Maybe this will finally bring the insanity of “instantaneous winds” to a close? Aspen airport remains closed after jet goes off runway; all Monday flights canceled
Hawker overrun ASE
- Thread starter pwttogfk
- Start date
sweeps
Undercarriage Actuator
What’s instantaneous winds?
Stone Cold
Well-Known Member
It sounds like they aborted the takeoff, if that audio clip is from this accident.
T/O w/FSII
Well-Known Member
Aspen is notorious for having a 9 knot tailwind reported by the tower when the atis says 12g18
Can Skywest guys answer what is your limitation? I went in behind a crj a few weeks back and they landed with a 12-15kt tailwind. We elected to circle as it was the only way we could legally get in. Ironic, because I know they aren’t allowed to circle.
How you “legally” use Aspen when it’s windy. The controller will wait till whatever winds you need are observed momentarily and then say something like “Winds 150 at 18 gust 24, instantaneous winds 150 at 9, cleared for takeoff.” Boom, you didn’t exceed a 10 knot tailwind! Until, literally, boom. Something about the normalization of deviance?
CFI A&P
Exploring the world one toilet at a time.
99% of Part 25 certified aircraft have a 10 knot tailwind limit, and with that and other constraints of terrain and available approaches Aspen's normal operations are to land south, depart north unless you're part of the select few operators that are permitted to circle in the valley to land north and avoid the tailwind problems of landing south. Often times you need a wind check from ASE tower to get a wind reading that is lower than what is advertised on ATIS.
When the winds are stiff, or anything else happens at ASE, Rifle (KRIL) becomes the busiest non-towered airport in the country until ASE resumes normal operations.
Roger Roger
Bottom of the list
If I can make it through my career without going into Aspen or Teterboro, I’ll retire a happy man
GypsyPilot
Mohawk Town
When I was there we had a limit of 10kts, which is a CRJ 700 limitation. No, we couldn’t circle as the 700 is a Cat C. Yes, the “instantaneous” winds are a thing if you know what you’re doing. The winds in Aspen are highly variable, and if just went off the ATIS there would be days you couldn’t get in when in reality the wind dies off at times and you can safely arrive. Using an instantaneous winds request from tower can help you get in as long as you have the big picture and monitor a few other variables like GS, etc. Most importantly, you have to be ready to bail (with a plan on place) if the winds pick up before you land.
If you know what you’re doing and frequent ASE a lot, it’s fine. But if you’re Joe Blow part 91/135 guy that flies up there a couple times per year, you probably shouldn’t be operating the same way as SkyWest/Netjets/local corp guys are.
I flew in and out of there as both a FO and CA for years during all four seasons, and never pushed anything that I or the other pilot was uncomfortable with or had any question of legality. I ended up diverting to GJT all the time, and had absolutely no qualms about bailing anywhere on the approach to do so.
Departing is a different story, as you can’t just bail on a whim. I never used instantaneous winds for taking off, I’d load up and go sit down by the deice pad until the winds very clearly calmed down and had a trend of calming down before going. Usually the winds were an issue with landing, not departing. But still there were definitely days where we ended up just canceling or waiting a few hours to go.
///AMG
Well-Known Member
Haha I remember while I was out in Fallon, I had an old commanding officer who was flying his last navy flight. It was his flight of 4 at the hold short, with winds well out of SOP (think opspec) limits due to both sustained and gust factor (it is an issue of our parachutes and surviving a post ejection parachute landing, not flight characteristics/performance). He kept asking for tower to "say winds". Eventually they reported something that was momentarily less than the limit, "XXXXX ready for takeoff"
sweeps
Undercarriage Actuator
Thanks. I was thinking something along those lines but wasn’t sure