# NTSB SEA94LA231: Cessna 172G, N4628L, Paradise, WA, September 5, 1994 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: September 5, 1994, 15:10 local (22:10 UTC) - Place: Paradise, WA - Location: 46.7862° N, 121.7354° W: Placed by OpenAirDocs: center of Paradise, WA, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=46.7862&lon=-121.7354&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 3 minor - Status: Completed, report September 24, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 42016 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA94LA231 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42016/pdf - Page: https://openairdocs.org/ntsb/SEA94LA231 ## Probable cause PROPER ALTITUDE WAS NOT MAINTAINED AND IMPROPER INFLIGHT PLANNING/DECISION. FACTORS TO THE ACCIDENT WERE MOUNTAINOUS/HILLY TERRAIN CONDITIONS AND LACK OF TOTAL EXPERIENCE. ## Analysis THE NEWLY RATED PRIVATE PILOT STATED THAT THE AIRPLANE WAS UNABLE TO MAINTAIN SUFFICIENT ALTITUDE TO CROSS A RIDGE. HOWEVER, PASSENGERS AND WITNESSES STATED THE PILOT MAINTAINED VERY LOW ALTITUDE THROUGHOUT THE FLIGHT. PASSENGERS REPORTED THE PILOT TURNED THE AIRPLANE INTO A MOUNTAINOUS DRAINAGE WHERE THE AIRPLANE STRUCK TREES, THEN IMPACTED TERRAIN. THE GRADIENT OF THE TERRAIN WAS DETERMINED TO EXCEED THE CLIMB GRADIENT CAPABILITY OF THE AIRCRAFT. ## Factual narrative On September 5, 1994, approximately 1510 hours Pacific daylight time (pdt), a Cessna 172G, N4628L, registered to Cloud Dodgers Flying Club, Inc., and being flown by Dwight L. Youngquist, a recently certificated private pilot, was destroyed during collision with trees/terrain while climbing eastbound in a drainage approximately one mile south of Chinook Pass, near Paradise, Washington. The accident took place within Rainier National Park. The pilot and two passengers sustained minor injuries and a fourth occupant was seriously injured. Visual meteorological conditions existed at the time, and no flight plan had been filed. The flight, which was personal in nature, was to have been operated under 14CFR91, and originated from Packwood, Washington, with a destination of Paine Field in Everett, Washington. A witness reported seeing the aircraft depart the Packwood Airport, located 17 nautical miles south of the accident site. The departure was approximately 1445 and the aircraft was observed to fly northbound. A hiker in the Tatoosh Mountains just south of Rainier Park reported observing a blue and white aircraft flying northbound from the direction of Packwood and toward the Park. The hiker, who observed the aircraft from an elevation of approximately 5000 feet, estimated the aircraft's altitude to be approximately 4000 feet. A diagram of the aircraft's ground track drawn by the hiker on a topographic map indicates that the aircraft would have to maintain a minimum altitude of 4200 to 4400 feet along the depicted ground track to avoid impacting terrain. The time of this hiker's observation was approximately 1500. Another hiker located on the south side of Naches Peak and approximately one mile north of the accident site witnessed the accident. He stated the aircraft was well below his elevation of approximately 5800 feet elevation and was climbing up the drainage eastbound when it flew into trees in a wings level attitude at low speed. He also reported that the sound of the engine was smooth and uninterrupted with no sound of surging or misfiring. The pilot stated in his report of the accident that the aircraft was "unable to maintain sufficient altitude to cross (the) ridge ahead." However, two of the passengers stated that the pilot maintained very low altitude above the terrain throughout the flight. One of the passengers estimated the pilot's level-off altitude after takeoff from Packwood as "probably less than a thousand feet (above) the ground". These two passengers also stated that the pilot videotaped ground scenery during the flight. The passengers stated that while flying north up the valley along the road leading from Packwood, the pilot turned right (eastward) into Dewey Creek valley where the aircraft struck trees, then impacted the ground. The direction of flight at the time of the impact was estimated to be approximately 130 degrees magnetic, based on measurements from initial tree impact damage to the main wreckage site. The passengers also reported that the stall warning horn sounded several times just before the initial impact with the trees. The aircraft impacted approximately 5100 feet above sea level, about 150 feet below the 5250 foot maximum saddle elevation over the Dewey Creek valley. Based on reported passenger and fuel loading, the aircraft was at an estimated gross weight of 2100 pounds at the time of the accident. Its maximum certificated gross weight in the normal category is 2300 lbs. At 2100 lb gross weight and accident site density altitude of 6500 feet (estimated from Yakima weather observation), performance charts in the 1966 Cessna 172G owner's manual indicate the aircraft would have an approximate maximum climb rate of 470 feet per minute at a best rate-of-climb airspeed of 76 mph (equivalent to a climb capability of 371 feet per statute mile) with mixture leaned for best power. As measured on a topographic map of the area, terrain at the impact site slopes upward at over 1000 feet per statute mile. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, climb - terrain condition - mountainous/hilly (contributing factor) - proper altitude - not maintained, pilot in command (cause) - lack of total experience, pilot in command (contributing factor) - in-flight planning/decision - improper, pilot in command (cause) ## Aircraft - Registration: [N4628L](https://openairdocs.org/deregistered/N4628L-1998-10-26), registration cancelled 1998-10-26, S/N 17254623 (OpenAirDocs) - Reported make and model: CESSNA 172G - Registry model: [Cessna 172G](https://openairdocs.org/model/cessna-172g) (registry code 2072420) (OpenAirDocs) - Category: Airplane - Serial number: 172-54623 - Airframe hours: 6380 - Engines: CONTINENTAL O-300-D 145 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Registered owner: Cloud Dodgers Flying Club - Airworthiness certificate: Standard, Utility; Standard, Normal - Last inspection: Annual, June 24, 1994, 68 hours before - Departed: 55S, PACKWOOD, WA - Destination: PAE, EVERETT, WA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 78 total, 56 in this make and model, 31 as pilot in command, 18 in the last 90 days, 4 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 70° at 4 knots - Visibility: 60 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 46 °F - Altimeter: 30.00 inHg - Observed at: YKM, 43 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19940905025349A](https://openairdocs.org/incident/19940905025349A), Sep 5, 1994: Cessna 172G, Paradise, WA, Destroyed. Flying too low in a mountain valley unable to outclimb rising terrain or turn around. Flew into trees. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.