BAe 125 Series 800
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Issued New Clearance; Flight Crew Landed As Precaution; Flight Crew Took Evasive Action; General Maintenance Action
Weather; Aircraft
The following event took place departing under FAR 135 with passenger onboard. On engine start snow rate increased and visibility had decreased from +6 miles on landing to 1 1/2 mi in mist and snow. Crew prepared for flight in IMC and ice as per previous flights that day; priming and running TKS anti ice system for 5 mins before takeoff. Departure roll was normal as was lift off and initial climb out with instructions to climb to 3000 FT on the runway heading. This was accomplished and crew extended TKS operation for 10 mins and turned on Eng Anti Ice. Normal indications in the systems allowed for continued flight in IMC in Ice. A 32 min flight indicated a busy climb and descent in NY airspace. Crew began to prepare for let down by programming approaches into [our destination]. Whilst pilot not flying (PNF) programmed FMS and tuned radios for ATIS; pilot flying (PF) extended TKS timer to an additional 10 mins as ice was observed to be accumulating on the wing tip leading edges. At this time the Anti Ice Lo Press annunciator illuminated indicating a loss of TKS movement to the protected surfaces. I interrupted PNF and called for checklist; which states leave icing conditions immediately. In initial climb icing had been reported from as low as 8000-16000 FT and crew had observed clear conditions at 17000-FL210 on previous leg. I called for a climb to exit icing and climb to 17000 as FL180 was not usable due to low pressure QNH 29.54. ATC approved and climb to VMC and clear of ice was accomplished. Wings had accumulated significant ice as had windshield. Checklist was completed and a discussion between PF and PNF began on what options we had to shed ice. The anti ice timer was shut off and re-engaged and timed taking 13 secs for the LO Press light to re-illuminate. After several attempts to push liquid on the wings and tail in an attempt to shed the accumulated ice crew observed no change. Referencing the checklist at this time it is noted that a flap 15 or flap up landing should be made. Center inquired as to issue and was informed of a total failure of TKS ice protection system and that significant ice had accumulated on the flying surfaces contaminating the wings. Center initiated descent however crew asked for delay to minimize exposure to ice and prepare for landing and delay to further accommodate any shedding of accumulate ice. This was approved. Crew completed checklist and moved to reduced flap and no flap checklist for landing with ice contaminated surfaces. Landing distance is twice that of flap 45 Far 135 60% and calculated weight of 20;500 lbs produced a landing distance of 4000 ft dry (8000 ft) and 4600 ft (9200 ft) wet which when doubled exceeded [our destinations] runway length 6549 ft. Crew discussed and a decision was made to divert to an airport with longer runway. [A nearby airport] was decided as a good diversionary alternative. Passenger was briefed on diversion and reasons why; adding safety of flight had not and would not be compromised and that diversion was the safer option for landing. Passenger agreed and seemed slightly nervous however crew encouraged safety first in landing at a longer runway was best option. Request for [the larger airport] was passed to ATC and approved. Direct to [our destination] was cleared by ATC and crew complied. A descent was given to 12000 FT and rejected by crew due to current ice layers and known levels of ice accumulation at that altitude. 10000 FT was cleared and again rejected. I explained to Center that aircraft had experienced anti ice TKS system failure and aircraft surfaces were contaminated with ice and were unable to shed accumulated ice. I requested descent to clear ice and IMC starting at 3000 FT. This was approved and Center passed us over to approach. Descent was initiated and maintained to minimize accumulation however accumulation still resulted in over 1' of ice on surfaces. I maintained manual control of aircraft during descent observing heavinessof roll and pitch. Positive control was maintained. Temperature at 3000 FT still measured 0C and thus ice melt was not established nor shedding allowed. Tracking to [our destination] I made decision that ice would not shed and decided to land as soon as possible and requested [the larger airport] direct declaring and asking for priority handling. Approach asked for Souls on Board and fuel. 3 SOBs and 1.5 hours fuel remaining. Approach cleared direct to [the larger airport] any runway. We discussed Runway XX however Runway YYL would result in same time frame and we were not emergency aircraft. Runway YYL was issued and crew started letdown and configuration for approach and landing. Ref was calculated and ref+45 in ice resulted in 165 knots calculated. Gear lowered for increased stability; a smooth landing was made on Runway YYL. Taxiing in all ice present on approach had shed airborne. Passenger was alighted and escorted into the FBO by crew. Passenger was extremely relieved and thankful to the great job crew accomplished. TKS anti ice pump was found to be inoperative on the ground although over 1/4 (30 mins) of fluid remained indicated on gage in cockpit. Pump was removed and replaced by technician the following day.
Hawker 800 Captain describes the diversion required when the TKS anti ice system fails in icing conditions.