Slowing the bird down

[mattsta]

Really struggling with the descent and approach

What's the best way to get the P51 slowed down from say a 270mph cruising speed to the start of your approach.

This beast does not want to slow down! And in a descent, it's even harder to control the speed

Closing the throttle makes the engine run really rough and I get a cockpit alarm (I don't know what it is). Raising prop RPM before the aircraft has slowed down sufficiently overspeeds the prop....!!!

Is it standard procedure to use the flaps to slow her down before finals?

Any advice would be greatly appreciated

I'm not a pilot by the way.

[Tug002]

Really struggling with the descent and approach

What's the best way to get the P51 slowed down from say a 270mph cruising speed to the start of your approach.

This beast does not want to slow down! And in a descent, it's even harder to control the speed

Closing the throttle makes the engine run really rough and I get a cockpit alarm (I don't know what it is). Raising prop RPM before the aircraft has slowed down sufficiently overspeeds the prop....!!!

Is it standard procedure to use the flaps to slow her down before finals?

Any advice would be greatly appreciated

I'm not a pilot by the way.

I dont know if I am doing it right but I use the flaps to slow down the P-51. The first notch can be used just under 400 MPH the rest the rest of the MAX flap speeds are 275,225,180 and 165 MPH. it is posted in the cocpit of the aircraft on the right side of the cockpit just behind the radio.The warning buzzer you hear is your gear warning, next time you hear it check your gear light and you will see it is red.

Hope this helps you a bit.
Keep smiling
Tug

[WarHorse47]

This is the technique I follow:

--Get down to the proper altitude for approach, about 2,500 ft. above the runway.
--Reduce power to a reasonable manifold pressure about 25 inches or so
--Use you elevator trim tab to a slightly nose high attitude, yet keep the aircraft level. By keeping downward pressure on the joystick you are using the plane itself to create some air resistance to slow down.
--When under 200 mph you can lower your flaps. First start at 10 degrees, then as the plane slows further you can lower the flaps more.
--At under 150 mph lower your gear.
--While following these steps make sure you maintain your glideslope and airspeed. What you want to do is keep your airspeed around 110 mph by the time you reach the end of the runway, but just before you touchdown. When the plane is dirty (fully flaps and gear down) then its a matter of working with your throttle to find the sweet spot.

--WH

[DHenriques_]

Really struggling with the descent and approach

What's the best way to get the P51 slowed down from say a 270mph cruising speed to the start of your approach.

This beast does not want to slow down! And in a descent, it's even harder to control the speed

Closing the throttle makes the engine run really rough and I get a cockpit alarm (I don't know what it is). Raising prop RPM before the aircraft has slowed down sufficiently overspeeds the prop....!!!

Is it standard procedure to use the flaps to slow her down before finals?

Any advice would be greatly appreciated

I'm not a pilot by the way.

The 51 is indeed a bit "slippery" and that has been accurately modeled into the A2A flight model.
Start PLANNING your approach and landing well out from the runway. Descending from cruising altitude keep your manifold pressure above 20 inches to keep the prop from driving the engine which could cause valve slap and other not so pleasant Merlin negatives.
Because of the extremely high flap speeds for your first 2 notches of flaps you can use them freely to help you slow down. Use those first two notches planning to keep the nose level. At 20 inches this will slow you down.
You can also S turn a bit in a snake weaving pattern to place some drag on the airplane. This will help but shouldn't be necessary if your planning was done properly.
Best pattern to fly in the Mustang is an overhead approach. If you have any excess airspeed at the break point on initial over the runway you can scrub that off to drag during the break turn to downwind. From there on it's gear speed and flaps as needed controlling airspeed with pitch and sink rate with power and flying the approach in a circular manner until your flare. Try for 105 knots over the end of the runway.
Good luck.
Dudley Henriques

[mattsta]

The 51 is indeed a bit "slippery" and that has been accurately modeled into the A2A flight model.
Start PLANNING your approach and landing well out from the runway. Descending from cruising altitude keep your manifold pressure above 20 inches to keep the prop from driving the engine which could cause valve slap and other not so pleasant Merlin negatives.
Because of the extremely high flap speeds for your first 2 notches of flaps you can use them freely to help you slow down. Use those first two notches planning to keep the nose level. At 20 inches this will slow you down.
You can also S turn a bit in a snake weaving pattern to place some drag on the airplane. This will help but shouldn't be necessary if your planning was done properly.
Best pattern to fly in the Mustang is an overhead approach. If you have any excess airspeed at the break point on initial over the runway you can scrub that off to drag during the break turn to downwind. From there on it's gear speed and flaps as needed controlling airspeed with pitch and sink rate with power and flying the approach in a circular manner until your flare. Try for 105 knots over the end of the runway.
Good luck.
Dudley Henriques

"Start PLANNING your approach and landing well out from the runway"

Certainly doing that..........though a long way from mastering landing the P51!

"Because of the extremely high flap speeds for your first 2 notches of flaps you can use them freely to help you slow down"

That's comforting to know. I was worried about using the flaps to slow her down but even the first flap setting will bleed off a considerable amount of speed if you are patient and 20 degree will bleed off the speed very quickly.

One thing I find very tricky is I have a throttle control on my joystick but I have to operate the prop control with the mouse. If I'm at about 65-70% throttle with the prop at around 2500rpm, the throttle quadrant obscures the prop lever and I can't adjust the prop speed very easily without momentarily moving the throttle quadrant. Not a satisfactory situation at all! LOL!

I think maybe I am coming in a little too fast and with the flaps lowered, the aircraft bounces (generates lift). It's a very fine line! Too little power and airspeed falls to a point where a stall is a very real possibility or your rate of descent is uncomfortably high, too fast and you kangeroo down the runway like a demented lunatic!!!!

I have got it back on the ground sucessfully several times without bending anything.........but not often down the middle of the runway!

It'll all come with practice I suppose.

[DHenriques_]

It'll all come with practice I suppose.

This is a huge advantage in the simulator. You can indeed practice and get better over time. In the real airplane you still get to practice but you can only error just so far without extreme penalty. This amounts to having things pretty much under control the first time you try it....or else.
Good luck with your efforts.
DH

[JoeS475]

Mattsta,

I also have a joystick with a built in throttle as you describe. I'm not sure what your particular settings are, but I believe by default "Ctrl-(F1-F4)" will control your prop, at least that's how I'm set up. So as I slow down I can adjust the prop by the keys without ever taking my hand off the joystick or having to adjust the throttle to make the prop control clickable for the mouse. It is smooth as silk this way, and once you get used to it, you will find flying MUCH easier (and more natural)!

FWIW "Ctrl-Shift-(F1-F4)" will control your mixture which will also save you using the mouse, thereby making your flights much more rewarding!

Hope this helps you

Joe

[EnDSchultz]

Yes, for prop control you can use ctrl-F2 and ctrl-F3 to decrease and increase RPM in steps. And yes, jamming the RPM to max will tend to overspeed the prop slightly before it stabilizes. This is generally not an issue as long as you don't simultaneously add power; I recall seeing a placard saying the engine is safe to temporarily over-rev as high as 3250. You can immediately bring the prop to max using ctrl+f4. For landing you probably want to set it to 2700 (I saw a 1940s training video that even said 2500) instead of max, I think the idea being you'll get a quicker thrust response if you need to add power and go around. In the event of a big bounce, I've found the response to power application to be very sluggish and it takes too long to rev to 3000RPM to really be of any use if I get a bad bounce. Incidentally, this is probably why a "power on" landing is recommended, where you leave a substantial amount of throttle in to maintain airspeed even in the flare, only completely idling once the wheels are actually down. If you need to go around, the power will come a lot quicker that way. You can definitely hear what I'm talking about in this video, where the power comes back and the engine starts popping the moment the wheels come down:

http://youtu.be/l4RBBrDsPgg?t=2m25s

You can never really totally close the throttle in flight without gumming up the spark plugs, although the lower you set your prop RPM, the lower it seems you can pull the throttle before running into problems. In my experience, about 20'' of manifold pressure or above is enough to keep it going smoothly in all phases of flight and RPM settings. The buzzer you hear at low power settings is the gear-unsafe warning, telling you your gear isn't down and locked. There is a silence button somewhere on the front panel of the cockpit (location is different for military and civilian models), though you have to hit it again every time you pull the throttle back.

Always be wary of which version you're flying. The military version has the airspeed indicator and speed placards (on the right side of the cockpit; USE THEM!) in miles-per-hour, whereas the civilian version is in knots. As has been said, the first notch of flaps can be used at pretty much any time in normal flight, since it's safe to lower as fast as ~400mph (349kts), and second notch 275mph (239kts).

The method Dudley mentioned is really the preferred one for the Mustang and for me it feels the best. The Mustang is made to go fast and as such, for my part, I really don't want to be dragging the plane down from cruise altitude at low speed with a bunch of flaps out. You might need one or two notches if you intend to observe the 250kt speed limit below 10,000 feet, but otherwise I don't really use them too much outside the pattern. As for the pattern, (assuming Dudley has taught me well), what I do is overfly parallel to the runway of intended landing, offset just a bit towards the pattern side so I can see the runway out the window, and then do a 180 degree turn away from the field to enter the downwind leg of the pattern. The harder you pull into the turn, the more speed you'll bleed off, but be sure to watch that airspeed so you don't pull it too hard into a stall. In my experience it's not hard to burn as much as 100kts or even more in a standard 4-G turn. By the time you roll out onto the downwind, you'll probably be be close to or below the gear deployment speed. At that point you're safe to drop the last two notches of flaps and the gear.

As Dudley said, big, square patterns are not the way of the Mustang, so aim to make a smooth, constant, descending turn directly onto short final. With full flaps and gear down, the Mustang glides about like a stone, so I prefer to aim for quite a steeper descent and tighter pattern than one might normally do in a GA aircraft, since in the event of an engine failure (and possible loss of hydraulic pressure), a power off glide with full flaps out can turn bad in a jiffy.

Here's a thread a few months back where I asked the very same question:

http://www.a2asimulations.com/forum/vie ... 93&t=39883

No doubt, the P-51 is a handful, but with so much power, speed, and performance, she's a total joy to fly and since buying her, my poor Cherokee and Cessna don't get much x-country time anymore!

[mattsta]

Mattsta,

I also have a joystick with a built in throttle as you describe. I'm not sure what your particular settings are, but I believe by default "Ctrl-(F1-F4)" will control your prop, at least that's how I'm set up. So as I slow down I can adjust the prop by the keys without ever taking my hand off the joystick or having to adjust the throttle to make the prop control clickable for the mouse. It is smooth as silk this way, and once you get used to it, you will find flying MUCH easier (and more natural)!

FWIW "Ctrl-Shift-(F1-F4)" will control your mixture which will also save you using the mouse, thereby making your flights much more rewarding!

Hope this helps you

Joe

Thanks Joe

That's gonna be very very handy to know!

I haven't even used the mapping software to customize the controls yet. In fact, I could do with a sample configuration file just to see how you guys have set up the simulation.

[mattsta]

Yes, for prop control you can use ctrl-F2 and ctrl-F3 to decrease and increase RPM in steps. And yes, jamming the RPM to max will tend to overspeed the prop slightly before it stabilizes. This is generally not an issue as long as you don't simultaneously add power; I recall seeing a placard saying the engine is safe to temporarily over-rev as high as 3250. You can immediately bring the prop to max using ctrl+f4. For landing you probably want to set it to 2700 (I saw a 1940s training video that even said 2500) instead of max, I think the idea being you'll get a quicker thrust response if you need to add power and go around. In the event of a big bounce, I've found the response to power application to be very sluggish and it takes too long to rev to 3000RPM to really be of any use if I get a bad bounce. Incidentally, this is probably why a "power on" landing is recommended, where you leave a substantial amount of throttle in to maintain airspeed even in the flare, only completely idling once the wheels are actually down. If you need to go around, the power will come a lot quicker that way. You can definitely hear what I'm talking about in this video, where the power comes back and the engine starts popping the moment the wheels come down:

http://youtu.be/l4RBBrDsPgg?t=2m25s

You can never really totally close the throttle in flight without gumming up the spark plugs, although the lower you set your prop RPM, the lower it seems you can pull the throttle before running into problems. In my experience, about 20'' of manifold pressure or above is enough to keep it going smoothly in all phases of flight and RPM settings. The buzzer you hear at low power settings is the gear-unsafe warning, telling you your gear isn't down and locked. There is a silence button somewhere on the front panel of the cockpit (location is different for military and civilian models), though you have to hit it again every time you pull the throttle back.

Always be wary of which version you're flying. The military version has the airspeed indicator and speed placards (on the right side of the cockpit; USE THEM!) in miles-per-hour, whereas the civilian version is in knots. As has been said, the first notch of flaps can be used at pretty much any time in normal flight, since it's safe to lower as fast as ~400mph (349kts), and second notch 275mph (239kts).

The method Dudley mentioned is really the preferred one for the Mustang and for me it feels the best. The Mustang is made to go fast and as such, for my part, I really don't want to be dragging the plane down from cruise altitude at low speed with a bunch of flaps out. You might need one or two notches if you intend to observe the 250kt speed limit below 10,000 feet, but otherwise I don't really use them too much outside the pattern. As for the pattern, (assuming Dudley has taught me well), what I do is overfly parallel to the runway of intended landing, offset just a bit towards the pattern side so I can see the runway out the window, and then do a 180 degree turn away from the field to enter the downwind leg of the pattern. The harder you pull into the turn, the more speed you'll bleed off, but be sure to watch that airspeed so you don't pull it too hard into a stall. In my experience it's not hard to burn as much as 100kts or even more in a standard 4-G turn. By the time you roll out onto the downwind, you'll probably be be close to or below the gear deployment speed. At that point you're safe to drop the last two notches of flaps and the gear.

As Dudley said, big, square patterns are not the way of the Mustang, so aim to make a smooth, constant, descending turn directly onto short final. With full flaps and gear down, the Mustang glides about like a stone, so I prefer to aim for quite a steeper descent and tighter pattern than one might normally do in a GA aircraft, since in the event of an engine failure (and possible loss of hydraulic pressure), a power off glide with full flaps out can turn bad in a jiffy.

Here's a thread a few months back where I asked the very same question:

http://www.a2asimulations.com/forum/vie ... 93&t=39883

No doubt, the P-51 is a handful, but with so much power, speed, and performance, she's a total joy to fly and since buying her, my poor Cherokee and Cessna don't get much x-country time anymore!

Thanks

All good advice!

[mattsta]

Deleted duplicate post

[NAA551WB]

On your descent you really have to plan it almost as if you were flying a corporate jet. It really builds speed up quickly, coming downhill I will descend at 1k fpm with the mp at 25-30 inches, prop still at 2300-2500. You will have to calculate how many miles out you are going to want to start your descent based on your airspeed and altitude.

Once entering the pattern I will bring the RPM up to 2700 and the manifold never below 20-25 inches. I always do an overhead at 1500 feet AGL and I want to be between 200-225 knots entering the break. Once I get to my break point I will enter a 2G turn and dump out the first two notches of flaps while keeping 1500 AGL. Once I get to 150 knots I should be about abeam the numbers or a little past and I'll drop the gear and wait a few seconds depending on the view to start my descent and turn to the runway. I will also drop another notch of flaps and from that point on I will add flaps as necessary. Over the fence I aim for 110-120, never below 100 knots. As far as the landing goes I always wheel land it.

The advantage of an overhead is that if flown correctly and accurately in the case of an engine failure you should be able to make it back to the runway if that should occur.

[EnDSchultz]

As a little addendum, the latest update also upgraded the warbirds' spark plug simulation so now the Mustang seems a LOT less prone to running rough at low power settings in flight.