A C208B pilot reported tks fluid odor from the prop slinger entered the cockpit after takeoff. The r...

Narrative:

I had not flown this aircraft for several days so prior to the flight I did a pre-flight test of the tks system in order to confirm its status. I ran the tks system just long enough (approximately 3 to 4 minutes) to confirm the proper operation of the system components and to achieve a moderate purge of the panels. It was a warm morning; so prior to departing the ramp I opened the left side fuselage air vent for taxi; intending to close it before takeoff. After takeoff; having just leveled off within 5 to 6 minutes of takeoff with the tks system turned off; I began to feel an irritation of my nose/throat and smelled a strong alcohol odor. I immediately realized that I had forgotten to close the side air vent before takeoff. Closing the left side air vent stopped the alcohol odor promptly and my nose/throat irritation dissipated a fairly short time later. I felt that there was no need for me to use the O2 mask in flight and chose to continue the day's flight legs with the tks system turned off/fuselage side vents closed. The overhead/wing air vents were left open in flight throughout the day without any evidence of alcohol fumes in the cockpit. From past experience with the tks system I feel confident that; even with the system turned off while in flight; residual tks fluid in the supply lines from my ground test had drained down to the prop slinger from higher points in the system where it was sprayed into the air stream and entered the cockpit through the open fuselage air vent. Evidence of this fluid drain-down when the system; with no apparent check valves in the fluid supply lines; is turned off after having been run is clearly visible when an aircraft is parked after a flight during which the tks system has been used. Large puddles of tks fluid that collect on the ground under the prop and the fuselage strut attachment points are a normal occurrence lasting more than 24 hours after a tks flight.in my experience this tks system off fluid drain down and subsequent entry of the fluid spray into the air stream can result in tks fumes being detected in the cockpit of an aircraft in flight that has a windshield or cockpit air leak.

Original NASA ASRS Text

Title: A C208B pilot reported TKS fluid odor from the prop slinger entered the cockpit after takeoff. The reporter preflight tested the system; but failed to close the fuselage left air vent. Reporter noted that residual fluid drains for an extended period with TKS system OFF.

Narrative: I had not flown this aircraft for several days so prior to the flight I did a pre-flight test of the TKS System in order to confirm its status. I ran the TKS System just long enough (approximately 3 to 4 minutes) to confirm the proper operation of the system components and to achieve a moderate purge of the panels. It was a warm morning; so prior to departing the ramp I opened the left side fuselage air vent for taxi; intending to close it before takeoff. After takeoff; having just leveled off within 5 to 6 minutes of takeoff with the TKS System turned OFF; I began to feel an irritation of my nose/throat and smelled a strong alcohol odor. I immediately realized that I had forgotten to close the side air vent before takeoff. Closing the left side air vent stopped the alcohol odor promptly and my nose/throat irritation dissipated a fairly short time later. I felt that there was no need for me to use the O2 mask in flight and chose to continue the day's flight legs with the TKS system turned OFF/fuselage side vents closed. The overhead/wing air vents were left open in flight throughout the day without any evidence of alcohol fumes in the cockpit. From past experience with the TKS system I feel confident that; even with the system turned OFF while in flight; residual TKS fluid in the supply lines from my ground test had drained down to the prop slinger from higher points in the system where it was sprayed into the air stream and entered the cockpit through the open fuselage air vent. Evidence of this fluid drain-down when the system; with no apparent check valves in the fluid supply lines; is turned off after having been run is clearly visible when an aircraft is parked after a flight during which the TKS System has been used. Large puddles of TKS fluid that collect on the ground under the prop and the fuselage strut attachment points are a normal occurrence lasting more than 24 hours after a TKS flight.In my experience this TKS System OFF fluid drain down and subsequent entry of the fluid spray into the air stream can result in TKS fumes being detected in the cockpit of an aircraft in flight that has a windshield or cockpit air leak.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1189291
Time
Date	201407
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Caravan 208B
Operating Under FAR Part	Part 135
Flight Phase	Cruise
Component
Aircraft Component	Propeller Ice System
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Commercial
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy Flight Deck / Cabin / Aircraft Event Illness Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

A C208B pilot reported tks fluid odor from the prop slinger entered the cockpit after takeoff. The reporter preflight tested the system; but failed to close the fuselage left air vent. Reporter noted that residual fluid drains for an extended period with tks system off.