Search the archive:
Simviation Main Site
|
Site Search
|
Upload Images
Simviation Forum
›
Real World
›
Real Aviation
› Temperature / pitot heat
(Moderators: Mitch., Fly2e, ozzy72, beaky, Clipper, JBaymore, Bob70, BigTruck)
‹
Previous Topic
|
Next Topic
›
Pages:
1
2
Temperature / pitot heat (Read 1097 times)
Reply #15 -
Sep 12
th
, 2009 at 5:29pm
DaveSims
Offline
Colonel
Clear Lake, Iowa
Gender:
Posts: 2453
Capt.Propwash wrote
on Sep 12
th
, 2009 at 3:39pm:
carb heat. = on BEFORE Idle, off BEFORE bat out of hell. -- gotcha.
pitot heat = (ugh i hate metric scale being i live in Farenheight land) -- (reported ground temp) - 3.5º F / +1000' MSL) = Temp aloft ???
90º summer day at KCHS .. will be flying at FL200 to KMIA VFR.... KCHS @ +46 ft MSL,
so..... may as well get use to turning it on anyways? even though ground temp is 90º.
just flip the switch when atc says "you are cleared for take off"
Temperature has no bearing on pitot heat. Most GA planes turn it on before entering visible moisture (clouds), regardless of temperature. Turbine aircraft turn it on before takeoff and leave it on until landed. Pretty simple.
Dave
www.flymcw.com
Back to top
IP Logged
Reply #16 -
Sep 12
th
, 2009 at 5:53pm
Hagar
Offline
Colonel
My Spitfire Girl
Costa Geriatrica
Posts: 33159
Fozzer wrote
on Sep 12
th
, 2009 at 4:41pm:
P.S. ..I must ignore the fact that my Firefox Dictionary keeps telling me that there are NOT
two
"T"'s in Carburettor...
...!
....
....!
I've told you many times before. Install the British English dictionary.
https://addons.mozilla.org/en-US/firefox/addon/3366
Founder & Sole Member - Grumpy's Over the Hill Club for Veteran Virtual Aviators
Member of the
Fox Four Group
Need help? Try
Grumpy's Lair
My photo gallery
Back to top
IP Logged
Reply #17 -
Sep 14
th
, 2009 at 5:43am
flaminghotsauce
Offline
Colonel
I love YaBB 1G - SP1!
Posts: 181
Good thread.
Just for clarification, carb heat doesn't take power from the engine. There is a cowl surrounding the exhaust which air is allowed to blow through, absorbing heat. This air is diverted into the carburetor. The hot air will change the fuel mixture, causing a slight loss of power. It's like a sudden density altitude change for the mixture. Less oxygen to burn, so the mix gets richer.
Back to top
IP Logged
Reply #18 -
Sep 14
th
, 2009 at 5:55am
Layne.
Offline
Colonel
Australia, Victoria, Melbourne
Gender:
Posts: 2654
In the A2A Piper Cub you get a bigger amount of power loss (not enough to stall) Is that usual in the Cubs??? or is it something i am doing wrong?
Windows 7 Ultimate x64 | 22" LED Monitor (1920x1080) | AMD Phenom II x4 970 Black Edition~3.5Ghz | 4gb RAM | ATI Radeon 6850 1gb | 1Tb HDD
[img]http://www.simviation.com/phpupload/uploads/1302666610.
Back to top
IP Logged
Reply #19 -
Sep 14
th
, 2009 at 6:00am
beaky
Offline
Global Moderator
Uhhhh.... yup!
Newark, NJ USA
Gender:
Posts: 14187
flaminghotsauce wrote
on Sep 14
th
, 2009 at 5:43am:
Good thread.
Just for clarification, carb heat doesn't take power from the engine. There is a cowl surrounding the exhaust which air is allowed to blow through, absorbing heat. This air is diverted into the carburetor. The hot air will change the fuel mixture, causing a slight loss of power. It's like a sudden density altitude change for the mixture. Less oxygen to burn, so the mix gets richer.
Yes, but effectively, it takes power away... maybe 1-200 rpm, but it's
very
noticeable when you're
already
losing rpm because of ice in the carb inlet... those few seconds (if you're lucky) when the carb heat is on and the ice hasn't melted can be a little disconcerting.
Back to top
IP Logged
Reply #20 -
Sep 14
th
, 2009 at 6:02am
beaky
Offline
Global Moderator
Uhhhh.... yup!
Newark, NJ USA
Gender:
Posts: 14187
Layne. wrote
on Sep 14
th
, 2009 at 5:55am:
In the A2A Piper Cub you get a bigger amount of power loss (not enough to stall) Is that usual in the Cubs??? or is it something i am doing wrong?
No, that's pretty normal for that little engine.
Back to top
IP Logged
Reply #21 -
Sep 14
th
, 2009 at 6:16am
Fozzer
Offline
Colonel
An elderly FS 2004 addict!
Hereford. England. EGBS.
Posts: 24861
Many unexplainable Aircraft crashes can be put down to Carburettor icing, but the ice has already melted in the Carburettor by the time the investigation is carried out, so there is no firm conclusion...
...!
As a ground check before take off, apply full engine revs with the brakes applied, and select Carb Heat. The engine revs should drop by approximately 150 RPM to ensure the system is working correctly.
The dangers of Carburettor Icing during flight, frightens me!...(even in the Sim!)...so I regularly apply it!....!
Paul...G-BPLF...FS 2004...
...!
...
...!
Dell Dimension 5000 BTX Tower. Win7 Home Edition, 32 Bit. Intel Pentium 4, dual 2.8 GHz. 2.5GB RAM, nVidia GF 9500GT 1GB. SATA 500GB + 80GB. Philips 17" LCD Monitor. Micronet ADSL Modem only. Saitek Cyborg Evo Force. FS 2004 + FSX. Briggs and Stratton Petrol Lawn Mower...Motor Bikes. Gas Cooker... and lots of musical instruments!.... ...!
Yamaha MO6,MM6,DX7,DX11,DX21,DX100,MK100,EMT10,PSR400,PSS780,Roland GW-8L v2,TR505,Casio MT-205,Korg CX3v2 dual manual,+ Leslie 760,M-Audio Prokeys88,KeyRig,Cubase,Keyfax4,Guitars,Orchestral,Baroque,Renaissance,Medieval Instruments.
Back to top
IP Logged
Reply #22 -
Sep 14
th
, 2009 at 9:30am
DaveSims
Offline
Colonel
Clear Lake, Iowa
Gender:
Posts: 2453
beaky wrote
on Sep 14
th
, 2009 at 6:00am:
flaminghotsauce wrote
on Sep 14
th
, 2009 at 5:43am:
Good thread.
Just for clarification, carb heat doesn't take power from the engine. There is a cowl surrounding the exhaust which air is allowed to blow through, absorbing heat. This air is diverted into the carburetor. The hot air will change the fuel mixture, causing a slight loss of power. It's like a sudden density altitude change for the mixture. Less oxygen to burn, so the mix gets richer.
Yes, but effectively, it takes power away... maybe 1-200 rpm, but it's
very
noticeable when you're
already
losing rpm because of ice in the carb inlet... those few seconds (if you're lucky) when the carb heat is on and the ice hasn't melted can be a little disconcerting.
Think that is bad, try using the mixture knob instead of the carb heat knob. Lesson there, always verify the handle, especially in an unfamilar aircraft.
Dave
www.flymcw.com
Back to top
IP Logged
Reply #23 -
Sep 16
th
, 2009 at 6:40pm
flaminghotsauce
Offline
Colonel
I love YaBB 1G - SP1!
Posts: 181
DaveSims wrote
on Sep 14
th
, 2009 at 9:30am:
beaky wrote
on Sep 14
th
, 2009 at 6:00am:
flaminghotsauce wrote
on Sep 14
th
, 2009 at 5:43am:
Good thread.
Just for clarification, carb heat doesn't take power from the engine. There is a cowl surrounding the exhaust which air is allowed to blow through, absorbing heat. This air is diverted into the carburetor. The hot air will change the fuel mixture, causing a slight loss of power. It's like a sudden density altitude change for the mixture. Less oxygen to burn, so the mix gets richer.
Yes, but effectively, it takes power away... maybe 1-200 rpm, but it's
very
noticeable when you're
already
losing rpm because of ice in the carb inlet... those few seconds (if you're lucky) when the carb heat is on and the ice hasn't melted can be a little disconcerting.
Think that is bad, try using the mixture knob instead of the carb heat knob. Lesson there, always verify the handle, especially in an unfamilar aircraft.
Just to clarify my clarification: I probably wasn't clear when I said it doesn't take power from the engine. When I say "take power from the engine" that's more like turning on an air conditioner that actually takes power... from the engine. Carb heat doesn't "take" power, but it prevents the power from being produced by changing the mixture.
Semantics I know.
I've pulled the mixture instead of the carb heat. Once. Never did that again!
Back to top
IP Logged
Reply #24 -
Sep 16
th
, 2009 at 8:00pm
DaveSims
Offline
Colonel
Clear Lake, Iowa
Gender:
Posts: 2453
flaminghotsauce wrote
on Sep 16
th
, 2009 at 6:40pm:
DaveSims wrote
on Sep 14
th
, 2009 at 9:30am:
beaky wrote
on Sep 14
th
, 2009 at 6:00am:
flaminghotsauce wrote
on Sep 14
th
, 2009 at 5:43am:
Good thread.
Just for clarification, carb heat doesn't take power from the engine. There is a cowl surrounding the exhaust which air is allowed to blow through, absorbing heat. This air is diverted into the carburetor. The hot air will change the fuel mixture, causing a slight loss of power. It's like a sudden density altitude change for the mixture. Less oxygen to burn, so the mix gets richer.
Yes, but effectively, it takes power away... maybe 1-200 rpm, but it's
very
noticeable when you're
already
losing rpm because of ice in the carb inlet... those few seconds (if you're lucky) when the carb heat is on and the ice hasn't melted can be a little disconcerting.
Think that is bad, try using the mixture knob instead of the carb heat knob. Lesson there, always verify the handle, especially in an unfamilar aircraft.
Just to clarify my clarification: I probably wasn't clear when I said it doesn't take power from the engine. When I say "take power from the engine" that's more like turning on an air conditioner that actually takes power... from the engine. Carb heat doesn't "take" power, but it prevents the power from being produced by changing the mixture.
Semantics I know.
I've pulled the mixture instead of the carb heat. Once. Never did that again!
At least you only did it once, it took me twice to figure out what was going on. The first time I was puzzled why I had a 1000 rpm drop (2400-1400) pushed it in and tried it again. Fortunately both times it restarted, and at the position I was in, could have easily made the landing at the airport.
Dave
www.flymcw.com
Back to top
IP Logged
Reply #25 -
Sep 16
th
, 2009 at 10:36pm
Splinter562
Offline
Colonel
Tampa, FL
Gender:
Posts: 217
Fozzer wrote
on Sep 14
th
, 2009 at 6:16am:
The dangers of Carburettor Icing during flight, frightens me!...(even in the Sim!)...so I regularly apply it!....!
I've had carb ice form in cruise over mountainous terrain when flying through foggy conditions a little bit above freezing. I noticed the engine sound had changed from it's cruise setting, like the throttle had slipped back. I pushed to full throttle and got little RPM change. This immediately set of the carb ice flag in my head. I pulled the carb heat and within 15 seconds the RPMs were coming back up again. If it is caught early, it is not really a big deal. The warning signs are subtle but unmistakable.
The danger is having the ice form in a high-workload situation when the signs are harder to notice. This is why carb ice in the pattern is of particular concern. With the pilot's attention divided and constant power changes, it is easy to miss the warning signs. This is why it is
always
a good idea to pull carb heat with power reduction. Even if ice doesn't form 999 out of 1,000 times, the one time it does form you could easily not notice until the engine stops when turning base.
Back to top
IP Logged
Reply #26 -
Sep 19
th
, 2009 at 6:58am
Mtns2Skies
Offline
Colonel
Fly FS
Gender:
Posts: 27
Capt.Propwash wrote
on Sep 12
th
, 2009 at 3:39pm:
90º summer day at KCHS .. will be flying at FL200 to KMIA VFR.... KCHS @ +46 ft MSL,
so..... may as well get use to turning it on anyways? even though ground temp is 90º.
just flip the switch when atc says "you are cleared for take off"
Well item #1, it is illegal to fly VFR at or above FL180, And as for Item #2 I'd say no because you do not produce as much power as normal, as stated before but on takeoff your exhaust temperature is MUCH higher causing the air going into the engine to be MUCH higher. You will lose roughly 400RPM's if you apply carb heat on takeoff and climb out in a Cessna. Rather than the standard 75-150 on run-up/ descent.
Back to top
IP Logged
Reply #27 -
Sep 20
th
, 2009 at 10:17am
Brett_Henderson
Offline
Colonel
EVERY OUTER MARKER SHOULD
BE AN NDB
Gender:
Posts: 3593
Mtns2Skies wrote
on Sep 19
th
, 2009 at 6:58am:
Capt.Propwash wrote
on Sep 12
th
, 2009 at 3:39pm:
90º summer day at KCHS .. will be flying at FL200 to KMIA VFR.... KCHS @ +46 ft MSL,
so..... may as well get use to turning it on anyways? even though ground temp is 90º.
just flip the switch when atc says "you are cleared for take off"
Well item #1, it is illegal to fly VFR at or above FL180, And as for Item #2 I'd say no because you do not produce as much power as normal, as stated before but on takeoff your exhaust temperature is MUCH higher causing the air going into the engine to be MUCH higher. You will lose roughly 400RPM's if you apply carb heat on takeoff and climb out in a Cessna. Rather than the standard 75-150 on run-up/ descent.
I'm sure he's talking about turning pitot heat on after takeoff
And I'm sure he meant VFR conditions, as in not IMC, as it would apply to pitot heat.
Back to top
IP Logged
Pages:
1
2
‹
Previous Topic
|
Next Topic
›
« Home
‹ Board
Top of this page
Forum Jump »
Home
» 10 most recent Posts
» 10 most recent Topics
Current Flight Simulator Series
- Flight Simulator X
- FS 2004 - A Century of Flight
- Adding Aircraft Traffic (AI) & Gates
- Flight School
- Flightgear
- MS Flight
Graphic Gallery
- Simviation Screenshots Showcase
- Screenshot Contest
- Edited Screenshots
- Photos & Cameras
- Payware Screenshot Showcase
- Studio V Screenshot Workshop
- Video
- The Cage
Design Forums
- Aircraft & 3D Design
- Scenery & Panel Design
- Aircraft Repainting
- Designer Feedback
General
- General Discussion
- Humour
- Music, Arts & Entertainment
- Sport
Computer Hardware & Software Forum
- Hardware
- Tweaking & Overclocking
- Computer Games & Software
- HomeBuild Cockpits
Addons Most Wanted
- Aircraft Wanted
- Other Add-ons Wanted
Real World
- Real Aviation ««
- Specific Aircraft Types
- Autos
- History
On-line Interactive Flying
- Virtual Airlines Events & Messages
- Multiplayer
Simviation Site
- Simviation News & Info
- Suggestions for these forums
- Site Questions & Feedback
- Site Problems & Broken Links
Combat Flight Simulators
- Combat Flight Simulator 3
- Combat Flight Simulator 2
- Combat Flight Simulator
- CFS Development
- IL-2 Sturmovik
Other Websites
- Your Site
- Other Sites
Payware
- Payware
Old Flight Simulator Series
- FS 2002
- FS 2000
- Flight Simulator 98
Simviation Forum
» Powered by
YaBB 2.5 AE
!
YaBB Forum Software
© 2000-2010. All Rights Reserved.