Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Are There Brakes On The Nose Gear?  
User currently offlineAirfoilsguy From , joined Dec 1969, posts, RR:
Posted (8 years 7 months 1 week 5 days 3 hours ago) and read 6512 times:

I don't seem to recall seeing break rotors on the nose gear of most aircraft. If they don't have breaks on the nose gear, why not? Wouldn't that help reduce stopping distance. I know cars use the front wheels for a majority of their stopping power.

17 replies: All unread, jump to last
 
User currently offlineJetlagged From United Kingdom, joined Jan 2005, 2548 posts, RR: 24
Reply 1, posted (8 years 7 months 1 week 5 days 3 hours ago) and read 6511 times:

The nose gear only takes about 10% of the aircraft's weight, so can't provide much braking force. There have been a few airliners with nosewheel brakes (some 727s had them). Generally they aren't seen as being worth the weight penalty.

I'd guess the front wheels of a car might be taking 60% or more of the weight of the car under heavy braking, which is why they provide most of the braking force.



The glass isn't half empty, or half full, it's twice as big as it needs to be.
User currently offlineAirfoilsguy From , joined Dec 1969, posts, RR:
Reply 2, posted (8 years 7 months 1 week 5 days 3 hours ago) and read 6509 times:

Quoting Jetlagged (Reply 1):
I'd guess the front wheels of a car might be taking 60% or more of the weight of the car under heavy braking, which is why they provide most of the braking force.

My though was that once breaking action started the center of gravity shifts toward the front of the plane, thus putting a greater percentage of the aircrafts weight forward.


User currently offline2H4 From United States of America, joined Oct 2004, 8955 posts, RR: 60
Reply 3, posted (8 years 7 months 1 week 5 days 3 hours ago) and read 6500 times:
AIRLINERS.NET CREW
DATABASE EDITOR



Convairs had them, too:




View Large View Medium
Click here for bigger photo!

Photo © Christian Waser






2H4





Intentionally Left Blank
User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 4, posted (8 years 7 months 1 week 5 days 2 hours ago) and read 6497 times:

Quoting Airfoilsguy (Thread starter):
Are There Breaks On The Nose Gear?

Only if the pushback tug hits the nose gear really hard...

Brakes on the other hand...  Wink


User currently offlineHAWK21M From India, joined Jan 2001, 31679 posts, RR: 56
Reply 5, posted (8 years 7 months 1 week 4 days 19 hours ago) and read 6422 times:

Since the Main Gear brakes take most of the Aircraft Weight.It makes sense to have them Installed there.On the B727 there were NLG brakes.
Cannot locate a pic though.
If the purpose can be served by The Main Gear brakes alone,the Weight savings along with the Mechanical complications can be avoided.
Also the NLG Brakes were effective only after approx 60% of the Main Brake application as I was told.

regds
MEL



Think of the brighter side!
User currently offlineLH4U From Germany, joined Jan 2006, 12 posts, RR: 0
Reply 6, posted (8 years 7 months 1 week 4 days 12 hours ago) and read 6349 times:

Quoting Airfoilsguy (Reply 2):
My though was that once breaking action started the center of gravity shifts toward the front of the plane, thus putting a greater percentage of the aircrafts weight forward.

Center of gravity doesn´t move when braking.... it´s only dependent on weight ditribution. The main wheels are almost always behind CoG, so when main gear braking starts, there will be a momentum on the nose gear. That´s probably what you mean. But still, with this momentum nose gear braking would have relatively little effect...

Greets


User currently offline2H4 From United States of America, joined Oct 2004, 8955 posts, RR: 60
Reply 7, posted (8 years 7 months 1 week 4 days 12 hours ago) and read 6346 times:
AIRLINERS.NET CREW
DATABASE EDITOR



I just found this quote from http://www.b737.org.uk, referring to the 737-200ADV:

Autobrake, improved anti-skid, automatic speedbrake for RTO, automatic performance reserve and even nose-brakes became available.

This is the first I've heard of nosewheel brakes being offered on the 737. Were any actually installed?




2H4





Intentionally Left Blank
User currently offlineJetlagged From United Kingdom, joined Jan 2005, 2548 posts, RR: 24
Reply 8, posted (8 years 7 months 1 week 4 days 12 hours ago) and read 6346 times:

Quoting Airfoilsguy (Reply 2):
My though was that once breaking action started the center of gravity shifts toward the front of the plane, thus putting a greater percentage of the aircrafts weight forward.

Still its a very small percentage on a small contact area. The vast majority of the aircraft's weight stays on the main wheels, even under braking. Also, the nosewheel tyres have enough work to do with nosewheel steering.

Car tyres start with roughly 50/50 fore/aft weight split (maybe 55/45 allowing for the engine). Braking g loads further increase this imbalance. In an aircraft, to transfer significant weight forward onto the nosewheel would required dramatic deceleration rates, which might not go down too well with the self loading cargo.



The glass isn't half empty, or half full, it's twice as big as it needs to be.
User currently offlineCosmicCruiser From United States of America, joined Feb 2005, 2255 posts, RR: 15
Reply 9, posted (8 years 7 months 1 week 4 days 11 hours ago) and read 6321 times:

Fedex had all the nose gear brakes removed on our 727s years ago.

User currently offlineElvisisalive From United States of America, joined Aug 2005, 24 posts, RR: 0
Reply 10, posted (8 years 7 months 1 week 4 days 8 hours ago) and read 6270 times:

Am pretty sure all the wheels on the 747-400 nose or main are the 3-1479-2
so if the -400 does not have nose brakes is there just a cavity in the wheel were the brake would be ?


User currently offlineFredT From United Kingdom, joined Feb 2002, 2185 posts, RR: 26
Reply 11, posted (8 years 7 months 1 week 4 days 8 hours ago) and read 6262 times:

Quoting Jetlagged (Reply 1):
Generally they aren't seen as being worth the weight penalty.

Not to mention maintenance!

Quoting Airfoilsguy (Reply 2):
My though was that once breaking action started the center of gravity shifts toward the front of the plane, thus putting a greater percentage of the aircrafts weight forward.

The center of gravity stays put, but the weight distribution among the wheels is changed by the torque generated by the braking force.

The Saab Gripen has nose wheel braking. Makes for a lot of stopping power, combined with lift dumping, canards doubling as giant airbrakes and anti-lock brakes that can be applied prior to touchdown. Hardly an airliner though...  Smile

So, who will be first to estimate the force on the nose wheels of an airliner during braking?

Cheers,
Fred



I thought I was doing good trying to avoid those airport hotels... and look at me now.
User currently offlineMatt72033 From United Kingdom, joined May 2005, 1617 posts, RR: 4
Reply 12, posted (8 years 7 months 1 week 4 days 7 hours ago) and read 6260 times:

Quoting Elvisisalive (Reply 10):
Am pretty sure all the wheels on the 747-400 nose or main are the 3-1479-2
so if the -400 does not have nose brakes is there just a cavity in the wheel were the brake would be ?

no brakes on the nosewheel of a 744


User currently offlineHAWK21M From India, joined Jan 2001, 31679 posts, RR: 56
Reply 13, posted (8 years 7 months 1 week 3 days 23 hours ago) and read 6170 times:

Quoting 2H4 (Reply 7):
This is the first I've heard of nosewheel brakes being offered on the 737. Were any actually installed

I heard on this forum someplace that it was an option.Although have never personally noticed a B737 equipped with NLG brakes.
regds
MEL



Think of the brighter side!
User currently offlineSaintsman From United Kingdom, joined Mar 2002, 2065 posts, RR: 2
Reply 14, posted (8 years 7 months 1 week 3 days 21 hours ago) and read 6161 times:

There are brakes fitted to some aircraft to stop the wheels spinning after they have been retracted. They are applied directly to the tyres.

User currently offlineMatt72033 From United Kingdom, joined May 2005, 1617 posts, RR: 4
Reply 15, posted (8 years 7 months 1 week 3 days 18 hours ago) and read 6149 times:

Quoting Matt72033 (Reply 12):
Quoting Elvisisalive (Reply 10):
Am pretty sure all the wheels on the 747-400 nose or main are the 3-1479-2
so if the -400 does not have nose brakes is there just a cavity in the wheel were the brake would be ?

no brakes on the nosewheel of a 744

but your right, i checked, and the part numbers are interchangeable!


User currently offlineHAWK21M From India, joined Jan 2001, 31679 posts, RR: 56
Reply 16, posted (8 years 7 months 1 week 3 days 13 hours ago) and read 6124 times:

Quoting Saintsman (Reply 14):
There are brakes fitted to some aircraft to stop the wheels spinning after they have been retracted. They are applied directly to the tyres

http://www.b737.org.uk/wheelwellnose_ng_labelled.jpg
They are referred to as Snubber pads.The above pic does not depict the total pads though,the Aft section is visable.Will post a better one when available later.
regds
MEL



Think of the brighter side!
User currently offlineGunships From United States of America, joined Nov 2001, 574 posts, RR: 6
Reply 17, posted (8 years 7 months 1 week 3 days 2 hours ago) and read 6050 times:

Quoting Saintsman (Reply 14):
There are brakes fitted to some aircraft to stop the wheels spinning after they have been retracted. They are applied directly to the tyres.

We used to call them "spin brakes" on the C-141. Just static brake pads installed near the top of the NLG wheel well that the NLG tires would contact as they retracted.

Eliminated the "gyro" effect of the tires spinning, which would add an unecessary force to an already heavily-stressed structure.


Top Of Page
Forum Index

Reply To This Topic Are There Brakes On The Nose Gear?
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...
What If The Nose Gear Collapsed On Takeoff? posted Sat May 20 2006 11:31:42 by F.pier
Carbon Brakes On The 737NG posted Mon Jan 30 2006 17:26:09 by LMP737
What Are Those "Things" On The Tail? posted Sat Nov 12 2005 22:34:35 by Bozo
Lights On 764 Nose Gear posted Sun May 22 2005 15:42:50 by TheFLCowboy
Whats With The Nose Gear posted Sat Oct 23 2004 08:46:36 by HAWK21M
Steering The Nose Gear: How? posted Wed Jun 2 2004 14:30:13 by RA-85154
What's On The Nose Of The A318/319/320/321? posted Wed Jan 21 2004 05:43:36 by Cancidas
Are 747Fs Loaded On The Belly Doors Too? posted Mon Jan 12 2004 00:21:01 by Bio15
Where Are The Brakes On A 737. posted Fri Sep 20 2002 00:50:00 by Norbert
What Are These Intakes For On The 777? posted Wed Nov 1 2006 04:13:28 by Gh123

Sponsor Message:
Printer friendly format