VC10 stalling

[paul26may]

Why does my VC10 keep stalling? I have recently loaded FS2004 on to a new machine but remember having this problem in the past. It happens both in and out of auto pilot.

[DaveB]

Hi Paul..

This is NOT a known problem on the VC10 as far as I'm aware mate though it IS possible to force it to happen if that makes sense.

When you say it keeps stalling.. when is this happening? Is it in the climb.. in the cruise.. in descent.. farting around in the pattern.. give us a clue amigo

The VC10 simply doesn't keep stalling without good reason.. in fact it doesn't stall at ALL without good reason.
ATB
DaveB

[paul26may]

In the climb. I was climbing to 360 and at about 320 it started to stall. I had engines at full power also and climbing at 600 ft per minute.

[TSR2]

Hi Paul, you should be using a step climb to get to those sort of FLs. Make sure your airspeed doesn't drop below 250 too.

[paul26may]

Thanks for that. How would you suggest I do that? This flight I was doing was London to New York and everything was going fine until I was passing over Gloucester. At about 320 the stall warning came on. I rectified it and carried on only for it to start again. It happened a few more times after that - at 240 and 260 - and I just gave up!

[DaveB]

Hi Paul

It sounds very much like you're climbing at too great a V/S mate. The VC10 will go like stink low down and very high angles of attack.. at least initially are the norm. However, like any jet.. it will run out of puff the higher you go so.. when your climb speed begins to fall off.. reduce the V/S to maintain it. You may end up with as little as 500fpm.. maybe lower on the dials as you approach cruise alt but that's the norm. Although the model will go higher, I generally cruise at FL320 with 310kias on the clock.. around M.83 I think.. been a long time.

BTW.. if you're using FS Flightplanner (the default bit of kit) to navigate with.. it WILL stall.. most aircraft will in my experience. This is because it tries to climb at the airspeed you set without regard for V/S.. the consequence of which is it pushes the nose higher to reach alt and stalls. I use FSNavigator which doesn't allow the aircraft to stall as it reduces V/S to maintain speed in the climb

ATB
DaveB

[TSR2]

There's no way you should be at FL320 by Gloster, depending on your routing, and fuel load (which will be pretty full if your going to JFK) you'd be at FL320 between Liverpool / IOM. As Dave says you'll easily get 3000 - 3500 on the climb out with your slats and first notch of flaps, then the slats / flaps come in (I do this at about 5000 - 6000ft) and keep the airspeed at about 200 - 220. If the airspeed drops off, reduce you climb rate. Try to keep it at about 2500ft/m up to FL100, above that you may need to bring it down to 2000ft/m up to about FL230, and the airspeed should creep up to about 300. Above FL230, set it to 1000ft/m which should get you up to FL310 or 320, but the airspeed will have tailed off to about 260KIAS. Level off and let the speed build up again to about MACH 0.82 then set the climb to FL340 at 500 - 1000 FT/m making sure the airspeed doesn't drop too much. Level off at FL340 and leave her there for an couple of hours, after that you can go up another few thousand feet because you'll have lost a load of weight.

If you look at a planefinder.net for example, you'll see many of them will leave EGLL and cruise at about FL320, then when they hit Iceland they'll go up a few thousand feet. If they are flying to LA, they'll often do another 2000ft step over the Canadian boarder.

[paul26may]

Thanks again - very useful information! Taking it a bit further, as I near the USA/Canada how should I start my descent and approach to KJFK? More often than not I fly a line following the Hudson river then line up over Manhattan.

[DaveB]

Hi Paul..

I've just planned a transatlantic for the VC10 at FL320/310kias in FSNavigator and have printed the plan over the U.S.



You'll see two BOD's.. the first is from FL320 to FL120.. the second from FL120 to Rwy 22L at JFK. Plan was using high level airways
Hope this helps
ATB
DaveB

[NigelC]

OK, Here we go!

CLIMB

Do NOT set a specific rate of climb! You should always fly the speed!

Down the runway, rotate and pull the nose up until you are climbing at V2+20. Hold this until about 3000ft above airfield elevation and then lower the nose to allow it to accelerate, retracting flap as you go and using PITCH to control the speed i.e. the pitch wheel on the autopilot. You should be at climb power of about 93%.

The aircraft cruises at about 480kts TAS so aim for about 320kts INDICATED in the climb adjusting pitch as you go to maintain this speed, you can reduce this speed if you wish to give you a better climb angle, I usually use 300kts.

You will notice that the indicated climb speed is 2/3 of the cruise TAS, and that the IAS/Mach transition at a FL roughly equal to the airspeed (320). You can use this rule of thumb for other aircraft i.e. BAC 1-11 cruises at 420Kts so climb at 280kts/M0.72, A320 450kts = 300kts/M0.78

As you climb your Mach number will increase and when 320Kts is equal to Mach 0.84 then maintain the Mach number from that point. Your IAS will then fall away. This should be about FL300-310. When you reach your cruising level, level off and reduce power.

You will notice that not once have I mentioned a rate of climb as this will vary with weight, temperature etc. The constants should be speed (320/M0.84) and power (93%).

DESCENT

Rule of thumb is 3 miles per thousand ft, so from FL350 to a sea level airfield is 105 nm. Rate of descent should be 5 x Ground speed, in still air this would be 5 x 480 = 2400 fpm or quickly half the ground speed and add a 0.

Adjust power to maintain a speed profile of M0.84 and then 320 kts as the IAS rises to meet the Mach number.

Nigel