REALLY Struggling with the T7

[craig_read 43]

Ok.. I like to think I can fly these sim aircraft quite well.. in fact I have absolutely no trouble at all with the 737NGX and the 747-400 from PMDG... can fly them around manually or with the automatics without any difficulty.. in all weathers.. with engines out.. etc etc.. but the T7.. I just can't land it to save my life!  I am wondering if it's me or if it's something in my sim that's causing the problem.. 

 

I've watched the T7 training video for the flight and taken into account every detail.. so here is how my approaches go.. 

 

I'm doing a circuit around Stansted.. (EGSS).. depart and land on RWY22... it's an ILS approach on 22... I don't bother with the SID because I just want the landing practice.. so.. basically take off runway heading.. up to 5k.. turn onto 040.. fly down the airfield.. I stick in the first waypoint on the ILS.. and set my target speed in the FMC for it... so it's 170/2500.. make it nice and easy.. So.. later on downwind I turn in to intercept the localizer.. starting my descent on the downwind leg.. I'm just SLIGHTLY fast at the first waypoint .. around 180.. it's flaps 30.. 136KT approach ref for me.. so.. on G/S capture I bang in flaps 20... and drop the gear.. sure enough.. she slows.. everything is lovely.. start on my approach nice steady descent.. get to 1200 radio alt... bang in flaps 30.. set MCP speed to 141KT.. (VREF + 5).. now.. here is where things go horribly wrong..

 

Basically from what I can see.. she pitches the nose up.. and doesn't throttle up anything like enough.. I am looking at a screen shot now.. I am doing 140KTs.. my angle of attack is about 12.5degrees... my descent rate is.. wait for it.. 1500fpm.. and I'm well below path... engines are at 46.9% N1... I can kinda see why the engines are so low as she's in SPD.. but why is she pitching up so much and causing the stall!?

 

Please help ... this will be the 4th time I have to knock off A/P.. throttle up and go around again now..

 

Here are some screenshots to help diagnose my issue.. my trim is 12.0 btw.. what is that about.. seems off to me..

 

Cheers

 

Craig Read

[yyzflier 11]

Hi Craig . . . Very weird. I'll be interested myself in what others say. it appears you've got the APP armed. Does the A/P track glideslope and localizer properly? 

Only other observation is that it appears you are carrying a lot of fuel for pattern work. More weight means higher stall speed. So reducing your fuel load may buy you some extra margin. But that may not be the problem.

[Jazz 1,046]

Easy on the fuel there fella. drop it so you only have a total of 10 tons in the tanks and see if that helps.

[devgrp 1,233]

If he is getting vref approach speed of 136kts, then I dont think he is too heavy or maybe he is just putting in those vref speeds without the fmc calculating it.

 

I know the fmc will not calculate the vref flaps speed unless the ZFW and most of the stuff is entered into the perf page.

[kevinh 409]

Ok.. I like to think I can fly these sim aircraft quite well.. in fact I have absolutely no trouble at all with the 737NGX and the 747-400 from PMDG... can fly them around manually or with the automatics without any difficulty.. in all weathers.. with engines out.. etc etc.. but the T7.. I just can't land it to save my life! I am wondering if it's me or if it's something in my sim that's causing the problem..

 

I've watched the T7 training video for the flight and taken into account every detail.. so here is how my approaches go..

 

I'm doing a circuit around Stansted.. (EGSS).. depart and land on RWY22... it's an ILS approach on 22... I don't bother with the SID because I just want the landing practice.. so.. basically take off runway heading.. up to 5k.. turn onto 040.. fly down the airfield.. I stick in the first waypoint on the ILS.. and set my target speed in the FMC for it... so it's 170/2500.. make it nice and easy.. So.. later on downwind I turn in to intercept the localizer.. starting my descent on the downwind leg.. I'm just SLIGHTLY fast at the first waypoint .. around 180.. it's flaps 30.. 136KT approach ref for me.. so.. on G/S capture I bang in flaps 20... and drop the gear.. sure enough.. she slows.. everything is lovely.. start on my approach nice steady descent.. get to 1200 radio alt... bang in flaps 30.. set MCP speed to 141KT.. (VREF + 5).. now.. here is where things go horribly wrong..

 

Basically from what I can see.. she pitches the nose up.. and doesn't throttle up anything like enough.. I am looking at a screen shot now.. I am doing 140KTs.. my angle of attack is about 12.5degrees... my descent rate is.. wait for it.. 1500fpm.. and I'm well below path... engines are at 46.9% N1... I can kinda see why the engines are so low as she's in SPD.. but why is she pitching up so much and causing the stall!?

 

Please help ... this will be the 4th time I have to knock off A/P.. throttle up and go around again now..

 

Here are some screenshots to help diagnose my issue.. my trim is 12.0 btw.. what is that about.. seems off to me..

 

Cheers

 

Craig Read

Your AOA is far too high, even in the first shot, so I can only suggest the weight in the FMS might be set wrong. If it is low that would mean your reference speeds are also too low for the weight you actually have.  You seem to have quite a lot of fuel for landing, 56900 lbs.

 

(copied from a duplicate thread as this one seems busier)

[craig_read 43]

Easy on the fuel there fella. drop it so you only have a total of 10 tons in the tanks and see if that helps.

Yup.. weights were way off! .. I'm an idiot

 

Regards

 

Craig Read

[yyzflier 11]

Also important to do the pre-flight in the FMC. That will give you the right weights and also the right speeds for both take-off and landing. 

[devgrp 1,233]

 

Yup.. weights were way off! .. I'm an idiot

 

Regards

 

Craig Read

 

 

How did you come up with that vref speed? I have landed with a full tank just fooling around and my vref speed for flaps 30 was around 170-180

[cavaricooper 2,613]

Craig-

 

Hang in there! I still remember your tutorial for the 744 (May even have a copy yet). The 777's a lovely girl, very Boeing, but very different from our a Fat Girl. She's coming along very nicely and as with the NGX will blossom with an SP or two. So much to learn, and look forward to...... Our girl commeth

[craig_read 43]

Going to check it tonight, but essentially the aircraft has no cargo at all, it is empty so even with 60k lbs of fuel I am not totally shocked with vref of 137kts... Going to check the fmc has the right fuel weight set tonight though...

 

Cheers

 

Craig Read

Craig-

 

Hang in there! I still remember your tutorial for the 744 (May even have a copy yet). The 777's a lovely girl, very Boeing, but very different from our a Fat Girl. She's coming along very nicely and as with the NGX will blossom with an SP or two. So much to learn, and look forward to...... Our girl commeth

Oh I know! The 744 still is my baby.. I wrote that tutorial when I was at uni! Some terrible mistakes in it though! Lol... Can't wait to see that and find out how much different the new fat girl will be.... I will check out these weights in more detail tonight

 

Loving the T7 though, so well done... Knew I had done something daft just couldn't see the wood for the trees! Lol

 

Regards

 

Craig Read

[craig_read 43]

Ok I have more to add to this now.. same problem.. here are the weight details:

 

GR WT  = 466.4 (1000 x Lbs) or 212,000 KGs

FUEL = 58.4LB CALC

ZFW = 408.0

CI = 100

 

In FS ACTIONS I have:

10 First Class

33 Business

117 Economy

 

FWD / AFT CARGO

17900 / 12400

 

BULK CARGO

2290

 

(1000 x Lbs)

 

So my load level is 54.7%, not really all that bad and surely it should land safely and easily in this configuration, but I have the same problem.  I am not really sure why since this weight to land is well within the aircraft capabilities.

 

T/O FLAPS 5 .. V1 135 VR 139 V2 147... not exactly needing a great deal of speed to get going.. and she clears easily at these speeds.. 

 

FMC calculated approach speeds are:

 

FLAPS 20 - 151KT

FLAPS 25 - 142KT

FLAPS 30 - 137KT

 

GROSS WT 465.4 (1000 x Lbs)

 

If I fly this aircraft like this, she stalls on approach before she hits VREF for landing at flaps 30.

 

Thoughts?

 

Craig Read

Also this table shows the VREF speeds for the 777-200... 

 

B.777-200 GE90-76B

 

Vref (kts)

 

WEIGHT

(1000) FLAPS

LBS KGS 30 25 20

550 250 151 159 164

528 240 148 156 161

506 230 145 152 158

484 220 142 149 154

462 210 139 145 150

440 200 135 142 147

418 190 132 138 143

396 180 128 134 139

374 170 124 131 135

352 160 121 127 131

330 150 117 123 127

308 140 113 118 123

 

Can someone shed some light on this.. or highlight my mistake please?

 

Craig Read

[Jd_jay 4]

Out of interest, do you have this same problem when you do an actual flight? Rather than a circuit?

[devgrp 1,233]

Something is definately not right because Ive taken off fly out about 20 miles turn around and autoland with no problem with full and empty tank of fuel.

 

Are you using the TOGA button on take off?

 

I just saw in the first post that your trim is 12.0. That may also be playing a roll in this situation. My trim has never been more than 3.75 with a full tank of fuel

[craig_read 43]

I've re-installed my entire O/S and so on.. I am going to retry this today to see if I can make it work..

 

Cheers

 

Craig Read

[kevinh 409]

I've re-installed my entire O/S and so on.. I am going to retry this today to see if I can make it work..

 

Cheers

 

Craig Read

Whatever this is it's almost certainly nothing to do with your OS. That should be your very last resort. Even reinstalling FSX is unlikely to help. Reinstalling the 777 possibly. But my guess is still finger trouble.

 

Edit:

 

Vref you get corresponds to my installation.