Re: IV-P crash (N101BX)
Recall the accident of N101BX in May 2008.
http://www.ntsb.gov/ntsb/brief.asp?ev_id=20080609X00814&key=1
I'm guessing that there was an ice induced
tail stall. I note that one winglet was found 4000 ft away from
the weckage, and this supports that the winglet departed the airframe
early in the process.
A friend has asked if the departure of one
winglet would cause uncontrolled flight, since warmer above freezing
temperatures were found below 14,000'. I can't believe that this
alone would cause serious control problems.
Any comments from experienced pilots and
engineers?
Jeff Liegner
LIVP
NTSB
Identification: NYC08LA176
14 CFR Part 91: General Aviation
Accident occurred Thursday, May 08, 2008 in Snow Hill,
NC
Aircraft:
Desalvatore Al Lancair IV-P, registration: N101BX
Injuries: 2 Fatal.
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.
On May 8, 2008, at 1310 eastern daylight time, an amateur-built
Lancair IV-P, N101BX, was destroyed when it impacted terrain following
an uncontrolled descent near Snow Hill, North Carolina. The
certificated commercial pilot and passenger were fatally injured.
Visual meteorological conditions prevailed, and an instrument flight
rules (IFR) flight plan was filed and activated for the personal
flight. The flight originated at Page Field (FMY), Fort Myers,
Florida, and was destined for Hartford-Brainard Airport (HFD),
Hartford, Connecticut. The flight was conducted under 14 Code of
Federal Regulations Part 91.
According to preliminary information provided by the Federal Aviation
Administration (FAA), the pilot departed FMY under visual flight rules
about 1030. While enroute, the pilot contacted air traffic control
(ATC) and requested visual flight rules flight following services. He
later requested, and was given, an IFR clearance. While flying at
17,000 feet, shortly before the accident, the pilot requested to
descend due to icing conditions. The pilot was cleared to descend to
15,000 feet. The final radar target was observed about 2 miles
southwest of the accident site at 15,000 feet.
The crew of a Beech 400 was in contact with ATC, and was flying in the
area of the accident airplane. Both the captain and first officer
provided similar written statements recounting what they heard and
observed. The crew was initially cleared to climb to 15,000 feet, but
was later told to stop their climb at 14,000 feet because a Lancair,
the accident airplane, was descending from 17,000 feet to 15,000 feet
due to icing. Upon reaching 14,000 feet, the crew observed a target on
their traffic alert and collision avoidance system (TCAS) that was
about 1,000 feet above them in altitude, at their 12 o'clock position,
and at a distance about 7 to 8 miles. The next update of the TCAS
showed the traffic at the same altitude, still at the 12 o'clock
position, and at a distance about 5 to 6 miles. The crew questioned
ATC if this was the traffic that they had previously been alerted to,
which was answered in the affirmative.
The next time the crew looked at the TCAS, the traffic was 2,000 feet
below them, at the 2 to 3 o'clock position, and a distance of 4 miles.
The crew did not observe any further TCAS updates of the traffic, and
shortly thereafter the crew briefly heard the sound of an emergency
locator transmitter in the background of the controller's
transmission.
Additionally, the crew reported that they were in instrument
meteorological conditions at the time of the event, and that while
flying at 14,000 feet, there was no icing present. They were not sure
of the outside air temperature, but they remembered that the ram air
temperature was over 10 degrees Celsius.
The airplane was examined at the accident scene by Federal Aviation
Administration (FAA) inspectors. According to the inspectors, the
entirety of the wreckage was accounted for at the scene, with the
exception of one winglet, which was found on the roof of a house about
4,000 feet from the main wreckage. The majority of the wreckage was
consumed by a post-impact fire. Control continuity was established
from the cockpit area to each of the flight control
surfaces.
The engine was transported to a recovery facility, where it was
further examined by a Safety Board investigator and a representative
of the engine manufacturer.
The engine was intact, with all of the accessories attached, with the
exception of the fuel pump. Two of the four propeller blades were
separated from the propeller hub, one blade was broken in half, and
the fourth blade was undamaged. The aft portion of the engine was fire
damaged, and the oil sump was crushed upward into the camshaft.
Borescope examination of all cylinders revealed that the piston heads
and cylinder domes did not exhibit any abnormal combustion deposits.
Rotation of the crankshaft at the propeller confirmed valve train
continuity, and compression was confirmed on all cylinders. Both
turbochargers were fire- and impact-damaged, and neither of their
driveshafts was free to rotate.
The top six spark plugs were removed, and examination revealed that
they exhibited light gray deposits in the electrode areas. The fuel
pump was separated from the rear of the engine, and was coated with
soot. The drive coupling was intact, but the drive shaft was not free
to rotate. Further disassembly revealed that the interior was dry and
heat discolored. No internal mechanical damage was observed.
Disassembly and examination of the fuel manifold revealed that the
fuel screen was absent of debris and fuel. The oil filter was fire-
and impact-damaged. Examination of the paper element revealed that it
was charred, but no metal particles were observed.
The pilot held a commercial pilot certificate with ratings for
airplane single and multi-engine land, and instrument
airplane.
The weather
conditions reported at Goldsboro-Wayne Municipal Airport (GWW),
Goldsboro, North Carolina, located about 9 nautical miles west of the
accident site, at 1320, included winds from 210 degrees at 5 knots, 7
statute miles visibility in light rain, scattered clouds at 600,
1,700, and 7,000 feet, temperature 70 degrees Fahrenheit (F), dewpoint
64 degrees F, and altimeter setting of 29.93 inches of
mercury.
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