Pa-31 power reduct.

[Hawkeye4077]

So guys... how do you do it? I`m talking about the TOC power reduction?


1 2 3 Go!!

Hawk

[Strega]

pull the throttles back

[iflyforpie]

then the props.

[Nark]

Then lean it out.

[The Old Fogducker]

But not too much or the boss gets mad.....but not too little, or the boss gets mad.

[skywardbound]

Lock the thread, perfect responses.

[Conquest Driver]

Close the cowl flaps.

[Big Pistons Forever]

open the box of doughnuts

Seriously though I am not sure what you want to know?

At TOC you do the same things you did in your C150 presolo, allow the aircraft to accelerate to cruise speed and set the power too what ever cruise setting your CP tells you to use. The only finesse item is the cowl flaps. I monitor the CHT's. On cold days the CHT's could be right around the cruise value even in the climb so I close the cowl flaps just before level off. On really hot days I wait untill the CHT's start dropping after level off before closing them.

[The Old Fogducker]

open the box of doughnuts

But only if its an empty leg ... don't share unless absolutely neccessary ... with someone who might buy lunch.

[trey kule]

Ah,big Pistons, there is one more important thing with a navajo. There are THREE, count them three limitations on the EGT. One for climb, one for cruise, and one for descent.
You would be surprised how many transitioning new pilots want to fly this just like the 152 and dont understand the limitations. Actually , you might be surprised how many pilots who claim to fly or have flown a navajo dont know these or put them into practice.
Now as to the origianl question, I have to bow out because , for the life of me I dont know what TOC is. Just guessing, but does it mean Take off check in some new pilot speak?
If so, then the AFM will provide you with a pretty decent check. If if doesnt mean that , thean the lead in word is TIC.

[Panama Jack]

Speaking of power reductions. I know that some guys pull the power & props back as soon as the gear handle comes up. Around 100 feet or so. Listened to a guy talk about engines at a seminar in the US who said never to make the initial power change until you are an an altitude where you can afford to take an engine failure: he said that statistically most engine failures happen on piston powered aircraft on the initial power reduction after takeoff (If it ain't broke don't fix it).

[Big Pistons Forever]

Ah,big Pistons, there is one more important thing with a navajo. There are THREE, count them three limitations on the EGT. One for climb, one for cruise, and one for descent.
You would be surprised how many transitioning new pilots want to fly this just like the 152 and dont understand the limitations. Actually , you might be surprised how many pilots who claim to fly or have flown a navajo dont know these or put them into practice.
Now as to the origianl question, I have to bow out because , for the life of me I dont know what TOC is. Just guessing, but does it mean Take off check in some new pilot speak?
If so, then the AFM will provide you with a pretty decent check. If if doesnt mean that , thean the lead in word is TIC.

TOC = Top Of Climb

With respect to EGT limits, you are correct and they are often not well known. However if you are leaning in climb or running anywhere close to the cruise limit you are not operating the aircraft correctly.

[The Old Fogducker]

Speaking of power reductions. I know that some guys pull the power & props back as soon as the gear handle comes up. Around 100 feet or so. Listened to a guy talk about engines at a seminar in the US who said never to make the initial power change until you are an an altitude where you can afford to take an engine failure: he said that statistically most engine failures happen on piston powered aircraft on the initial power reduction after takeoff (If it ain't broke don't fix it).

Let me add to your excellent observation Jack, and throw in a reference to them making the radio call while the gear is retracting, and power reducing ........ all the while taking off with flaps extended from a long paved runway.

They are sufferring from as yet undiagnosed, potentially fatal Hub Disease.

The Old Fogducker

[rigpiggy]

No reduced power takeoffs, either

[CJ6]

For PA31 TOC power reductions....

1)100' below level off call cowl flaps closed
2)Level off at alt.
3)Accelerate to 150 kts, then call for cruise power, cruise checks
4)PNF then reduces MP to 31"" and then props to 2200 rpm (as you pull the props back the MP will increase so initially pull MP to 30'', then when you set props if will end up at 31"")
5) Lean out mixtures to peak EGT minus 150 (obviously to do not exceed redline when finding peak). Maximum of 425C on the cylinder head temp in cruise. If its night you can tell a lot by looking at the exhaust, they should have a nice glow to them...without looking like they are on fire.

Hope this helps.....Hawkeye

[Big Pistons Forever]

425 deg is too hot. You should try to keep the cylinders below 380 deg. The cylinders are the weakest part of the Navajo engine particularly the J2BD varient found in the chieftain and keeping the cylinders cool as well as avoiding shock cooling is critical to avoid problems with the top end of the engine. The other factor is sufficent fuel flow. Full rich fuel flow should be carefully monitored on takeoff and in the climb. A bit higher than book is no big deal but any fuel fow that is lower than book in these stages of flight should be snagged for maintainance action as the engine will overheat if it is starved of fuel.

[CJ6]

425C is actually a AOM limitation/specification for cruise (J2BD), personally I liked it about 400C. But anything in that range is perfectly acceptable and not that hard on it...to keep it around 380C you will not get your 240lbs/hr fuel flow and will not run them as clean. I've run them that way for thousands of hrs and never had problems with the jugs...its all about being kind to the engines with proper power backs, thats what will kill your engine in no time.

[Big Pistons Forever]

To all new CPL's

Do not buy Navajo time with the idea it will get you a job.....you are just throwing your money away.

[The Old Fogducker]

To all new CPL's

Do not buy Navajo time with the idea it will get you a job.....you are just throwing your money away.

BPF ... if they bought maybe 5,000 hours they could likely find a job ... LOL.

OFD

[x15]

I am new to the Navajo. And I am trying to get some more information on stage cooling and mixture control.

I have heard of cracked jugs at various companies that was attributed to improper cool down. However I think also that it could come from the surge of cold fuel being introduced to cylinders when the mixture goes full rich on final and the fuel in the tanks is super cold in the winter.

I know in some of the Cessna products there is altitude compensation built into the mixture system. So you can leave the mixture leaned all the way down and put it full rich only in the event of a go around. I wasnt able to find specifics on this in the POH from Piper. Can anyone tell me if the Navajo is like the Cessna's with automatic altitude compensation.

In addition who puts the mixture full rich on final and who waits for a possible go around to put the mixtures forward in the chieftain or straight HO?

Thanks in advance for the help.

[CJ6]

X15,

No Navajo's are not the same as Cessna's when it comes to the mixtures, there is no altitude compensation built in to the mixture system. And as far as going full rich on final approach, that was the SOP for the company I flew for. But when you do put them full rich on final do it gently (I was always told 3 sec. to go full rich). If you just jam them full rich it is harder on the jugs, especially if its cold out.

There are lots of little things that can really save the engines on a Navajo. But also some big ones. Like how you set take-off power when the turbos kick in through 30'', power reduction for cruise, mixture leaning, and power backs for descent/approach. Its important to always be good to the engines, becuase it may not cause you a problem, but it may your buddy who is taking the plane right after you!

As for the guys who give the impression that Navajo time isn't worth much (if I took the posting correctly, if not I apologize), you are wrong. If you can fly around a twin piston with a standard six pack, no autopilot and shoot NDB approaches to mins in shitty weather you're set. Anyone here will agree that flying a turbine is easy/easier, and typically by the time you make it to a Jet they have enough automation on board to help you out with pretty much everything anyways. Navajo's take planning cause you can't go down and slow dowon on a Navajo either...unless you wanna blow your engines. So don't under rate twin piston time. Some of the big companies love to see guys with this time, because they know it can be challenging...more so then getting out of Flight School and getting right on to a B1900.

[CJ6]

But at the same time...I wouldn't go buy Navajo time...

[x15]

Thanks for the responses.

I am looking forward to my first left seat job flying the chieftain. Mainly for the reasons expressed. An opportunity to build skill and proficiency and development of my personal flight discipline. You gotta start somewhere. Figure I might as well ask people that have gone before me while on the ground with the engines are off instead of wishing I knew some things on that dark dirty night when things go awry.

[xsbank]

I seriously doubt that pushing mixtures rich on final will cause any damage. There is no significant heat in there when you are on an approach. What will kill them is shock cooling and not religiously idling for 5 minutes before shut-down.

I would also caution you that you MUST get rated manifold pressure at take-off. If you do not, you will NOT be able to maintain on one. If you work for an outfit that thinks the engines will last longer if the waste-gates are adjusted to give lower MP on take-off, go straight into the hangar and kick the maintenance manager in the ass!