Quote:
Originally Posted by N121PP
A few weather questions:
Can the temperature ever be too hot for takeoff? I recall hearing a story out of Phoenix a few years back where the temperature got to 122 and they canceled flights until it got down below 122.
Yes, definitely. That's why we now depart Cairo at midnight instead of 10 a.m. We had instances in the past (daytime departures) where, due to rapidly rising temperature, we had to return to the gate to offload some weight (cargo and/or people and bags). Then we'd go out again and the temperature would have gone up another 5 degrees necessitating another return to gate to offload
more weight.
Believe it or not, takeoff performance data can vary from airline to airline even if they're flying the same type of plane. It's not like we're all using engineering performance data supplied by the manufacturer.
I remember when I flew the CRJ at ACA, we were more limited out of Colorado Springs than Air Wisconsin flying the same plane. That's because they contracted with a different service for their performance data (a more expensive service) and their data allowed for higher takeoff weights. I know this sounds insane (and I tend to agree), but that's the way it was. It's also possible that the performance data being supplied has an upper temperature limit, i.e. they just don't provide takeoff data for temps exceeding, for example, 45° C (113 ° F). So now if you're somewhere that's reporting a higher temperature (Vegas, Dhubai), you can't go.
Or you may have data for the high temperature, but it shows that you won't have the required single-engine performance (in case of an engine failure on takeoff) at any weight. Again, you can't go in this case.
Quote:
Could it ever be cold enough on the ground to see contrails while a plane was taxiing?
I don't think so. The temperatures at which contrails appear are down in the neighborhood of -40°C (which, coincidentally, is -40°F) or colder. But besides temperature, the ambient air pressure plays a role in contrail formation. While you may be able to find -40°C somewhere on the planet, you'll never find a surface pressure as low as what we have at cruise altitude.
Quote:
Have you ever done a Zero/Zero Landing? If so, did you use the heads up display?
The closest I've ever been to zero/zero was a landing in the MD-88 at Pensacola, Florida. We saw the runway at about 50' and the viz was about 600'. No HUD on that airplane (and I've never flown a plane equipped with a HUD).