Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Anti Skid.  
User currently offlineSudden From Sweden, joined Jul 2001, 4130 posts, RR: 6
Posted (11 years 10 months 1 week 3 days 10 hours ago) and read 3445 times:

My question about this system goes back to when I worked at GOT airport.

It was winter and the ramp was very slippery. We were standing waiting for our KLM flight (737-400), and when they came on to the ramp, and was about to make a right turn on to the gate, the A/C just kept on going straight. What you might call a "overshoot".  Smile
The A/C came to a stop, and the pilot just stepped on it and made a 180 and blocked at the gate.
The pilot was taxiing way to fast for the conditions that occurred on the ramp.

Ok,
my question is basically if this system also works as a ABS system on newer A/C's? To prevent skidding like the above mentioned incident.
Also, what speed is required for the Anti Skid system to get activated?

Thanks in advance.

Sudden



When in doubt, flat out!
9 replies: All unread, jump to last
 
User currently offlineDhltech From United States of America, joined Sep 1999, 15 posts, RR: 0
Reply 1, posted (11 years 10 months 1 week 3 days 10 hours ago) and read 3435 times:

as far as boeing 727's are concerned the anti-skid is deactivated below a speed of about 20 kts. otherwise you would never be able to stop.

User currently offlineVC-10 From United Kingdom, joined Oct 1999, 3700 posts, RR: 34
Reply 2, posted (11 years 10 months 1 week 3 days 9 hours ago) and read 3427 times:
Support Airliners.net - become a First Class Member!

A340-300 in-active below 10 Kts

A340-600 in-active below 10 Kts except under heavy braking



User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 3, posted (11 years 10 months 1 week 3 days 4 hours ago) and read 3377 times:

>>>Ok, my question is basically if this system also works as a ABS system on newer A/C's? To prevent skidding like the above mentioned incident.

Anti-skid systems have been around on aircraft for years, and automotive ABS are the more recent offshoot.

The main task of the anti-skid system isn't prevent slow speed ramp skids like you the situation you decsribed. The purpose of the anti-skid system is to greatly increasing braking effectiveness, primarily on landing, but also on takeoff should it be aborteed...


User currently offlineCdfmxtech From United States of America, joined Jul 2000, 1338 posts, RR: 27
Reply 4, posted (11 years 10 months 1 week 3 days 3 hours ago) and read 3367 times:

First of all, are you sure he skidded??

I don't think the B737-3/4/500 have a minimum skid control speed. That doesn't mean that the aircraft will never be able to stop. As long as there is no skid condition, then things will be OK. Also, the B737-3/4/5s have antikid control switches as it CAN be selected OFF. When we taxi the 37s, our checklist has us turn off antiskid. I think with the aircraft being so light during a mx taxi, it would skid easily if brakes not applied correctly.

I have to research some other things about the classic, but I couldn't find a minimum speed anywhere. The NGs, B757 and 67 are approx 8 knots. BTW, there is no ON OFF siwtch for those aircraft.

Will get back to u.


User currently offlineB747skipper From , joined Dec 1969, posts, RR:
Reply 5, posted (11 years 10 months 1 week 3 days 1 hour ago) and read 3336 times:

In the old "Classic" 747s, the antiskid switch stays "ON" at all times, including taxi speed... it is deactivated automatically at low speeds... some "nervous" pilots (or old habits they took with previous airplanes they flew) sometimes like to "disarm" the antiskid for taxi...
xxx
It is NOT on the Boeing's check lists and SOP... but... OK...
xxx
(s) Skipper


User currently offlineAirplay From , joined Dec 1969, posts, RR:
Reply 6, posted (11 years 10 months 1 week 2 days 3 hours ago) and read 3268 times:

About a month ago while I was waiting in Toronto for a flight, I witnessed a towing incident with an A340.

The tug was pulling the airplane too fast, and when he tried to make a turn, the airplane didn't agree. The tug jacknifed and ended up under the airplane aft of the nose gear. I have pictures if anyone is interested.

What we learn from this, is that a large airplane has alot of momentum and if the nose wheel loses traction or the tug doesn't have a similar amount of momentum, the airplane will continue on it's trajectory no matter which way the nose wheel is turned.


User currently offlineCdfmxtech From United States of America, joined Jul 2000, 1338 posts, RR: 27
Reply 7, posted (11 years 10 months 1 week 1 day 15 hours ago) and read 3226 times:

It is NOT on the Boeing's check lists and SOP... but... OK...

I should have been more specific. We have AMT Taxi/Towing Checklists that we use (There are in all our flightdecks along with the crew checklists).


User currently offlineSudden From Sweden, joined Jul 2001, 4130 posts, RR: 6
Reply 8, posted (11 years 10 months 1 week 11 hours ago) and read 3178 times:

I'm sure he skidded!

He turned the nosewheel, but the A/C kept on going straight.
What is the conclusion of this? That the anti skid was turned off?
Looked more like he was doing iceracing.  Big grin



When in doubt, flat out!
User currently offlineB747skipper From , joined Dec 1969, posts, RR:
Reply 9, posted (11 years 10 months 1 week 1 hour ago) and read 3146 times:

Dear Cdfmxtech -
xxx
Well when we write facts here - we (all) should be a little more specific, as many quote us with statements that are construed "erroneous"...
xxx
When a say "Boeing" check list, I mean the check lists from Boeing's own QRH, which are generally used by foreign airlines - in the USA, each airline have a tendency to make "their own" check lists (because they know the airplane better than Mr. Boeing himself)...
xxx
I remember the check lists (Boeing's or airline specific) from the 707 and 727, and yes indeed, the "anti-skid" switch was OFF for taxi... see their check lists... But on the 747 classic, the anti-skid switch gathers dust, it is left ON and CAPPED at all times, and not part of the Boeing QRH before taxi or takeoff check lists... my airline recognized that they are not 747 experts, and they trust Boeing's own designed standard procedures, as is, out of the Boeing book...
xxx
Those of our technicians and ground engineers who are "taxi qualified" are required to use the very same QRH used by flight crews, when they position the aircraft around the airport...
xxx
I personally dont like pilots to "make their own procedures" - even if they mean to "improve" safety... i.e. ex-737 pilots have a habit to prefer the anti-skid OFF for taxi operations in the 747... As it is not on the check list, WHAT IF they forget it for takeoff, since it is NOT on the check list... Let us stick to our SOPs, as defined by our operations, for the sake of safety...
xxx
 Smile/happy/getting dizzy
(s) Skipper



Top Of Page
Forum Index

Reply To This Topic Anti Skid.
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...
Anti Skid..... posted Mon May 9 2005 01:10:18 by Jamie757
Anti Skid. posted Fri Sep 20 2002 10:39:23 by Sudden
Anti Ice Procedures posted Sun Nov 5 2006 22:30:53 by Qantas744ER
Anti-Misting Kerosene, Should It Be Re-evaluated? posted Tue Oct 10 2006 00:58:51 by FLY2HMO
Anti-Skit Fundamentals/ Emergency Situations posted Tue Oct 3 2006 08:18:18 by Speedracer1407
Piaggio Avanti Propeller De/anti-ice posted Sat May 13 2006 08:02:57 by Bucchinij
Any Anti-Gravity Updates? posted Sun Oct 23 2005 22:59:32 by Lumberton
A380's Anti Collision Lights posted Thu Apr 28 2005 12:39:00 by Glidepath73
Effect Of De/Anti-ICE Fluids On Wing Components posted Sun Feb 20 2005 20:19:33 by Pilotaydin
Engine & Wing Anti-ice posted Thu Nov 11 2004 23:10:16 by Santhosh

Sponsor Message:
Printer friendly format