Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Flickering Lights On Ground Power  
User currently offlineAnalog From United States of America, joined Jul 2006, 1900 posts, RR: 1
Posted (6 years 9 months 1 week 2 days ago) and read 3314 times:

Last week I was on a CO 735 that had the most awful, seizure-inducing flickering cabin light. One of the bulbs was going bad (I assume). The flicker stopped when we pulled away from the gate. Why is this?

I assume that the flicker stopped when the aircraft stopped using ground power. Is this because ground power is at 60Hz and power generated on board is 400Hz? Or is it related to voltage (ground power or APU vs. generators on the engines)?

This wasn't the first CO 73x that had this problem. The previous one (733) flickered at the front of the F cabin where the FAs work. I can't believe that the FAs can live with this. If I were an FA I'd make damn sure to bitch and moan until these things were fixed. Sorry, I would bring this to the attention of the appropriate persons in an effort to resolve this maintenance issue.

6 replies: All unread, jump to last
 
User currently offlineTdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 1, posted (6 years 9 months 1 week 2 days ago) and read 3304 times:



Quoting Analog (Thread starter):
Last week I was on a CO 735 that had the most awful, seizure-inducing flickering cabin light. One of the bulbs was going bad (I assume). The flicker stopped when we pulled away from the gate. Why is this?

It sounds like a bad ballast in lamp (I'm assuming it was a fluorescent). Could be that ground power was just flaky enough to throw it off but aircraft power was OK.

Quoting Analog (Thread starter):
Is this because ground power is at 60Hz and power generated on board is 400Hz?

Ground power is 400 Hz too (plus or minus some tolerance).

Tom.


User currently offlineBartonsayswhat From Canada, joined Oct 2007, 436 posts, RR: 0
Reply 2, posted (6 years 9 months 1 week 1 day 23 hours ago) and read 3288 times:

yeah ground power constantly fluctuates, be it from bridge power or a diesel GPU. APU power is much more consistant, which is why most of the fmc updating is done on the APU, as a power surge can wipe out the whole thing, or so i've been informed. also does anyone know, just as a plane arrives or leaves the gate, when it is switched from GEN/APU to GPU the lights flick once?

User currently offlineHAWK21M From India, joined Jan 2001, 31712 posts, RR: 56
Reply 3, posted (6 years 9 months 1 week 1 day 20 hours ago) and read 3252 times:

Depoending on the condition of the GPU connected at that time.Its difficult to tell from here,but I presume the GPU could have had a voltage fluctuation issue.
regds
MEL



Think of the brighter side!
User currently offlineAirbus_A340 From Hong Kong, joined Mar 2000, 1560 posts, RR: 19
Reply 4, posted (6 years 9 months 1 week 1 day 18 hours ago) and read 3234 times:

Quoting Bartonsayswhat (Reply 2):
does anyone know, just as a plane arrives or leaves the gate, when it is switched from GEN/APU to GPU the lights flick once?

On the Airbus the Ground Power Control Unit (GPCU) produces what's called a 'reference frequency' used by the Ground Control Unit to provide sycronisation for No-Break-Power-Transfer (NBPT).

In English, that means u don't get the lights flickering or horrible 'clunk' sounds when you change from GPU to APU or APU to engine Gens, or vice versa that you would find on other older aircraft.

Usually APU is turned on about 20 minutes before departure, and turned off after pax have disembarked, unless it's a quick turnaround.

[Edited 2008-03-26 03:30:11]


People. They make an airline. www.cathaypacific.com
User currently offlineDALMD88 From United States of America, joined Jul 2000, 2615 posts, RR: 14
Reply 5, posted (6 years 9 months 1 week 1 day 14 hours ago) and read 3179 times:

Even relatively new ground power units can cause all sorts of strange happenings. Here in BOS our new terminal has new units at every gate. We frequently get calls in the morning about systems not testing correctly. The standard answer is switch to apu power and run the test again. If it is still a problem call back and will send someone out. I think the 737NG tends to have the most issues with flakey ground power.

User currently offlineAnalog From United States of America, joined Jul 2006, 1900 posts, RR: 1
Reply 6, posted (6 years 9 months 1 week 1 day 13 hours ago) and read 3167 times:



Quoting HAWK21M (Reply 3):
Depoending on the condition of the GPU connected at that time.Its difficult to tell from here,but I presume the GPU could have had a voltage fluctuation issue.

It was only 1 bulb out of many, though I guess "bad" power may well bring a marginal bulb/ballast over the edge.


Top Of Page
Forum Index

Reply To This Topic Flickering Lights On Ground Power
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Hardest To Land: In Water Or On Ground? posted Wed Mar 12 2008 10:54:19 by B747forever
Redundant Anti Collision Lights On DC-10s? posted Sat Nov 24 2007 15:19:00 by NASCARAirforce
Landing Lights On At Cruise Altitude posted Sun Sep 16 2007 09:14:10 by Thai744
Lights On Planes...? posted Mon Aug 27 2007 22:17:03 by Pizzaandplanes
B752 Main L/G Door Closure On Ground Video. posted Wed Jul 4 2007 21:57:29 by HAWK21M
Baggage Handling On Ground: How Does It Work? posted Tue Jun 26 2007 22:39:32 by Evan767
DC-8 Landing Gear Doors Open On Ground. Why? posted Tue Apr 17 2007 01:50:02 by Jeffry747
On Ground De-/ Anti-icing: Wing Heating System? posted Sun Feb 18 2007 15:14:44 by Starglider
Some Sort Of Smoke In Cabin While Acr On Ground posted Fri Jul 28 2006 21:25:19 by A380CGN
DC4 DC6 DC7 - Balance On Ground posted Sun Jul 9 2006 13:55:28 by NZ8800

Sponsor Message:
Printer friendly format