JF Piper Arrow - What am I doing wrong?

[pwfsav 13]

Firstly, I'm a bit of a novice to all this....

Thought I'd purchase the Just Flight Piper Arrow as it was getting some good reviews and praised for it's flight model.

So trying to fly from Munich to Innsbruck. Need to climb above those hills! Have throttle on full, RPM full, Mixture SIM controlled but at 100%.
Plane is doing 90 knots and sitting pretty level. If I try to get it to climb, speed drops and get stall warnings.
Gear is up!! Flaps retracted. So where am I going wrong?

 

[Glenn Fitzpatrick 3,799]

5 minutes ago, pwfsav said:

Firstly, I'm a bit of a novice to all this....

Thought I'd purchase the Just Flight Piper Arrow as it was getting some good reviews and praised for it's flight model.

So trying to fly from Munich to Innsbruck. Need to climb above those hills! Have throttle on full, RPM full, Mixture SIM controlled but at 100%.
Plane is doing 90 knots and sitting pretty level. If I try to get it to climb, speed drops and get stall warnings.
Gear is up!! Flaps retracted. So where am I going wrong?

 

What altitude are you at ?

[CFIJose 5,485]

Your altitude is important. Above 3000 feet AGL you must lean the mixture (IRL) if you want the engine to perform at it's optimum level. Also, keep in mind that for every 1000 feet you climb, you will lose one inch of mercury. This means that without a turbo charger (as you climb and those air molecules become less) you will have less and less performance the higher you climb.

To find the service ceiling for a normally aspirated Arrow III the pilot checks the POH. Maybe at around 15,000 ft the airplane might stop climbing. It depends on the engine's age and airplane.

[Chock 17,769]

First up, you're not doing stuff wrong, you're in the process of learning how to do stuff right. 🙂

Essentially you're going to need to control the aeroplane's mixture yourself if you want to get the best out of it. This isn't hard to learn how to do and I'm sure you understand the concept. You might even have noticed this in a car or a motorcycle if you drive any of those. In cold weather, when the air is more dense, your car or motorbike will often develop a bit more power because it can take in more volume of air into its carburettor more easily, so it can mix that with the fuel in a better ratio and thus create a bit more power.

Same thing with an aeroplane, as it climbs, it gets into thinner air, so unless you thin out the fuel mixture by leaning it off with the mixture lever, there's too much fuel going into the carburettor for the amount of available air, so the engine loses power (and wastes fuel as well).

With your aeroplane, basically you can listen to the engine's noise and watch the engine gauges. On the ground at or near sea level, shove the mixture lever all the way forward for starting and taking off. As you climb, back the red mixture lever off toward you a bit, if the engine note drops or the power reduces, you've backed it off too far, so nudge it forward a bit.

What you probably will also need to do, is progressively reduce the climb rate of the aeroplane too, possibly down to as little as maybe 100-200 feet per minute when you're getting up higher, i.e. don't pitch the nose up too high, because as the power is reducing with you going into thinner air, the wings are getting less air as well, so you don't want to be too steep or you will start slowing down, and you don't want that because you usually need to keep the speed up in thinner air for the wings to be able to generate a decent amount of lift. So it's often a bit of a balancing act when flying an aeroplane.

This is all part of the fun of flying aeroplanes. Good luck and above all, have fun. 🙂

Edited March 17, 2021 by Chock

[Farlis 2,319]

And if you can't go above the mountains fly southeast from munic first and look for the Inn river and then just follow it up to Innsbruck. This way you will not need to climb over anyhting. 😉

[Chock 17,769]

12 minutes ago, Farlis said:

And if you can't go above the mountains fly southeast from munic first and look for the Inn river and then just follow it up to Innsbruck. This way you will not need to climb over anyhting. 😉

Another thing about going around something rather than climbing over it, is that even though you might fly a longer distance, you might actually do it quicker and use less fuel as well, since you're not wasting energy and time trying to get up high. Worth bearing in mind too - more in real aeroplanes which can have engines which break down, than in simulated ones where that's unlikely - is that if you can avoid being over hilly terrain in a single-engined aeroplane, that's not a bad idea either, for obvious reasons. If you do however decide to fly over the hilly terrain, pick a flight path where there would be an obvious 'escape route' where you could glide to some flat terrain for a forced landing if the engine conked out. This is something you'd typically do in the real thing if you were a sensible pilot.

Oh and one last thing. Check the fuel and weight panel when the sim loads. It might have defaulted to setting your aeroplane up with a passenger and some baggage on board and that will not help with its maximum attainable altitude, but you will notice that it is ever-so-slightly less stable with one person on board rather than two, since it has all the weight in the cabin on the left side.

The real PA-28 Arrow does have four seats in it and room for a lot of baggage, but to be honest this is a bit optimistic, since it has to carry fuel and its payload of passengers and baggage, so if you stick four people in it, that limits the amount of fuel it can carry before it would be over its maximum allowable weight.

Just for a bit of fun, you might like this:

http://www.csgnetwork.com/pa28r-200arrowwbcalc.html

Edited March 17, 2021 by Chock

[Av8ing1 46]

Pull that mixture back, at high altitudes you are making a lot less power. All that extra fuel at full rich is to cool the cylinders at high power settings and lower air speeds by dumping more fuel than will burn in the cylinders. At altitude you aren't at high power, low density air without a turbo charger, it will not have enough air to make much power even though you are at full throttle (you will see lower manifold pressure.) At cruise, high speed, you get plenty of cooling air over the cylinders and you engine output is much lower so you don't need the cooling effect of the extra fuel. There are proper methods on how to lean it out, probably explained in the POH. If I recall it was something like lean to peak EGT then bump it just a tad richer from that. You might end up at say 50% mixture at 8K Ft. As a result of proper leaning at altitude you will make a bit more power. It would also be helpful to calculate the best climb speed of the aircraft. Slower or faster than this speed will result in less climb rate. 

Edited March 17, 2021 by Av8ing1

[Bobsk8 12,856]

The JF Arrow makes it really easy to properly lean the engine, there is an EGT gauge on the panel. lean to the gauge peaks, and richen it a tad from that point. ( That is what I do, some leave it at peak) . 

[Glenn Fitzpatrick 3,799]

9 minutes ago, Bobsk8 said:

The JF Arrow makes it really easy to properly lean the engine, there is an EGT gauge on the panel. lean to the gauge peaks, and richen it a tad from that point. ( That is what I do, some leave it at peak) . 

The Lycoming manual manual says peak for max economy.cruise or 150°F on rich side of peak for max power cruise:

https://www.lycoming.com/sites/default/files/O-HO-IO-HIO-AIO %26 TIO-360 Oper Manual 60297-12.pdf  (see page 38)

Quote

GENERAL RULES

Never exceed the maximum red line cylinder head temperature limit.

For maximum service life, cylinder head temperatures should be maintained below 435°F (224°C) during high performance cruise operation and below 400°F (205°C) for economy cruise powers.

Do not manually lean engines equipped with automatically controlled fuel system. On engines with manual mixture control, maintain mixture control in “Full Rich” position for rated takeoff, climb, and maximum cruise powers (above approximately 75%).

However, during take-off from high elevation airport or during climb, roughness or loss of power may result from over-richness. In such a case adjust mixture control only enough to obtain smooth operation – not for economy. Observe instruments for temperature rise. Rough operation due to over-rich fuel/air mixture is most likely to be encountered in carbureted engines at altitude above 5,000 feet.

Always return the mixture to full rich before increasing power settings. Operate the engine at maximum power mixture for performance cruise powers and at best economy mixture for economy cruise power; unless otherwise specified in the airplane owner’s manual.

During letdown flight operations it may be necessary to manually lean uncompensated carbureted or fuel injected engines to obtain smooth operation. On turbocharged engines never exceed 1650°F turbine inlet temperature (TIT).

1. LEANING TO EXHAUST GAS TEMPERATURE GAGE.

a. Normally aspirated engines with fuel injectors or uncompensated carburetors.

(1) Maximum Power Cruise (approximately 75% power) – Never lean beyond 150°F on rich side of peak EGT unless aircraft operators manual shows otherwise. Monitor cylinder head temperatures.

(2) Best Economy Cruise (approximately 75% power and below) – Operate at peak EGT.

 

 

[jimcarrel 688]

Kudos to all who responded to OP. He or she hasn't even come back yet and you have given the A+ info to answer the OP's question. Really cool!

[marsman2020 1,310]

Another thing to watch out for in addition to the mixture tips people have already given, is that the JF Arrow currently has the aerodynamic/performance impacts of icing but no visual indication (JF has indicated some visuals will be added in a future update).  So if you fly through even a small amount of whispy clouds at OAT <0C, it may ice up and you won't know it.

[pwfsav 13]

Hi,

Thanks for loads of fantastic advice/information. Just reading it now as was out for a nice walk in the sunshine here.
Looks like I have a bit of reading to do to understand what everyone is telling me.
To answeer some of the questions, I was at around 4000 feet and was struggling to get to 5000. I will re-check, I think I have the option on that icing is
only visible and has no actual effect (even though as it has been pointed out that needs a fix in the Arrow).
i need to go away and understand the insatruments better instead of just winging it (no pun intended 🙂 )

Really appreciate the help. Thanks a million

 

[Phantoms 800]

Everyone has filled you in on mixture control, but you stated you had automixture on in MSFS. MSFS actually does a decent job of controlling the mixture with Automixture on.

If you'd like to learn how to control the mixture yourself (automixture turned off), plenty have already chimed in with good advice. All I'll add is that in the control keybindings you can bind a key or button for Best mixture and use that to help you learn to control the mixture. Hitting that key will set the mixture to the optimum place and you can compare that with where you had manually set mixture. After a while it will become second nature to just manually adjust mixture to highest EGT and then back off 1½ to 2 notches on the EGT gauge and you won't even need the best mixture binding anymore.

[Glenn Fitzpatrick 3,799]

On 3/18/2021 at 7:14 AM, Phantoms said:

Everyone has filled you in on mixture control, but you stated you had automixture on in MSFS. MSFS actually does a decent job of controlling the mixture with Automixture on.

The OP stated mixture was at 100% at 4000' .

That does not seem right, if the auto mixture was actually working you would expect it to be leaner then 100% .  Though possibly the auto mixture has set full rich for 100% power ?

Edited March 20, 2021 by Glenn Fitzpatrick

[Phantoms 800]

8 hours ago, Glenn Fitzpatrick said:

The OP stated mixture was at 100% at 4000' .

That does not seem right, if the auto mixture was actually working you would expect it to be leaner then 100% .  Though possibly the auto mixture has set full rich for 100% power ?

When automixture is on, MSFS handles the mixture in the background and where the lever is at matters not (except for all the way back which cuts the engine).

 

Now if instead you have automixture off but use the binding for best mixture, then it will actually move the mixture lever to match what it's set at.

Edited March 20, 2021 by Phantoms