DeIceing QUestions

[Lomcevak]

In the days before CRM, when an AIr Florida flight was planted in the Potomac River, the CVR contained some comment to the effect that "they should have something like a car wash that the planes go through on the way to the runway". Well, it seems that at KPHL, they do. Flew out this morning. OAT was 12F. No visible moisture below a deck which was several thousand feet up and about as thick. Plane had already made one flight before arriving at KPHL and was bound to a warmer clime. No visible ice on wings; could not see tail.

However, it seemed that many [if not all] planes leaving were subject to a full body deiceing. There were five lanes set up for the purpose and one or two planes waiting at each spot. There were enclosed cherrypickers on each side of each aircraft, and it seemed they sprayed whatever they sprayed not only on the flight surfaces but the entire airplane.

My questions are basically -- is this a new policy worldwide, or a policy of KPHL (several different airlines were getting what looked like unnecessary care and attention)? Could they have possibly been spraying an anti-iceing agent rather than a de-iceing one? And with five lanes running nonstop, what becomes of the runoff?

[Gabriel]

Could they have possibly been spraying an anti-iceing agent?

Does such a thing exists?

[3WE]

I recall some more-than-lively discussions on AD.com.

No such thing as ANTI ice as I recall.

If everyone was getting deiced, I would assume that there was something there....maybe a little frost.

Also, there was quite the temperature inversion and some surface-icing happening in the Central/Eastern US....maybe some freezing rain was in the area???

[RadarContactLost]

UPS at SDF has the mother of all de-icing systems, an overhead gantry that is programed by airplane type to set the wingspan and control how many nozzles are used. Many airports have an area for deicing where the drains try to separate the deice fluid from normal runoff. There is sort of a herd mentality about deicing, if they're doing it maybe I should.

[ZeroAltitude]

There used to be more or less gigantic semi-automatic de-icing facilities at Munich (MUC/EDDM) airport (for types up to 747 size).
They have been decommissioned, though, several years ago.
I'll try to find some backgrounds on the net.

[ZeroAltitude]

Only found some German-language resources on the Munich deicing system.

Bottom line:
It was in use for eight years from 1992 (inauguration of the new Munich airport) and was a taxi-through device located over the taxiways near the take off points (of 26L/R if I remember correctly).
The system would have had to be extended to accomodate winglet-equipped planes and larger types such as 777 and A380, and this was deemed uneconomical because meanwhile the operating cost of modern deicing trucks had diminished.

[Dmmoore]

The "Car Wash" style anti-ice systems were designed to recover most of the de-icing fluid and therefore would reduce cost overall.
In use it was discovered that the system sprayed more fluid than trucks typically dispense and the recovered fluid wasn't enough to off set the difference.
Some airports are using an area where aircraft can taxi past a group of trucks that de-ice the aircraft in a place where fluid recovery is possible. It works more efficiently than the fixed spray systems but several such locations are required for efficient operation.

Back in the dark ages, we departed three 747 daily from ANC to NRT at 10 minute intervals. Two other 747's were added 3 days a week, all falling into a 60 minute window for departure. We used a single Trump D-40 de-icing truck. We would start de-icinf the first aircraft as soon as the cargo doors were closed on one side. Typical delay for the first aircraft was 10 - 15 minutes. Recharging the truck took 15 minutes. The second aircraft was 30 - 45 minutes late. Each aircraft in line was that much later.

We got a new VP. After reviewing the delay report he wanted justification for the "escalating" delays. He commented that at SLC Western airlines departed 20 aircraft in 90 minutes without taking a single delay exceeding 10 minutes.

My comment was; "How many de=icing units did you use?"

His comment; "I don't know, 8 or 10."

My comment; "Try it with one."

We had a second truck the next winter. Delay lengths dropped by 70%.