Bae ATP landing gear causes excessive pitch up when lowered

On final approach with the Bae ATP lowering the landing gears causes the nose to pitch up

very steep. The nose slowly keeps rising almost to a stall attitude. My airspeed is: 140 - 130 knots.

 

I've never had an aircraft's gears to cause nose pitch up. The Bae ATP flies just fine except for the Landing Gear Pitch UP.

 

It feels like you have extended 70 degrees of flaps at one time.

Hello,

 

Must be some bad set in the Air file

The only solution is to correct the Air file ...

 

Regards.http://smilies.sofrayt.com/%5E/a/bye.gif

I suggest flying straight and level at around 3000 feet or so at around flaps 1 speed low enough to extend the gear. Go to spot view for a profile and operate the gear control looking at all control surfaces to see if any unexpected surfaces are operating.

 

Now, lowering the gear adds drag so you may have to increase power to maintain a safe speed above stall. If you are on a glide slope with AP engaged if your speed decreases too much the AP will increase pitch to maintain altitude to prevent sinking so that is another thing to watch for. If you are using auto-throttle then it should take care of maintaining the speed you set but allow for a delay in reaction.

 

Finally, make sure your weight and balance are within landing restrictions. Make sure you are following the flap/speed schedule.

Hello,

 

OK .. get out the dusty box the ATP BAe and performed test ...

Established with AP help a straight and level flight at speed of 160 knots

Disengaged AP ... AC continue to flight straight and level ... nothing special happend

Lowered the gear ... and immediately the speed begin to decrease and a little pitch down begin to appears ....

So all this is normal for the ATP BAe ...

No sudden pitch up !

After I performed a ILS approach (speed manually controled) .. and I seen nothing abnormal with the aircraft behavior when lowering gear and flaps .....

My final approach speed was 125 knots

Flying time = 10 minutes :)

Note:

Nothing modified in the aircraft.cfg about weight .. fuel .. etc ...

Regards.http://smilies.sofrayt.com/%5E/a/bye.gif

What was your fuel level or landing weight at the time of the approach? Was it within max limits?

Hello,

 

What was your fuel level or landing weight at the time of the approach? Was it within max limits?

If this question is adressed to me .. you have already the answer in my message :)

 

Flying time = 10 minutes

Note:

Nothing modified in the aircraft.cfg about weight .. fuel .. etc ...

 

Regards.http://smilies.sofrayt.com/%5E/a/bye.gif

What I'm talking about is looking at the fuel and CG. Pause the sim and open to FS menu bar at the screen top. I think you click aircraft and in the dropdown click "fuel and payload"which should bring up the fuel load adjustment and also display the center of gravity and the CG limits.

 

 

This is to clarify mainly to the OP.

 

Now look at the aircraft specs and determine the maximum landing weight. There might be a performance graph that adjusts for density altitude (temperature modified MSL altitude).

 

If at the start of the approach "frozen in time here" insure that the fuel remaining after being burned off does not exceed the allowable limits. The amount of fuel to be loaded at departure must be taken into consideration based on the estimated fuel to be burned plus a reserve for contingency. If it is a relatively short hop then the trip might have to be started with less than full tanks.

 

Another consideration is the fuel tank draw down schedule. Tanks must be emptied to maintain lateral balance plus pitch balance where center tanks are used in addition to wing tanks. Generally center tanks are drawn down first with the flight finishing on wing tanks. Sometimes aircraft have multiple center tanks and fuel is pumped between them to maintain CG within limits.

 

Now, a note about the display:

 

This example states a payload of zero. This is because the model designer decided to average the passenger and cargo weight into the "stations" as a single average point, that is a constant passenger count and cargo weight for all flights and is included in the empty weight calculation. The only weight variable then is fuel.

 

Some advanced aircraft models come with a utility that lets you adjust seat layout and passenger count plus cargo weight and placement. The PMDG B737NG series is one model with such a utility.

 

The fuel planner I use connects to a weather snapshot and with the aircraft performance profile chosen and cruise altitude a trip minimum fuel weight is anticipated. It allows adding taxi time, reserve time, and contingency fuel, and gives the total fuel weight and shows the maximum weight allowed by the profile. Very helpful.

 

The summary of all this stuff is to adjust filling your tanks to accommodate the length of your trip (plus reserve) especially if relatively short so you do not have too much fuel weight remaining as you start your destination approach. As you slow the elevator has less authority to adjust pitch due to the reduced airflow over it. If you are outside of the correction limits for the approach airspeed then it may not be possible to bring the nose down to the correct attitude for your airspeed. This can induce a stall.

 

An example is an aircraft that takes off for a long haul flight and has an emergency that requires a return to destination or the nearest capable airfield where the fuel used is not enough to bring the gross weight down within landing weight limits. The aircraft either circles to burn off fuel or if so equipped goes out to a safe area to dump fuel (pump out through nozzles) to achieve a safe landing weight.

 

I don't have the Bae ATP aircraft so don't have access to its manuals but in general the procedures I describe are all part of the preflight planning for any aircraft.

I just want to thank Avechelice and Ronzie for their help. Thanks for taking the time to

explain my problem. I don't think it is the aircraft's falt now. I'm going to take both

of your answers under advisement and do some test flying. I was not that taken by

Turboprops in the past, but now I really like these Bae ATP's by: enigma simulations.

There in the library here. Thanks again ... Ira

I installed the enigma version enigma_atp_basepack.zip from the library here. I just loaded it up and checked the weight and balance. This model has individual "weight stations" that can be modified in fuel and payload tab unlike most models that have the average anticipated weight built into the empty weight value.

 

The first thing I noticed that with full tanks the aircraft exceeds gross eight limits.

 

I searched Internet wide for a pilot's/operator's manual without success except for a highly priced download or hard copy from an FBO.

 

The operator's manual that came with it does not say too much about operating it. An approach speed range is:

 

"-Landing Vref 115-120 kts at full flap"

 

They state there is a maximum take-off weight but not the amount. Nothing on landing weight.

 

I looked at the specs on airliners.net for the base version. With maximum loading the range is only good for about 350 nm. Lighter loads can get 800 nm. It looks like to me this aircraft was not meant to be flown with heavy loads except on very short hops.

 

My FS controls are not setup right now so I can't take it for a ride in standard weather (clear). I need to digest the aircraft.cfg to see if I can come up with a performance profile for fuel planning at standard cruise speed.

 

This model's panel was aliased to the default King Air which I modified with a bit of advanced displays for the PFD and an enhanced nav display below it. The King Air panel only has three flap settings - take-off, off, and approach.

 

I have Mike Stone's Saab-Fairchild 340B turbo prop and of course the default King Air. I'll try to derive performance from there.

Hello, Ira:

 

I read your PMs.

 

The default aliased King Air panel won't cut it because of its three position flap handle. Besides up, there are four flap positions in the model as shown in the aircraft.cfg file.

 

I looked at several Bae ATP cockpit photos on airliners.net and made out up plus four positions on the flap handle.

 

In the FS9 panels lib here I found beaatppn.zip. I replaced the panel folder in the aircraft folder with the panel folder in this download. Out of the box, it will come up with a missing payware fmc. There are instructions on how to modify the panel.cfg to use the FS9 default GPS instead of the payware fmc.

 

Although the flap control has six positions including up, it worked by dragging into the four positions or just stepping through with the flap button or hot key you use.

 

Your test flight from KSEA to KPAE is pretty short. I would not reduce the weight stations to zero but just put maybe 50% in the fuel tanks. I would think that would fall within the maximum landing weight. Reducing the weight stations to zero might alter the CG to far in the other direction. The weight stations might also be in the .air file so there might be a conflict. Having to light a gross eight can also allow the aircraft to float too much on the runway when landing.

 

Glad you found that the CG was aft of the limits. That would certainly pitch your nose up as the elevator ran out of authority as you slowed.

 

Try this panel and see if this new quadrant works better for flap control. The labels will be a bit off but close enough. I'll search for another proper throttle quadrant with up plus four steps.

Hello,

 

the enigma version

OK we are not on the same frequency .. :)

I use this Bae ATP .... the BSMP model ( Blu-Sky Mine Productions ) .. give it a try .....

http://simviation.com/1/search?submit=1&keywords=bsmpat10.zip&x=21&y=11

 

Regards.http://smilies.sofrayt.com/%5E/a/bye.gif

Hello,

 

 

OK we are not on the same frequency .. :)

I use this Bae ATP .... the BSMP model ( Blu-Sky Mine Productions ) .. give it a try .....

http://simviation.com/1/search?submit=1&keywords=bsmpat10.zip&x=21&y=11

 

Regards.http://smilies.sofrayt.com/%5E/a/bye.gif

 

Thanks. When I searched by name for BSMP I came up with a different none related site. I'm downloading to look at it.

 

However the aeronautical theory and practice remains the same.

 

I saw both the Enigma and BSMP mentioned in the discussion and was not sure which version the OP used.

 

The Enigma has 5 different models mostly for different antenna placements. They are not be default enabled in the aircraft.cfg for added flightsim() sections. The aircraft.cfg is pretty detailed using individual weight stations. Although the author talks about later versions I didn't catch any.

 

In the BSMP version aircraft.cfg I noticed that flaps position 0 and 1 are set to zero. First time I've seen that. I'll fire it up later.

 

Also I noticed that the values for the weight stations are less than the Enigma.

 

I am very cautious about freeware .exe installations but I trust your judgement :) .

 

 

 

I'll look at the BSMP later after installing.