Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
777: Why No Noise When Thrust Revers Applied?  
User currently offlineThrust From United States of America, joined Sep 2003, 2690 posts, RR: 10
Posted (10 years 4 weeks 1 day 19 hours ago) and read 4112 times:

Both times that I flew a 777, which was for AA, I noticed that the landing was different than any other type of aircraft before it. For some reason, the roar that we typically hear when the thrust reversers of an aircraft are applied on the runway was not present with the 777. The only thing I heard and felt was the thump of the landing gear on the runway and the aircraft slowing down...the noise literally remained the same the whole way through the landing...you could've sworn that the aircraft was still flying. Anyway, getting to my question, I wanted to know what in the world makes these thrust reversers add little or no noise to the aircraft when deployed on landing? How on earth can such powerful engines be so quiet on landing?


Fly one thing; Fly it well
15 replies: All unread, jump to last
 
User currently offlineDfwRevolution From United States of America, joined Jan 2010, 976 posts, RR: 51
Reply 1, posted (10 years 4 weeks 1 day 19 hours ago) and read 4084 times:

AA might not have been using reverse thrust on your particular flight. B6 does this as well to reduce community noise and some engine wear at a few airports.

User currently offlineKlaus From Germany, joined Jul 2001, 21460 posts, RR: 53
Reply 2, posted (10 years 4 weeks 1 day 19 hours ago) and read 4059 times:

I remember an explanation given earlier by pilots that they frequently deploy the reversers without revving up the engines again ("idle reverse"). That would give only marginal braking assistance (so the brakes have to work harder), but there is much less noise to the environment than in "full reverse". It seems many airports recommend this mode of operation for their neighbours´ sake.

User currently offlineGoboeing From United States of America, joined Jun 2000, 2698 posts, RR: 14
Reply 3, posted (10 years 4 weeks 1 day 18 hours ago) and read 3985 times:

It is an SOP to use reverse thrust at most airlines / aircraft with them. It may have been unlocked and put in idle, but it was at least there, ready to go to full reverse thrust if it was needed.

Nick


User currently offlineSimProgrammer From France, joined Aug 2004, 193 posts, RR: 0
Reply 4, posted (10 years 4 weeks 1 day 17 hours ago) and read 3935 times:

Thrust:

Was this a late night or early morning landing?

UA and BA's 777's deploy reverse thrust and can be adequately heard, but during unsociable hour landings many airports don't allow reverse thrusts to be deployed or excessive thrust during taxi.



Drive a bus, an Airbus, easier than a London bus!
User currently offlineCdfMxTech From United States of America, joined Jul 2000, 1341 posts, RR: 26
Reply 5, posted (10 years 4 weeks 1 day 17 hours ago) and read 3928 times:

The B777 is equipped with carbon brakes. Carbon brakes are much more effective when they are heated up. For this reason, the Thrust Reversers are deployed, but left in Idle reverse. This can extend the life of the engine (less High EGT ) and decrease the chances of FOD damage.

User currently offlineCancidas From Poland, joined Jul 2003, 4112 posts, RR: 11
Reply 6, posted (10 years 4 weeks 1 day 16 hours ago) and read 3897 times:

don't forget, it's not reversers that stop airplanes, it's the brakes.


"...cannot the kingdom of salvation take me home."
User currently offlineJeffDCA From , joined Dec 1969, posts, RR:
Reply 7, posted (10 years 4 weeks 1 day 15 hours ago) and read 3892 times:

Having flown on a fair few 777's (including AA) it seems to me that on both of your flights reverse was simply not used. You can hear it just as much as on any other aircraft, even if at idle reverse.

Cheers,

Jeff


User currently offlineLorm From United States of America, joined Jun 2004, 409 posts, RR: 1
Reply 8, posted (10 years 4 weeks 1 day 14 hours ago) and read 3856 times:

If there's a long runway, it's not high traffic hour, and the 777 you're on doesn't need to vacate the runway early, chances are they won't use reversers. Like the replies above, the 777 has very effective carbon brakes. I remember the first time I flew on the 777, landing in ORD several years ago, I was so surprised that landing on 22R we never utilized thrust reversing.

My last 2 trips in June, on legs flown with the 777 we used thrust reversers once. On my ORD-SFO on UA137, that leg we flew an international equipped 777 and I was seated in 1J in F/C. Upon landing on 28R I could hear only slightly the wind noise from the cascades opening up. Sometimes it is less obvious if you're sitting up front ahead of the engines.

Last leg to HNL on UA61 which arrived around 4pm, we landed on 4R, not commonplace as usually before 630p, the majority of heavy jet traffic lands on 8L. Anyways on 4R the normal practice is to roll down to the end and then do a turnoff, which we did without reversers deployed. Still with 9000' of runway we were out of autobraking and coasting before we crossed 8L, so we easily slowed down even with a full load of passengers. I had to sit near the engine at 22J  Crying and even idle reverse wasn't used.
-Mike



Brick Windows
User currently offlineAaron747 From Japan, joined Aug 2003, 8149 posts, RR: 26
Reply 9, posted (10 years 4 weeks 1 day 12 hours ago) and read 3822 times:

I flew AA SJC-NRT and back last March, and noticed this upon arrival. We came in on 34L on a rainy day and touched down a bit long but still didn't use anything more than idle reverse. 34L/16R has at least 11,000' of landing distance though so we simply braked for a bit and exited one of the high speeds for the short jaunt to the terminal.

Coming back to SJC however, we were hot the whole way down to 30L and came down a bit long. There was definitely reverse thrust applied as we slowed *very* quickly.



If you need someone to blame / throw a rock in the air / you'll hit someone guilty
User currently offlineModesto2 From United States of America, joined Jul 2000, 2801 posts, RR: 5
Reply 10, posted (10 years 4 weeks 1 day 4 hours ago) and read 3704 times:

Dfwrevolution, Jetblue (like most airlines) always uses reverse thrust. However, most flights will keep it at "idle reverse" and nothing more.

User currently offlineStar_world From Ireland, joined Jun 2001, 1234 posts, RR: 0
Reply 11, posted (10 years 3 weeks 6 days 9 hours ago) and read 3412 times:

I've noticed this many times at LHR in early mornings, I usually leave my car in the car park right next to 27R - probably only a few hundred metres from the runway itself. I've seen 777s land right next to me with virtually no noise - quiet enough that you probably wouldnt notice it unless you were looking! They always had the thrust reversers deployed, but with just idle reverse in use.

User currently offlineThrust From United States of America, joined Sep 2003, 2690 posts, RR: 10
Reply 12, posted (10 years 3 weeks 5 days 23 hours ago) and read 3314 times:

I must confess, SimProgrammer, my first route on a 777 was on AA, BOS-LHR. We touched down at LHR at about 6:00 A.M. in the morning London time. But strangely enough, when I flew LHR-JFK like a week later, we landed at JFK during a perfectably sociable hour, like late afternoon or early evening, New York time. the second landing was no different from the first other than that we were landing at JFK instead of LHR.


Fly one thing; Fly it well
User currently offlineBeachthing From United States of America, joined May 2004, 71 posts, RR: 0
Reply 13, posted (10 years 2 weeks 1 day 21 hours ago) and read 2775 times:

starworld: the image of 777s silently landing in th early morning: what a pretty thought! Love that plane.

User currently offlineThrust From United States of America, joined Sep 2003, 2690 posts, RR: 10
Reply 14, posted (10 years 2 weeks 1 day 12 hours ago) and read 2636 times:

Yes, the 777 is truly a magnificent beast...you have to fly it to believe it  Big thumbs up


Fly one thing; Fly it well
User currently offlineBa299 From United Kingdom, joined Jun 2003, 173 posts, RR: 1
Reply 15, posted (10 years 2 weeks 1 day 4 hours ago) and read 2563 times:

Often you don't heard the T/R because we use it only at idle. Using the autobrakes the aircraft stop in the same distance with o without reverses. So we prefer (when we can) to avoid the use on the reverses for noise abatement and for more comfort of the paxx.

Top Of Page
Forum Index

Reply To This Topic 777: Why No Noise When Thrust Revers Applied?
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...
Why No Winglets On The 777? posted Sun Sep 12 2004 12:19:58 by Regis
Why No Further A330 Stretch? posted Fri Nov 10 2006 03:50:51 by MarkC
A340-600 Why No Body Gear Steering? posted Fri Nov 3 2006 18:16:18 by BALandorLivery
Why No Retractable Gear On Aerobatics Planes? posted Thu Nov 2 2006 20:54:17 by QFA380
Why No Papi On W/B Rwys At LAX? posted Wed Oct 18 2006 06:58:06 by Adipasqu
Why No Douglas Competitor To The Boeing 727? posted Mon Jul 31 2006 21:51:50 by 747400sp
Why No Short Haul Versions? posted Fri Jul 28 2006 14:34:18 by Tobi3334
Why No Auto-Land? posted Thu Jul 27 2006 16:38:03 by Marklaw
Why No JT9D-7R4G2 Powered 747sp posted Mon Jul 3 2006 00:03:37 by 747400sp
Why No PW 6000 737NG? posted Sat Jun 24 2006 14:10:12 by 747400sp

Sponsor Message:
Printer friendly format