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View Full Version : Here's something different - HOT weather corrections?


Captain Over
15th Nov 2003, 04:52
Cold weather altimeter corrections are important, but where can you look up about HOT weather corrections?
Check out the Altimeter when it is, eg, +44 C. The readout of 2,000' doesn't jive with the Radar Altimeter *ON APPROACHES THAT TAKE YOU OVER THE OCEAN - AKA "SEA LEVEL" for those that sometimes land near the ocean....* (see someone's reply below). Of course these hot weather errors are not on the bad side of the glide, but still if there are any correction value "rule of thimb" available out there, for those what want to know, it would help some of us sleep better.

Jepp's "tables" section only covers cold weather flying. Are there any good websites that go over this? (I have yet to locate one on hot weather corrections that goes into detail.)

Thanks in advance.
C.O.

*edit to clarify example for those who haven't landed over water before

411A
15th Nov 2003, 11:34
Hardly surprising that the 2000' baro reading would not agree with the 2000' RA.

Few approach paths are that flat.:E

CaptainProp
17th Nov 2003, 15:29
The altitudes shown on app. plates shows MINIMUM altitudes and hard altitudes....These can NEVER be lowered!

bookworm
17th Nov 2003, 18:08
The temperature correction for indicated altitude is the same magnitude in each direction -- about 0.35% per degC deviation from standard. So for a ISA+33degC (44 degC @ 2000 ft) it's 10%. The altimeter will underread by 200 ft.

Northern Highflyer
17th Nov 2003, 18:28
Just covered this in my ATPL studies.

Temperature error correction is 4ft per 1000ft for every degree deviation from ISA.

SO for ISA +33 at 2000ft

= 4*2*33 = 264ft

as it is warmer it is under-reading so actual will be 2264ft when the altimeter reads 2000ft.