FTW95IA022
FTW95IA022

HISTORY OF FLIGHT:

On October 16, 1994, at 2051 central daylight time, a Canadair CL 600, N600RE, lost engine power on both engines at FL310 near Nacogdoches, Texas. The crew and two passengers were not injured. Instrument meteorological conditions prevailed for the business cross country flight. The crew was able to restart both engines and landed uneventfully at Shreveport, Louisiana.

During interviews, and on the enclosed statements, the crew reported the following information. The flight departed Alexandria, Louisiana, on the morning of October 16, 1994, making stops at Nassau, Bahamas, Fort Lauderdale, Florida, Dallas/Fort Worth Airport, Texas, and Tucson, Arizona, with a return to Alexandria. Total flight time on October 16, 1994, was 10.4 hours with a total refueling of 3,002 gallons of fuel from 4 separate locations. During the cruise climb from Tucson, the ice warning light illuminated twice. The airplane was flying in clear weather at the time and the anti-ice systems were not activated. At about 1 and 1/2 hours into the flight, the airplane was at FL370, 150 miles west of Alexandria when, prior to entering a cloud layer, the captain requested that the copilot turn the engine anti-ice to the "ON" position. The flight encountered turbulence, requested a descent clearance, and was cleared to FL330.

When power was brought up for the level off, the ITT responded with an increase; however, the N1 did not respond. Airspeed started decreasing, the crew requested a lower altitude, and the airplane started descending. The airspeed continued to decrease and at FL310 the left engine flamed out. Subsequently, the crew declared an emergency and requested vectors to the nearest airport. The first officer reported that a cross bleed air start was attempted at FL310 (flight manual air start limitation for a cross bleed air start is FL300); however, before the attempt was completed the second engine flamed out, and the dual engine failure checklist was initiated. The crew did not recall selecting Continuous Ignition, In-Flight Ignition, nor the Relight Ignition Switch. The captain established an airplane descent rate of 2,500 to 3,000 feet per minute (fpm) with an airspeed of 230 knots. During the descent, the airplane flew through heavy precipitation.

The air driven generator (ADG) circuit breaker was reset and the ADG deployed. The crew had pulled the automatic deploy circuit breaker earlier that day for a flight over water; however, this procedure is neither recommended/nor required by the ADG manufacturer. The first officer reported that he initiated the start procedures for the auxiliary power unit (APU) as the airplane descended through FL250 (flight manual limitation for an APU start is FL200). The APU started at FL200 and communication was established with Shreveport Approach Control.

During interviews, the crew reported an APU assisted right engine start at 15,000 feet MSL. Then they requested and received radar vectors for landing at Shreveport, Louisiana. They further stated that the left engine was restarted at 9,000 feet MSL and engine parameters stabilized by 5,000 feet MSL. According to the Canadair representative, the APU cross bleed air start procedure is an applicable procedure. The crew stated that once the engines' parameters were stabilized, the integrated drive generators (IDG) were activated for electrical power. According to the Canadair representative, the sounds recorded on the cockpit voice recorder (CVR) tape (transcript enclosed) as the airplane landed, suggest that the ADG was powering the CVR. Shreveport Approach Control vectored the airplane for the ILS runway 32 at Shreveport, Louisiana, where the flight landed at 2111 without further incident.

PERSONNEL INFORMATION:

During interviews, the crew stated that they had never attended a formal training course for the CL 600. They obtained training in N600RE from the captain of the airplane's previous owner. Type ratings for the crew were administered by a Federal Aviation Administration (FAA) designated examiner with the first officer obtaining the CL 600 type rating on March 28, 1994, and the captain obtaining his on May 9, 1994. The crew had accumulated 350 hours in N600RE.

AIRCRAFT INFORMATION:

The Canadair Challenger Model CL60-1A11, S/N 1079, was manufactured in 1983. Lycoming Turbofan Engine Model ALF502-L2 serial number LF03149 and serial number LF03156 were installed on the left and right positions, respectively. A maintenance record review conducted by the investigator-in-charge and the Federal Aviation Administration (FAA) inspector (statement enclosed) did not reveal any discrepancies.

METEOROLOGICAL INFORMATION:

The NTSB Meteorologist Factual Report (enclosed) indicates the following meteorological information. At FL370 outside air temperatures were about -49 degrees Centigrade (C), at FL330 about -39 degrees C and at FL230 about -16 degrees C. For the area where the airplane first reached FL330, doppler radar data showed echoes; the airplane location at FL330 was about 10 nautical miles north of an area of very cold radiative temperatures with tops near 55,000 feet. Cloud tops in the vicinity of the airplane were estimated at 50,000 to 51,000 feet. and a plot of streamlines and wind speeds for FL330 and FL370 showed winds generally from the southwest at about 55 knots.

Area forecasts (FA) throughout north central and eastern Texas included widely scattered embedded thunderstorms and moderate rain showers. In flight weather advisories included airmets for IFR due to moderate turbulence at 20,000 to 40,000 feet due to windshear associated with the jetstream. Convective sigmets for areas of thunderstorms with tornadoes and hail with wind gusts to 50 knots were effective in the area where the airplane first reached FL330. An Urgent Center Weather Advisory (UCWA) range for strong to intense thunderstorms moving north-northeast at 25 knots with maximum tops to 55,000 feet, hail aloft to 1 inch with 50 knot wind gusts included the area of the airplane at FL330.

FLIGHT RECORDERS:

The cockpit voice recorder (CVR) committee convened at NTSB headquarters in Washington, D. C., on October 25, 1994. A transcript (enclosed) was prepared of the entire 30:43 minute recording. Air traffic control data (enclosed) from Fort Worth Air Route Traffic Control Center (ARTCC), Houston ARTCC, and Shreveport West Radar Approach Control (RAPCON WEST), Shreveport Tower (ATCT) was reviewed. All times are converted to central daylight time unless otherwise noted in the following CVR and ATC data.

At 2043:34 the captain asked "We ain't loadin' up with ice, are we" (between FL336 and FL330) and at 2043:38 the second pilot replied "hope not." Then at 2044:24 the copilot states "that's anti ice" and at 2044:54 (FL330) the captain states "we're gettin' some ice now." During interviews the crew stated that there "was no visible evidence of ice on the airplane and no warning lights in the cockpit."

There was a crew discussion about power at 2045:13 (FL330) and at 2045:43 (FL330) the captain asked "you got the engine heat on, don't you"? and the first officer says "no I don't, but I'll." There is further discussion among the cockpit crew about the command for turning the engine heat off.

There was a CVR sound at 2045:52 of decreasing frequency similar to decrease in engine RPM followed by a crew discussion of which engine was flaming out. At 2046:15 N600RE declared an emergency and stated that they had to descend due to a loss of engine power. N600RE was cleared to FL290 and then to FL240.

There was a CVR sound at 2055:40 similar to operation of ADG (air driven generator) and at 2055:43 there were sounds similar to heavy precipitation on the windshield.

Company personnel identified the captain and first officer voices throughout the CVR recording. The first officer performed cockpit commands, initiated checklist, and made callouts to the captain about airspeed and altitude. Cockpit checklist usage (challenge/response) was not evident on the CVR.

TEST AND RESEARCH:

Examination of the airplane on October 17, 1994, at Shreveport, Louisiana, did not reveal evidence of mechanical discrepancies. Fuel debris was noted and fuel samples (enclosed list) were taken and forwarded for testing to AlliedSignal Aerospace (report enclosed) at Stratford, Connecticut. Water was present in the samples tested.

On October 28, 1994, during the removal of the left engine (serial number LF03149), additional fuel samples were taken. Analysis (report enclosed) performed by Precision Petroleum Labs, Inc., of Houston, Texas, indicated the presence of water. According to the manufacturer representatives, the water in all fuel samples is of insufficient quantities to have been a factor in this incident.

Engine inspections (report enclosed) were conducted at AlliedSignal Aerospace at Stratford, Connecticut, from November 1 through November 19, 1995. Borescope inspection of the left engine (LF03149) revealed mechanical damage on the trailing edge of 1 second stage stator vane. Borescope inspection of the right engine (LF03156) found 1 second stage blade bent and 1 first stage blade bent at the leading edge tip. Disassembly and inspection of LF03156 confirmed a second stage blade bent opposite to the direction of rotation and forward with the leading edge tip exhibiting rolled over metal. One first stage compressor blade was bent near the leading edge tip. The NTSB powerplant engineer attending the examination stated that the "findings indicated ice."

Engine test cell performance calibrations indicated that the aerothermodynamic performance was within acceptable limits. Testing showed that the bleed band operation was not within acceptable test limits and bench testing of both actuators confirmed actuation curves typical of valve sleeve wear. Functional testing of both engine anti-ice systems at Stratford, Connecticut, found both systems functional.

The compressor of the right engine was cranked by the starter while water was sprayed into the inlet to simulate windmilling in rain and water filled the ecology tank (300 cc) in less than 1 minute. Both engines were operated 5 minutes with the ecology tanks filled with 300 cc of water. These test revealed that the ejector pump on the left engine did not operate at ground idle. Further testing of the left engine ejector pump verified it as operational at 90 percent N1. According to Allied Signal Aerospace, the engines were "fully capable of operation" as water from full ecology tanks bled back into the system.

From November 17, 1995, through November 30, 1995, the airplane was examined at Shreveport, Louisiana, by an FAA inspector and manufacturer representatives. It was determined that the left wing anti-ice valve was stuck in the open position.

The fuel control units were tested (enclosed report) at AlliedSignal Aerospace, Stratford, Connecticut. The functional testing results revealed discrepancies in start and acceleration schedules for the fuel control units (FCU). According to AlliedSignal Aerospace, this "would be expected to cause difficulty in ground starting, producing hot or hung starts"; however, not "contributory to the reported flameout." The fuel control units were forwarded to Hamilton Standard, Windsor Lock, Connecticut, for further examination (report enclosed). No additional discrepancies were noted. A Canadair representative stated that the high ratio units "would effect the engine during starts."

ADDITIONAL INFORMATION:

The airplane was released to the owner.

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