# Passenger Planes & Height.

**URL:** <https://boards.straightdope.com/t/passenger-planes-height/175938>\
**Category:** Factual Questions\
**Created:** [May 17, 2003, 7:58pm UTC](https://boards.straightdope.com/t/passenger-planes-height/175938 "2003-05-17T19:58:12Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![Pavlos](https://avatars.discourse-cdn.com/v4/letter/p/ac8455/32.png) [@Pavlos](https://boards.straightdope.com/u/Pavlos)\
**Post date:** [May 17, 2003, 7:58pm UTC](https://boards.straightdope.com/t/passenger-planes-height/175938/1 "2003-05-17T19:58:12Z")

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I flew back from Spain the other day and the Pilot told us we were flying at an altitude of 37,000 ft.  
I can remember on all my other flights the Captains telling me the same thing.

so why do they fly so high ?

couldn’t they just fly at say 4,000 ft ?

and also wouldn’t the lower height make them faster ?

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**Author:** ![Pavlos](https://avatars.discourse-cdn.com/v4/letter/p/ac8455/32.png) [@Pavlos](https://boards.straightdope.com/u/Pavlos)\
**Post date:** [May 17, 2003, 7:59pm UTC](https://boards.straightdope.com/t/passenger-planes-height/175938/2 "2003-05-17T19:59:17Z")

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sorry meant less journey time NOT faster.

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**Author:** ![DarrenS](https://avatars.discourse-cdn.com/v4/letter/d/977dab/32.png) [@DarrenS](https://boards.straightdope.com/u/DarrenS)\
**Post date:** [May 17, 2003, 7:59pm UTC](https://boards.straightdope.com/t/passenger-planes-height/175938/3 "2003-05-17T19:59:22Z")

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WAG - the air friction is lower at those altitudes, due to the atmosphere being thinner, meaning they save on fuel costs.

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**Author:** ![pilot141](https://avatars.discourse-cdn.com/v4/letter/p/e0b2c6/32.png) [@pilot141](https://boards.straightdope.com/u/pilot141)\
**Post date:** [May 17, 2003, 8:11pm UTC](https://boards.straightdope.com/t/passenger-planes-height/175938/4 "2003-05-17T20:11:53Z")

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Jet engines get more efficient at higher altitudes. Flying at FL 370 burns MUCH less gas than flying at 4,000 ft. Also, you do fly “faster” - the higher you go, the higher your true airspeed for the same indicated airspeed. High altitude also allows you to avoid most of the weather: clouds=turbulence, so avoiding weather makes for a smoother flight.

Any flight across the ocean uses sophisticated internal navigation systems that don’t need ground-based navaids, but for airplanes that need to tune up these stations, higher altitude means a greater signal range.

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**Author:** ![Pavlos](https://avatars.discourse-cdn.com/v4/letter/p/ac8455/32.png) [@Pavlos](https://boards.straightdope.com/u/Pavlos)\
**Post date:** [May 17, 2003, 8:12pm UTC](https://boards.straightdope.com/t/passenger-planes-height/175938/5 "2003-05-17T20:12:50Z")

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thanks 🙂

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**Author:** ![Lodrain](https://avatars.discourse-cdn.com/v4/letter/l/c4cdca/32.png) [@Lodrain](https://boards.straightdope.com/u/Lodrain)\
**Post date:** [May 18, 2003, 5:19pm UTC](https://boards.straightdope.com/t/passenger-planes-height/175938/6 "2003-05-18T17:19:41Z")

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Plus, if your plane loses engine power, you have a lot more glide distance. There was a thread about this a few weeks ago. Search under ‘jumbo jet gliding’ or something similar and you’ll find it.

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**Author:** ![postcards](https://avatars.discourse-cdn.com/v4/letter/p/8e8cbc/32.png) [@postcards](https://boards.straightdope.com/u/postcards)\
**Post date:** [May 18, 2003, 6:35pm UTC](https://boards.straightdope.com/t/passenger-planes-height/175938/7 "2003-05-18T18:35:35Z")

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[Here.](http://boards.straightdope.com/sdmb/search.php?s=&action=showresults&searchid=624980&sortby=lastpost&sortorder=descending)

And one of my favorites: [The Gimli Glider.](http://www.wadenelson.com/gimli.html)