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Gtristain

(Help!) FSX 737 tilting/stalling on approach!

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When my default 737-800 is on approach it tilts up a TON, so much so that I cannot even see the runway below me. This tilting up eventually turns into an uncontrolled stall smashing me into the ground.

 

This only happens when I am flying level. Not when I am descending or ascending. (It remains titled even when flying level)

 

(Manual landing)

-speed is set at 155 knots (autothrottle & speed hold on)

-altitude is set to 2000-2500ish (the airport is at 1555 ft)

-All autopilot items disengaged on minimums for flare.

 

Any help solving this issue would be greatly appreciated!

 

-GT

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Hi GT,

 

Further questions:  what is your flap setting when AoA increases dramatically?   does this event take place when you descend to your 2000 ft altitude setting?   is 155 kts the correct approach speed given your aircraft landing weight and other aircraft landing configuration (speed brakes, landing gear, etc)?    have you attempted a manual approach, say from 3000 ft, to identify whether it is an aircraft problem or you needing to make corrections for a normal approach and landing?

 

If you are using the default B738, then you are probably also subject to default ATC instructions.   One can follow those instructions, but it should not preclude you from making adjustments to your descent rate (i.e. if you are at FL150 and are told to descend to 5000 ft, it's not good practice to descend at the default rate of 1800 ft/min.   That may need to increase or decrease to compensate for your altitude, distance to runway, and runway elevation ASL).   Just a few thoughts for you to consider.

 

Chris 

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At what weight? If you've got heavy loads this will happen. Also what are your flap settings?

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Although we have all been there, there are a number of flight and physics fundamentals which you need to understand before you launch into flying a heavier/big aircraft.  Start small and learn the basics.  Its fun to learn how it all works ad it makes the experience more enjoyable.

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Like the others have mentioned, landing weight and speed are very important!  What is your fuel

 

state at the time of landing?  Depending on runway length, full flaps may not be necessary. 

 

I find that with the default 737-800 and with most 3rd party addon 737s. the angle at level flight

 

is about 5-8% nose up.   Are you using a joystick, yoke assy, or keyboard for your control inputs? 

 

If it's the keyboard, I highly recommend a joystick.  For a visual approach I normally kill all

 

AP and AT inputs at about 10 miles out.

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Thank  you for all the responses, here are all the stats:

 

-Runway length I am landing at: 12303 FT by 148 FT (SCEL)

-I land at full flaps (usually) (It does the same thing even without flap up/down just a minor minor decrease in tilt)

-I do not usually use speed breaks in air unless I really am going too fast, even so only about 10%-20% of it (in air)

-Landing gear is lowered a bit after I have visual of the airport.

-I do not use ATC because of it being a bit too complicated atm (but if it's essential I will learn it)

-I'm using the Saitek Pro Flight Yoke System

-When I do a complete manual approach I also have to remain tilted up to keep altitude at a decent rate (If I tilt down it looses a ton of altitude and almost crashes)

 

Empty weight: 85710 Pounds
Payload: 22850 Pounds
Fuel: 6830.35 Gallons
Gross weight: 154323 Pounds
Max gross weight: 155500 Pounds
Max allowable fuel: 6875.00 Gallons
 
Center of gravity is in the cockpit area of the aircraft (in picture displayed)
 
-GT

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Empty weight: 85710 Pounds

Payload: 22850 Pounds

Fuel: 6830.35 Gallons

Gross weight: 154323 Pounds

Max gross weight: 155500 Pounds

Max allowable fuel: 6875.00 Gallons

 

 

I am only assuming these are your fuel and weight stats for take off.  How long is your flight and what is the FOB when landing?

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It's a 20 minute flight across the Andes mountains from El Plumerillo Airport, Argentina to Comodoro Arturo Merino Benítez International Airport, Chile. So the fuel quantity is still probably very high during landing. I can get an exact fuel quantity if you really need it by reflying the flight. (And yes, those are the takeoff stats.)

 

(this still happened on a four hour flight) (I cannot remember how severe it was, though.)

 

-GT

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OK, in my opinion, your weight is extreme!  I just flew into SCEL and was given an ILS approach to 17L.  I changed it to a visual approach

 

to the same runway.  Because of the mountains surrounding this area,  it turns out to be a dive from over 10,000 about 10 miles out, to

 

the runway at 1500 feet elevation.  My fuel weight at landing was around 7,800 lbs.  Landing speed was around 143 knots, 30% flaps,

 

spoilers set to autodeploy.

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Ok thanks, what do you suggest I put my weight at for takeoff in order to prevent this from happening again?

 

-GT

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For a short flight, let's say 500 miles or less I start with no more than 50% in each tank.  Cruise altitude of at least FLT340, MACH speed set at cruise

 

of about .72.  I create IFR flight plans and let ATC run me ragged with all of the altitude and heading changes.  If you haven't tried an ILS approach

 

yet, it may be a good time to learn this proceedure.

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Okay, I will try flying the same route with 50% fuel in each tank in a bit here, thanks.

 

-GT

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You are flying the 737 grossly overweight.  For a 20 minute flight load 10,000-20,000 pounds of fuel total (200-300 us gallons).  Use a load of less than full.  Fly it at an altitude of 14,000-15,000 feet.

Intercept the ILS 5nm outside the OM at 2000' above the airport elevation.

 

Have fun.

 

jetjerry

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GT, I agree with the others, you're way overloaded with fuel.

 

You can use a freeware fuel planner found here to give you an approximation of how much fuel you'll need. You just enter the aircraft your flying from the drop down and then enter your arrival and destination airports. It doesn't account for winds or payload, but if your just starting out and flying default aircraft it will be good enough.

 

http://fuelplanner.com/

 

Here's what it lists as fuel needed for your trip, including reserves. If you didn't take an hour of reserves you could get by on 6,000 pounds of fuel. So no wonder you were struggling with the weight you were carrying.

 

Screenshot_2015-08-11-22-51-40.png

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Thanks to all! Using all these answers I managed to fly & land without the tilting! (Issue resolved!) (issue was infact the weight of the fuel)

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To add to what the other are saying, SCEL is about 1,500 feet above sea level, and probably hot. Very hot. This affects the `density altitude` (the apparent altitude from temperature, pressure and weather conditions rather than the actual height above sea level) and changes drastically the speed settings for the load. 

 

All this, combined with the weight is probably contributing to the issue. To echo what others are saying , the Learning Center is a really good training tool as it is sim-specific and will use the default aircraft to show you what correct practices and procedures you should adopt.

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