ctempleton3 From United States of America, joined Mar 2008, 14 posts, RR: 0 Posted (2 years 1 month 4 weeks 1 day ago) and read 3613 times:
I my last flight I noticed that my ear's start to pop on taxi before takeoff. What would cause this? Is the pressure in the cabin decressed or increased before takeoff in any way?
Fly2HMO From , joined Dec 1969, posts, RR: Reply 1, posted (2 years 1 month 4 weeks 23 hours ago) and read 3608 times:
Quoting ctempleton3 (Thread starter): What would cause this? Is the pressure in the cabin decressed or increased before takeoff in any way?
On some planes the cabin is pressurized slightly to put some pressure against door seals. Also if the pilot is moving the throttles briskly often the cabin outflow valves may take a bit to adjust or "catch up" to the changes in bleed air being fed into the cabin.
wncrew From United States of America, joined Jun 2006, 1317 posts, RR: 9 Reply 2, posted (2 years 1 month 4 weeks 22 hours ago) and read 3554 times:
As a side-note when working AFT Cabin, I can tell when the FWD door has been closed because I can feel the slight pressure change in my ears. I too notice this on taxi-out occasionally.
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
113312 From United States of America, joined Apr 2005, 536 posts, RR: 1 Reply 3, posted (2 years 1 month 4 weeks 15 hours ago) and read 3437 times:
Most Boeing aircraft are designed to have about .125 psid prior to takeoff and landing to minimize pressure bump. However, any more differential than that would make it nearly impossible to open emergency exits and that is why such a small amount of pressurization is permitted on the ground.
KingairTA From United States of America, joined Feb 2009, 445 posts, RR: 0 Reply 5, posted (2 years 1 month 4 weeks 4 hours ago) and read 3299 times:
Could also be a test of the pressurization system prior to take off. Prior to every flight we test the system to ensure the cabin will pressurize. Each bleed air source is tested. This could also be the pressure you feel.
HAWK21M From India, joined Jan 2001, 31201 posts, RR: 58 Reply 6, posted (2 years 1 month 4 weeks 1 hour ago) and read 3238 times:
Quoting KingairTA (Reply 5):
Could also be a test of the pressurization system prior to take off. Prior to every flight we test the system to ensure the cabin will pressurize. Each bleed air source is tested. This could also be the pressure you feel.
What type are you referring to......On most larger commercial Aircraft the tests are carried out automatically with power up & vide Air Ground sense or vide the CPCs.
regds
MEL.
XFSUgimpLB41X From United States of America, joined Aug 2000, 3952 posts, RR: 36 Reply 8, posted (2 years 1 month 3 weeks 5 days 14 hours ago) and read 2934 times:
While that is a procedure on the king air, it is not a procedure on any boeing, airbus, or douglas plane (or the canadair regional jet). Pressurization is fully automatic, and the cabin is slightly pressurized on takeoff partly for door seals, party for the pressure bump, and also the structural integrity of the plane in the event of an excursion.
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