Re: Whats the Trick? NDB Partial Panel Holding......

Download ForPilots Logbook today! Forpilots Logbook is the award-winning computerized logbook solution. The software features a simple, easy to use user interface that looks just like a paper logbook, but adds advanced statistics and reporting capabilities. Download ForPilots logbook for free!

Thanks for the tips, Paul. They all sound good to me.

In addition, I've found this little nav tool to be a very good tool to use
when you are first trying to understand the basics of nav. Here's the
website:

http://www.visi.com/~mim/nav/

He also has a zipfile you can download if you don't want to use the online
java program.

--
Scott Brazell

"Pilots are just plane people with a different air about them."

Paul Lynch wrote:

> Flying NDB approaches or holding requires 3 fairly simple concepts. With
> a
> little practice you can easily hold on an NDB even if you are partial
> panel.
>
> 1. Understand ADF tracking techniques
> 2. Visualize your position relative to the NDB
> 3. Be "wind smart"
>
> Let's examine these individually...
>
> 1. Tracking an NDB bearing using a fixed card is a mental math
> challenge.
> Simplify it and you will have fewer problems. Let me give you an
> example.
> We'll assume that we are close to the NDB (as in holding or an approach).
>
> You should be tracking the 360 bearing to the NDB. Your heading is 360,
> but
> the ADF needle is indicating 15 left. Visualizing this we are right of
> track and must turn left, but how much??? Make it simple and use 30
> degrees. Why 30? Because that is clearly marked on the ADF card.
> Having
> turned 30 left the needle will now be right of the nose (remember we push
>
> the nose of the needle away and drag the tail towards our goal; think of
> a
> dog). When the needle is 30 right on the ADF card turn to the base
> heading
> (360 in this case). You are on the 360 bearing. Now be wind smart and
> put
> a crab in so you track 360 to the NDB.
>
> 2. Visualize your position. Take a "God's eye view." Look at the
> approach
> plate or chart. Where are you relative to the NDB and the desired
> bearing.
> Where is the wind from? What is your heading? Get this pictured in your
>
> mind.
>
> 3. Crab for the wind. Some simple rules of thumb. Think in terms of
> ground speed and miles per minute. If you are at 90 KIAS that is 1.5
> miles
> per minute; 120 KIAS is 2 miles per minute. For 90 KIAS you need to crab
>
> 1.5 degrees for every knot of crosswind component. At 120 KIAS you need
> to
> crab 2 degrees for every knot of crosswind component. Apply the
> appropriate
> amount of crab to track the desired bearing. Remember the needle will be
> displaced
> the same amount as the crab, if you are on the bearing. Crab double the
> normal amount on
> the outbound leg for holding or you will overshoot the inbound bearing.
>
> Some additional technique tricks...
> - When turning outbound start the clock when you get wings level and the
> needle is
> at 90 degrees left/right of the nose. The needle will normally start
> ahead
> of that position and move aft (remember that dog above?). If it is
> already past 090/270,
> then you are past abeam so start the clock when you get wings level.
> - On the outbound leg, if you are the correct distance away from the
> inbound
> track, the needle should be about 30 degrees off the tail after 1 minute
> .
> (Think about the classic teardrop holding entry where you turn 30 degrees
>
> for one minute; you end up in the basically the same position). If the
> needle
> is <30, then you are closer and will likely overshoot the inbound desired
> track;
> >30 and you are wider and will likely undershoot (an easier and more
> desirable
> error).
> - Turning inbound requires you to watch the progress of the ADF needle
> relative to your desired inbound heading. If the ADF needle is ahead of
> your desired heading, you undershot the turn. Roll out 30 degrees early
> and
> wait for the needle to get 30 degrees from the nose... then turn to the
> inbound
> heading (you will be on the bearing) and get wind smart (apply a crab
> correction).
> Now for the opposite case... If the ADF needle is trackng behind the
> desired
> inbound heading you will overshoot the desired inbound track. Continue
> the
> turn 30 degrees past the inbound heading and wait for the needle to fall
> 30
> degrees. Turn to the inbound heading and be wind smart.
>
> Practice this on a simulator. A PC flight game works great if it has ADF
>
> capability. Use the autopilot and focus on the navigation problem and
> the
> instrument indications. Do a few without wind. Intentionally get
> yourself
> off track by going to wide/close on the outbound leg. Watch the
> instrument
> indications for these conditions. Try to use a NDB that is part of a
> localizer
> approach and dial up the localizer so you can better visualize what is
> happening.
> Now program wind (20 knots). Vary the wind directions. After doing this
> for
> a while, you will understand what happens and what the indications will
> be
> when you fly an airplane.
>
> As for entering holding...
> 1. Preflight your approach plates. Takes a plotter or compass out and
> draw the
> 70/110 line on the plate. Label the parallel and tear drop sectors.
>
> 2. Use timed turns. 10 seconds for 30 degrees, 15 seconds for 45
> degrees...
>
> 3. Get a vertical magnetic compass card instead of the floating kind.
> It makes a
> huge difference. You still have ANDS and lag/lead errors, but it doesn't
> bounce
> around and you intuitively turn in the correct direction.
>
> Now jump in that $70 flying training aid and fly some NDB work. You will
> find
> ADFs work great. If you have a hand held or installed GPS, note the
> ground track
> versus your heading.
>
> Hope this helps!
>
> Scott wrote:
>
> > Ok, What is the trick? I have practiced and practiced NDB partial
> > panel holding and I can't seem to get them down. The problem is the
> > entry. Once I get the entry down, the rest is a piece of cake. I
> > dont know if it is just the fact that working with the wet compass is
> > throwing me off or what.
> > This is the only problem that I am having with finishing my Insturment
> > rating.
> >
> > If there is anyone with some "Tricks of the Trade" please pass them
> > along.
> >
> > Thanks
> > Scott
> > Newbie with 165 hours