r22 manifold pressure placard

[rtrnewboy]

Can one of you help me with reading the limit manifold pressure placard - it has divisions -20 -10 0 10 20 30. What if the temp is say 5 or 15 which would logically be on the line or do you take the block closest to the temp eg if its 8 degrees does the 10 block apply or the 0 block because thats 0 to 10 ?? . SL is obviously 0 to 2000 but the temps confuse me a bit - dont want to appear confused - know what I mean.

[Camp Freddie]

have you tried interpolating? i believe thats what they expect you to do

or if its a beta, multiply the OAT by 3, put the decimal point in front then add to 24 and deduct (i think) 0.1 for every 500ft indicated with 1013 set e.g.

15c = 24.45 less correction for pressure, should be same as graph (beta only)

regards

CF

[manfromuncle]

Can anyone fly the R22 more accurately that 0.5 inches?!


A power limit of 22.2 is useless in my opinion. Best to round it to the nearest 0.5"

Plus the governor is always moving the MAP around as well.

[tegwin]

no MAP guage is ever going to be accurate, so a rough interpolation between the two figures given isnt going to hurt...unless of course you are wanting to do an out of ground effect hover with only 1" to play with:E

[rtrnewboy]

Na -- just got an instructor who isnt sure if I can read properly - really do want to know - I have UNI level applied maths (Africa) and I am not sure of this one - its a bit of a Robinson thing - maybe he was saving on ink and didnt want to indicate ranges. :) Sure the amount of MAP you can use is defined by Newtons Laws initially but they are sticky here about it as a lot of flying is done where you lift at 6000ft and above in hot conditions. I am at SL but if I get hppl means I can fly anywhere in this country with big differences in prevailing conditions. As I said in the previous post the altitude blocks down the left seem to be obvious as they go SL - 2000- 4000 and I assumed the first block indicates 0 to 2000 ft as its difficult to fly below sea level. The Temperature blocks not so obvious - can you fly at less than -20 - not in this country but in Siberia or Chicago I suppose you can - Scotland definitely - you guys tell me. So does the first block marked -20 mean -20 to -10 or -whatever to -20.

[Camp Freddie]

they are snapshots not blocks,
so temp 10c means at 10c
2000ft means at 2000ft
sounds to me like you are trying to make something that is easy difficult !
you need to interpolate
is there an echo in here :)

regards

CF

[Gordy]

As previous posters have commented----quit trying to overcomplicate it. You cannot fly that accuratley...

http://i76.photobucket.com/albums/j35/helokat/8uzn8y1164932566.jpg

[rtrnewboy]

Ok - got it - thanks

[Name of Pen]

Hello Chum,

This is echo speaking.

The MAP limit chart is based on pressure altitude.

Dial in 1013MB on the altimemeter subscale and read off from there.

If you are not sure what interpolatin is, round the temperature down.

Then reduce by .2" per 1000ft.

and yes, I can fly that accurately :}


I hope this helps

Best regards