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. Turbo engines; density altitude not a major player, certainly not at 7,500 feet.

    3. Density altitude not a major factor with turbo charged engines.

  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?

    3. Were you two little bitches married to each other previously??!....I would bet one ...or both....are AP Mechanics!! ;-)

  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

  7. Counting their blessings. Fatal stats show 400 series Cessnas are a real handfull in trouble after takeoff.

  8. For insight see N6866K Cessna 421C @ ABQ accident.

    1. N6866K accident was improper response to a forward baggage door opening on takeoff. As someone mentioned in earlier comments, both forward baggage doors are missing in these N66NC post crash photos.

      You can see all the way thru both baggage door openings in second photo. No hinge arm remnants are visible on the starboard side opening. Seems odd to have both doors missing with fire fighters still on scene. Fire fighters don't unfasten hinge arm thru-bolts.

      Example Baggage Door Photo:

      N6866K Report:

    2. N6866K was partially improper response to forward baggage door opening but the biggest problem was the pilot feathering the wrong propeller.

      It doesn't sound like the manual requires an engine be shutdown after a baggage door opens. Only reason I could see an engine needing to be shut down after losing a baggage door is if the door hit the propeller and caused damage creating an out of balance situation.

  9. Glad everyone got out. As a former 421C owner I can only relay my experience that they are wonderful airplanes with lots of power. You need to be well-trained to fly them. My only negative experiences were due to the finicky nature of the mixture setting on those engines. The pilot's comment and airport elevation would make me want to look at that first.

  10. One of the things I’ve heard and never forgotten: it’s always better to go off the end of the runway slowing down than to try and nurse a sick plane into the air. Glad everyone survived.

  11. Can someone explain to me something that another person said about the props would be facing forward if the engines were not producing enough power? I mean at 90+ knots whether they were or weren’t producing enough power would they not bend back at that speed?
    Also as to the baggage doors if one door was missing it would baffle me, but it is obvious that the nose of the aircraft hit square on the ground and that blew both doors off at the same time I suppose as it collapsed a little bit they were blown out.