Taxi Speeds

tomcatsburg · Post by **tomcatsburg** » Tue Dec 25, 2007 9:35 pm

Hi all,

Don't know if this idea already passed the scene.

The minimum taxi speed is 20 Knots. BUt at some airports, like EHAM Schiphol, on some taxiways, high-speed taxi is approved.
In case of EHAM, a pilot may taxi 30 knots on the Victor taxiway, to speed the things up a bit.

Our(Global Airlines Group) HUB is Schiphol, and the Polderbaan(36L/18R) is very often in use. But to reach the runway, you've to taxi about 15 minutes in total.
So on the V-taxiway, you often taxi(with permission from ATC) 30 knots.

But when you do so, you pas the limit of 20 knots, and your rating goes down!

Don't know if this can be fixed/done in the airports database.

Merry x-mas,

Tom

vaccaro · Post by **vaccaro** » Tue Dec 25, 2007 10:48 pm

Agree with Tom.
A similar request from me, also for the airports where we have to backtack a rwy for t/o.

Cheers,

Kimis · Post by **Kimis** » Wed Dec 26, 2007 9:41 am

would say same thing is with 250kt limits as well. ATC can permit you fly faster if it is needed.
Usualy it is heavy transport climb speed issue, it simply unsafe to fly slower.

Post by **sp762** » Sat Dec 29, 2007 4:15 am

Just to follow up on this - having flown a few times in the RW recently. The taxi speed seemed to be higher than 20kts. I'm in favour of upping the limit to 30kts...

Miikoyan · Post by **Miikoyan** » Sat Dec 29, 2007 7:46 am

I have reached a taxi speed of 25 knots without hearing a ding. My record is 27 knots (I think) without a ding or penalty.

Post by **joefremont** » Sat Dec 29, 2007 8:34 am

While the client is not my area, I believe you need to average above 25kn for a 60 second period.

SenseiMatty · Post by **SenseiMatty** » Sun Dec 30, 2007 6:21 pm

I suggested this too.
My example is for taxiing on rwy 16C on Rome Fiumicino.
Also for high speed under 10.000 ft. It would be great to have an option that automatically disable the 250 limit only when flying online. Offline flights don't need to disable this, but online controllers often give you the high speed instruction for traffic separation.

Dave Athay · Post by **Dave Athay** » Sun Dec 30, 2007 10:32 pm

My current work-around for the taxi speed limit is to increase the sim rate to 2x or 4x once I've set a good taxi speed. I know that's kinda cheesy, but it works if you've got a two-mile straightaway or something and don't want to spend five minutes rolling in a straight line. After all, this is flight simulator and not taxi simulator or the latest "Need for Speed" installation. Just keep an eye on your groundspeed!

I remember reading in some documentation for some download somewhere (I think it was the POSKY 738) that prolonged high taxi speeds are bad for the aircraft because they heat up the tires and may cause them to blow

. Anybody know if this is really the case? I'm sure FS doesn't simulate tire temperature, but I'm just curious...

Miikoyan · Post by **Miikoyan** » Sun Dec 30, 2007 11:03 pm

Yep its true (at least in theory), since friction causes tires to melt and/or blow up. If you ever travelled in Germany in a BMW 325xi at a speed of 400 km, you would need to replace your tire after three or four hours since it gets burned up. If you ever watched F1, sometimes the racing car's tire(s) blows up because of too much friction. So yea, the same thing applies to airplance tires.

CAPFlyer · Post by **CAPFlyer** » Mon Dec 31, 2007 12:05 am

There are many airplanes as well that require a lot of use of braking while taxiing and those brakes will heat up and cause blowouts as well. We call it "thermaling" as what is actually happening is that the thermal expansion plug is being blown out. This plug is designed to blow out at a certain pressure to prevent overpressuring the tire (causing a blowout or delamination of the tread) and giving a controlled deflation, thus minimizing damage to the aircraft.

727s, 747s, and the DC-10 have these issues. Some 747s are equipped with brake fans to alleviate this problem, but the other aircraft just have to be handled with care and "cool down" periods given if long taxis are expected.

Post by **joefremont** » Mon Dec 31, 2007 5:55 am

If your using the airspeed indicator (or the control-Z speed on the top of the screen) the local wind can make you look like you are travelling slower than you really are. I will often keep the GPS open so I can see my true speed.

IslandBum · Post by **IslandBum** » Mon Dec 31, 2007 6:11 am

Just a thought - but seeing as most of ground times in the real world airline are a minimum of 15 minutes and at places like KLAS, KDEN, etc etc can exceed 30 minutes - will someone please show me an airport where, in real life you can taxi faster than 20 mph???? besides as Chris says there is a matter of wear and tear on the wheels themselves - tricycles are not inheritantly stable especially when turning - Allegiants company policy says (As do most airlines) that taxi speeds be kept at "a brisk walking pace" so patience being a virtue enjoy the ride and the view of the 757 ahead of you in the conga line, OR,. start
your flight using "active runway" - Konny and company had to have some rule of thumb to use as a "restriction" so smile, accept the rule which the programmers and admin have applied . and quitcherbitchin - Hey Chris, did I spellthat correctly

mahalo

Leif

Airboatr · Post by **Airboatr** » Mon Dec 31, 2007 6:27 am

I havn't had a problem with the way things are

IslandBum · Post by **IslandBum** » Mon Dec 31, 2007 7:00 am

Me either Joe (after I figured out the autotaxi on the PF F28

Leif

tomcatsburg · Post by **tomcatsburg** » Mon Dec 31, 2007 10:35 am

IslandBum,

like I said at Schiphol Amsterdam Airport in the Netherlands, EHAM, on the V-taxiway highspeed taxi is approved up to 30 knots, but only with permission from ATC.

Tom