A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Instrument Flight Rules
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Primus 1000 FMS brain damage



 
 
Thread Tools Display Modes
  #1  
Old February 2nd 08, 06:34 AM posted to rec.aviation.ifr
Ron Garret
external usenet poster
 
Posts: 199
Default Primus 1000 FMS brain damage

Today I departed out of RIL as a passenger on a Citation V Ultra being
flown under Part 135. Despite the winds and terrain favoring a
departure from runway 26, we departed runway 8. One of the consequences
of this was that we needed a 5500 foot ceiling, which we darn near
didn't get and we almost got stuck there.

When I asked why they departed runway 8 instead of 26 (whose departure
minimums require only a 3500 foot ceiling) I was told that the Honeywell
Primus 1000 FMS could not be programmed to properly fly the Squat 1
departure (http://204.108.4.16/d-tpp/0801/06741SQUAT.PDF). In
particular, the procedure requires that the plane fly to YIRDU
intersection before turning towards SQUAT, but the Primus 1000 always
interpolates its turns (i.e. it would start turning towards SQUAT
slightly before reaching YIRDU), and this cannot be overridden.

This all sounded a little farfetched to me. Leaving aside the fact that
it's only a 15 degree turn, I don't understand how any IFR-certified GPS
(let alone one that they would install on a freakin' jet) could not
properly fly a published GPS departure procedure.

Can anyone here shed any additional light on this situation? Is this
really true, or did I get told a tale?

Thanks,
rg
  #2  
Old February 2nd 08, 08:27 AM posted to rec.aviation.ifr
Scott Skylane
external usenet poster
 
Posts: 150
Default Primus 1000 FMS brain damage

Ron Garret wrote:
/snip/

When I asked why they departed runway 8 instead of 26 (whose departure
minimums require only a 3500 foot ceiling) I was told that the Honeywell
Primus 1000 FMS could not be programmed to properly fly the Squat 1
departure (http://204.108.4.16/d-tpp/0801/06741SQUAT.PDF). In
particular, the procedure requires that the plane fly to YIRDU
intersection before turning towards SQUAT, but the Primus 1000 always
interpolates its turns (i.e. it would start turning towards SQUAT
slightly before reaching YIRDU), and this cannot be overridden.

This all sounded a little farfetched to me. Leaving aside the fact that
it's only a 15 degree turn, I don't understand how any IFR-certified GPS
(let alone one that they would install on a freakin' jet) could not
properly fly a published GPS departure procedure.

Can anyone here shed any additional light on this situation? Is this
really true, or did I get told a tale?

Thanks,
rg

Ron,

I'm not sure what they were trying to tell you, but there are no "fly
over" waypoints on this procedure, they are all "fly past", i.e. it's
perfectly acceptable (and expected) to anticipate any turns. Yes, any
competent FMS can handle this easily (though, I'm not familiar with the
Primus 1000 specifically).

Which direction was your destination? If it was eastbound, this
particular procedure takes you quite a bit out of your way. Perhaps the
crew wanted to save gas/flight time by departing 8. That doesn't make
much sense, though, if it meant a real possibility of getting stuck
there, instead of actually departing. Not only that, but both of the
Rwy 8 DP's allow a 400-1 takeoff minimum, assuming you can maintain 320'
per NM on the climb out, something I would think a Citation could handle.

Happy Flying!
Scott Skylane
  #3  
Old February 2nd 08, 08:36 AM posted to rec.aviation.ifr
Ron Garret
external usenet poster
 
Posts: 199
Default Primus 1000 FMS brain damage

In article ,
Scott Skylane wrote:

Ron Garret wrote:
/snip/

When I asked why they departed runway 8 instead of 26 (whose departure
minimums require only a 3500 foot ceiling) I was told that the Honeywell
Primus 1000 FMS could not be programmed to properly fly the Squat 1
departure (http://204.108.4.16/d-tpp/0801/06741SQUAT.PDF). In
particular, the procedure requires that the plane fly to YIRDU
intersection before turning towards SQUAT, but the Primus 1000 always
interpolates its turns (i.e. it would start turning towards SQUAT
slightly before reaching YIRDU), and this cannot be overridden.

This all sounded a little farfetched to me. Leaving aside the fact that
it's only a 15 degree turn, I don't understand how any IFR-certified GPS
(let alone one that they would install on a freakin' jet) could not
properly fly a published GPS departure procedure.

Can anyone here shed any additional light on this situation? Is this
really true, or did I get told a tale?

Thanks,
rg

Ron,

I'm not sure what they were trying to tell you, but there are no "fly
over" waypoints on this procedure, they are all "fly past", i.e. it's
perfectly acceptable (and expected) to anticipate any turns. Yes, any
competent FMS can handle this easily (though, I'm not familiar with the
Primus 1000 specifically).

Which direction was your destination?


Due west. Burbank.

rg
  #4  
Old February 2nd 08, 08:51 AM posted to rec.aviation.ifr
Scott Skylane
external usenet poster
 
Posts: 150
Default Primus 1000 FMS brain damage

Ron Garret wrote:



Which direction was your destination?



Due west. Burbank.

rg


Well, then I am at a complete loss. The appropriate DP in that case,
given a Rwy 8 departure, would be the EDUKY ONE. That DP is the only
one that *does* contain a "fly over" waypoint, the very thing your pilot
said his FMS *couldn't* do!

Happy Flying!
Scott Skylane
  #5  
Old February 3rd 08, 05:44 PM posted to rec.aviation.ifr
Sam Spade
external usenet poster
 
Posts: 1,326
Default Primus 1000 FMS brain damage

Ron Garret wrote:
Today I departed out of RIL as a passenger on a Citation V Ultra being
flown under Part 135. Despite the winds and terrain favoring a
departure from runway 26, we departed runway 8. One of the consequences
of this was that we needed a 5500 foot ceiling, which we darn near
didn't get and we almost got stuck there.

When I asked why they departed runway 8 instead of 26 (whose departure
minimums require only a 3500 foot ceiling) I was told that the Honeywell
Primus 1000 FMS could not be programmed to properly fly the Squat 1
departure (http://204.108.4.16/d-tpp/0801/06741SQUAT.PDF). In
particular, the procedure requires that the plane fly to YIRDU
intersection before turning towards SQUAT, but the Primus 1000 always
interpolates its turns (i.e. it would start turning towards SQUAT
slightly before reaching YIRDU), and this cannot be overridden.

This all sounded a little farfetched to me. Leaving aside the fact that
it's only a 15 degree turn, I don't understand how any IFR-certified GPS
(let alone one that they would install on a freakin' jet) could not
properly fly a published GPS departure procedure.

Can anyone here shed any additional light on this situation? Is this
really true, or did I get told a tale?

Thanks,
rg


You got a tale, on a number of levels, plus I have to wonder about the
competence of that crew.

First, an IFR FME (or for that matter a panel mount) must be able to
handle both flyover (FO) and fly-by (FB) waypoints. There are two RNAV
DPs for Runway 8 and one for 26.

There is also a VOR/DME based ODP for Runway 8, but not for 26.

So, the basic takeoff minimums apply to the ODP for Runway 8 and to the
SQUAT RNAV DP for Runway 26. (26: 3400-3 or standard with a min CG of
360/NM to 10,000. 8: 5500-3 or standard with a min CG of 370/NM to 13,000)

The basic Runway 8 takeoff minimums do not apply to the two RNAV DPs for
that runway. They each have their own takeoff minimums and CGs. The
two RNAV DPs have the mandatory 400-1 requirement even with a CG,
whereas the "steam gauge" ODP is standard with its climb gradient.

Seems that they were not willing to do any of the three RNAV DPs, thus
opted for the steam gauge ODP.

Not a good choice at this airport. Runway 26 is downhill and with the
use of the SQUAT ONE there is virtually no terrain threat. In fact,
engine failure procedures off Runway 26 should be a piece of cake
compared to Runway 8.

SQUAT is a FB waypoint. The only FO waypoint for any of the three RNAV
DPs is USUNE.

Squat is speed limited so the turn doesn't occur two early for the AWRAW
or EDUKY transitions. There is no speed limit for the JNC transition
because there is a very small course change.

And, you say they needed a 5500-1 ceiling for Runway 8. True, but only
if they couldn't do 370 per mile to 13,000. If that airplane can't do
that, it shouldn't be doing IMC charters at an airport like Rifle.

Departing on the SQUAT on Runway 26 requires a slightly less climb
gradient and only to 10,000 feet, which is far less demanding.

I can only speculate:

Maybe they don't really know how to do RNAV DPs? Maybe their database
was out of date? Maybe they misunderstood the takeoff performance
requirements for each runway?

Bottom line: Anyone with their act together in an RNAV aircraft would
have departed Runway 26.
  #6  
Old February 4th 08, 01:01 AM posted to rec.aviation.ifr
Bonehenge (B A R R Y)
external usenet poster
 
Posts: 31
Default Primus 1000 FMS brain damage

On Sun, 03 Feb 2008 08:44:52 -0800, Sam Spade
wrote:


First, an IFR FME (or for that matter a panel mount) must be able to
handle both flyover (FO) and fly-by (FB) waypoints. There are two RNAV
DPs for Runway 8 and one for 26.


I always learn from your posts... G
  #7  
Old February 4th 08, 08:27 AM posted to rec.aviation.ifr
Ron Garret
external usenet poster
 
Posts: 199
Default Primus 1000 FMS brain damage

In article ,
Sam Spade wrote:

You got a tale, on a number of levels, plus I have to wonder about the
competence of that crew.


I dunno. I grilled them pretty hard and they seemed to know what they
were doing. They didn't get defensive about it or anything.

First, an IFR FME (or for that matter a panel mount) must be able to
handle both flyover (FO) and fly-by (FB) waypoints.


The crew was quite specific that this one could only do FB, except with
an upgrade that the company was unwilling to pay for. (I even asked
them why don't they just hand-fly the DP, and the answer was that they
could, but that the CDI would still direct them according to the FB
routing, so that wouldn't actually help.)

There is also a VOR/DME based ODP for Runway 8, but not for 26.


[xnip]

Seems that they were not willing to do any of the three RNAV DPs, thus
opted for the steam gauge ODP.


Yes, exactly. That is exactly what they said.

Not a good choice at this airport.


That's what I thought, and that's what they thought. But they said that
according to the regs they didn't have a choice.

And, you say they needed a 5500-1 ceiling for Runway 8. True, but only
if they couldn't do 370 per mile to 13,000. If that airplane can't do
that, it shouldn't be doing IMC charters at an airport like Rifle.


It can certainly do that with both engines, but with an engine out it's
dicey (this, again, according to the crew).

I can only speculate:

Maybe they don't really know how to do RNAV DPs?


Inconceivable.

Maybe their database was out of date?


Possible, but that's not what they said.

Maybe they misunderstood the takeoff performance
requirements for each runway?


Ditto.

Bottom line: Anyone with their act together in an RNAV aircraft would
have departed Runway 26.


Yeah, that's what I thought.

rg
  #8  
Old February 4th 08, 04:14 PM posted to rec.aviation.ifr
Sam Spade
external usenet poster
 
Posts: 1,326
Default Primus 1000 FMS brain damage

All the details aside, there is no RNAV system certified that won't
handle both flyby and flyover waypoints.

Such a limited system could not fly any GPS approaches, because they all
have a flyover waypoint to begin the missed approach.

So, you were being fed some kind of BS.

Also, as to Part 135 single-engine contingencies, they could have a
different procedure than the ODP for Runway 8, if their company chose to.

I will check out the Primus 1000 with some pilots that fly that system. ;-)
  #9  
Old February 4th 08, 04:16 PM posted to rec.aviation.ifr
Sam Spade
external usenet poster
 
Posts: 1,326
Default Primus 1000 FMS brain damage

Did you note that the SQUAT 26 DP doesn't have any flyover waypoints?
  #10  
Old February 4th 08, 06:48 PM posted to rec.aviation.ifr
Sam Spade
external usenet poster
 
Posts: 1,326
Default Primus 1000 FMS brain damage

I got the info.

What the crew told you was about right.

That model, as delivered from Cessna, is not RNAV-1 compliant.

It requires a couple of hardware mods/additions to become RNAV-1. So,
none of the RNAV stuff at RIL was avaiable to them.

Not the best configuration to dispatch to RIL in weather conditions.
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Storm Damage john smith Piloting 0 June 23rd 06 10:05 PM
brain scan study on errors about to be made Jose Piloting 0 October 26th 04 12:40 AM
X-15 damage Paul F Austin Military Aviation 7 May 23rd 04 09:11 PM
No Damage History? CFLav8r Owning 26 January 13th 04 06:53 PM
Help me clear up my brain fart Ekim Piloting 63 November 13th 03 08:23 PM


All times are GMT +1. The time now is 02:34 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AviationBanter.
The comments are property of their posters.