# Commercial aviation questions **URL:** \ **Category:** Factual Questions\ **Created:** [April 1, 2014, 12:41pm UTC](https://boards.straightdope.com/t/commercial-aviation-questions/685070 "2014-04-01T12:41:54Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![ElvisL1ves](https://avatars.discourse-cdn.com/v4/letter/e/5daacb/32.png) [@ElvisL1ves](https://boards.straightdope.com/u/ElvisL1ves)\ **Post date:** [April 1, 2014, 4:05pm UTC](https://boards.straightdope.com/t/commercial-aviation-questions/685070/21 "2014-04-01T16:05:50Z")
> [@Richard\_Pearse](#): > > The assumption is that you’ve been around long enough to know where to go but new captains may need to ask for directions. The FAA eliminated implicit taxi clearances a few years ago. You now get the full thing every time, including runway crossing clearances and turn directions, and you have to read it back with your call sign, too. That’s part of an overall program to reduce the rate of runway incursion incidents, which they had identified as the top cause of accidents that they could do something about. Clearer and more numerous markings are part of that effort, too. ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [April 1, 2014, 4:11pm UTC](https://boards.straightdope.com/t/commercial-aviation-questions/685070/22 "2014-04-01T16:11:39Z")
We have to be cleared to cross a runway but don’t always get the full instruction for the rest. It’s possible the late night controllers are just being slack though. They relax a bit after midnight. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [April 1, 2014, 4:53pm UTC](https://boards.straightdope.com/t/commercial-aviation-questions/685070/23 "2014-04-01T16:53:20Z")
> [@Richard\_Pearse](#): > > No downwash means no Bernoulli, no Bernoulli means no downwash, they are intrinsically linked. Quite right. The trouble with the Bernoulli explanation isn’t that it’s wrong, but that it typically fails to include this essential point. So to the neophyte it comes across as “air passing over the wing magically produces low pressure and thus lift”. When the essential linkage between downwash and lowered pressure is included, it makes perfect sense, and there’s no longer any disconnect between this and the “Newtonian” (action-reaction) explanation. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [April 1, 2014, 5:32pm UTC](https://boards.straightdope.com/t/commercial-aviation-questions/685070/24 "2014-04-01T17:32:55Z")
> [@Pixel\_Dent](#): > > Here’s one for [Raleigh (RDU)](http://flightaware.com/resources/airport/RDU/APD/AIRPORT+DIAGRAM/pdf). All the little letters on the taxiways on the map are on signs at the airport. It’s easier than finding your way around a typical suburb with a street map. Related question based on this map: where are “airfield elevations” actually taken from? Is there a standard point or is it essentially random? On that map it says “Field elev 435” but the western end of the north runway appears to be only 367’. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [April 1, 2014, 5:38pm UTC](https://boards.straightdope.com/t/commercial-aviation-questions/685070/25 "2014-04-01T17:38:28Z")
I’m sitting here imagining a big passenger jet in which the pilot is being guided around the airport by a GPS device. (“In 100 yards, turn right. Turn right now. Recalculating. At the next available opportunity, make a u-turn.”) ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [April 1, 2014, 5:52pm UTC](https://boards.straightdope.com/t/commercial-aviation-questions/685070/26 "2014-04-01T17:52:17Z")
> [@Machine\_Elf](#): > > -How does a commercial pilot find his way around an airport to the correct gate? Suppose I’m a pilot who has never landed at Denver International Airport before … This would be quite unusual – generally pilots have flown as a co-pilot into the airport a few times before they are allowed to be the senior pilot on a flight there. So besides the charts, they would have actually traveled around the field a few times before. At least, that’s the way it used to be – the pilot friend who told me this was a co-pilot many years ago – some airlines might do it differently now. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [April 1, 2014, 5:53pm UTC](https://boards.straightdope.com/t/commercial-aviation-questions/685070/27 "2014-04-01T17:53:01Z")
> [@Colophon](#): > > where are “airfield elevations” actually taken from? Is there a standard point or is it essentially random? This is usually given as the highest point on any usable runway. [Previous page](https://boards.straightdope.com/t/commercial-aviation-questions/685070.md?page=1)