Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
DC-9 Take-off Flap Setting  
User currently offlineLogan22L From , joined Dec 1969, posts, RR:
Posted (9 years 10 months 1 week 2 days 12 hours ago) and read 4772 times:

I couldn't find any related threads, so I hope you can help with answers to two questions regarding the DC-9.

1. On take-off yesterday in a DC-9-50, I noticed that the flaps were just barely deployed (hardly even looked like 5 degrees), unlike a typical take-off setting in other aircraft. We were full, and going DTW-BOS; temp was ~35 F. This seems very strange, as I have heard of some jets using very little flap deployment, but not DC-9s (the co-oincidence of being in DTW (MD-80, 1987) added a bit to my apprehension).

2. Last Friday, BOS-DTW in a DC-9-30 I sat in the exit row (seat 11F). Despite many flights, my first exit row. Anyway, as we taxied, I could clearly hear the engines in a much different way than normal. It was as if there were a conduit from the engines to the emergency exit door, and I could hear the engine with much more clarity than I have from other seats. I actually asked the purser if this was normal, and he said everything was fine, but it almost seemed as though I could hear the outside, as if the door were not sealed. Everything went fine, and I could not notice this in flight. Just during taxi and on take-off roll. Any thoughts?

These both go to show that despite any layman's concerns (such as mine), the flight crew and the airlines know what the heck is going on.

Thanks,

Logan

8 replies: All unread, jump to last
 
User currently offlineSlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 68
Reply 1, posted (9 years 10 months 1 week 2 days 11 hours ago) and read 4726 times:

Not familiar with, or at least not qualified on the -50 but I've heard that on the -30 it was not uncommon to make a slats-only, no-flap takeoff from hot and high airports, where 2nd segment climb was the performance limiter.

That does not sound like a cold day at DTW issue.

Perhaps someone with experience in that subtype can jump in.

As to the noise, it may well be that insulation and soundproofing are not as good near the emergency exits as in the rest of the cabin.



Happiness is not seeing another trite Ste. Maarten photo all week long.
User currently offlineAirWillie6475 From United States of America, joined Jan 2005, 2448 posts, RR: 1
Reply 2, posted (9 years 10 months 1 week 2 days 10 hours ago) and read 4630 times:

I could hear the outside, as if the door were not sealed

Even if the door wasn't sealed, initially, that wouldn't be a problem on a pressurized jet. Unless there was a big hole... If your afraid of abnormal noise in an aircraft riding the DC9-30 probably wouldn't be a good idea. Like an old car they sometimes make strange noises.


User currently offlinePrebennorholm From Denmark, joined Mar 2000, 6539 posts, RR: 54
Reply 3, posted (9 years 10 months 1 week 2 days 5 hours ago) and read 4354 times:

Having flown in the back of a DC-9 a hundred times, mostly on -40 and to a lesser degree the -20:

On the -40 most often very little flaps were used for take off. Only a few degrees, hardly noticeable.

On the -20 mostly some 10 or 15 degrees was used.

The exit seats are somewhat more noisy since the fuselage here contains more substantial metal structures which leaves less space for sound proofing material.

Maybe one day you should take a ride on a military C-130 Hercules transport or such without sound proofing. Then you will appreciate what sound proofing of airliner cabins does to our wellbeing.



Always keep your number of landings equal to your number of take-offs, Preben Norholm
User currently offlineSlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 68
Reply 4, posted (9 years 10 months 1 week 2 days 2 hours ago) and read 4326 times:

I was thinking of a ride in an early Sikorsky helicopter with the engine in front of you and the transmission overhead, with the tail rotor drive shaft extending beyond that. Now there is a noise level!



Happiness is not seeing another trite Ste. Maarten photo all week long.
User currently offlineAvionicMech From United Kingdom, joined Jan 2005, 315 posts, RR: 3
Reply 5, posted (9 years 10 months 1 week 2 days 2 hours ago) and read 4319 times:

You will find that on almost every aircraft it is noisier near the exits for the pure reason that there is less insulation on the door. This is because behind the trim panel that you can see there is all the opening mechanism which doesn't like having an insulation blanket tangled in it. So for this reason there is usually a thin blanket which doesn't provide anywhere near as much heat and noise insulation as the rest of the cabin. This is one of the downsides of an exit row, you may get the legroom but it can be colder and more noisy than the rest of the aircraft.

Avionic Mech


User currently offlineHAWK21M From India, joined Jan 2001, 31712 posts, RR: 56
Reply 6, posted (9 years 10 months 1 week 1 day 22 hours ago) and read 4289 times:

2nd segment climb
What exactly is a 2nd Segment climb.[Reply#1].

The exit seats are somewhat more noisy since the fuselage here contains more substantial metal structures which leaves less space for sound proofing material
Freighters usually have the Insulation Blankets removed from the Main deck areas,to reduce Weight.Its noisy but a lot of weight saving  Smile

regds
MEL



Think of the brighter side!
User currently offlineLogan22L From , joined Dec 1969, posts, RR:
Reply 7, posted (9 years 10 months 1 week 1 day 13 hours ago) and read 4270 times:

Thanks for the replies. I didn't mind the engine noise so much as I just wanted to be sure the door was secure.

Anyway, a few of you have indicated that DC-9s use no or very little flap on take-off. Remember the MD-80 that went down at DTW in 1987 due to zero flaps? Why does the MD-80 have a problem with this, because it is larger/heavier than a DC-9?

Logan


User currently offlineSlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 68
Reply 8, posted (9 years 10 months 1 week 1 day 13 hours ago) and read 4277 times:


Quoting HAWK21M (reply 6):
2nd segment climb
What exactly is a 2nd Segment climb.[Reply#1].


Under US regulations, for performance purposes the takeoff and climb are divided into segments. In each case they refer to a situation where an engine has failed after V1.

Intial is from liftoff through 35 feet which can be assumed to be the gear retraction height. (there is a bit more to it but that is a fair statement)

Second segment is with gear UP and flaps in the takeoff setting.

Final climb can be thought of as after flap retraction.

Each segment has its own climb performance criteria and from 2nd segment on these differ for 2, 3, and 4 engine airplanes.

There are many variables, some of them not obvious. Sometimes the runway will be the limiting factor, sometimes one of the climb segments. Hot days and high elevation airports it is quite common for 2nd segment to be the most restrictive.



Happiness is not seeing another trite Ste. Maarten photo all week long.
Top Of Page
Forum Index

Reply To This Topic DC-9 Take-off Flap Setting
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...
RTO(Rejected Take Off) Setting On AutoBrake posted Sat Oct 29 2005 19:28:02 by Julesmusician
Boeing Equivalent To Take Off Flex posted Wed Dec 6 2006 23:53:21 by Aak777
Boeing 737 Minimum Take-off/Landing Requirements posted Fri Nov 3 2006 16:22:57 by NZ8800
Heavy Take-off With Tailwind posted Fri Oct 27 2006 20:02:52 by BA84
737 Take Off Question posted Mon Jul 17 2006 22:03:04 by Shamrocka330
Did The Concorde Need A Long Take Off Roll? posted Sat Jul 8 2006 01:46:49 by 747400sp
RPM Of Jet Engines During Take-off posted Fri Jun 9 2006 18:00:26 by MerlinIIIB
77W TAKE-OFF Question posted Mon Jun 5 2006 18:50:07 by Orlando666
A Derated Take Off Question - Some Confusion posted Thu May 25 2006 19:14:31 by JulianUK
Weather Radar Use Taxing To Take Off Question posted Sun May 21 2006 19:28:11 by JulianUK

Sponsor Message:
Printer friendly format