Wednesday, July 21, 2021

Cessna 421C Golden Eagle II, N66NC: Accident occurred July 10, 2021 at Vance Brand Airport (KLMO), Longmont, Boulder County, Colorado

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.

The National Transportation Safety Board did not travel to the scene of this accident. 

Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Denver, Colorado 

Registration Pending
Applicant: Fly High Fly Free LLC

Location: Longmont, CO 
Accident Number: CEN21LA315
Date & Time: July 10, 2021, 09:20 Local 
Registration: N66NC
Aircraft: Cessna 421C 
Injuries: 4 Minor
Flight Conducted Under: Part 91: General aviation - Personal

On July 10, 2021, about 0920 mountain daylight time, a Cessna 412C airplane, N66NC, was substantially damaged when it was involved in an accident near Longmont, Colorado. The pilot and three passengers received minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

After the airplane lifted off from the runway, the pilot didn’t feel that the engine(s) were making full power. The airplane settled back onto the runway, then exited off the departure end of the runway. The airplane came to rest upright, and a small post-crash fire developed. Substantial damage was noted to the airplane’s fuselage and wings.

The airplane wreckage was retained for further examination.

Aircraft and Owner/Operator Information

Aircraft Make: Cessna
Registration: N66NC
Model/Series: 421C
Aircraft Category: Airplane
Amateur Built: No
Operator: On file 
Operating Certificate(s) Held: None
Operator Designator Code:

Meteorological Information and Flight Plan

Conditions at Accident Site: VMC 
Condition of Light: Day
Observation Facility, Elevation: KLMO,5056 ft msl 
Observation Time: 09:15 Local
Distance from Accident Site: 0 Nautical Miles
Temperature/Dew Point: 26°C /9°C
Lowest Cloud Condition: Clear
Wind Speed/Gusts, Direction: 3 knots / , 140°
Lowest Ceiling: None
Visibility: 10 miles
Altimeter Setting: 30.31 inches Hg 
Type of Flight Plan Filed:
Departure Point: Longmont, CO

Wreckage and Impact Information

Crew Injuries: 1 Minor
Aircraft Damage: Substantial
Passenger Injuries: 3 Minor
Aircraft Fire: On-ground
Ground Injuries: 
Aircraft Explosion: None
Total Injuries: 4 Minor
Latitude, Longitude: 40.16726,-105.16927 (est)

LONGMONT, Colorado (CBS4)- Two people were hurt in a plane crash at the Longmont Airport on Saturday morning. Police say the private plane was in the process of taking off, and gained some altitude but later came back down.

The impact broke the landing gear causing the plane to skid off the runway.

Four people, in total, were on board, but the pilot and a woman were taken to the hospital, treated and released. Police describe the passengers as a 39-year-old man, a 44-year-old man and two women, both 37 years old.

Two people were taken to the hospital Saturday with injuries that were not life-threatening after a private plane crashed at Vance Brand Airport before it was airborne.

Longmont police Sgt. John Wederquist said the crash occurred about 8:30 a.m. There were four passengers in the plane: two men, ages 39 and 44, and two women, both 37. He said the passengers were able to walk away from the crash, with no extrication needed for emergency responders to reach them.

The cause of the plane crash remains under investigation by the airport and the National Transportation Safety Board. 

The plane traveled about 50 feet off the runway. Its engine caught fire after the crash. Responding Longmont firefighters put out the blaze. Wederquist said he was not sure what type of plane it was that crashed.

The airport’s runways were shut down for approximately 30 minutes while first responders worked at the scene.


  1. Density altitude at the time was 7500 feet. No surprises here.

    1. Almost certainly more nuanced than that alone; registered engines were GTSIO-520 SER Continentals. and with only 4 on board? Lucky, though! Could've easily been a fireball...

  2. Ah, 4799ft ? 915am local. Not that late in the day "Unknown"


      Works out to a density altitude of 7171'

  3. Wondering who removed the nose baggage doors.

  4. Right prop was not pulling when touched the earth. If it was the blades would be bent forward.

    1. Look closer chief...the visible blades in both photos, top and horizontal one, and bent back and curled back at the tips.

    2. Thanks for confirming that they are bent back which means they were not producing power on contact. If powered up the blades bend forward. Chief?

  5. 10:18:18 6 groud L
    10:24:32 73 4700 L
    10:24:51 93 4700 L
    Speed: 93 kt
    Altitude: 4,700 ft
    Vert. Rate: 64 ft/min
    Track: 302.7°
    Pos.: 40.168°, -105.171°

  6. Turbocharged engines don't feel the density altitude until reaching and exceeding the altitude where the waste gates are fully closed.

    At the 7000+ density altitude he was at the waste gates would only be partially closed and he would have been producing near sea level power if the engines were operating properly.

    The props and wings would be feeling the density altitude which would reduce performance some but shouldn't have been a problem for this plane wit everything working properly.

    I'm guessing the pilot knows his plane better than any of us so I'm believing if he felt something was wrong, aborting was the correct choice rather than hoping it would keep flying. Everyone walked away from this one. Most likely would have ended badly if he continued on