Help!!! (Trident)

[forthbridge]

Not sure if this is the correct list - but here goes....

I'm currently 'learning' the Trident - it has been difficult to steer clear of the '10 in the A/C selection window, but unless I am toying around, I need to spend a long time on type to get used to it....

Anyway I appear to be having a strange problem - and I am not sure if it is me, or what....


I am mainly flying around Glacier Bay while I (slowly) get all the add-ons back in to FS as it's the only area I've so far installed.....

Now, I am typically loading about 40% fuel into the Trident (except at Skagway where it's 10% and a cut payload) - and I am finding the Aircraft very manageable in takeoff, and quite sprightly. I am presently doing circuits at Juneau Intl - as the natural 'bowl' of the surrounding hills give good markers for turning points so I can get lined up visually. My main issue with landing is slight floating, which will remedy in time so I am not worried about.

What is strange is that in Glacier Bay, when I rotate, the Trident feels nicely able to *climb* and is up to 3000AGL in no time. It positively gets airborne.

But, my other two stomping grounds - Edinburgh and Leuchars - with EXACTLY the same fuel loads and trimmed up, when I rotate, the rear wheels stay firmly on the deck and *eventually* the A/C lifts off - and the climb feels rather sluggish....

Can anyone hazard a guess (apart from my ineptitude) why the A/C feels and apparently handles differently in Alaska to Edinburgh????????

[SkippyBing]

Not being familiar with Glacier Bay I'm assuming it's at the same elevation as the other two? Also when you say nicely able to climb to 3000' AGL, how do the climb times compare to 3000' AMSL?

[forthbridge]

Edinburgh is about 130ft AMSL and Juneau is at sea level...

I haven't actually timed the time to 3000 feet..

I have Vr at 139kts, V2 is 145 kts.

At Glacier bay, *as soon* as I rotate at 139kts, the plane lifts as the nose rises. I basically hold the climb speed by pitch at around 180 kts, keeping the gear etc down as I'm only doing circuits. With the same settings at Edinburgh, when I rotate, the nose rises and the rear wheels stay on the ground, with the A/C not actually lifting until about V2 +20 (160-170kts) - it is necessary to be careful not to tailstrike whereas at glacier bay the plane is up before there would be any chance of that! In fact, the rotation induces some drag which seems to inhibit the gaining of speed slightly, (better to keep the nose down) - and it just does not happen at juneau!

The plane then struggles to maintain airspeed in the climb - just feeling underpowered. Weather is set at zero so there's no wind influence. All engine settings including booster are correct, and I make sure I click the thrust index to set it.

I'd say all things being equal, it takes a good two or three seconds longer to get airborne at Edinburgh than Juneau. (quite a distance at 150kts+)

Once the A/C is up and stabilized it feels the same - it is just the initial lift where it feels like it's running out of puff at around Vr and not wanting to lift

[SkippyBing]

Only other thing I can think of is the OAT and pressure settings, I'm not sure if there's a global climate model that's used if you're not using real weather that would affect these. If so set them both to a standard atmosphere (1013mb and +15 deg C) and see if that makes a difference.

[forthbridge]

Well, I'm using clear weather and TI and pressure is checked and set at each location.

:think:

[petermcleland]

Are you sure you are still using reduced fuel load...Or are you using a Saved flight that has put you back to full fuel?

[forthbridge]

50% fuel load - checked. I've even started up the sim from new (rather than 'go to') and set everything up - starting with a default cessna, then switching to the trident and making the necessary fuel changes.

Excepting the figures, it is very noticeable in that from the cockpit, at juneau, it 'feels' like a takeoff -whereas at rotation at Edinburgh, the feeling is 'What's happening here??' - not a massive difference in speed altogether.

At Skagway, 50% fuel gives a V2 of 142kts. At 2.5 tail pitch and 23 degrees flap, (one more click than 16deg) (with a pushback onto the chevrons) the Trident gets airborne at 144 kts - and it is possible to climb straight out and get over the mountains easily.

I've not managed to get it off the deck in less than that at Edinburgh at that weight for that speed.

**If** the figures are correct to real life, that is a takeoff in 1000 metres - yet on the crosswind (1700 metres) at Edinburgh, liftoff is at least 500 metres later.

In all instances, I wind up the engines before releasing the brakes, switch on the booster, pressure and thrust index set top temp, and have tried with and without water injection.

[petermcleland]

What about the OAT...Could be a lot colder at Skagway

Edit...If you are using "Cleared Weather" then the OAT will be about 15C in both places so not relevant...BTW Water injection not actually fitted. The switch is a hangover from something. In real life, the Boost engine would probably be required at Skagway but probably NOT at Edinburgh unless it was a very hot day with a full load.

[forthbridge]

Yes, temp, dewpoint and altimeter settings are the same.

I'm really struggling with this one - performing as near identical rotations as I can, it is always about 10 knots higher indicated speed at Edinburgh before the rear wheels lift. I've stopped using the booster as I'm using Juneau which is long enough.

I've just performed a fully laden takeoff in real weather from R06 at EDI. Wind 042 at 9kts. Vr was 160kts, and I was using the booster engine. The trident bacame Airborne just at the TDZ markers for 24. It actually felt better with a bit of wind toward the nose.

Perhaps I just need to allow an extra few knots for rotation in still weather.

[petermcleland]

Perhaps I just need to allow an extra few knots for rotation in still weather.

No, you always rotate at VR on the ASI...If there is a headwind then that just means you will achieve that IAS with more runway left ahead of you and your Groundspeed at lift off will be lower by the amount of the Headwind component (which is really irrelevant). Don't take-off in the Trident with a tailwind or it will live up to its nickname of "Ground Gripper".