VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #1  
Old 01-11-2018, 09:39 AM
bob888 bob888 is offline
 
Join Date: Jul 2012
Location: Fresno, CA
Posts: 198
Default Carbon monoxide

I am consistently getting low CO readings in flight, generally in range of 20 - 30 on the monitor (default alarm set at 50). This is not related to heater because unchanged whether heat is on or off. The question is whether this is typical for the -10, and acceptable. If not, any suggestions as to where exhaust may be getting into the cabin?
Reply With Quote
  #2  
Old 01-11-2018, 09:43 AM
vic syracuse vic syracuse is offline
Super Moderator
 
Join Date: May 2005
Location: Locust Grove, GA
Posts: 2,265
Default

I have a CO detector in the 10 and always see O ppm. This is the 2nd 10 I've had one in, and have installed them in a few others and have not seen any readings.

Vic
__________________
Vic Syracuse

Built RV-4, RV-6, 2-RV-10's, RV-7A, RV-8, Prescott Pusher, Kitfox Model II, Kitfox Speedster, Kitfox 7 Super Sport, Just Superstol, DAR, A&P/IA, EAA Tech Counselor/Flight Advisor, CFII-ASMEL/ASES
EAA Homebuilt Council Chair/member EAA BOD
Van's East Coast Representative
www.Baselegaviation.com
Reply With Quote
  #3  
Old 01-11-2018, 10:59 AM
BigD BigD is offline
 
Join Date: Jul 2012
Location: MS
Posts: 299
Default

Same as Vic - always 0. Kinda want to light up a cigar or something just to see what it would look like if there was CO...

==dave==
N102FM
Reply With Quote
  #4  
Old 01-11-2018, 11:18 AM
KeithB KeithB is offline
 
Join Date: Mar 2014
Location: Granbury, TX
Posts: 154
Default

I have an RV-14A with a dash-mounted Guardian CO detector. I am experiencing similar periodic low CO readings (10-20) on my EFIS - no alarms (set at 50).

No cause yet determined, so following this thread with interest.
__________________
Keith Brown

RV-14A Builder - kit #136
N314KC - First flight Mar 8, 2017, >270 hrs
RV-6A sold
Sport Pilot (weight-shift control) - Airborne XT912
Dues paid 11/2017
Reply With Quote
  #5  
Old 01-11-2018, 11:29 AM
rvbuilder2002 rvbuilder2002 is offline
 
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 7,557
Default

Quote:
Originally Posted by bob888 View Post
I am consistently getting low CO readings in flight, generally in range of 20 - 30 on the monitor (default alarm set at 50). This is not related to heater because unchanged whether heat is on or off. The question is whether this is typical for the -10, and acceptable. If not, any suggestions as to where exhaust may be getting into the cabin?
I suggest starting with a light penetration test of the firewall.

At night in a darkened hangar with the cowl removed, have a helper pan a bright light across the entire firewall and watch for any light penetration on the aft side.
__________________
Any opinions expressed in this message are my own and not necessarily those of my employer.

Scott McDaniels
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
Reply With Quote
  #6  
Old 01-11-2018, 01:27 PM
Lote Lote is offline
 
Join Date: Jan 2011
Location: Dublin, OH
Posts: 68
Default Beware: CO could be sign of exhaust crack

My CO detector started chirping intermittently on a long trip. Due to my ignorance I just carried on figuring I'd investigate when I got home, instead of pulling the cowling right away. After all, it was only chirping once in a while, never steady on, and only for a few seconds at a time. I could fly for an hour with no chirps at all. When I got home I found the number 2 exhaust pipe cracked almost all the way around at the bottom edge of the flange weld. My firewall is very tight but I suspect every firewall has little leaks that would allow CO to trickle into the cabin. So I would treat this as a valid indication and investigate.

I pulled the pipe (Vetterman system from Vans) and Vetterman's welded on a patch and had it back to me in short order where it has been fine for many hours ever since. I now inspect my exhaust system more carefully and very regularly. These cracks can start out as a hairline that can be hard to see. The area is in shadow and you need a good light.

Despite blazing hot exhaust gases coming out of the crack, the direction of it was such that no damage was done to any adjacent hoses, wires or cowling. I was very fortunate.

An exhaust crack can obviously lead to a fire and is not something to take any chances on.

LeRoy Johnston RV-6A Esperanza 1200 hours.
Reply With Quote
  #7  
Old 01-11-2018, 02:15 PM
leok leok is offline
 
Join Date: Apr 2013
Location: Clarkston, MI
Posts: 203
Default could be background

Does the level change from start up/Taxi to flight?

If not, it could be a bad baseline on the meter or a background level if you are in an urban area.

For Reference:

Recommended 8 hour exposure limit (REL) is 35 ppm. Permissible Exposure Limit is 50 ppm. These are from NIOSH and are for continuous exposure.

Short Term Exposure Limit (STEL) of 400 ppm. STEL is typically 20 min time weighted average (TWA).
__________________
Building my RV-10 since Oct 5th 2014
Flying .. once I figure out how to pay for everything
http://www.mykitlog.com/leok
RV Hotel
Dues paid 2018
Reply With Quote
  #8  
Old 01-11-2018, 04:45 PM
Ron B. Ron B. is offline
 
Join Date: Nov 2007
Location: Yarmouth, Nova Scotia
Posts: 2,202
Default

My 14 had intermittent alarm sound on my Co Gaurdian early on (20 hrs. or so ). No heat on and I would open the air vent or turn on the heat to supply more air in the cabin and the alarm would go out. I looked for the cause but before finding it, problem went away. If I recall it usually occurred on decent . I tried plugging off the water drain holes in the bottom of the fuselage (temporary tape) , I sealed the rear bulkhead thinking fumes might be back drafting, no change. I looked for firewall leakage, nothing found and no sealant added. Then it stopped. I thought it might be my monitor but somehow I drained my battery and did not know it, then tried to start the engine. My Co unit would not work after that. A new one was installed and it has not sounded off either, so it should not be the unit. I have no idea what it was, unless it was a defect with the first unit and that had something for it going bust and not trying to start the engine with a low battery. Prop never made a turn and I gave up and put a charger on it. CO unit never worked after, power spike?
__________________
Thanks Ron
RV-10 SOLD
RV-14 Flying
Reply With Quote
  #9  
Old 01-12-2018, 06:26 AM
Nukeflyboy Nukeflyboy is offline
 
Join Date: Aug 2007
Location: Granbury, TX
Posts: 90
Default Carbon monoxide

I have a CO detector and it, too, sometimes alarms. It seems to occur at low speeds, ie., nose up flight as in a climb or slow flight maneuvering, but only infrequently. Sitting in the queue waiting for takeoff at OSH has alarmed it due to the idling plane in front of me. I have tried several things to isolate the cabin, including the baggage compartment bulkhead, but have not found a fix.

Increasing speed usually makes it go away pretty quickly. I do not get anything above 0 in cruise.

The cabin has a very low pressure relative to the outside and is impossible to seal completely. I suspect inflow from the wing root fairing and into the cabin via the large hole where the aileron push-pull tube passes. I cannot prove that. Temporary extensions on the exhaust pipes had no effect.

I will try the light trick and look for a firewall path.
__________________
Dave Moore
Granbury, TX
RV-10 and Breezy
Reply With Quote
  #10  
Old 01-13-2018, 06:21 AM
tchevy56 tchevy56 is offline
 
Join Date: Dec 2016
Location: Tucson
Posts: 14
Default

Quote:
Originally Posted by KeithB View Post
I have an RV-14A with a dash-mounted Guardian CO detector. I am experiencing similar periodic low CO readings (10-20) on my EFIS - no alarms (set at 50).

No cause yet determined, so following this thread with interest.
Keith,
Tell Chris she's just gonna have to lay off the weed inflight...
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


All times are GMT -6. The time now is 02:41 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.