I don’t know about you, but we’ve had a few snow and ice storms this winter in our neck of the woods. As a flight instructor, bad weather offers the opportunity to teach students about runway condition and braking action, among other things, and it’s a good time to reinforce the importance of checking NOTAMs before heading to the airport.
During a recent winter storm, we were snowed in for three days. We were all getting antsy, wanting to get out of the house and fly. So after the clouds cleared, a student and I scheduled a flight for the first VFR day after the snowstorm. The weather looked fantastic - clear below 12,000, light winds and sunshine. Everything looked great… except for just this one thing:
!TTA 01/015 TTA RWY 03/21 FICON ICE BA POOR OBSERVED AT 1601241330. 1602241405-1602241900.
What does all that mean? In short, it means that there was still ice on the runway, and braking action was poor. This is a NOTAM(D) for runway condition, and yet another good reason to always check NOTAMs! While the weather outside was great VFR flying weather, we were still stuck on the ground. Here’s a breakdown of this NOTAM:
A NOTAM for field condition - what we call FICON - can be issued for any of the following runway conditions:
- Snow and Ice
- Drifting or drifted snow
- Snow banks
- Frost Heave
- Cracks, Ruts, Soft Edges
Here are two more examples:
!MIV MIV RWY 10/28 FICON 1/4 IN LSR WEF 1112201200
NOTAM for Millville Municipal Airport (MIV), runway 10/28 is covered in ¼ inch loose snow, observed December 20, 2011 at 1200 UTC.
!ENA 5HO RWY 16/34 FICON THN PSR WEF 1109131520
NOTAM issued by Kenai for Hope Airport (5HO), thin layer of packed snow on runway 16/34, observed at 1520 UTC on September 13, 2011.
But what does that really mean? Can you - or should you - land under these conditions? For pilots, there are a few things to consider when taking off or landing on runways with any type of contamination. FICON NOTAMs will often include braking action reports, given as GOOD, FAIR, POOR or NIL, like in the example above. These values are often reported by pilots as they land.
Sometimes, braking action is reported as a MU value. MU is the mathematical term for the coefficient of friction, and its value is determined by a friction measuring device at airports. A value of 40 or above would mean braking action is good. A value of below 40 MU can mean a significant reduction in braking action.
Landing on any runway with less than GOOD braking action can be hazardous. It’s always best to avoid landing on runways covered in snow and ice. Even water can decrease braking action significantly. If you must land on an icy or snowy runway, use extreme caution, make a normal, stabilized approach use aerodynamic braking as much as possible before touching down. Try to keep the nose wheel straight during the landing rollout to prevent skidding. And remember that the taxiways are often in worse condition than the runways - even if the runway has been cleared, there’s a good chance the parking area hasn’t been.