Accident - Aviation NTSB Report

1.7 Meteorological Information
1.7.1 National Weather Service Information
A terminal aerodrome forecast prepared for PUB by the National Weather Service (NWS), which was issued at 0442 and was valid at the time of the accident, stated, in part, the following:

winds 080° at 8 knots, visibility greater than 6 miles, skies scattered at 2,000 feet and overcast at 2,500 feet. Temporary condition between 1200Z[24] to 1600Z,
visibility 3 miles in light freezing drizzle, mist, skies overcast at 1,000 feet. From 1600Z, winds 070° at 8 knots, visibility greater than 6 miles, skies scattered at
1,000 feet and overcast at 2,500 feet.

The NWS also issued several winter weather advisories on the morning of the accident.25 The advisories issued at 0750 and 0934 warned that freezing drizzle existed along the accident flightpath through the midmorning hours.

24 Weather forecasts are transmitted in coordinated universal time (UTC). The "Z" designation that follows the time in the weather observation stands for Zulu, which indicates UTC time. Mountain standard time is 7 hours behind UTC time.

25 Although winter weather advisories are not aviation-related products, they provide additional information about atmospheric conditions.

Base reflectivity image data were derived from the Weather Surveillance Radar-1988 Doppler system, which is located 15 nm northeast of the accident site. Data
from the system’s 0911 atmospheric profile showed weak reflectivity values near the accident site, consistent with the presence of freezing drizzle atmospheric conditions. Geostationary Operational Environmental Satellite 10 data from the National Oceanic and Atmospheric Administration satellite indicated cloud top temperatures from -19° to -11° C and the presence of cloud layers in the area surrounding the airplane’s flightpath.

The 0500 upper air sounding (that is, a vertical profile of atmospheric conditions) from Denver, Colorado (about 92 nm northeast of the site), showed temperatures below freezing from the surface to 30,000 feet. The sounding showed no layers in the atmosphere with temperatures above freezing.

1.7.2 Airport Weather Information
Weather observations at PUB are made by an automated surface observing system (ASOS) located about 3 nm west of the accident site. The ASOS records continuous information on wind speed and direction, cloud cover, temperature, precipitation, and visibility and transmits an official meteorological aerodrome report (known as a METAR) each hour. The 0853 METAR indicated the following:

wind 060° at 8 knots; visibility 8 miles; skies broken at 900 feet and overcast at 1,400 feet; temperature minus 3° C; dew point temperature minus 5° C…Remarks
[cloud] ceiling varying between 700 to 1,100 feet.

The 0944 METAR indicated the following:

wind 070° at 7 knots; visibility 6 miles; skies overcast at 600 feet; temperature minus 3° C; dew point temperature minus 4° C…Remarks [cloud] ceiling varying between 400 and 900 feet.

The PUB ASOS provides unofficial weather observations that are recorded every 5 minutes. At 0910, the PUB ASOS indicated the following: winds 070° at 7 knots and 6 sm in mist. At 0915, the PUB ASOS indicated the following: winds 060° and visibility 8 sm. Both reports reported the following: clouds broken at 900 feet and overcast at 1,400 feet, temperature -3° C, and dew point -4° C.

Additional Icing Information
Scientists from the National Center for Atmospheric Research (NCAR), Boulder, Colorado, conducted studies for the National Transportation Safety Board to determine whether the accident airplane encountered supercooled26 large droplet (SLD) conditions, which are more conducive to the accumulation of thin, rough ice on or aft of the protected surfaces, and to estimate the amount of airframe ice accumulation. NCAR reported that, on the basis of surface, radar, upper air, and satellite data, the airplane likely encountered SLD conditions from about 9,400 to 6,100 feet (the calculated altitude at which the upset occurred). NCAR indicated that, during the time that the airplane was in this cloud layer (about 4 1/2 minutes), from 1 to 4 millimeters (mm) (0.039 to 0.157 inch) of ice likely accumulated along the wing leading edges.27 Severe icing conditions are those in which 5 mm (0.195 inch) of ice accumulates in 5 minutes.

Several pilot reports (PIREP) were provided around the time of the accident in the area over PUB. A PIREP received about 0646 from a pilot flying a Swearingen Merlin IV reported moderate mixed icing on final approach to runway 8. A PIREP received about 0809 from the pilot flying a Hawker jet who had landed on runway 8 about 1 minute earlier reported light to moderate and/or mixed icing and a "little" ice accumulation on the wing leading edges. A PIREP received about 1020 from a pilot flying a Learjet 31 reported light to moderate rime icing on final approach to runway 8. An urgent PIREP28 received about 1023 from a pilot flying a Beechcraft King Air 90 at an altitude of about 6,000 feet reported moderate mixed icing and ice accumulation from 1/4 to 1/2 inch on final approach to runway 8.

1.8 Aids to Navigation
No problems with any navigational aids were reported.

1.9 Communications
No communications problems between the pilots and any of the air traffic controllers who handled the accident flight were reported.

26 Supercooled is the liquid state of a substance that is below the normal freezing temperature for that substance.

27 The ice accumulation estimates do not account for all of the effects of SLD conditions, including the effect of the droplets’ running aft of the protected surfaces before freezing.

28 FAA Order 7210.3, "Facility Operation and Administration," states that weather phenomena reported by a pilot that represents a hazard or a potential hazard to flight operations, including severe icing, should be disseminated as "urgent PIREPs."

Airport Information
PUB is located about 5 nm southeast of Pueblo at an elevation of 4,726 feet. PUB has one set of parallel runways, 8L/26R and 8R/26L, and runway 17/35.

1.10.1 Air Traffic Control
PUB has a combined tower and radar approach control facility. The tower is located on the south side of the airport, left of and about midway down runway 26R. PUB tower controllers use DBRITE (digital bright radar indicator tower equipment), which provides a visual display of the airport surveillance radar (ASR)-7 data and radar and beacon signals received from the PUB automated radar terminal system IIE radar processing system.

1.10.2 Air Traffic Control Guidance
FAA Order 7110.65, "Air Traffic Control," paragraph 2-6-3, "PIREP Information," states that, when an air traffic controller receives a PIREP that involves icing, the controller should record the icing type and intensity and the air temperature in which the icing is occurring. The order states that controllers are required to "relay pertinent PIREP information to concerned aircraft in a timely manner" and the flight service station (FSS) "serving the area in which the report was obtained."

As noted previously, about 0809 (about 1 hour before the accident), the pilot of a Hawker jet, who had flown inbound to PUB from the southeast and had just landed, reported to the PUB local controller that a little bit of ice had accumulated on the airplane’s wing leading edges. The controller asked the pilot if the icing conditions were "moderate mixed," and the pilot replied that the icing conditions were "light to moderate but it looks like it’s mixed." The controller did not provide the PIREP to the accident flight crew or to the Denver FSS. In postaccident interviews, the controller stated that he had interpreted the pilot’s statement as "a trace or less" of ice and, therefore, not a reportable amount.

FAA Order 7110.65, Section 9, "Automatic Terminal Information Service Procedures," paragraph 2-9-1, "Application," states that controllers should "use the ATIS information, where available, to provide advance non-control airport/terminal area and meteorological information to aircraft." ATIS information includes the landing runway in use; however, air traffic controllers are allowed to amend the ATIS information at any time as situations change. ATIS information "Juliet," which was effective at 0753, broadcast that the landing runway in use at PUB was 8L; however, at 0905:56, the PUB local controller instructed the flight crew to expect to land on runway 26R. During postaccident interviews, the controller stated that he was often asked by corporate pilots to use the runway opposite that being advertised on ATIS and that, as a service, he would provide the closest runway as a matter of course as long as the winds allowed it.

Flight Recorders
1.11.1 Cockpit Voice Recorder
The accident airplane was equipped with a B&D Instruments and Avionics CVR, serial number A01148. The exterior of the CVR exhibited slight structural damage. The CVR was sent to the Safety Board’s laboratory in Washington, D.C., for readout and evaluation. The tape was played back normally and without difficulty. The recording consisted of three separate channels of good quality audio information:29 the captain and first officer audio panels and the cockpit area microphone (CAM). A transcript was prepared of the entire 31-minute, 36-second recording (see appendix B).

1.11.1.1 Cockpit Voice Recorder Sound Spectrum Study
The accident CVR recording was examined using computer signal and spectrum analyzers30 at the Safety Board’s laboratory to determine whether the stall warning system generated any aural alerts during the last 60 seconds of the flight. Specifically, the CAM channel was examined to determine whether any sounds could be identified that corresponded to the rotation rate of the stickshaker motor or weights. The study showed that the stall warning appears to have activated at 0912:44.5 (about 1 second after the loss of control) and continued to 0912:50.5. The stall warning appears to have reactivated at 0912:53.4 and continued to 0912:54.5 (the end of the recording).

1.11.2 Flight Data Recorder
The airplane was not equipped with a flight data recorder nor was it required to be so equipped.31

1.12 Wreckage and Impact Information
The airplane wreckage was located about 4 nm east of runway 26R at an elevation of about 4,600 feet. The debris field was about 550 feet long and extended along a 230° magnetic heading. All of the airplane’s major structures, including the cockpit, wings, 29 The Safety Board rates the quality of CVR recordings according to a five-category scale: excellent, good, fair, poor, and unusable. See appendix B for a description of these ratings.

30 The computer signal analyzer provides detailed analysis of the analog waveform and provides the specific frequency content of the signals and detailed timing information. The spectrum analyzer provides a visual presentation of the frequency content of the recorded signals.

31 On December 22, 2003, the Safety Board issued Safety Recommendation A-03-65, which recommended that the FAA require that all turbine-powered aircraft manufactured before January 1, 2007, being used for commercial or corporate purposes under Part 91 be retrofitted with a crash-protected image recording system by January 1, 2010. The Board reiterated Safety Recommendation A-03-65 on January 24, 2006. For additional information, see National Transportation Safety Board, Collision with Trees and Crash Short of Runway, Corporate Airlines Flight 5966, British Aerospace BAE-J3201, N875JX, Kirksville, Missouri, October 19, 2004, Aircraft Accident Report NTSB/AAR-06/01 (Washington, DC: NTSB, 2006).

Evidence of a postcrash fire was found along the debris field, beginning about 55 feet after the initial impact marks. Both engines were found separated from the
airplane. The engines showed no indications of uncontainment, case rupture, or in-flight fire. Both engines were disassembled at PWC’s facility in Bridgeport, West Virginia, under Safety Board supervision. Disassembly of the engines revealed no preexisting defects or malfunctions.

1.13 Medical and Pathological Information
Fluid and tissue specimens obtained from the captain and a fluid specimen obtained from the first officer were transported to the FAA’s Civil Aerospace Medical
Institute for toxicological analysis. The specimens tested negative for alcohol and a wide range of drugs, including drugs of abuse.32

1.14 Fire
No evidence of an in-flight fire was found.

1.15 Survival Aspects
According to the Pueblo County Coroner’s Office autopsy report, the cause of death for the captain, first officer, and six passengers was "multiple traumatic injuries."

1.16 Tests and Research
1.16.1 Enhanced Ground Proximity Warning System Data Study
The EGPWS computer, which contained two flash memory chips, was recovered on site. One of the memory chips exhibited several visible cracks to the package, and the other chip was found undamaged. The two memory chips were sent to Honeywell’s facility in Redmond, Washington, for examination and data recovery.

32 The drugs tested in the postaccident analysis include (but are not limited to) marijuana, cocaine, opiates, phencyclidine, amphetamines, benzodiazapines, barbiturates, antidepressants, antihistamines, meprobamate, and methaqualone.

1.16.2 Airplane Performance Study
The Safety Board conducted an airplane performance study using EGPWS data, PUB ASR-7 radar data, manufacturer-provided aerodynamic data, and meteorological information to establish a time history of the airplane’s motions and to estimate the airplane’s performance parameters (including ground speed, airspeed, descent rate, and aircraft pitch and roll angles) for the final portion of the flight. Nominal error or uncertainty in the radar and wind data led to variables in the airplane performance parameters; therefore, the performance parameters should be considered approximations.

According to the airplane performance study, the airplane started its final descent from 7,000 feet at an airspeed of about 155 knots about 0911:26. Over about the next 30 seconds, the descent rate was about 800 feet per minute (fpm). By about 0912:30, as the airplane was passing through about 6,200 feet, the descent rate had decreased to about 490 fpm, and the airspeed had decreased to about 98 knots. Over the next 10 seconds, the airspeed continued to decrease to about 90 knots. Immediately after passing through about 6,100 feet, the airplane experienced the onset of a large roll to the left concurrent with a sudden decrease in the pitch angle, consistent with the motion of an airplane that has experienced an aerodynamic stall.

1.17 Organizational and Management Information
At the time of the accident, Circuit City Stores, Inc., which is headquartered in Richmond, Virginia, owned and maintained operational control of the accident airplane, another Cessna 560 airplane (the sister ship), and a Cessna Citation 650 airplane. Martinair, Inc., is a Part 135 aircraft charter and management company that began operations in July 1986. Martinair has provided pilots and maintenance support for Circuit City Stores airplanes through a management services agreement since 1993. At the time of the accident, Martinair managed 15 aircraft, operated 11 aircraft, and had 33 full- and part-time pilots and 8 aircraft mechanics. Martinair’s chief pilot stated that, although Circuit City Stores flights fell under 14 CFR Part 91 operating rules, company pilots generally adhered to Part 135 operating rules for these flights and used the same checklists and standard operating procedures used for Part 135 flights.

Operational Guidance
1.17.1.1 Normal Operations
According to the SimuFlite Cessna Citation V Technical Manual,33 a typical ILS approach should be flown, in part, as follows:

When established on the localizer inbound to the FAF [final approach fix], ensure that flaps are set to T.O. [takeoff] and APPR [approach].

Maintain airspeed at Vref+20+wind factor and initiate the Before Landing
checklist…

At glideslope intercept, start timing, begin descent, and extend full flaps.

Complete Before Landing checklist to the autopilot/yaw damper.

Maintain airspeed at Vref+10+wind factor…

Reduce power slightly to ensure crossing the runway threshold at Vref+wind factor.

Martinair’s Operations Manual stated that, under normal circumstances, the airspeed on final must be held at Vref+10 ±5 knots and that the airspeed must be bled off to ref at the runway threshold.

1.17.1.2 Operations in Icing Conditions
The SimuFlite Cessna Citation V Technical Manual contains the following

[34]
warning: "with any residual ice present do not attempt to fly uncorrected Vref/Vapp speeds. Stall speeds increase and stall warning margins decrease." The technical manual also contains the following caution:

In icing conditions, a small amount of residual ice forms on unprotected areas. This is normal, but can cause an increase in stall speeds. When any amount of residual ice is visible, the stall speeds increase by 8 knots; the Vref/Vapp speeds and landing distances and the maximum landing weight permitted by brake energy must be corrected.

Assuming some residual icing was present on the airplane’s surfaces during the accident flight, the corrected Vref would have been 104 knots. At 0859:29, the CVR recorded the first officer stating that the Vref was 96 knots.

33 The guidance for operating in icing conditions in the Simuflite Cessna Model 560 Citation V Technical Manual, which was used as the training manual for Martinair pilots, is in accordance with the guidance contained in the Cessna Model 560 Citation V AFM.

34 Vapp is the landing approach airspeed with approach flaps and landing gear up.

Anti-Ice and Deice Systems Usage
According to the SimuFlite Cessna Citation V Technical Manual, when operating in visible moisture and when the outside air temperature is between -30° and +10° C, the pitot static heat and engine anti-ice systems should be turned to ON. The manual also states that, if the temperature is above -18° C, the windshield bleed air switch should be turned to LOW, and, if the temperature is below -18° C, the windshield bleed air switch should be turned to HIGH.

According to SimuFlite’s technical manual (and the Cessna AFM), the surface deice boots should be used when ice buildup is estimated to be between 1/4- to 1/2-inch thick. The manual further states, "Early activation of the boots may result in ice  bridging[35] on the wing, rendering the boots ineffective. Late activation (if accumulation is more than 1/2-inch thick) may not clear the ice." The manual also states the following:

When reconfiguring for approach and landing…with any ice accretion visible on the wing leading edge, regardless of thickness, activate the surface deice system.
Continue to monitor the wing leading edge for any reaccumulation.

1.17.2 Flight Crew Training
Martinair provides initial in-house ground school training to company pilots. After the in-house training, pilots attend flight simulator training at CAE SimuFlite.

1.17.2.1 Operations in Icing Conditions
During postaccident interviews, several SimuFlite instructors stated that guidance on operations in icing conditions is taught in initial and recurrent ground school. The
training includes a review of the anti-ice and deice systems and their usage and anti-ice failure scenarios. The instructors also stated that icing operations in the simulator involved introducing ice on the wings. Pilots are taught to activate the deice boots after about 1/4 to 1/2 inch of ice has accumulated on the wings and to use the anti-ice systems when flying in visible moisture36 and when the outside air temperature is between -30° and +10° C.

According to the SimuFlite instructors, the specific items to be covered during simulator training on operations in icing conditions are left to the discretion of the
individual instructors. A review of SimuFlite’s training syllabus also revealed that no specific instruction exists to evaluate a pilot’s performance of the AFM procedures to increase the airspeed and operate the deice boots during approaches when ice is present on the wings. Further, one of the SimuFlite Cessna 560 instructors was unaware of these AFM procedures. Investigators also interviewed a Cessna 560 instructor from another

35 Ice bridging is a phenomenon in which ice in the shape of an inflated deice boot forms after the boot is cycled. Ice bridging had been known to occur on older deice boot designs that used larger tubes and lower pressures, resulting in slower inflation and deflation rates.

36 The manual indicates that visible moisture includes, but is not limited to, the following conditions: fog with visibility less than 1 mile, wet snow, and rain.

major flight training center, and he stated that, although he believed that each instructor emphasized the icing approach procedures during simulator training, the center’s syllabus contained no instruction to ensure that the instructors are evaluating the procedures.

1.17.2.2 Stall Recovery
A SimuFlite instructor indicated that stalls in the clean, takeoff, and landing configurations are covered during training and checkrides. He stated that stall recovery in the Cessna 560 should be initiated at stickshaker activation and that recovery from an impending stall consisted of adding maximum power while conserving the altitude as much as possible.