Power-check How-to

[LongDogger]

Hi folks,

 

I'm studying the Astar POH and I'm having hard time understanding the power check charts.

 

It sez in Section 4 that once you have your parameters, to enter the chart first with Tq - Nr - Alt, and then from OAT to Ng. I don't have a problem with the bottom portion, but I'm a little confused about the top part. If i'm deducing this right, I go from my OAT a straight horizontal to intersect with Ng, then vertical to the diagonal separating the correct/incorrect regions of the chart, then back horizontal to intersect my vertical up from Alt. Is this correct?

 

Also, for the B2, it sez MCP = 98%.............................Delta Ng -3.5

 

Is 98% an absolute ? Is it the lesser of the two ? Greater of the two?

 

Another detail. The Intec filter STC states OAT must be increased by 4 degrees C in the BA POH for power check, but not in the B2 POH. Why is that?

 

Last Q: Anybody got "virgin" large format Astar power charts to share?

[Gftp]

Dogger

 

 

Pick and altitude write it down 3000' say you can use any ALT.

 

Fly straight and level pull in 98% max Cont torque hold that .

 

Write down OAT

Write down T4

write down Nr

 

Depending on the filter deduct temperature as per instructions to correct for OAT

 

Plot'er on the chart. ( photocopy enlagre by 25%) make it easier if you forgot your reading glasses :shock: Just make sure you use the right chart as per the PFM.

 

 

Hope this help's

 

JW

[skullcap]

LD

 

You are plotting it correctly. There is a computer program that works as well.

 

That gauge is pretty cool, but 98 and -3.5 Delta are always the same, strange but true. You do have to subtract for certain things such as bleed air heat on.

 

By intec do you mean FDC filter? If so you do have to subract 4'C from OAT for power check. If you mean the AFS no clue why descrepancy.

 

hope it helps

p

[shaggy]

you are on the right track (and not to muddy the waters mind you) but keep in mind if you are at a low enough pressure altitude and you can only pull to 94% Q and you haven't reached 98% NG that will be your first limit. you might be overtorqueing the machine 98 % NG at 40 + kts IAS. as long as the bleed valve is closed you can still do a power check.

[Over-Talk]

It has been years since I have driven one of these, but I remember a lot of confusion over the power check charts.

 

I recall you drew a calculation up from one side, then drew a calculation up from the other side, then intersected these two points together (i.e. one across and one up to where they meet).

The result laid on either the correct or incorrect part of the chart.

 

(Your pencil should not stop and/or change directions when it passes the correct/incorrect diagonal line).

[T tail]

Don't you just love the B3

 

TT

[LongDogger]

LD

 

You are plotting it correctly. There is a computer program that works as well.

 

That gauge is pretty cool, but 98 and -3.5 Delta are always the same, strange but true. You do have to subtract for certain things such as bleed air heat on.

 

By intec do you mean FDC filter? If so you do have to subract 4'C from OAT for power check. If you mean the AFS no clue why descrepancy.

 

hope it helps

p

 

The physical filter is an FDC, but the "kit" is Intec (I was told Intec was bought by FDC some years ago, but the STCs still bear the Intec name).

 

You mentioned a computer program ? Who does one have to kill to get that ?

[skullcap]

Here is the link, works excellent, have been using it for 3 years and seems very accurate.

 

 

http://www.hhssoftware.com/powercheck/

 

 

 

Am sorry but looking thru the supplement for the filter available on the FDC website:

 

http://www.fdcaerofilter.com/pdf/1350_1200_Rev_F_signed.pdf

 

I cannot see any difference in procedure for BA or B2, maybe am missing something?

[CIEH]

Hello

 

Be sure all bleed air are off when you do a power check. Heater / demist, sand filter (Eurocopter) must also be closed. You go to your first max continuous limit (TQ 83% for BA, 94% for B2, OR NG 98% for both). When you reach your first limit, take your readings, keeping altitude (3000 feet for example)

 

First limit will be most likely NG in summer / high altitude, or TQ in winter / low alt.

Make sure your bleed valve is closed. In winter, you may have to climb to close it.

 

The 3rd limit is T4. But if you reach it during a P. check with an Arriel, I think you are in trouble

 

Fly safe

[ray]

I believe the FDC filter states that you use the charts for the sand filter to plot power checks. This is off the top of my head.

 

And I believe you subtract the temperature on the B2 chart as well. I'm at home right now, so I can't confirm that.

 

In any case, it's not the same as plotting a +/- spec on the 206. It's either good, or not.