NACO Approach Plates

[JaredYng]

I realize that this is rotorheads and theres not a whole lot of instrument flying with them but the reason I asked here is because I didn't know where else to ask and my question relates to an IAS of 80kts which we are more familiar with.

Anyway, my question is this. How do I calculate the time on the approaches(if applicable for that approach) for an IAS of 80kts? Thus far, I've taken my instructors Jepp plates and doubled his 160kt time. I have my check ride coming up soon and I don't want to use that reason for obtaining the time.

Also, does anyone know where I can find the IFR Airport Minimum Requirments online? I can't seem to find them but I find everything else. Thanks

[Senior Pilot]

Originally Posted by JaredYng

where I can find the IFR Airport Minimum Requirements online

Have you checked this page of the FAA site? I haven't read through it all, but it seems a good place to look!

[JaredYng]

Thanks Senior, I had not looked on that page before. After looking it over I still could not find the answers to my questions.

Perhaps it's late and I just overlooked it. At any rate, I'll check again tomorrow. Thanks!

[212man]

Anyway, my question is this. How do I calculate the time on the approaches(if applicable for that approach) for an IAS of 80kts?

The first thing to realise is that the timing is based on Groundspeed, not IAS, so you need to have an idea of what that might be. Looking at a Jepp Approach chart for a Non-Precision Approach (NPA) I see the timings are based on groundspeeds of 70, 90, 100, 120, 140 and 160 kts. So, if the g/s is 80 kts you can either double the 160 kt time , or interpolate bewteen the 70 and 90 kt times.

Not sure what you mean by the Aerodrome minimums - are you talking about something different to the approach minima depicted on the charts?

PS, there is probably more IFR experience on this site than perhaps you give credit for........

[flap flap flap]

All USA IFR approach plates can be found online here

http://www.naco.faa.gov/digital_tpp....end=06-04-2009

[ADRidge]

You know, it's not the most accurate assessment, but I just SWAG it. It worked on my instrument checkride. Say my 90kts time is 2:30, and I've got a 70kts GS. I figure it'll be somewhere around 2:10. If not, I'll be close enough to figure everything else out. It's unscientific, but then again, I'm FAA trained.

[212man]

That's a very curious kind of calculation - the slower you go, the less time it takes to reach the Mapt! I hope you are either joking or had a brain failure while typing.......

[rotorbrent]

Any E6-B type of calculator can give you the time at your 80Kts groundspeed or any groundspeed you choice. The chart just have the commonly used airspeeds on approaches precalculated for you.

[JaredYng]

Wow, thanks guys. I have no idea why I never even thought of using my flight computer to figure that out but I just did it, and it works perfectly! I feel like an idiot now! My instructor didn't think of that either so I guess I'm not the only one. I tried it interpolate and there is no set formula that you can use and interpolation would be a good quick guess if you had to on the spot I guess but it's not ass accurate as the calculator. So thanks, now I know how to explain! Oh another thing, I was never taught it was GS as opposed to IAS but that makes sense. I guess I never thought of that either. My head is spinning from all the stuff I have to learn.

flap, I know of the link that you sent me but unfortunately that link or anything else on the FAA website tells the IFR Alternate Airport Minimums section E1. Do you understand what I'm looking for?

[Gomer Pylot]

As stated above, the time to MAP is based on groundspeed, not indicated airspeed. If your groundspeed is not exactly on the chart, you interpolate. If you have a 70kt and 90kt groundspeed shown, and your groundspeed will be 80kt, then your time will be halfway between those for the 70 & 90 figures.

I'm not sure what you mean by "IFR Airport Minimum Requirments". Minima are published for approaches, not airports.

[JaredYng]

Gomer, I understand your interpolation and thank you. That's very helpful and informative as I didn't know before.

The "IFR Alternate Airport Minimums" starts at section E1 and it tells whether or not an airport is approved to be an alternat and what approaches are approved. It also includes whether or not the approaches are only available when tower is in operation and things like that.

I apologize, I had the name wrong in my previous post but thet aforementioned quoted title is exactly as it appears on my book. Thanks!

[JaredYng]

That's exactly what I was looking for. I feel like a complete idiot now! It wasn't clicking that it would be one of the listings for an approved airport! I was looking at airports that weren't approved hence why I couldn't find it.

I'm sorry to have bothered you guys with this. I was just having a brain fart! My mind is like fried from all this studying and stress with checkride coming up.

Thanks so much.