Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Droppings After Take-off  
User currently offlineAlexEU From Serbia, joined Oct 2007, 1817 posts, RR: 2
Posted (6 years 8 months 2 weeks 5 days 18 hours ago) and read 3089 times:

I've seen several a.netters mentioning droppings after take-off. I feel it aswell, but only on 737s or A320s. I never felt it in A340 or an turboprop/piston aircraft. My question is: what are the kind droppings after-take-off?

Cheers

11 replies: All unread, jump to last
 
User currently offlineN710PS From United States of America, joined Oct 2006, 1166 posts, RR: 4
Reply 1, posted (6 years 8 months 2 weeks 5 days 18 hours ago) and read 3088 times:

Droppings? You mean as in birds tend to like the narrow body medium range jetliners more so than others?  Wink


There is plenty of room for Gods animals, right next to the mashed potatoes!
User currently offlinePilotboi From United States of America, joined Sep 2007, 2366 posts, RR: 9
Reply 2, posted (6 years 8 months 2 weeks 5 days 18 hours ago) and read 3084 times:

Are you talking about the feeling of going down? Could this be when flaps are retracted? Flaps increase lift on takeoff and when they are retracted, lift is slightly decreased, reducing in a lower VSI then before retraction, which can create a negative G feeling. This is very obviously if you've ever flown the Piper Arrow (or any Piper) and do a go-around or touch-and-go. When the flaps are brought up, you can definatly feel a drop. Scary sometimes, especially if you have trees right below you. You start screaming "climb, baby, climb".

User currently offlineAlexEU From Serbia, joined Oct 2007, 1817 posts, RR: 2
Reply 3, posted (6 years 8 months 2 weeks 5 days 17 hours ago) and read 3076 times:



Quoting Pilotboi (Reply 2):
Could this be when flaps are retracted? Flaps increase lift on takeoff and when they are retracted, lift is slightly decreased, reducing in a lower VSI then before retraction, which can create a negative G feeling.

I tought this aswell, but it doesn' t make sence, because they happen before flap retraction, and i felt it as soon as wee took-off (maybe 5 seconds). It also happens in first minute of flight, several times.


User currently offlineSoku39 From United States of America, joined Nov 2000, 1797 posts, RR: 9
Reply 4, posted (6 years 8 months 2 weeks 5 days 16 hours ago) and read 3030 times:



Quoting AlexEU (Reply 3):
i felt it as soon as wee took-off (maybe 5 seconds). It also happens in first minute of flight, several times.

Well I only fly Cessna's, so I have no idea how a turbojet's takeoff profile workds however, I know at that point (5-60 seconds after take off) I would only be 100-500 feet above the ground at that point, which is plenty low enough to catch windshear on a really windy day. What happens is sometimes you will have a large headwind, say 10-20 kts and that wind may stop and start back up. This will cause the airplane's wings to lose lift, as less air flows over the wings. Due to the phase of the flight you have to pitch down some to keep your airpspeed up (avoiding departure stalls), and this can result in a "sinking feeling" in the seat of the pants. Jets are also affected by windshear though not as dramaticaly at lower wind velocities, due to the fact they have so much more thrust compared to their weight. For a jet to experience this you will need to be dealing with higher wind velocities. All that being said, when you got the sinking feeling did those take offs occur on gusty days, maybe days where the wind was gusting as much as 30, or 40 knots?, because you will catch heavy windshear on up to the boundary layer.



The Ohio Player
User currently offlineYWG From Canada, joined Feb 2001, 1146 posts, RR: 2
Reply 5, posted (6 years 8 months 2 weeks 5 days 15 hours ago) and read 2984 times:



Quoting Pilotboi (Reply 2):
Could this be when flaps are retracted? Flaps increase lift on takeoff and when they are retracted, lift is slightly decreased, reducing in a lower VSI then before retraction, which can create a negative G feeling.

This is correct. In addition, this negative G feeling is coupled with the reduction of thrust as the crew powers back a bit as the plane picks up speed through the air makes for a mixed bag of feelings in your stomach. It happens in everything from general to commercial aviation.



Contact Winnipeg center now on 134.4, good day.
User currently offlineDragon6172 From United States of America, joined Jul 2007, 1202 posts, RR: 0
Reply 6, posted (6 years 8 months 2 weeks 5 days 12 hours ago) and read 2910 times:

My hypothesis is that this is caused by the opposite of the ground effect air cushion that causes the plane to float on decent to the runway. Shorly after lift off, leaving that "cushion", the plane settles just a bit, percieved as a drop.


Phrogs Phorever
User currently offlineBoeingOnFinal From Norway, joined Apr 2006, 476 posts, RR: 0
Reply 7, posted (6 years 8 months 2 weeks 5 days 11 hours ago) and read 2889 times:

I was thinking the same thing, ground effect. Although I can't say I have experienced it myself, and it is of course less likely to be felt in a high winged C-172, it is plausible that you can feel the small decrease of lift as you gradually leave the ground effect (at a height of about half the wing span in general).

If it was a one time thing, you can get slightly less than 1G when your trim is not set correctly, causing over rotation. You push the stick forward to correct it, and a loss of lift can be experienced.



norwegianpilot.blogspot.com
User currently offlineStarlionblue From Greenland, joined Feb 2004, 17003 posts, RR: 67
Reply 8, posted (6 years 8 months 2 weeks 4 days 22 hours ago) and read 2747 times:



Quoting N710PS (Reply 1):
Droppings? You mean as in birds tend to like the narrow body medium range jetliners more so than others?

I just thought the plane was pooping. This preoccupation with poop comes from having small kids.



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineIwok From Sweden, joined Jan 2005, 1108 posts, RR: 0
Reply 9, posted (6 years 8 months 2 weeks 3 days 6 hours ago) and read 2562 times:



Quoting AlexEU (Thread starter):
I've seen several a.netters mentioning droppings after take-off. I feel it aswell, but only on 737s or A320s. I never felt it in A340 or an turboprop/piston aircraft. My question is: what are the kind droppings after-take-off?

No wonder people run to the loo as soon as the aircraft hits 10,000ft.  Smile

Serisouly, I think this just is a feeling that indicates that the G force level has reduced maybe from flaps coming in, LG coming in, AOA being reduced or anything else that we tend to reduce the rate of climb. The body senses a reduced g level and thinks it is dropping down. This is why flying by the seat of the pants is not recommended.

iwok


User currently offlineJush From Germany, joined Apr 2005, 1636 posts, RR: 3
Reply 10, posted (6 years 8 months 2 weeks 3 days 4 hours ago) and read 2545 times:

I noticed this too and in my case it was not a drop but the pilot starting to increase climb. Sounds strange but that sometimes creates a feeling of a drop.
That and the flap case.

Regds
jush



There is one problem with airbus. Though their products are engineering marvels they lack passion, completely.
User currently offlineAlexEU From Serbia, joined Oct 2007, 1817 posts, RR: 2
Reply 11, posted (6 years 8 months 2 weeks 2 days 21 hours ago) and read 2478 times:



Quoting Jush (Reply 10):
I noticed this too and in my case it was not a drop but the pilot starting to increase climb. Sounds strange but that sometimes creates a feeling of a drop.

Yes, but as soon as he increases, he decreases and so on, like some sort of frequency. The higher we climb it becomes less and less noticeable.


Top Of Page
Forum Index

Reply To This Topic Droppings After Take-off
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Gear Down Long After Take Off posted Thu May 5 2005 23:36:54 by Sergy2k
Wheel Rotation After Take-off posted Mon Nov 15 2004 22:25:10 by Manzoori
Whining Noise On 319/320 After Take-off? posted Sun May 23 2004 19:10:26 by HottIEBOi1989
Why Sometimes No Gear Retraction After Take Off? posted Tue Jul 8 2003 11:42:05 by KM732
"brake The Wheels After Take-off" posted Wed Sep 26 2001 11:06:12 by Mr.BA
10,000 After Take-off? posted Fri Aug 11 2000 21:28:30 by Modesto2
How Does A Plane 'take Off?' posted Thu Jul 26 2007 13:38:00 by BritMidDC9
A300 Take Off Performance posted Fri Jul 13 2007 05:44:00 by Boeingluvr
CRJ-100 Take Off Performance posted Wed May 2 2007 17:58:16 by Flyingjeep
Do 747s Take-off Differently To Smaller Aircraft? posted Mon Apr 23 2007 03:41:55 by Danielnz

Sponsor Message:
Printer friendly format