![]() |
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. |
|
|
Thread Tools | Display Modes |
#10
|
|||
|
|||
![]()
On Apr 18, 4:43*am, Stefan wrote:
WingFlaps schrieb: I see you don't know. In fact an altimeter is calibrated to the standard atmosphere so if the temp. is not standard it will not read field elevation when local QNH is applied. Wrong. *From The ICAO Manual of Radiotelephony (ICAO Document 9432) Glossary: QNH: Altimeter sub-scale setting to obtain elevation when on the ground So an altimeter set to local QNH will always read field elevation *by definition*. * Pretty basic knowlege for a PPL Indeed. Yes it may say that but it's being loose because it forgt to include the "barometric pressure reduced to MSL by application of the ISA". Alltimeters are calibrated for the standard atmosphere. -right? Think about it, if an ARFOR gives QNH how could it be correct for all terrain if local temperatures differed? I covered this in my PPL tech course -was this not covered in your manuals? just in case you still don't see it, from Wiki: "The altimeter is calibrated to show the pressure directly as an altitude above mean sea level, in accordance with a mathematical model defined by the International Standard Atmosphere (ISA)... An altimeter cannot, however, be adjusted for variations in air temperature. Differences in temperature from the ISA model will, therefore, cause errors in indicated altitude." OK? Cheers |
Thread Tools | |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Looking for TSO Altimeter | Rob Turk | Home Built | 0 | June 9th 07 03:52 PM |
Altimeter off | kevmor | Instrument Flight Rules | 11 | March 26th 07 12:11 PM |
Altimeter discrepancy | Gene Whitt | Instrument Flight Rules | 6 | August 1st 05 07:11 PM |
ATC Altimeter Settings | O. Sami Saydjari | Instrument Flight Rules | 81 | April 11th 05 08:07 PM |
Altimeter Disassembly | Dick | Home Built | 3 | April 2nd 05 01:27 PM |