C525 Questions

[gjhome]

Hi,
I have a couple of questions about the CJ1 that I hope someone of you can anwser.
1. When you shutdown the engines at parking, is there some way to silence the voicewarnings that results from the low oilpressure etc? Because of the small cabin every passeger hear this and we would like to avoid that.
2. When we program the flightplan in the UNS-1K fms, the route shows on the map with magenta lines connecting each waypoint. Why dosen´t these lines show up when you put in a SID or STAR? There are no lines between the waypoints, and this makes it difficult to visualize the procedure.
3. We also have some problems with the headsets. I tried my lightspeed anr headsets and the headphones were working, but the mike did not, when I transmitted there was a high screaming tone sounding, why? Second, is there not any kind of squelch in the pilot intercom system? We like to always wear hedsets to keep the passengers from be disturbed from the atc chatter. The problem is that the other pilots mike always makes this quite high static noise on the intercom. On every other plan I been flying there have been a squelch setting but I can not find it in this aircraft.
I hope you can help me with this!
Thanks

[om15]

Switch the avionics OFF prior to shut down, the audable warnings only work with avionics on.
Squelch control is on the audio selector panel.
Best regards,
om15

[checklist69]

UNS-1K FMS SID/STAR

The lines do not show up on a SID/STAR if the track between the two waypoints is indeterminate; i.e. dependant upon turn radius vs groundspeed. However, with FMS/NAV engaged, the aircraft will navigate correctly between the waypoints.

Any "Straight-line" segment between two waypoints will be represented by a line.

Happy tracking....

'69

[gjhome]

Thank you for the anwsers!
om15: I am looking at the audiopanel right now, wich knob is the
squelch? We have on one knob, Speaker volume and headset volume, and on the other, passenger speaker volume and Sidetone. Is it the sidetone you mean? We tried it, and could'nt get any effect, but maybe we just have to experiment some more.
Thanks again!

[checklist69]

gjhome:

My guess is that you may have disabled the automatic squelch by pulling out the on/off/volume control (OFF PULL/TEST) knob. This will certainly cause a background static problem.

'69

[gjhome]

checklist6: No, I am shure thats not the problem. I belive it is the left hand headset that is the problem. The mike does'nt cutoff. This would be cured if there was a squelch for the intercom system. I know there is an autosquelch in the radios, but it's the intercom I would like to change.

om15: We were thinkig about the avionics power yesterday, but now when we looked, it have always been before the "throttles off" on the checklist, so this did'n cure the problem. It seems like the only solution is to cancel every warning before the voice warning sounds.

Thanks

[gjhome]

Ok, that answers the question. I find this solution a little bit strange, but I will have to get used to it.

Thanks!

[om15]

gjhome,
My apolgies for duff gen, I don't have a 525 to play with at the moment, however I have discussed this with my avionic collegues, we believe that if the avionics are OFF you do not recieve voice warnings through the speaker, however you do recieve through the headset.
If the aircraft is N reg you do not require to have voice warnings, however G reg aircraft do. If your aircraft is N reg you can ask Engineering to disable the voice warning by selecting the switch on the back of the annunciator panel.
We think that checklist 69 has the correct answer re the squelch, next time we have a 525 in the hangar we will look at this and report further.
Best regards,
om15

[LearjetGA]

Hi there,

We operate a couple of CJ2 and 2+. We have on some airplanes an Audio Speaker/Headphones and a Headphones only knob. The knob is pretty hard to find: on one of the planes it is located at the end of the EGPWS switches and on another one we have it on top of the GNSs. Go figure out!!!

For the headset: I use a Sennheiser ANR and its working fine. A colleague tried a telex and the first officer was not able to hear or transmit.... i get a continuous tone when we try the oxygen mask mikes. if we have a continuous tone, i usually reset the first officers mike jack and it is working again! (Any logic behind that?)

On the CJ2+, they finally assessed the problem and the audio panel is quite good.

Hope this helps...


LearjetGA

[CJ Driver]

The CJ, CJ1 and CJ2 audio systems are quite fussy about the headsets you use, and the only "approved" headset is the Telex Airman 750 which was the original equipment. We've tried others, but they often suffer from various forms of interference (RF or audio) or other mismatches.

We have however had success with the ANR Telex Airman 850, but you need to install them in pairs for the best result. If you have a 750 and an 850, it's very difficult to get the knobs set so that you can hear each other and the radio at the same sensible level.