NTSB Identification: CEN12FA161
14 CFR Part 91: General Aviation
Accident occurred Sunday, February 19, 2012 in Hayden, CO
Probable Cause Approval Date: 05/23/2013
Aircraft: CESSNA 414A, registration: N4772A
Injuries: 2 Fatal,4 Serious.
NTSB
investigators either traveled in support of this investigation or
conducted a significant amount of investigative work without any travel,
and used data obtained from various sources to prepare this aircraft
accident report.
The pilot performed an instrument approach to
the runway with an approaching winter storm. A review of on-board global
positioning system (GPS) data indicated that the airplane flew through
the approach course several times during the approach and was
consistently below the glideslope path. The airplane continued below the
published decision height altitude and drifted to the right of the
runway’s extended centerline. The GPS recorded the pilot’s attempt to
perform a missed approach, a rapid decrease in ground speed, and then
the airplane descend to the ground, consistent with an aerodynamic
stall. Further, the airplane owner, who was also a passenger on the
flight, stated that, after the pilot made the two “left turning circles”
and had begun a third circle, he perceived that the airplane “just
stalled.” An examination of the airframe and engine did not detect any
preimpact anomalies that would have precluded normal operation. The
airplane’s anti-ice and propeller anti-ice switches were found in the
“off” position. A review of weather information revealed that the
airplane was operating in an area with the potential for moderate icing
and snow. Based on the GPS data and weather information, it is likely
that the airframe collected ice during the descent and approach, which
affected the airplane’s performance and led to an aerodynamic stall
during the climb.
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The
pilot’s inadvertent stall during a missed approach. Contributing to the
accident was the pilot’s operation of the airplane in forecasted icing
conditions without using all of its anti-ice systems.
HISTORY OF FLIGHT
On
February 19, 2012, at 1525 mountain standard time, a Cessna 414A
airplane, N4772A, impacted terrain at the Yampa Valley Airport (KHDN),
Hayden, Colorado. The commercial pilot and one passenger were fatally
injured and four passengers were seriously injured. The airplane was
substantially damaged. The airplane was registered to and operated by a
private individual under the provisions of 14 Code of Federal
Regulations Part 91 as a personal flight. Instrument meteorological
conditions developed for the flight, which operated on an instrument
flight rules (IFR) flight plan. The flight departed the Dalhart
Municipal Airport (KDHT), Dalhart, Texas, approximately 1415 central
standard time.
A review of air traffic control communications
revealed that the pilot was cleared for the instrument landing system
(ILS) approach to runway 10 via the initial approach fix REVME.
Airfield
personnel and airfield rescue and firefighting (ARFF) provided an
enhanced universal communications (UNICOM) service for inbound traffic
and were monitoring both the UNICOM and Denver Center radio frequencies,
at the time of the accident. Airfield personnel heard the pilot report
he was on final approach over the UNICOM frequency. Airport personnel
then selected the airport lights to high, and the pilot acknowledged the
light status. There was no report of a distress call being made by the
pilot.
In an interview with the airplane's owner, who was also a
passenger, he stated the airplane was maneuvering to land at KHDN. The
pilot had made two left turning circles and had begun a third circle
when the he perceived that the airplane "just stalled." He added that
the airplane fell straight down and impacted terrain. In addition, he
recalled that the engines were running at the time of the accident. In a
subsequent statement made by the owner, he stated that immediately
preceding the crash, he heard a very load “pop” or “bang” from the right
side of the airplane, possibly the right engine, moments before the
airplane “went down.” He recalled the pilot looking to the airplane’s
right and that the pilot immediately reached towards the center console
near the throttle controls. Moments later, the airplane crashed.
PERSONNEL INFORMATION
The
pilot, age 75, held a commercial pilot certificate with ratings for
airplane single engine land, airplane multi-engine land, airplane single
engine sea, instrument airplane, and gliders. In addition, the pilot
held a flight instructor certificate for airplane single engine,
airplane multi-engine, instrument airplane, and gliders. The pilot was
also an airframe and power-plant mechanic who would perform some
maintenance tasks on the accident airplane. On March 31, 2011, the pilot
was issued a second class medical certificate with the restriction to
wear corrective lenses. A review of pilot training information revealed
his previous flight review was on October 27, 2011, in the same make and
model as the accident airplane.
AIRCRAFT INFORMATION
The
airplane was a two engine, low wing, eight seat Cessna 414, serial
number 414A005, and was manufactured in 1978. It was powered by two,
310-horsepower Continental Motors TSIO-520-NB engines that drove
three-bladed, variable pitch, McCauley propellers. A review of
maintenance records revealed that the previous annual inspection was
completed on December 8, 2011, at a total airframe time of 8,245 hours, a
left engine time since major overhaul of 2,028.9 hours, a right engine
time since major overhaul of 901.6 hours, and a tachometer time of
2,794.7. At the accident site, the airplane’s tachometer read 2,833.9
hours. The airplane’s published stall speed is 70 knots.
METEOROLOGICAL INFORMATION
The
National Weather Service Surface Analysis Chart issued at 1400 mountain
standard time depicted two low pressure systems over eastern Colorado
associated with a cold front moving across the Rockies and a developing
warm front over eastern Colorado. Satellite imagery showed extensive
cloud cover over the accident area with cloud tops near 27,000 feet. An
upper air sounding taken near Grand Junction, Colorado, reported a
freezing level at 5,703 feet mean sea level (msl), with conditions
favorable for icing in clouds and in precipitation above the freezing
level.
At 1515, an automated weather reporting facility located
at KHDN reported wind from 310 at 8 knots, 5 miles visibility, few
clouds at 800 feet, scattered clouds at 1,700 feet, broken ceiling at
2,900 feet, temperature -1 Celsius (C), dew point -3 C, and a barometric
pressure of 29.62 inches of mercury. At 1535, wind from 290 at 10 knots
gusting to 14 knots, visibility 1/4 mile, ceiling overcast at 400 feet,
temperature -2 C, dew point -3 C, and a barometric pressure of 29.62
inches of mercury. This facility does not report precipitation, however
conditions were favorable for the production of heavy snow.
A
review of HDN’s weather observation data revealed that between 1430 and
1445, a front passed over the airfield, which shifted the wind from the
east to the west and deteriorated the ceiling and visibility. Weather in
the area could produce snow that continued through to the time of the
accident, when the lowest visibility and ceiling was reported.
An
automated weather reporting facility at the Craig-Moffat Airport
(KCAG), located about 14 miles west of KHDN, could report precipitation,
with the exception of freezing rain. At 1506, the station began
reporting light snow with a wind shift having occurred at 1450. At 1525,
it reported light snow and freezing fog. Then at 1553, moderate snow
and freezing fog was reported.
Several Airmen’s Meterological
Information (AIRMETs) were active for the time of the accident flight.
These AIRMETs warned for IFR conditions, mountain obscuration,
occasional moderate turbulence below 18,000 feet, and moderate icing
between the freezing level and 18,000 feet.
AIDS TO NAVIGATION
The
approach flown by the pilot was the ILS to runway 10. The inbound
course was 104 degrees, with the initial approach fix (REVME) located
along the localizer course at 15 nautical miles, and the final approach
fix (INEDE) located along the localizer course at 8.1 nautical miles.
The decision height was at 7,371 msl, with a weather requirement of an
800 foot ceiling and 2 ¾ miles visibility. The touchdown zone elevation
for runway 10 was 6,591 feet msl.
COMMUNICATIONS
A review
of radar audio revealed that the pilot had checked in with Denver Center
and requested a visual approach if the ceiling was greater than 1,000
feet. Denver Center replied that a previous airplane flew the ILS
approach into KHDN and had broken out of the clouds at minimum altitude
(800 feet). The pilot then accepted an IFR clearance and was cleared to
fly the ILS approach into KHDN.
AIRPORT INFORMATION
The
Hayden/Yampa Valley airport (KHDN) is located approximately 2 miles
southeast of Hayden, Colorado, with a field elevation of 6,606 feet and a
single runway oriented along 100/280 degrees. Runway 10 had a precision
approach path indicator located to the left of the runway, and had a
medium intensity approach light system with runway alignment indicator
lights. The airfield is non-towered so pilots utilized UNICOM to
coordinate their movements on the airfield. As previously noted, ARFF
provided advisories to pilots over UNICOM.
WRECKAGE AND IMPACT INFORMATION
The
accident site was located about 95 yards south-southwest from the edge
of runway 10. The wreckage path aligned generally along a 090 degree
heading. The debris path contained the left aileron and right propeller.
The main wreckage came to rest facing 320 degrees. The fuselage
displayed buckling and crushing throughout its length. Damage to the
left and right wings was nearly symmetric. The elevator counter weights
separated in a downward direction. All major airplane components were
accounted for at the accident site. Flight control continuity was
established from the controls to their respective surfaces. The flaps
and landing gear were found in the retracted position. The airplane’s
electric anti-ice and propeller anti-ice were found in the “off”
position. No preimpact anomalies were detected with the airframe that
would preclude normal operation of the airplane.
The engines were
removed and shipped to Continental Motors Inc., Mobile, Alabama, for
test runs. Under the auspices of the NTSB, both engines were placed on
test beds, started, and operated throughout their power ranges. No
preimpact anomalies were detected with the engines that would preclude
normal engine operation.
MEDICAL AND PATHOLOGICAL INFORMATION
An
autopsy was performed on the pilot by the Douglas County Coroner’s
Office, Castle Rock, Colorado, as authorized by the Routt County
Coroner. The autopsy noted the following findings:
Right coronary artery narrowed more than 90 percent, with evidence of recanalization.
Severe cardiomegaly, with a weight of 570 grams.
Myocardial fibrosis of the left ventricle.
The
Federal Aviation Administration Bioaeronautical Sciences Research
Laboratory, Oklahoma City, performed forensic toxicology on specimens
from the pilot. Testing was negative for carbon monoxide, cyanide,
ethanol, and drugs.
ADDITIONAL INFORMATION
Garmin GPSmap 295
A
global positioning system (GPS) was located in the cockpit area of the
airplane and sent to the NTSB laboratories in Washington, D.C. A
download of the device displayed the airplane’s flight path along the
ILS approach. The airplane turned inside of the initial approach fix for
the ILS 10 approach. During the approach, the airplane crossed through
the approach course several times. The pilot crossed INEDE 260 feet
below the published altitude for the final approach fix and was
consistently below glide slope during the approach to the airport.
Utilizing the GPS altitude, at 1523:25, the airplane was below glide
slope, drifting right on the localizer approach course, and three miles
from the airport, when the airplane reached the decision height of 7,331
feet msl. The airplane continued to drift to right of the localizer
course while continuing to descend to an altitude of 6,591 feet msl,
before it climbed to 6,824 feet, and then descended towards terrain.
During this climb, the airplane’s groundspeed decreased to 78 knots.
NTSB Identification: CEN12FA161
14 CFR Part 91: General Aviation
Accident occurred Sunday, February 19, 2012 in Hayden, CO
Aircraft: CESSNA 414A, registration: N4772A
Injuries: 2 Fatal,4 Serious.
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. NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.
On February 19, 2012, approximately 1530 mountain standard time, a Cessna 414A, N4772A, impacted terrain while attempting to land at the Yampa Valley Airport (KHDN), Hayden, Colorado. The commercial pilot and one passenger were fatally injured and four passengers were seriously injured. The airplane was substantially damaged. The airplane was registered to and operated by a private individual and operated as a personal flight under the provisions of 14 Code of Federal Regulations Part 91. Instrument meteorological conditions developed for the flight, that operated on an instrument flight rules (IFR) flight plan. The flight departed the Dalhart Municipal Airport (KDHT), Dalhart, Texas, approximately 1415 central standard time.
An initial review of air traffic control information revealed that the pilot was cleared by air traffic control to the initial approach fix (REVME) for the instrument landing system (ILS) approach for runway 10.
Airfield personnel provided an enhanced UNICOM service for inbound traffic and were monitoring UNICOM and Denver Center at the time of the accident. Airfield personal heard the pilot report he was on final approach over the UNICOM frequency. Airport personnel then selected the airport lights to high, and the pilot acknowledged the light status. There was no report of a distress call being made by the pilot prior to the accident.
In an interview with the airplane's owner, who was also a passenger, he stated the airplane was maneuvering to land at KDHN. The pilot had made two left turning circles and had begun a third circle when the he perceived that the airplane "just stalled." He added the airplane fell straight down and impacted terrain. In addition, he commented that the engines were running at the time of the accident.
The accident site was located about 95 yards south-southwest from the edge of runway 10. The wreckage path was aligned generally along a 090 heading. The debris path contained the left aileron and right propeller. The main wreckage came to rest facing a 320 heading. The fuselage displayed buckling and crushing throughout its length. All major airplane components were accounted for at the accident site.
At 1515, an automated weather reporting facility located at KHDN reported winds from 310 at 8 knots, 5 miles visibility, few clouds at 800 feet, scattered clouds at 1,700 feet, broken ceiling at 2,900 feet, temperature -1 Celsius (C), dew point -3 C. At 1535, winds were reported from 290 at 10 knots gusting to 14 knots, visibility 1/4 mile, ceiling overcast at 400 feet, temperature -2 C, dew point -3 C. This facility does not report precipitation.

Airport Manager Dave Ruppel said a team of investigators from the NTSB, the Federal Aviation Administration, Cessna and Continental, which manufactured the plane’s engine, spent Monday and Tuesday taking photos and measurements at the crash site in an effort to determine what caused the Cessna 414A to crash short of YVRA’s runway, killing pilot Hans Vandervlugt and passenger Gaby Humpal.
Airport officials reported the private plane crashed as it attempted to land in a heavy snowstorm with zero visibility.
Messages left with the lead NTSB investigator who traveled to Hayden were not returned Monday or Tuesday.
Still recovering
Sara Humpal, 10, the youngest survivor of Sunday’s plane crash, remained in serious condition at Children’s Hospital Colorado in Aurora on Tuesday evening.
Her father, Scott Humpal, and her brothers Tad, 18, and Dillon, 13, also survived the crash and were released from Yampa Valley Medical Center in Steamboat Springs at about 3:30 p.m. Tuesday after they were treated for injuries ranging from broken bones to cervical instability. The family was traveling to Aurora on Tuesday night to be with Sara, family and friends reported.
Vandervlugt, 75, was flying Scott and Gaby Humpal and their three children from Corpus Christi, Texas, to Steamboat for a ski vacation when the Cessna 414A crashed 30 to 40 yards short of the runway at YVRA.
Russell Hanks, a friend of the Humpal family who works at one of the physical therapy clinics Scott Humpal owns in Corpus Christi, reported Sara was able to move her arms and legs after she had procedures at YVMC to reinflate collapsed lungs and fix fractures to her legs. He said that the boys were recovering well and that Sara had another surgery Tuesday morning to treat a compartment syndrome in her leg. He added that a procedure doctors initially planned to fix a fracture in her T6 vertebrae was not performed Tuesday afternoon and may be unnecessary.
“She still has some lung issues they are trying to correct,” he said. “Last I heard, she was stable.”
A devoted mother
Family and friends of Gaby Humpal, 44, said Tuesday that she always will be remembered as a loving mother.
“Gaby hated for you to ring the doorbell. She would just expect for you to come in, and she would always greet you with a warm hug and a smile,” said Michelle Braselton, who met the Humpals through a couples Bible study group Gaby started with fellow worshippers at the Bay Area Fellowship in Corpus Christi. “She was very warm and hospitable.”
Braselton said Gaby met Scott Humpal while living in Monterrey, Mexico, and was a strong Christian woman devoted to all of her children’s endeavors. She added that Gaby loved to entertain.
Robert Vasquez, Gaby’s brother-in-law, said she was an avid tennis player and jogger, but most importantly, she always put her children first.
“She was a striking woman with a beautiful character, and she was very, very lovable,” he said. “She was a devoted mother and wife, and she lived her life for her children.”