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Approach speed control


hjwalter

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Hi Guys,

 

The approach speeds of some of my aircraft are extremely difficult to control, even with full flaps, gear down and engine(s) at idle. I've tried to increase the drag entry figure in the flaps sections of their aircraft.cfg files but this only seems to partially help, if at all. Maybe this only works in combination with something else, hopefully not with something within their AIR files because I'm certainly no AIR file expert.

 

Any ideas or fixes anyone ?

 

Thanks in advance for any reactions.

 

Regards

 

Hans

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Mr Zippy,

 

Thanks for your reaction but most of the aircraft I was referring to do not have speed brakes. Take as an example the default Mooney, which seems to be so streamlined that only extremely flat and unrealistic approaches are possible. My feeling is therefore that this kind of rather basic problem just must have been addressed/solved somewhere, either in their aircraft.cfg and/or in their AIR files.

 

Anyone, please.

 

Hans

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Mr Zippy,

 

Thanks for your reaction but most of the aircraft I was referring to do not have speed brakes. Take as an example the default Mooney, which seems to be so streamlined that only extremely flat and unrealistic approaches are possible. My feeling is therefore that this kind of rather basic problem just must have been addressed/solved somewhere, either in their aircraft.cfg and/or in their AIR files.

 

Anyone, please.

 

Hans

 

Interesting that you mentioned the default Mooney. In my Sim, the default Mooney has spoilers.

Still thinking about a new flightsim only computer!  ✈️

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The approach speeds of some of my aircraft are extremely difficult to control, even with full flaps, gear down and engine(s) at idle.

What's the maximum rate of descent you can achieve with full flaps and gear down at e.g. 100kts?

 

For drag verification; Engine out glide speed is 92kts and the ROD should be ~800fpm

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It's not hard at all to get your aircraft to an approach speed. I have a felling you're not doing it far enough away from the airport before approach.

 

Look on your GPS. When you are about 15 miles from the airport slow down even further to the aircraft's approach speed based on weight. Prior to 15 miles of the airport you should have stepped down your speed in increments. So say at 50 miles out you'd be at one speed, then at 30 miles out you'd be at another speed, then at 15 miles set the approach speed. Once you get used to this you can set your approach speed at 10 miles out.

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So say at 50 miles out you'd be at one speed, then at 30 miles out you'd be at another speed, then at 15 miles set the approach speed. Once you get used to this you can set your approach speed at 10 miles out.

The question is, how high is he at e.g. 50NM? At 2000ft at level flight, slowing down isn't a problem. If he's at FL200 50NM out, it will be difficult to slow down during the descent.

 

Nevertheless I wouldn't even think about slowing down 30-50NM out. Even with a heavy jet I can easily keep 250kts until 10-15NM out.

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The idea is to help him slow down way out there until approach.

 

For me I fly around with the F-22 at FL500 at mach 2.35 all the time so I just know what altitudes and distance from airport I need to be at for stepping my speed down.

 

 

Something as simple as a Cessna Shouldn't be an issue at all.

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Hope I am not stating the obvious here - but I can't see it mentioned.

 

Many aircraft will be too heavy and fast on approach if the loading isn't managed correctly. Fuel is the critical factor, but passenger/cargo load can have an effect too. It is both sensible and practical to calculate the fuel load such that on approach to the destination there is only enough to deal with go-arounds and emergency diversions.

 

John

http://www.adventure-unlimited.org

 

My co-pilot's name is Sid and he's a star!

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Thanks guys for all your reactions and yes Mr. Zippy, the default Mooney does in fact have visible spoilers/speed brakes but seemingly with no effect when deployed. I went into the Mooney's AIR file and found an entry "Spoilers available = FALSE" ?? I changed it into TRUE and this now does seems to have at least some effect.

 

However, what I learned from this is that even although most (light) aircraft do not have visible spoilers and/or speed brakes, these can in fact be installed anyway and used to further reduce approach speeds when full flaps and extended gear have little or no effect. However, this will not become my standard practice but only for those aircraft with which I need to dodge hills and trees during already very flat approaches.

 

Thanks again.

 

Hans

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Where on earth did you get that idea?

CRJ_simpilot is correct. In case of a serious emergency you don't have much of a choice and there's no reason why this shouldn't be possible. Not all aircraft, not even all heavies, have the capability to dump fuel.

 

Furthermore the worst case for the tires and brakes isn't an emergency relanding, but a rejected takeoff at MTOW.

 

That said, specially with airliners this can be a very demanding maneuver and shouldn't be considered if not absolutely necessary.

 

As long as you are staying below the max landing weight, everything is ok :)

 

Mentioning weight was a good idea. I've seen too many youtube videos where people are flying around with 100% fuel, way over any limit.

Edited by pzl 104
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However, what I learned from this is that even although most (light) aircraft do not have visible spoilers and/or speed brakes, these can in fact be installed anyway and used to further reduce approach speeds when full flaps and extended gear have little or no effect. However, this will not become my standard practice but only for those aircraft with which I need to dodge hills and trees during already very flat approaches.

I would not make any changes to an aircraft's files unless you know that they are wrong.

 

The descent and approach will take some planning and you will have to start early enough.

 

Walk us through one of your approaches and then we can give some more input.

-Wich aircraft.

-Altitudes.

-Speeds.

-Descentrates.

-Distances.

-Powersettings.

-Configurations.

-Times.

Edited by jeroen79
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What's the maximum rate of descent you can achieve with full flaps and gear down at e.g. 100kts?

 

For drag verification; Engine out glide speed is 92kts and the ROD should be ~800fpm

 

Finally an educated response versus a guess.

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Jeroen79,

 

The aircraft in my example is the default Mooney Bravo.

The VFR approach altitude is an almost flat 500 ft AGL already from a long distance in my efforts to reduce the plane's speed before touchdown.

The speed is then between 70 and 80 knots, nose high.

The load is 30% fuel. All further loads are default.

The descent rate is not fixed, e.g. via autopilot and is as low as possible to avoid increasing speed.

The distance from the runway touchdown point can be as much as 6Nm.

Power setting: Idle.

Configurations: Full flaps and gear down.

Times: Day, VFR

 

I've initially made a change in the plane's aircraft.cfg file (flap drag entry from 1.0 ----> 2.6). The "Spoilers Available= FALSE ----> TRUE" edit in it's AIR file, seems to help as well.

 

Could this "FALSE" entry have been an original AIR file error ? Can any of you guys confirm this seemingly original entry ? Am I the only one who had this Mooney Bravo speed reduction problem ?

 

Regards, groeten.

 

Hans

Netherlands

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You can do turns (right, left, back to straight at Rnwy) and reduce speed that way. You can also make sure you land into the wind. Ever try doing an ILS landing using AP to use as a 'teaching' tool?

 

For crying out loud - the Mooney is practically a Cessna but with 2 engines. Doesn't make sense that you 'can't slow down'. Something (we can't tell WHAT) is amiss here. Did you 'soup' the Mooney up by changing engine values in cfg or air? Did you change ANYTHING in cfg or air? Fess up dude!

Chuck B

Napamule

PS: you can be doing aproach at 500 kts at 1 NM out in a heavy or military jet and slow to 120 kts to land. How? DRAG: gear, flaps, spoiler settings in AIR file. It would not be 'real' but it can be done. But the MOONEY? Come ON!

i7 2600K @ 3.4 Ghz (Turbo-Boost to 3.877 Ghz), Asus P8H67 Pro, Super Talent 8 Gb DDR3/1333 Dual Channel, XFX Radeon R7-360B 2Gb DDR5, Corsair 650 W PSU, Dell 23 in (2048x1152), Windows7 Pro 64 bit, MS Sidewinder Precision 2 Joy, Logitech K-360 wireless KB & Mouse, Targus PAUK10U USB Keypad for Throttle (F1 to F4)/Spoiler/Tailhook/Wing Fold/Pitch Trim/Parking Brake/Snap to 2D Panel/View Change. Installed on 250 Gb (D:). FS9 and FSX Acceleration (locked at 30 FPS).
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Just out of curiosity (because I've had the problem before), are you certain your throttle is actually reaching idle in the sim, and that you're not inadvertently carrying extra power? IIRC, a quick press of F1 should make sure the throttle fully retards to idle. Edited by nagpaw
Added the last sentence.
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The VFR approach altitude is an almost flat 500 ft AGL already from a long distance in my efforts to reduce the plane's speed before touchdown.

The speed is then between 70 and 80 knots, nose high.

The distance from the runway touchdown point can be as much as 6Nm.

Power setting: Idle.

Configurations: Full flaps and gear down.

 

I've initially made a change in the plane's aircraft.cfg file (flap drag entry from 1.0 ----> 2.6). The "Spoilers Available= FALSE ----> TRUE" edit in it's AIR file, seems to help as well.

 

Although 80 is a bit slow, it shouldn't descend in a nose high attitude. Just tried a payware Mooney with a very good FDE and at 80kts the nose should be still be a few degrees below the horizon with the ROD close to 1000ft/min. At 100kts the ROD increases to 1500ft/min

 

That's without spoilers. (At 80kts spoiler shouldn't have any noticeable effect anyway)

 

As mentioned by others, are you sure that power is at idle and the prop control full forward?

What's the RPM and MP at idle?

 

With the greatly increased flap drag she should drop like a stone. Not sure if you don't have altered anything else unintentionally.

Since the spoilers should not have any significant effect at such low speeds I strongly suggest to use the original aircraft.cfg for further tests.

 

Concerning the idle problem; suggest to try the default 172 for comparison.

 

@napamule2 the Mooney is practically a Cessna but with 2 engines???

Edited by pzl 104
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C172: GWt: 2550.......................Mooney: 3662

" 4 Pass/400 Lbs..................." 4 Pass/700 Lbs

" HP: 180............................." HP: 270

" Spd: 115 (163).................." Spd: 180 (195)

" Flaps: 4 Pos........................" Flaps: 3 Pos

0, 12, 25,38...............................0, 8, 33

 

The HP of engine(s) is the significant difference. But, like most 'default' aircraft in Sim, the cfg and air values (ie: missing or incorrectly set by MS) makes a difference in Sim, compared to the performance of the specific aircraft in 'real' life.

Chuck B

Napamule

Edited by napamule2
i7 2600K @ 3.4 Ghz (Turbo-Boost to 3.877 Ghz), Asus P8H67 Pro, Super Talent 8 Gb DDR3/1333 Dual Channel, XFX Radeon R7-360B 2Gb DDR5, Corsair 650 W PSU, Dell 23 in (2048x1152), Windows7 Pro 64 bit, MS Sidewinder Precision 2 Joy, Logitech K-360 wireless KB & Mouse, Targus PAUK10U USB Keypad for Throttle (F1 to F4)/Spoiler/Tailhook/Wing Fold/Pitch Trim/Parking Brake/Snap to 2D Panel/View Change. Installed on 250 Gb (D:). FS9 and FSX Acceleration (locked at 30 FPS).
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I've initially made a change in the plane's aircraft.cfg file (flap drag entry from 1.0 ----> 2.6).

If this didn't have any effect, can you confirm that the flaps are actually extending? The nose high attitude during the approach and the too little drag are an indication that they are still retracted.

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pzl 104

 

Yes, the flaps are fully extended, both visibly and according to the panel gauge. Not only that but the gear is down and the engine RPM is at idle according to it's gauge and audible sound.

 

There's now quite obviously something very wrong with my default Mooney Bravo, so in the meantime I've downloaded a few complete third party versions from the library here and will test those to see if they have the same problem, something which I don't really expect.

 

I have some other flyables with the same problem but not half as bad as that of my default Mooney.

 

Anyway Guys, thanks for all your reactions and if I find out what caused my problem, I will certainly report back in this thread.

 

Hans

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After a heck of a lot of further testing and trying I finally admitted defeat and downloaded what seemed to be a Mooney Bravo repaint, which also included it's model, aircraft.cfg and AIR files. A lot of cutting and pasting followed, especially in the aircraft.cfg file and eventually I was able to fly a "normal" Mooney Bravo again, including making "normal" approaches in it.

 

The only thing I can afterwards think of, of what was wrong with my problematic Mooney, is/was a corrupted AIR file. How, why and when this could have happened I have no idea but I will now try to use the same procedure for the other aircraft, which have more or less, the same approach speed problems.

 

Regards

 

Hans

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