Maintenance Test Flight Gets A Little Out Of Control
The NTSB has just filed a
preliminary report on a Hawker 125-800A maintenance test flight
that got more than a little out of hand... with a stall that not
only required aggressive recovery, but apparently a recovery that
at some points, was conducted in IFR conditions. Read the NTSB
Prelim and see if you don't get that same "Pucker" sensation
we got when reading this thing. We'd hate to have been the
folks who had to clean this airplane after THIS flight...
NTSB Identification: CHI06IA127
14 CFR Part 91: General Aviation
Incident occurred Thursday, May 04, 2006 in Lincoln, NE
Aircraft: Corporate Jets Limited BAE125-800A, registration:
Injuries: 6 Minor.
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 4, 2006, about 1800 central daylight time, a Corporate
Jets Limited BAE 125-800A (file photo, below), N71MT, owned and
operated by Raytheon Aircraft Company on a maintenance test flight,
lost control while setting up for a stall series at 17,000 feet
mean sea level (msl) near Lincoln, Nebraska. The flight was being
conducted under 14 CFR Part 91 on an instrument flight rules (IFR)
flight plan. Visual meteorological conditions prevailed at altitude
and during landing. Instrument meteorological conditions were
encountered during the uncontrolled descent prior to recovery. The
2 pilots and 4 passengers sustained minor injuries. The local
flight departed LNK at 1729 and landed at 1816.
The pilot reported that the flight was entering a stall series
in accordance with the test flight procedures. Flight crew
calculations indicated that the stick shaker was expected to
activate at 115 knots, with stick pusher activation at 107.5 knots.
Aerodynamic stall was expected at 105.5 knots at the current
operating weight. The pilot stated that "as the airplane slowed
through [approximately] 126 knots [indicated airspeed], it abruptly
rolled off / dropped the right wing and the nose fell rapidly." He
noted that, although the autopilot was on as required by the test
procedure, he was holding the control wheel and felt "no vibration
or abnormal indication" prior to the event. He reported that the
airplane rolled 5 to 7 times, both to the right and the left.
The pilot reported that the airplane entered an underlying cloud
layer approximately 12,000 feet msl. The airplane exited the cloud
layer about 10,000 feet msl and was "descending vertically,"
according to the pilot. He stated, "I neutralized the ailerons with
the yoke and began a higher than normal back pressure pull-out,
experiencing [approximately] 4 - 5 Gs. The aircraft responded, and
we stopped the descent somewhere below 7,000 [feet msl]." The
flight subsequently returned to LNK and the crew executed an
no-flap landing without further incident.