NTSB Factual Report

HISTORY OF FLIGHT

On December 9, 2008, at 1058 central standard time, a Mitsubishi MU-2B-60, N452MA, was substantially damaged while returning to land, following a reported loss of engine power, at Millington Regional Jetport (NQA), Millington, Tennessee. The certificated airline transport pilot incurred minor injuries, and visual meteorological conditions prevailed. The airplane was operating on an instrument flight rules flight plan from NQA to Charles W. Baker Airport (2M8), Millington, Tennessee. The positioning flight was conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 91.

According to the pilot, the airplane was based at 2M8. He had flown to NQA to buy fuel, and was on his way back to 2M8 to meet a passenger.

The pilot also noted that he had twice been held on the ground by air traffic control for 15 minutes to let storm cells pass by. After being cleared to depart, the pilot took off from runway 4, utilizing 20-degree flaps. After takeoff, he raised the landing gear, maintained the 20-degree flaps, and headed northwest. About 2 1/2 miles from the airport, the pilot noticed a loss of power from the right engine. He believed that it could have gone to “continuous ignition,” but was not sure, and that the loss of power could have been a result of rain. As the torque dropped to about 40 percent, the pilot decided to feather the propeller while he was still able to do so. After it was feathered "with no problem," the pilot secured the engine.

The pilot subsequently added full power to the left engine while maintaining the 20-degree flaps. The controller asked if he would like to continue to 2M8, and the pilot responded no, he'd like to go back to NQA. The controller also noted the possibility of landing on route 51, which the pilot declined. About that time, winds and wind shear increased, and the airplane encountered heavy rain.

The pilot also reported that he was only able to maintain altitudes between 1,000 feet and 1,400 feet due to turbulence. When asked if he felt the airplane could climb, the pilot stated that he didn't know, that he tried to climb a couple of times but didn't know if wind shear was preventing it. He also stated that he felt the airplane "conformed to standards."

Approaching mid-field NQA, the pilot attempted to land on runway 22, but had difficulty because he was "in too tight" and wanted to make half turns with only one engine. He made the approach about 105 knots; it was normally about 100 knots; and landed about 2/3 of the way down the runway. During the landing, the nose landing gear and the left wing collapsed, and the airplane veered off the left side of the runway.

A review of air traffic control transcripts revealed that,

At 1037, the airplane was released for departure.

At 1041, the airplane was radar-identified, and the controller told the pilot to climb to 2,300 feet. The pilot initially requested a visual approach to 2M8, but subsequently opted for a GPS (global positioning system) approach to runway 18. The controller then provided 020-degree vector.

At 1044, after two more vectors, the pilot stated, “we’re starting to have a problem with the right engine.” The controller asked the pilot if he’d like to continue to 2M8, and the pilot responded that he would. The controller then gave the pilot a final vector, and cleared him to join the localizer.

At 1045, the pilot stated, "we’re losing power on the right engine," and subsequently declared an emergency. The controller asked the pilot if he’d like to continue to the approach, and the pilot initially said he would. After additional transmissions, at 1047, the pilot stated, “…trying to maintain altitude down to two thousand.”

The pilot and controller subsequently discussed approach options, and the pilot decided to attempt the ILS (instrument landing system) runway 22 approach “into uh Millington, we’re going to need a long approach if I can hold this altitude.”

The controller then provided vectors for the approach, along with the current weather.

At 1050, the controller advised the pilot that the airport was “one o’clock four miles.” The pilot replied, “looking no joy,” then, “and we’re losing altitude.”

At 1051, the controller stated, "low altitude alert," and the pilot responded, "we’re trying." The controller then told the pilot that the airport was “one to one thirty and three miles,” and the pilot responded, “i-m-c.”

The controller continued to provide vectors for the ILS runway 22 approach, and the pilot asked the controller to call the pilot’s office and advise them, “lost an engine and don’t know why.” He then added, “heard a popping noise and then some kind of uh sound like a lock up.”

After the controller provided another vector and the pilot provided contact information, the pilot stated, “still losing altitude.” When the controller reported the airplane “about seven and a half miles out,” the pilot stated, at 1055, “still losing altitude, down to eight hundred.” He later stated, “terrain warning,” followed by, “down to a hundred and twenty knots.”

The controller subsequently pointed out highway 51, and that the airport was 5 miles southwest of the airplane’s position.

At 1057:12, the controller advised the pilot that the airport was “twelve o’clock two and a half miles,” and the pilot responded, “giving it all I can give it.” The controller then responded, “about ten degrees left should set you almost straight into runway two two,” and the pilot responded, “barely above the trees.”

After additional transmissions, at 1057:51, the controller advised the pilot that highway 51 was “just off your right, airport at eleven thirty and about two miles,” and the pilot responded, “too many people on fifty one.”

At 1058:09, the controller advised the pilot to turn 10 degrees to the left, and about 15 seconds later, asked “do you have Millington in sight?” The pilot responded, “I got Millington in sight but, I’m off the, it’s not, uh.” The controller then advised, at 1058:34, “November two mike al alpha, you’re cleared to land any runway at Millington.”

The pilot was not in radio contact with the tower. However, just prior to the landing, the tower controller advised airport crash/rescue, “emergency aircraft just turning mid-field to land.”

According to Millington Fire Department reports, units were staged in anticipation of the landing on runway 22. When the airplane appeared, it was “in line with the runway but looked extremely unstable. The plane seemed to be about 15 to 30 feet above the ground and stayed that way all the way down the runway until he reached about the bravo area and he crashed onto the runway and immediately turned left.” The airplane continued left, crossed a taxiway, and impacted the airport property fence before coming to a stop. Firefighters then followed the path of the airplane, and upon arriving on scene, found that the pilot was still inside the airplane, the right engine was shut down, and the left engine was still running "at high speed." Firefighters subsequently sprayed foam into the left engine to stall it, and after it shut down, they removed the pilot from the airplane.

PILOT INFORMATION

The pilot, age 42, held an airline transport pilot certificate with airplane single-engine land, and multiengine land ratings. The pilot reported 5,311 hours of total flight time with 4,246 hours of multiengine time and 662 hours in make and model. His latest FAA second class medical certificate was obtained on March 1, 2007, and his latest flight review was completed on July 17, 2008, in the accident airplane.

AIRPLANE INFORMATION

The airplane was powered by two (Honeywell) Garrett Turbine Engine Company TPE 331-10-511M turboprop engines flat rated to 715 shaft horsepower. Each engine drove a Hartzell four-blade, constant speed, full feathering, reversible pitch, 98-inch diameter propeller.

According to maintenance records, the latest 100-hour, 200-hour, and 1-year engine inspections occurred on June 24, 2008.

AIRPORT INFORMATION

Runway 22 was 8,000 feet long and 200 feet wide. Airport elevation was 320 feet above mean sea level.

RADAR INFORMATION

Radar information indicated that the airplane reached a maximum of 2,400 feet msl at 1042:49, and maintained between 2,300 feet and 2,400 feet until 1045:54. The airplane then began a descent, until the last radar contact, at 600 feet msl, at 1058:40. The last radar contact was about 1/4 nautical mile, 330 degrees from the threshold of runway 22, about 300 feet above the ground.

WRECKAGE INFORMATION

According to the Federal Aviation Administration (FAA) inspector in charge of the on-scene investigation, tire marks consistent with the position of the left main landing gear were first located about 6,200 feet from the beginning of the runway, about 3 feet from the runway's left edge. The marks headed about 200 degrees, off the left side of the runway and into the grass. Additional tire marks, consistent with the position of the nose landing gear were found about 50 feet beyond the first marks, and tire marks consistent with the position of the right main landing gear were found about 200 feet beyond those. Subsequent ground tracks revealed a "shallow arc to the left for a distance of over 250 yards." The tracks then went through a chain link fence, and continued beyond the fence for another 150 yards.

The majority of the left wing was found broken off about halfway along the ground track, and where the airplane came to rest, the left fuselage was found severed in the vicinity of the left propeller.

The flaps were found extended to 20 degrees and the landing gear were down.

The right engine was found in the feathered position, and appeared to be undamaged except for a dent in the spinner dome. The propeller appeared to rotate "normally," and there was no damage evident in the first stage compressor or third stage turbine wheel.

METEROLOGICAL INFORMATION

Weather, recorded at the airport at 1050, included calm winds, visibility 3 statute miles, light rain, mist, scattered clouds at 500 feet, a broken cloud layer at 1,200 feet, an overcast cloud layer at 2,300 feet, temperature 12 degrees Celsius, dew point 12 degrees Celsius, and an altimeter setting of 29.82 inches of mercury (Hg).

A special weather observation, at 1101, included winds from 080 degrees true at 3 knots, visibility 4 statute miles, light rain, mist, a few clouds at 400 feet, scattered clouds at 2,300 feet, a broken cloud layer at 3,100 feet, temperature 12 degrees Celsius, dew point 12 degrees Celsius, and an altimeter setting of 29.82 inches Hg.

According to an on-scene firefighter report, “heavy rain/thunderstorms were present the entire time of the incident.”

Transmissions between two air traffic control facilities, at 1037, indicated “heavy and extreme weather is east of Charles Baker now…moving east northeast.” There was also “a little bit of heavy precipitation just north of Charles Baker.”

TESTS AND RESEARCH

After the airplane was moved to a storage facility, both engines were removed and forwarded to Honeywell for further examination and if feasible, testing, under FAA Los Angeles Aircraft Certification Office (ACO) oversight. An Examination and Test Cell Report was subsequently produced by the manufacturer, which included:

“No preexisting condition was identified on either the left or right engine that would have interfered with normal operation prior to the accident sequence.” In addition:

The left engine torsion shaft was separated, which precluded engine test cell runs. A disassembly of the engine revealed rotational scoring on the first-stage and second-stage compressor shrouds, and all three turbine stator shrouds, and metal spray was found at various positions along the gas path.

The right engine did not exhibit any preaccident damage, and no unusual noises were noted while turning the rotating elements of the engine. There was no visible debris on either the oil filter element or the fuel filter element. Initial engine test cell startup attempts required test cell instrumentation debugging. However, once the engine was started, it indicated a maximum of 1,018 shaft horsepower (shp), which was 18 shp more than that required for an overhauled or repaired engine, and 2 shp less than that required for a new production engine.

Right engine torque transducer calibration checks revealed that, at 100 percent torque, the voltage output was 0.120 volts lower than the lower limit, which translated to a 3.0 percent indicated torque error.

Additional engine examination and test results may be found in the NTSB Public Docket associated with this accident.

ADDITIONAL INFORMATION

Excerpts from the Airplane Flight Manual (AFM) include:

Under “Normal Procedures”:

- AFTER TAKEOFF-

When positive rate of climb is established:

1. Maintain pitch attitude 13 degrees Nose UP maximum.

When positive rate of climb is established:

2. Landing Gear…Up

3. Airspeed……………120 CAS (5 degrees Flap Takeoff)113 CAS (20 degrees Flap Takeoff)

4. Flaps – After gear retraction complete

a. 20 degrees Flap Takeoff……to 5 degrees

b. 5 degrees Flap Takeoff………to UP

5. Airspeed………………………………140 KCAS MINIMUM

6. Flaps (20 degrees Flap Takeoff)………UP

7. Airspeed (Normal Climb)……………155 KCAS

-VISIBLE MOISTURE ENCOUNTERS –

Entering Visible Moisture from Dry Conditions (Cruise at 650 degrees C EGT)

Engine EGT will decrease when entering visible moisture. Unless a critical thrust condition exists:

1. Power Levers………DO NOT MOVE. MONITOR EGT. IF EGT DECREASES BELOW 630 DEGREES C, ADJUST POWER LEVERS TO MAINTAIN 630 DEGREES C UNTIL CLEAR OF VISIBLE MOISTURE.

Under “Emergency Procedures”:

- ENGINE FAILURE AFTER LIFTOFF – GEAR DOWN OR IN TRANSIT -

Warning. If flaps twenty degrees takeoff is selected and engine failure occurs after liftoff, continued climb performance is not assured unless the landing gear has completely retracted, the gear doors are closed, and the flaps are at 5 degrees or less.”

- ENGINE FAILURE IN TAKEOFF CLIMB – GEAR FULLY RETRACTED -

2. Flaps…5 degrees.

5. Flaps…Up.

- ENGINE SHUTDOWN PROCEDURE -

If engine failure occurs, or if a sudden loss or significant fluctuation (plus or minus 7.75 percent) of indicated torque pressure occurs, as indicated by airplane yaw, promptly shutdown the affected engine and determine the cause prior to further operation.

The AFM did not have a procedure for an engine failure in flight, except for a DRIFTDOWN PROCEDURE with a failed engine above 25,000 feet. Neither the DRIFTDOWN PROCEDURE nor the ENGINE SHUTDOWN PROCEDURE addressed drag influences such as landing gear or flaps.

- SINGLE ENGINE LANDING -

Warning – Do not attempt a go-around below 400 feet or after 20 degrees of flaps are selected.

Under “Performance”:

- Single Engine Best Rate of Climb -

The chart criteria assumes:

Operating Engine: Maximum Continuous Power

Inoperative Engine: Propeller Feathered

Climb Speed: Best Rate of Climb Speed

Landing Gear: Retracted

Flaps: Up

Bleed Air: Off

Wings: Level

Based on the above criteria, the ambient conditions, and the weight of the airplane at the time of the accident, as provided by the pilot, the airplane should have been able to climb about 650 feet per minute on one engine at 145 knots calibrated airspeed.

- Single Engine Best Rate of Climb –

The chart criteria assumes:

Operating Engine: Takeoff power

Inoperative Engine: Propeller Feathered

Climb Speed: 135 KCAS (Vyse)

Landing Gear: Retracted

Flaps: 20 degrees

Bleed Air: Off

Based on the above criteria, the ambient conditions, and the weight of the airplane at the time of the accident, as provided by the pilot, the airplane should have been able to climb about 350 feet per minute on one engine at 135 knots calibrated airspeed, with the flaps extended to 20 degrees.

In response to follow-up questi

NTSB Probable Cause

The pilot’s improper configuration of the airplane following an engine shutdown, which resulted in a low-altitude, unstabilized approach. Contributing to the accident was a loss of engine power for undetermined reasons.