(pensive music) (water spraying)
- Determining how you spray the airplane
is different every time you spray an airplane.
- [Narrator] This is Jim Decker,
director of ramp operations for United Airlines
at Dulles International Airport.
He knows a lot about deicing aircraft.
- If there's heavy snow on it,
and there's no wind, you can kind of do a fan pattern.
- [Narrator] He's been deicing planes
for more than 30 years.
In his role, it's a part of daily operations.
And that's not just in winter season.
That is 365 days a year.
- [Narrator] That's because this takes
a lot of coordination.
Get it right, planes take off smoothly.
Get it wrong, flights are delayed.
So Decker is here to explain how deicing is done,
what this orange liquid is exactly
and how the time you spend here ensures you get here.
(lively music)
- So when there is precipitation coming down,
there are two steps.
There's Type I, which is deicing the airplane
and Type IV, which is anti-icing the aircraft.
- [Narrator] Type I and Type IV,
those refer to the types of liquids used in each step
and the two main types used in the US.
But before spraying even begins,
the pilot inspects the aircraft to see if it's needed.
- Here we do spray though almost every day for frost.
- [Operator] Copy, Flight 667. (indistinct)
- [Narrator] Once the call is made,
the planes at Dulles move to the deicing pad
where United has cleaned more than 450 aircraft
so far this season.
The pilot then configures the aircraft
for deicing by moving the wings and the tail
to allow fluid and ice to easily slide off the plane.
Then the trucks roll in and spraying begins.
(lively music)
- When we deice an aircraft,
we're using Type I fluid.
Type I fluid is a mixture
of glycol and water.
We usually do it at 50-50
and then we heat it to approximately 180 degrees.
- [Narrator] Also in this mixture, orange dye,
so when the fluid hits the white snow,
it's easy to spot and see rolling off the aircraft.
- When figuring out how much fluid to use per aircraft,
if it's a light snow or a frost,
you could use maybe 7 to 10 gallons of deicing.
When it's a heavy snow,
you could use up to 1,000 gallons per aircraft.
- [Narrator] These trucks hold as much as 1,500 gallons
of Type I fluid,
which is sprayed from the detached deicing pods
where operators control the spray's pressure
and flow rate.
- It's kinda like your garden hose
where you can adjust it to either be a straight stream
or you can have a fan pattern on it.
And if there's no wind,
a fan pattern will work much better
and you can get much more area.
But when you have wind
and you have heavy icy snow conditions,
you really wanna have that powerful stream,
kind of like a fire hose.
- [Narrator] Spraying typically begins
at the nose of the plane,
moving down the aircraft,
hitting the fuselage and then the wings
and making sure to avoid hitting any windows
or sensors directly.
United typically puts two to four trucks
on an aircraft depending on need.
- The glycol soaks into the snow
and kind of melts it, and kind of starts loosening it.
Then we'll go back and we'll spray it clean.
- [Narrator] But keeping it clean,
especially during active snowfall,
typically requires another spray
but not with this orange stuff.
(lively music)
- Any time there's precipitation coming down,
after we've cleaned the aircraft,
we always wanna go back and anti-ice the aircraft
and that's using Type IV fluid.
- [Narrator] Type IV's most noticeable difference
from Type I?
It's green.
Decker's team also uses a mixture
that's 100% glycol and they put it on the aircraft cold.
- It's thick but you don't cover the entire airplane,
you just cover your critical surfaces,
which are your wings, and your tail.
- If Type I is a cleaner, Type IV is a protective coating
against the falling precipitation meant to keep new ice
from forming on the aircraft.
And Decker says it only takes about 25 to 100 gallons
of Type IV to do the job.
But the protection from Type IV only lasts so long.
- It does not protect you in the air,
it protects you getting to the air.
(lively music)
- [Narrator] After planes leave deicing,
a clock is set with something called holdover time.
- Holdover time is the amount of time
from the time you sprayed anti-icing, Type IV,
to the time the aircraft
actually starts rolling down the runway for takeoff.
- [Narrator] Holdover time is determined by precipitation,
temperature and aircraft type.
Generally the wetter and colder it is,
the shorter the holdover time.
- If it's just a light snow,
you can actually have a two to three-hour holdover time.
If you have freezing rain,
you will have maybe up to 15 minutes of hold time.
These times are set to ensure planes take off
before more ice can form
because in order to get the lift needed to take off,
planes need a smooth surface.
Ice the thickness and roughness of sandpaper
can reduce wing lift by as much as 30%.
- If it's a rough surface,
then that's when the airplane starts rocking
and it doesn't have the ability to lift up.
It has to be a smooth surface.
I always say like glass like, a column like.
- [Narrator] The Federal Aviation Administration
publishes updated guidance on holdover times each year.
United uses software to determine these times
for its aircraft.
If a plane sits past its holdover time...
- There's a possibility that the fluid
is contaminated with snow and ice,
and you won't have that clean surface.
So you have to restart the whole process over again.
- [Narrator] And that means more time spent on the ground.
Even if a plane only goes through deicing once,
it adds time to your trip.
How much depends on the weather
and the aircraft type.
- This is a 737 model.
So this is one of our narrow body aircraft,
our smaller aircraft.
In order to clean it,
which is deicing fluid on it,
clean it all off and then anti-ice it, protect it,
it'll take anywhere from 17 to 25 minutes.
On a wide body, it could take anywhere
from 35 minutes to an hour
to actually spray off a wide body aircraft.
- [Narrator] To address the additional time needed,
Decker's team works with the control center
to create a deicing scheduled.
This can result in the flight to delay boarding
to wait for an open spot on the deicing pad.
United says it warns travels ahead of time
if winter weather's expected to cause delays,
offering passengers the chance to rebook,
in some cases, before coming to the airport.
Of course, knowing if it's worth the potential added cost
to change your flight is a tough call.
Kinda like predicting the weather.
(lively music)