"Whilst on the subject of temperature corrections.

Consider minimum altitudes in 'cold' regions. (basically at altitudes)

Does anyone out there have a table for regions / climatology (coldest temp for a time of year) / correction chart?

Do companies prescribe minimum flight altitudes for certain areas at certain 'cold' times?

What are your policies on minimum altitudes?

safe wishes."



I used to fly for a company whose routes were mostly in the Arctic , all aircraft have temperature correction charts and they are used. I don't worry too much until the temp goes below freezing and then I apply the correction to the altiitudes.

I am also on the topic of temperature corrections.

How do you correct for it during a VNAV approach(B737NG)? According to Boeing you shouldn´t alter anything from FAF onwards because you are messing up the programmed approach logic, except as stated in FCTM 5.36 “... crews should make cold temperature altitude corrections by applying a correction from an approved table to the waypoint altitude constraints.”
:confused:
So what should we do?
Use the descent forcast page?
Change values from FAF onwards?

I am quite sure the isa dev on the descent forcast page allows only for a rather high temperature(can´t recall the value) and I anyway don´t know if that is only for descent planning anyway.

Anyone in the know? Meanwhile I am back to good old V/S.

Regards, the Walter

I reckon what alf5071h was trying to say is that a normally working glideslope has no lower lobe as someone else was suggesting. So catching a 6° slope as the next possibile slope should get everybodies attention fairly quickly. An erronoeus glideslope is, of course, a different beast.

Mathematically, I can accept that. But practical experience hasn't borne the same conclusion. One morning arriving at KDEN, dog-tired after a long night of flying, I settled into the routine of flying a visual approach, backed-up with the ILS, into our home airport. Captured the glideslope and decended on it, too tired to care about much of anything.

At about 10 DME things started to get my attention, as the farmfields I was idly gazing at were whizzing by rather close. A check of the radar altimeter showed less than 2000 feet. (1500? It's been awhile) My first officer had just noticed the same thing. We stopped the descent, recaptured the real G/S, and continued.

But this glideslope felt real. Solid as a rock, no flags, and produced the usual 750fpm rate of descent. It was just in the wrong place. Weird stuff happens.