which was great. So feeling encouraged I disconnected the autopilot and woo instant nose up and crashed into the ground tail first vertically.................Back to square one! 

Is there any chance of someone doing a tutorial video of how to land the Tristar Pro, I do have the other Tristar that is available by another developer which I can land manually fine no problems, so I am wondering if it is me or the aircraft?

Are other people still having the same issue or have they now got it sorted?
Happy Flying

David Phillips
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eker View Drop Down
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Joined: 27 Feb 2015
Points: 16 		Post Options Post Options   Thanks (0) Thanks(0)   Quote eker Quote  Post ReplyReply Direct Link To This Post Posted: 01 Mar 2015 at 11:08pm
Try this:

Fly at approx. 6000` not approaching a runway. Keep it level with no descend. Reduce speed and select down to flap 22 as speed drops.

Then select flap 33 (sink rate at 0 to -500 f/min) and anticipate the ballooning by trim down. If out of control then flap up to 22 and add power. Regain control and select flap 33 again.

With some practice you will have control at flap 33 and sink rate at -500 -700.

The good thing now it is very stable at this sink rate. It takes time to increase or reduce sink rate. Try to adjust + -100 sink rate now. It is rather easy.

The bad thing if you want major change. Say you are over GS and need to drop down to -1500 sink rate. You try to adjust but nothing happens, until it suddenly drops, and you are passing through GS with -2000. Fighting to climb again nothing happens until goes up again as a rocket.

Following a GS is usually around -700`/min sink rate.

Now try a GS. Fly into the GS - and select flap 33 while at around -500`/min. Now the Tristar is rock steady at approx. flying down GS. Fine adjustment is now easy to carry out.

Remember that GS is very sensitive near runway. Do not chase it - just aim for a touch down point at the runway at final.
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