Narrow Runways

[mutt]

We are used to 45-60m wide runways, but do any airlines have restrictions on the minimum runway width?

Mutt

[LEM]

Not mine. (B737)

Maybe others operating bigger jets, but I bet you've identified another grey area in aviation.

[enicalyth]

mutt, g'day

firstly as you will appreciate in godzone country we might and indeed do things differently.

so as a bit of background reading try this http://www.casa.gov.au/rules/1998casr/139/139m06.pdf

runway width can be a touchy subject and as i've retired and had more than my say on the subject i'll let others have a goanna.

listening out qantas, virgin blue, rex.

best rgds

the "e"

PS if the pdf directs you to another chapter, eg Chapter 13, just delete the 06 bit and type in the chapter number. In passing the runway strip and RESAs are either enlightening or frightening by parts.

[DBate]

Yes, we do have a limit for minimum RWY width (A320).

Limitations:
- Minimum runway width 30m
- Autoland is not allowed.

Requirements for dispatch:
Dispatch from/to narrow runways is not allowed in case of:
- nose wheel steering inoperative
- one brake or more inoperative.

Furthermore some VMCG corrections have to be applied for takeoff performance calculations.

So long,
DBate

[underread east]

Doesn't seem to bother Springbok much!

Check this out:

http://www.skypark.org/747Landing.htm

[alexban]

same here-30m
also ,chief pilot approval required to operate on such rwy.

[320DRIVER]

Normally the A320 is limited to 45 m .. for below than that you need some AFM paperwork (which will cost you) to go down to the minimum of 30 m.

[john_tullamarine]

There has been the odd post on this subject in various threads in recent years.

Some years ago, ICAO looked at varying the geometric runway width limits by requiring actual aircraft Type demonstration to show a capability to operate from a given width standard.

As far as I am aware, only Oz took this up (without looking at my files, probably 20-25 years ago, and imposed a requirement for runway width testing).

Some aircraft have no problems, some have significant problems and possibly ought not to be operating from the standard runway width requirements ....

[Pontius' Pilot]

We operate our A319's into a 30m wide runway. In addition to the restrictions in the FCOM our company has imposed more restrictive cross wind limits, visibility requirements and crew qualifications for this operation. It is on a volcanic island and as a result has some impressive alto granite rising in close proximity to it.

[mutt]

J_T,

As you are aware we operate a very diverse VIP fleet, some of our requested destinations are quite interesting. Presently we use 45m as a minimum, but the latest request was for a MD90 to operate to a 20m wide runway, we were informed that the local oil company happily operate B737's into this 1700 m field.

Do you have any reference to the criteria used by ICAO/CASA for determining the minimum width required?

Mutt

[enicalyth]

mutt

if j_t doesn't lay his paws on it i surely have it somewhere as will ozexpat.

it was a hot topic of mine once.

[john_tullamarine]

Mutt,

Not immediately to hand. Will track it down for you. In addition, I have sent you via PM the relevant CASA email contact if you want to get the current story from the man in the chair.

The basic deal was that, if an operator wished to operate on widths less than the ICAO geometric limits, the aircraft Type had to demonstrate a capability to do so.

The testing was pretty straightforward - critical cases addressed (under the desired crosswind conditions - this was the problem, as always .. getting the bird, the people and the wind to align their respective diaries).

(i) minV1 desired/established - Vmcg divergences might well limit the minV1 to something in excess of the AFM figure for this reason. Usually, the divergence problems are near Vmcg as the speed/divergence characteristics are very speed critical.

(ii) simulate wet runway by disabling rudder steering ... or doing the testing in the wet

(iii) look at takeoff failures at minV1 with reject and continue. The problem generally is greater for continue and may require some consideration of V1/VR split where appropriate.

(iv) look at the sidestep approach to land manoeuvre. This doesn't appear to present too much of a problem.

(I can't recall anything else which needed to be done ...)

Normal FT report - measurements of centreline deviation and correlation to timebase and speed, etc.

Techniques varied from siting long lens video (800-1000mm - equivalent to having around 2500-3000mm hanging off a 35mm camera) at the runway head to using high tech on board electronics. Either is fine and, for the low cost needy, the video approach works surprisingly well, allowing scale measurements down to around 10cm.

Once the regulator is satisfied, a FMS provides the approval vehicle.

Thinking back to DC9 characteristics, I would suspect that the MD90 would be a bit tight on 20M unless the minV1 is pushed up a bit. Certainly, I would be a bit uncomfortable flying either aircraft out of 20M without some serious thought to sensible operational restrictions.

.. and this is the crux of the problem which led to consideration of running flight tests - the usual concessions one sees around the place give little, if any, thought to tracking problems under critical conditions.