typeII/IV fluids

[punkalouver]

If type I fluid is unavailable, are you allowed to use type II or IV only?

[Intruder]

If your OpSpecs, FHB, or other manuals allow it...

[oldebloke]

Requires a certain airspeed,prior to liftoff,to shift it.....Ergo Type 4 wasn't approved for certain Turboprops...
Cheers:ok:

[punkalouver]

Anybody have an answer to the original question?

[Intruder]

There is no single answer. It depends on the circumstances, the airplane, and your authorized Anti-Ice/De-Ice program. What do your manuals say? :confused:

[punkalouver]

The reason I posted in the first place was because of an article I read recently. It says "...unless all surfaces are aerodynamically clean, the aircraft must first be de-iced with type I fluid. All type II/IV fluid must be removed with type I fluid before departure if the parking time has exceeded four hours."

I have not seen this in our de-ice manual. Is it in yours?

[Empty Cruise]

Hi punkalouver,

I cannot see that as preventing use of typ. II & IV fluids. It only states that - of such types had been applied earlier, they will - after 4 hours (:} ) have watered down so much that they consitute more of a freezing threath than any kind of protection - and must therefore be removed like all other contaminants. You would only run into this problem if you - after being deiced/anti-iced had a delay for more than 4 hours...

However - I can read that paragraph as prohibiting the use of a one-step procedure. First you must remove the contaminants using type I - and than onto anti-icing with type II/IV. So you're right - you will need type I to comply with the wording in that paragraph.

Used to fly in Norway - on runways where the ATR did not like type II/IV (if you wanted to carry anything but yourselves and a few drops of fuel). Solution - board pax in hangar, then apply type I fluid. Since in the hangar - the HOT had not yet started. Then start 2 in H-mode (with prop-brake), push-out while starting 1, and then hurry off to the runway. Seem to remember we had 7 min. HOT from when the tail first stuck out of the hangar :ouch:

Brgds
Empty

[punkalouver]

Thanks for the interesting post empty cruise. I as well read that a two step procedure is required. Is any one out there authorized sprayed down contaminated wings with just the type II or IV ?

[alatriste]

Of course, this is the standard procedure all over european airports (don´t know about turboprops). Type II/IV fluids when heated (60ºC) and diluted may be used for deicing and antiicing in a single step.
If you want to know more check:
www.boeing.com/commercial/aeromagazine/aero_08/deice
www.aea.be
www.alpa.org/internet/alp/2000/nov00p15.htm