Caravan 208B
Flight Crew Air Transport Pilot (ATP)
Confusion; Distraction; Situational Awareness; Physiological - Other
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Illness / Injury
Flight Crew Became Reoriented; General Physical Injury / Incapacitation
Aircraft; Company Policy; Environment - Non Weather Related; Procedure
OAT 104 [degrees] F; cockpit temperature 130 [degrees] F (No air conditioning) extremely hot. New hire Training flight in TKS equipped Caravan. Open doors on aircraft; TKS aircraft all have chemical odor in the extreme heat that is very apparent upon opening doors. Pilots demonstrated preflight check of TKS. Both pilots noted strong chemical odor from TKS fluid dripping from aircraft (normal odor from TKS aircraft). TKS fluid observed running into cabin air inlet at top of struts (typical). Pilots closed pods; noting aircraft latches and handles are constantly sticky from TKS fluid. During flight; instructor noted throat irritation and nausea. Upon landing instructor asked trainee how he felt; trainee complained of very bad taste in his mouth; nasal passages burning; and one eye burning. Both pilots were 'sticky' after flight. Both pilots again discussed the odor of TKS aircraft in the extreme heat.TKS aircraft are sticky inside and out; including door handles and pod latches. Crew comes in contact daily with TKS dripping on them; and while closing up aircraft latches. It appears aircraft cabin air system is contaminated with TKS and spraying the crew while in cockpit. It appears the extreme heat is making the vaporization of TKS fluid much worse. Pilots have noted closing pods; latches being sticky; and then placing a piece of gum in their mouth and feeling sick later.
The reporter stated that the C208B ventilation system allows air intake through two ram air inlets; one on each wing at the upper end of the wing struts. These aircraft's TKS systems are comprised of a TKS fluid holding tank with two pumps which when activated supply the fluid to open ended wing mounted titanium panels with microscopic laser drilled holes. The TKS fluid seeps through the wing panel holes at about 4 PSI then flows over the wings. The fluid leaves the holding tank under approximately 135 PSI.TKS System pre-flights are conducted before flight during winter months; but may be delayed until in-flight during summer months. The system is functionally tested weekly in all weather conditions because experience has shown dirt and other contaminants can clog the microscopic holes. If conducted during ground preflight; environmental concerns require precautions which vary depending on the airport. Some measures may be as extreme as protecting the aircraft's foot print to capture the TKS fluid for safe removal and disposal.During flight; seeping fluid can enter the ventilation system through the wing intakes in turn coating all cockpit and internal surfaces with fluid. Pilots then breathe the fluid; touch it on cockpit surfaces and in some cases ingest it if food items are touched; then placed in a pilot's mouth. Systematic cockpit cleaning to remove the fluid residue does not happen. The reporter stated that recently he laid his open chart manual on the right seat and pointed the air vent in that direction. When he later handled the manual TKS fluid blown on it makes the manual sticky. One pilot recently called the reporter to say he felt physically impaired and could not safely drive home. The reporter stated that he has had to pull off the road and recover before driving home following a flight on which the TKS system was activated. Also; a Ramp Agent approached him to displayed chemical burn from TKS fluid which had dripped on him during the previous day's preflight. Reporter stated other pilots have also addressed this issue with the reporter's company. The pilots are aware of the MSDS Chemical Data Sheet hazards and cannot believe this fluid is being used.
A C208B pilot reported adverse reactions while operating an aircraft with the TKS anti-ice system installed; during both summer and winter operations.