Essential IATRA formulas?

Bob A. Booey · Post by **Bob A. Booey** » Wed Jun 20, 2007 6:59 am

I have been reading the wealth of information regarding the ATPL and IATRA exams presented here. Any updates on the IATRA, from recent writers?

Also just wondering what the most essential formulas are. I know %MAC is one and obviously I have the questions already posted to work from. I will start this thread and then add to it after I go write late this week or early next for those that follow.

Regards!!!

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short bus · Post by **short bus** » Wed Jun 20, 2007 7:35 am

critical point and point of no return are the only formulas i needed to know on the copy of the iatra that i wrote, i've heard there's only 2 versions of this test. Wrote it over a year ago so I don't know if it's changed since then. If memory serves correct the weight & balance questions were for a king air, i could be wrong though.

privateer · Post by **privateer** » Wed Jun 20, 2007 3:10 pm

same here . Wrote it back in march and most of the questions were on that post that someone had up here not too long ago. I found the exam tricky and time comsuming but i managed to pull off a 90%. The stuff you will probably get wrong will be the easy suff. That was my problem

Elessar_44 · Post by **Elessar_44** » Thu Jun 21, 2007 9:08 am

Is it possible to do the critical point stuff with an old fashioned E6-B? I'm trying to do the Aerocourse questions about CP and it's a pain in the ass with my metal E6-B because of the larger numbers, like 60kt winds.

TBh I didn't even know what CP was until I started studying for my IATRA heh. I had to hit google because the Turbine Pilot's Manual doesn't have anything on CP, only %MAC forumlas and stuff.

Grey_Wolf · Post by **Grey_Wolf** » Thu Jun 21, 2007 10:43 am

I wrote mine back in Oct '06 ... from what i can recall there was 2 questions on CP, one asking for the CP and the other the time to reach it. There also was a question on SAR and SGR. At the time i had also memorized PNR formulas as well, but didn't use them on the IATRA. Other than that, the classic weight shift question was asked along side a W&B questtion. Payload was aked on the ATPLs however (wrote those in april of '07). Hope it helps.

sanjet · Post by **sanjet** » Thu Jun 21, 2007 12:18 pm

Does anyone know a website where I can review the Critical Point / Point of no return formulas? I need to get my IATRA done asap!

Grey_Wolf · Post by **Grey_Wolf** » Thu Jun 21, 2007 12:39 pm

sanjet,

In the back of the Aerocourse would be a start

otherwise, here you go ...

Distance to CP = (D * Hr) / (Or + Hr)

where
D = total Distance
Or = Reduced or 3 Engine Groundspeed Out
Hr = Reduced or 3 Engine Groundspeed Home

as for PNR ...

Flight Time to PNR = (E * H) / (O + H)

where
E = Safe Fuel (Endurance)
H = Full Groundspeed Home
O = Full Groundspeed Out