| Author | Post |
|---|
JimP
Member
|
Posted: Sat Apr 22nd, 2006 04:23 am |
|
On an IFR flight plan recently (KSLE - UBG - KHIO) I was flying the leg inbound to UBG VOR. I was given the ATC instructions: Fly direct UBG, cleared for the "straight-in" VOR/DME C approach Hillsboro. (I cannot remember the exact prasiology).
Activating the approach put the undesired outbound course and proceedure turn into my flight plan. When I deleted the proceedure turn... I also lost my direct course to UBG... and instead I was intercepting extension of the course from UBG to KHIO... not what I wanted.
When I first tried it on the simulator... I got the exact same results. However... on all subsequent atempts on the simulator... I cannot reproduce the problem.
What I am doing now is:
1) Load the approach (Activate works ok too)
2) Highlighting "proceedure turn" in the waypoint list
3 "CLR" and confirm the proceedure turn deletion,
4) Activate the approach (if not already done in step #1)
Everything seems to work OK now on the simulator... and I cannot figure out what I was doing wrong during the flight, or my first attempt on the simulator. Any clue on which proceedure I might have done wrong? I would hate to have this happen again on a real flight.
/Jim
____________________
Visit my family web page at http://www.pappasfam.com
|
rkaplan
Administrator
|
Posted: Sat Apr 22nd, 2006 03:40 pm |
|
Hi Jim.
I would not recommend editing or deleting portions of approaches.
What I would do here would be to load the approach with UBG as the IAF. Then press FPL, turn on the cursor by pushing the right small button, scroll down with the right large button to the UBG waypoint listed after the procedure turn, and press DIRECT ENTER ENTER.
P.S. I will assume you were in radar contact and at some time the controller told you to expect radar vectors to the final approach and that "Direct UBG, Cleared Straight-In" was essentially the controller's radar vector to you. If you were not in radar contact then the procedure turn is required on this approach.
Attachment: hio530.jpg (Downloaded 81 times)
____________________
Richard Kaplan, CFII
rkaplan@flyimc.com
http://www.flyimc.com
|
JimP
Member
|
Posted: Sat Apr 22nd, 2006 03:50 pm |
|
This is pretty obvious... why didn't I think of the simple solution??? 
In your example you never activated the approach... but you manually advanced the cursor into the approach portion of the FPL. Does that have the same affect as activating the flightplan?
/Jim
____________________
Visit my family web page at http://www.pappasfam.com
|
rkaplan
Administrator
|
Posted: Sat Apr 22nd, 2006 04:01 pm |
|
JimP wrote: This is pretty obvious... why didn't I think of the simple solution???
It is aways easier flying in your living room  .
JimP wrote:
In your example you never activated the approach... but you manually advanced the cursor into the approach portion of the FPL. Does that have the same affect as activating the flightplan?
Yes -- same effect.
____________________
Richard Kaplan, CFII
rkaplan@flyimc.com
http://www.flyimc.com
|
JimP
Member
|
Posted: Mon Apr 24th, 2006 03:16 am |
|
Here is a similar quesiton about "going direct" during a flight plan.
Yesterday, on an IFR flight from KPAE to KHIO, I received the folllowing clearance:
Cleared Hillsboro via Paine 2 departure, initial heading 220, V287, OLM, V165, UBG, KHIO. Note that the Paine 2 departure is simply "radar vectors"
I loaded the following into my flightplan. Note that ARPEE and OLM are used to define the segment of V287 that I would intercept.
During my departure, and before reaching V287 I was given the ATC command: "cleared direct OLM". At this point I pressed FPL, Cursor, Highlight OLM, Direct, Enter, Enter, and then hit "NAV" on the autopilot. At this point, my 530 was as follows:
Things were going great... but after several minutes of flight... I noticed that my plane was beginning a hard turn to right. I disconnected the AP, resumed my heading, and looked at the flight plan... but the heading next to OLM was 347... the reciprical of the path between ARPEE and OLM.
Something is definately wrong here. I re-applied the "direct OLM" sequence... and all of a sudden my 530 flightplan was correct (no incorrect heading), and I resumed using the autopilot.
I am not 100% certain... but the error might have been introduced as I passed the point adjacent to ARPEE where my original flight plan would have progressed.
Does anyone know any reason why the 530 should act as I described? I am perplexed. I wish I had the frame of mind to check the flight plan on GNS 530 #2... but I didn't... and now it is too late.
I will look more carefully on future flights... and if I ever get such an error again, I will cross-check against the other 530, or my 296.
/Jim
Last edited on Mon Apr 24th, 2006 06:20 am by JimP
____________________
Visit my family web page at http://www.pappasfam.com
|
rkaplan
Administrator
|
Posted: Mon Apr 24th, 2006 03:25 am |
|
Jim,
Your screenshots and/or photos did not post... I'll be glad to look at it if you can post them.
Off the top of my head without that data.... is it possible that you accidentally hit the OBS button at some point?
____________________
Richard Kaplan, CFII
rkaplan@flyimc.com
http://www.flyimc.com
|
JimP
Member
|
Posted: Mon Apr 24th, 2006 04:09 am |
|
Strange... I can see them just fine. If you send me your email address, I will forward you the photos via email. I set the URL to my deskptop... that is probably the problem.
/Jim
Last edited on Mon Apr 24th, 2006 04:11 am by JimP
____________________
Visit my family web page at http://www.pappasfam.com
|
rkaplan
Administrator
|
Posted: Mon Apr 24th, 2006 04:12 am |
|
JimP wrote: Strange... I can see them just fine. If you send me your email address, I will forward you the photos via email. I set the URL to my deskptop... that is probably the problem.
You can email them to me at rkaplan@flyimc.com. But even better would be if you can post a valid URL so others can benefit too. Thanks.
____________________
Richard Kaplan, CFII
rkaplan@flyimc.com
http://www.flyimc.com
|
JimP
Member
|
Posted: Mon Apr 24th, 2006 06:22 am |
|
Fixed. (at least hopefully)
/Jim
____________________
Visit my family web page at http://www.pappasfam.com
|
rkaplan
Administrator
|
Posted: Mon Apr 24th, 2006 06:37 am |
|
Is it possible you accidentally entered OLM both before and after ARPEE in your flight plan?
Otherwise is it possible you pressed OBS momentarily and the GPS read the incorrect DTK from your HSI?
____________________
Richard Kaplan, CFII
rkaplan@flyimc.com
http://www.flyimc.com
|
JimP
Member
|
Posted: Mon Apr 24th, 2006 06:47 am |
|
rkaplan wrote: Is it possible you accidentally entered OLM both before and after ARPEE in your flight plan?
Otherwise is it possible you pressed OBS momentarily and the GPS read the incorrect DTK from your HSI?
I am 100% sure that OLM was only in my flightplan once as shown in the screenshot above
I am 99% sure that I did not hit the OBS button on GNS530 #1... which is the unit that I was using to navigate, and to control the autopilot.
However... I did hit the OBS button on GNS530 #2 at one point while I was playing with the remote annunciator that the FSDO made me install since the 2nd 530 was too far out of my field of view. See circled device in the pic below:
The two 530's are crossfed with each other. Could pressing the OBS switch on the 2nd 530 change the flightplan in my primary 530? I am not an OBS expert (yet)... but I did not think that was the behavior.
/Jim
Last edited on Mon Apr 24th, 2006 06:50 am by JimP
____________________
Visit my family web page at http://www.pappasfam.com
|
rkaplan
Administrator
|
Posted: Mon Apr 24th, 2006 06:53 am |
|
Yes, if they are crossfed then pressing OBS can cause this to occur.
When you press OBS whatever course is dialed into your HSI or CDI becomes the DTK (desired track) to the active waypoint. You probably had your # 2 CDI set to a course of 347 and then when you pressed OBS this got transferred to both 530s.
For this reason and many others, I would suggest you have your # 1 530 feed data to the # 2 but not the other way around. You want to be able to use your # 2 530 to play navigational "what if" questions without affecting your # 1 530 which is your primary navigational device.
This example with the remote annunciator is a good example of how FAA installation rules can create more problems than they solve.
____________________
Richard Kaplan, CFII
rkaplan@flyimc.com
http://www.flyimc.com
|
JimP
Member
|
Posted: Mon Apr 24th, 2006 07:08 am |
|
This still doesn't entirely make sense to me.
First of all... I understand the dual crossfeed issue and I will more than likely disable the crossfeed from #2 to #1. Good tip... and I am pretty sure I can do this via the GPS setup.
The part that confuses me is the OBS operation. I was north of OLM heading south. If 347 was put into the flightplan as the desired course to OLM... wouldn't the desired course be from the south... and heading north to OLM? In that case... I would need to continue flying south to reach the desired track into OLM.
The problem is that my flightplan was indicating that I needed to fly north... and I was still north of OLM.
/Jim
____________________
Visit my family web page at http://www.pappasfam.com
|
rkaplan
Administrator
|
Posted: Mon Apr 24th, 2006 07:34 am |
|
OBS works just like the OBS knob on your VOR.
When you press OBS whatever is dialed as the course in your HSI or CDI becomes the DTK in your GPS.
What may be puzzling here is that in OBS mode you can be navigating either TO or FROM a waypoint. So if you were North of the active waypoint (OLM) and pressed OBS with 347 dialed into your CDI then the GPS would have been navigating on the 347 radial FROM OLM. This is just the same as a VOR would do if you had dialed in 347 on your CDI in the same location and tuned in OLM.
When you are in OBS mode it does not matter what your flight planned DTK may be -- the GPS takes the dialed course on your HSI or CDI and makes that the new DTK in the flight plan for that segment. Even if you then turn off OBS, the change in the DTK still stays.
____________________
Richard Kaplan, CFII
rkaplan@flyimc.com
http://www.flyimc.com
|
JimP
Member
|
Posted: Mon Apr 24th, 2006 03:04 pm |
|
Richard,
Thanks again. Given your explaination, I now understand what happened. When I hit OBS on the 530#2 remote annunciator, it selected the undersired radial, set it as the DTK FROM OLM, and then crossfilled it to my main navigator.
I had only turned a few degrees before shutting off my AP and correcting my course. Then... when I "re-applied" the direct to OLM... my flightplan was fine again.
Good to know that I do not have a problem with the 530
/Jim
____________________
Visit my family web page at http://www.pappasfam.com
|
rkaplan
Administrator
|
Posted: Tue Apr 25th, 2006 12:00 am |
|
You are quite welcome Jim.
Situations like this are fairly common as avionics gets more complex... imagine the corresponding situations which can occur in an aircraft with a fully automated flight management system including vertical navigation planning.
I think there is a balance beween automation and manual flying which each pilot needs to think through for a given situation. I often wonder specifically about the risks vs. benefits in particular of flying a coupled approach in low IMC for this reason. Perhaps a good compromise is to use an autopilot in heading/pitch control mode but not in nav mode when at low altitude in IMC.
____________________
Richard Kaplan, CFII
rkaplan@flyimc.com
http://www.flyimc.com
|
Current time is 06:01 am | |
|
