ATC/Pilot responsibilties for Cold Weather Ops

[Elmotower]

I am an air traffic controller in Burlington, Vermont. I have been pushing an issue with the FAA for over a decade that could someday have a devastating effect on some poor flight crew. Cold Weather Altimeter Errors.
At BTV we have an ILS approach to RY33 that starts approx 35 miles away(the transition). When BTV approach is open(5am-midnight) we vector to about an 18 mile final. When we close, Boston Center has the acft do the long transition.
Here is the problem. The USA does NOT have cold weather MVA/MIA/MEA charts for its' controllers. Canada does.
Vermont can have some very cold temperatures. In fact, for the next few days, we are expecting -30C.
The ILS 33 approach has step-down fixes/altitudes until glideslope intercept at approx 9 miles. The problem is the 3rd highest mountain in Vermont on a 14 mile final. The mountain is about 1/2 mile right of course and is 4088' high. The altitude a pilot can be at that point is 4800". During -20C and below, acft are actually at or below the peak just hundreds of yards right of course. In the years since the ILS33 was commissioned, myself and another controller took it upon ourselves to prevent a disaster. We got the facility to make the minimum crossing altitude over the mountain to be 6000' during -20C or lower. We have had no close calls as a result. Just a week ago, the transition became effective and now Boston Center is not using our stopgap measure and this approach is dangerous once again. I am using all avenues to get this corrected and would appreciate any knowledge of any incidents involving cold weather altimeter errrors.
Jeff

[Elmotower]

One more thing. Are there any pilots here that have flown in the continental US that DID tell the controllers that they were correcting for cold temps? I have been a controller in the USAF and FAA for over 30 years and I have yet to hear a pilot tell or ask me about cold weather correction. The mountain I referred to in my post has a B-24 bomber on its' southeast flank just below the top where it has been since 1944. I am sure cold wx played the critical role in its' demise. Let me know what you guys do in extreme cold and on higher than normal approaches. We also have a GPS33 approach that starts 6000' above field elevation and I think that is at risk as well.
Jeff

[Atcham Tower]

Jeff, I guess you have Googled for more but just in case you missed this:

http://www.bluecoat.org/reports/Long_98_Cold.pdf

It mentions an MD-80 in Canada breaking off an approach in low temps after a GPWS alert.

[Spitoon]

Whilst I don't know of any specific accidents or incidents related to this topic, it does come up periodically on this forum. If you do a search you might come up with:

http://www.pprune.org/questions/407793-when-cold-temperature-correction-effect.html
http://www.pprune.org/tech-log/400418-temp-correction-all-approaches.html
http://www.pprune.org/tech-log/399521-low-oat-altimeter-corrections.html
http://www.pprune.org/tech-log/390443-cold-weather-altimeter-corrections.html
http://www.pprune.org/atc-issues/356458-cold-weather-altimetry-seasonal-changes-minimum-altitudes.html
http://www.pprune.org/tech-log/337909-altimeter-cold-temperature-correction-policy.html
http://www.pprune.org/questions/291873-approaches-very-low-temperatures.html This one mentions a specific accident.
http://www.pprune.org/tech-log/124008-low-temperature-correction.html
http://www.pprune.org/military-aircrew/164329-altimeter-correction-temperature.html
http://www.pprune.org/tech-log/162550-cold-temp-corrections.html
http://www.pprune.org/safety-crm-qa-emergency-response-planning/108076-temperature-error-correction-lack.htmlThis one has pointers to some incidents.
http://www.pprune.org/tech-log/81305-cold-wx-altimetry-procedures.html

About the only thing you can glean for certain from these threads is that the procedures related to the topic are poorly defined and, often, poorly understood. Different States have different policies, perhaps even with local differences in application. Different operators have different procedures in their OMs, perhaps even a few with no reference to the topic (and I'm thinking of the ones that might operate in low temperatures). And different navigation technologies and systems function differently when handling cold temperature corrections.

Oh, and none of it is very transparent.

It is clearly a potential and specific hazard in your environment - I wish you well in getting a safe solution in place. In theory, any (and your) Safety Management System should have a method of handling the concerns that you raise.

[Elmotower]

Thank you for those links. For you Europeans....Do the controllers there use cold weather MVA maps for approach control? Canada does but the USA does not and that is the major concern that I have here. Pilots on vectors are assurred that the altitude given them is safe but on certain days of the winter they certainly are not. In the US, MVA's are suppose to give at least 1000' clearance from terrain and in mountainous areas 1500'. We have a mountain in our airspace(Mt.Marcy-highest mountain in New York) that our MVA is 7000'. At -30C, at 7000', the aircraft will actually be at about 5650' msl. Mt.Marcy is 5344'. 306' is not acceptable over the Adirondacks. Take away the 200' error that is acceptable to ATC for their Mode C and it might be 106'. I am fighting the FAA to establish Cold Weather MVA maps for the approach controllers and MEA/MIA charts for the Center controllers who clear aircraft into smaller non-towered fields.

[samotnik]

In Europe radar controllers definitely use low temperature correction for MRVA. Anyway, at least in Poland, there is no correction for MSA/AMA, but it seems that it has enough obstacle clearance margin included.

However, why don't you just add the correction yourself, regardless of FAA regulations?

[Elmotower]

Thanks for the info!
I do use higher altitudes when it is -10c or lower. Many of the radar controllers at BTV do as well. The problem is that management turns a blind eye to the problem and actually is a hinderence to getting a national solution. This can't be a one facility or some in one facility option as someday the law of averages will doom some aircrew.
Still fightin' the fight!
Jeff

[bfisk]

Keep up your good work, Elmotower. This business needs more people like you.


Flight crew in Norway here, and we definately think a lot about temperature correction. Here, the rule is that when under positive radar control, the controller is responsible, and otherwise ourselves - and even though the controllers are generally very good, we've had to refuse some altitude clearances because we deemed them too low for the meteorological conditions.