Cessna 421B N8005Q

Summary

On 19 November 1996 at about 16:10 local time, a Cessna 421B registered N8005Q, operated by Crossings Aviation, was involved in an accident near Olympia, Washington, United States. 3 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

19 November 1996 at 16:10

Classification

Accident

Location

Olympia, Washington, United States

Nearest airport

Olympia (OLM)

Coordinates

46.9700, -122.8706

Aircraft

Cessna 421B

Registration

N8005Q

Category

Airplane

Engines

2

Operator

Crossings Aviation

Operating rule

Part 91: General Aviation

Purpose of flight

Business

Phase of flight

Not recorded

Route

Tacoma → Ontario

Aircraft damage

Substantial

Weather

IMC

Light

Dawn

NTSB number

SEA97LA030

Nobody was injured.

inoperative deicing equipment, due to multiple wing boot holes and malfunctioning control/shuttle valves; subsequent build-up of airframe (wing) ice; and failure of the pilot to maintain adequate airspeed during the flare for landing. Factors relating to the accident included: the adverse weather (icing) conditions, and inadequate maintenance concerning the deicing equipment.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot stated that during climbout on an IFR flight, he frequently checked the wings for ice accumulation, noting what appeared to be a 'mere' trace of ice. At about 13,000 feet msl, with almost no climb at 125 knots indicated airspeed, the pilot pulled the yoke back a little to climb, and the aircraft began to shudder. The pilot then decided to divert, again checking the wings, seeing what he described as a trace of ice. He said he cycled the deice boots with no apparent change in wing appearance. While on approach, he again cycled the boots between 3000 and 2000 feet msl. The pilot stated that about 20-30 feet above the surface, he started a slight roundout, but when he eased back on the yoke, the airplane shuddered and the nose did not raise. At that point, he was ready to touch down, so he pulled back on the yoke while adding power; however, the airplane landed hard and was damaged. Later, the surface deice system was tested. The boots did not hold pressure due to multiple wing boot holes and a shuttle valve internal leak. Functional tests revealed that the control valves did not direct proper pressure to the system, and that the shuttle valves did not direct pressure properly to the boots (there was leakage to the vacuum side of the valves).

Quoted verbatim from the NTSB record.