Flyboy8784

Alright boys and girls....heres the deal...

Last week I got stuck going the dreaded PIT-EWR shuttle....any LGA based Whisky Pilot dreads seeing this pairing on his line.

Anyway on our way back to EWR we had to sit for 2 hours....the weather in PIT started going to crap....heavy snow...low vis all that good stuff.

We get released....and deiced and head back to EWR. About 20 mins left I go and pull up the ATIS for PIT to check the Breaking Action Reports. The MU scale is reporting NIL (According to our Supplemental Checklist) on 2 runways and Poor on the Dept. runway. We ACARS company and ask if we are reading the reports the right way...sure enough...we are...they say to call on the ground in EWR.

So we land in EWR hoping to just Repo to LGA so we can be done. Dispatch tells us another A/C landed there 10 mins ago and reported fair to poor B/A.... clearly not checking the B/A reports on the ACARS.

Anyway we end up being connected to our fleet manager who basically says that we are right....because the only data we have says that we CANT land there....we cant be dispatched. Mind you 3 other company aircraft land in during this whole ordeal....the ATIS hasnt changed.

Long story short.....we leave 2 hours later after the runways have been cleared....un-eventful.

Anyway my point is...if the snow is coming down...please read the full ATIS...Im sure most of you are good enough to land in conditions like that.....but if god forbid something stupid happens....the first thing the FEDs are gonna ask is why did you attempt to land with NIL breaking action?

Rant Over....fly safe!

BlueMoon

What were the MU readings(MU readings are not braking action reports)? AS the MU scales does not report "good" "fair" "poor" or "nil" They merely report runway friction on a scale of 0-100. (Think Co-efficient of friction from physics class)

As stated in the AIM 4-3-9(g)

g. No correlation has been established between MU values and the descriptive terms "good," "fair," "poor," and "nil" used in braking action reports.

MU is a runway friction report...not a braking action report.

The whole section of the AIM

4-3-8. Braking Action Reports and Advisories
a. When available, ATC furnishes pilots the quality of braking action received from pilots or airport management. The quality of braking action is described by the terms "good," "fair," "poor," and "nil," or a combination of these terms. When pilots report the quality of braking action by using the terms noted above, they should use descriptive terms that are easily understood, such as, "braking action poor the first/last half of the runway," together with the particular type of aircraft.
b. For NOTAM purposes, braking action reports are classified according to the most critical term ("fair," "poor," or "nil") used and issued as a NOTAM(D).
c. When tower controllers have received runway braking action reports which include the terms poor or nil, or whenever weather conditions are conducive to deteriorating or rapidly changing runway braking conditions, the tower will include on the ATIS broadcast the statement, "BRAKING ACTION ADVISORIES ARE IN EFFECT."
d. During the time that braking action advisories are in effect, ATC will issue the latest braking action report for the runway in use to each arriving and departing aircraft. Pilots should be prepared for deteriorating braking conditions and should request current runway condition information if not volunteered by controllers. Pilots should also be prepared to provide a descriptive runway condition report to controllers after landing.
4-3-9. Runway Friction Reports and Advisories
a. Friction is defined as the ratio of the tangential force needed to maintain uniform relative motion between two contacting surfaces (aircraft tires to the pavement surface) to the perpendicular force holding them in contact (distributed aircraft weight to the aircraft tire area). Simply stated, friction quantifies slipperiness of pavement surfaces.
b. The greek letter MU (pronounced "myew"), is used to designate a friction value representing runway surface conditions.
c. MU (friction) values range from 0 to 100 where zero is the lowest friction value and 100 is the maximum friction value obtainable. For frozen contaminants on runway surfaces, a MU value of 40 or less is the level when the aircraft braking performance starts to deteriorate and directional control begins to be less responsive. The lower the MU value, the less effective braking performance becomes and the more difficult directional control becomes.
d. At airports with friction measuring devices, airport management should conduct friction measurements on runways covered with compacted snow and/or ice.
1. Numerical readings may be obtained by using any FAA approved friction measuring device. As these devices do not provide equal numerical readings on contaminated surfaces, it is necessary to designate the type of friction measuring device used.
2. When the MU value for any one-third zone of an active runway is 40 or less, a report should be given to ATC by airport management for dissemination to pilots. The report will identify the runway, the time of measurement, the type of friction measuring device used, MU values for each zone, and the contaminant conditions, e.g., wet snow, dry snow, slush, deicing chemicals, etc. Measurements for each one-third zone will be given in the direction of takeoff and landing on the runway. A report should also be given when MU values rise above 40 in all zones of a runway previously reporting a MU below 40.
3. Airport management should initiate a NOTAM(D) when the friction measuring device is out of service.
e. When MU reports are provided by airport management, the ATC facility providing approach control or local airport advisory will provide the report to any pilot upon request.
f. Pilots should use MU information with other knowledge including aircraft performance characteristics, type, and weight, previous experience, wind conditions, and aircraft tire type (i.e., bias ply vs. radial constructed) to determine runway suitability.
g. No correlation has been established between MU values and the descriptive terms "good," "fair," "poor," and "nil" used in braking action reports.


At my airline it states that no aircraft will take off and land with a NIL braking action report. It talks about MU values only supplementing the decision making process and not controlling.

StillInstructin

Well the chart in our FOM and the suppliment in the a/c says a Mu reading of 10-25 is equal to NIL. Our FOM says no ops in NIL.

Flyboy8784

Exactly...thats how we do it as well

ultradrvr

thats how we do it (did it) no where in ground school did we cover the AIM. The MU reading was converted in our ops man. NIL is NIL, no ops what so ever. We had a capt get called on the carpet a few years back for calling the braking action NIL. As he was getting his hindend chewed, somebody stuck their head in the office and said "sorry to interupt but we have a DC-8 off into the overrun" . Meeting over!

flyguyniner11

Thanks for the insight AB

Oberon

Not a very good feeling when the brakes to the floor feels the same as no brakes at all!!

Spooled

Pinch-a-nickels Manuals:

Mu's 20 or less are Nil.


Alternate airport must be filed if braking action is poor or nil. So we can dispatch to Nil airports, but an alternate must be filed.

Never compromise safety................

s10an

Interesting.. I'm to lazy to double check but I just had recurrent here at TSA and I think we have MU less than 10=Nil.

macflyer

I love reading ATIS I read them all the time!