SEA97LA030 · Cessna 421B
Crossings Aviation Cessna 421B · Accident: in flight encounter with weather en route
From Tacoma Narrows Airport (TIW) to Ontario Municipal Airport (ONO)
Event
- NTSB case
- SEA97LA030
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Instrument Meteorological Cond
Cessna 421B
- Aircraft type
- Cessna 421
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N8005Q
- Operator
- Crossings Aviation
- Onboard fatalities
- Unknown
- Route
- From Tacoma Narrows Airport (TIW), Tacoma, WATo Ontario Municipal Airport (ONO), Ontario, OR
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · climb to cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- In flight encounter with weather
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Airframe › Ice
- Anti-ice/deice system › Inoperative
- Pilot in command › Airspeed, inadequate
- Pilot in command › Flare, not attained
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
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).
Probable cause
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.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA97LA030
- Event ID
- 20001208X07119
- Case number
- SEA97LA030
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 642cf9a439981e200ee1d718e3362ec68510a0e0a60cbac9e215fc149789de32; retrieved 2026-09-22T20:46:10.436Z.