If I were to declare that an approach and landing in a twin-engine airplane with one engine inoperative is essentially the same as a two-engine approach and landing, I'd probably be branded as incredibly simplistic and lacking knowledge of what a pilot who's coping with an emergency needs to do to ensure a safe outcome. Yet, that's what the FAA says in its Airplane Flying Handbook, publication FAA H-8083-3A. It then goes on to provide tips about when to lower the landing gear and flaps, the need to maintain proper airspeed and trim, and the desirability of a normal three-degrees glidepath.
What isn't said is that your success in safely completing an engine-out landing is going to be tied to your overall skill, ability to think and act with precision, the amount of engine-out practice you've had, the condition of the remaining engine and the environmental conditions you're facing. Occasionally, the NTSB is called upon to investigate what went wrong during an engine-out landing attempt.
A twin-engine turboprop Cessna 441 crashed in Nashville, Pa., while approaching York Airport (THV) in nearby Thomasville, Pa. The commercial pilot was killed. He was the only occupant. It was night VFR. The flight originated at Long Beach, Calif., and operated on an IFR flight plan.
According to the FAA, the airplane departed Long Beach just after 8 a.m., Pacific Standard Time, and climbed to FL 330. It subsequently climbed to FL 350. It began its descent to the destination at about 4:39 p.m., local time. At 7:07 p.m., the pilot cancelled the IFR flight plan with New York Center, and at 7:16 p.m., he terminated flight following with Harrisburg Approach Control.
Radar data indicated that at 7:19 p.m., the airplane was about 24 miles west of THV at 1,700 feet. The airplane continued eastbound and entered a 45-degree left downwind for runway 35.
An airport employee told investigators that the pilot radioed for airport advisories, and when the airplane was about midway through the base leg, the pilot transmitted that he had an "engine out." The airplane didn't then turn onto the final approach leg, but continued through it, heading east. The pilot then called "base to final," quickly followed by the airplane turning to the south, then to the west. The employee saw the angle of bank increase to where the airplane's wings were vertical, then inverted, and saw the airplane then make at least one-and-a-half rolls and descend.
Measurements of plotted radar positions versus time indicated an approximate ground speed of 112 knots during the downwind leg, slowing to 102 knots at the beginning of the left base leg. During the subsequent right turn, the ground speed slowed to about 75 knots while the airplane maintained altitudes of 1,100 to 1,200 feet.
The pilot held a commercial pilot certificate with ratings for airplane single-engine land and multi-engine land airplane, and instrument airplane. According to the last entry in the pilot's logbook that appeared to have been written during the accident flight, the pilot had flown 1,409 total hours with 951 hours—of that being in multi-engine airplanes and 463 "turbine" hours. He held an FAA third class medical certificate.
An investigation determined that the right propeller didn't exhibit any outward signs of significant power at impact. The propeller hadn't been feathered. No mechanical problems could be found that would have resulted in a loss of power from the right engine, and the reason for the power loss to the right propeller couldn't be determined.
The wreckage was located on open, rolling terrain, about 1.56 miles from THV runway 35. Ground indentations were consistent with an almost vertical descent. There was no evidence of either an in-flight or post-crash fire. Calculations and physical evidence indicated ample fuel for completion of the flight.
The left engine throttle was near flight idle, and the right engine throttle was full forward; however, the effects of ground impact on their positions couldn't be determined. The NTSB didn't suggest that the pilot had improperly set the throttles.
The NTSB determined that the probable cause of this accident was the pilot's failure to maintain minimum controllable airspeed after a loss of power to the right engine, which resulted in an uncontrollable roll into an inadvertent stall/spin.
A Cessna 414A medical transport aircraft was about one mile west of the Kahului Airport on Maui, Hawaii, when it entered an uncontrolled descent and crashed. The ATP-rated pilot and two medical attendants were killed. The air ambulance was on a Part 91 positioning flight that originated at Honolulu International Airport. Weather was VFR, although an IFR flight plan had been filed for the flight that began at dusk. A patient was supposed to have been picked up on Maui.
Witnesses near where the crash occurred told investigators that the airplane was maneuvering between 100 and 300 feet. They saw the airplane's landing and position lights, and could see the wings rolling at bank angles of up to 60 degrees. They could hear engine sounds and reported that the airplane dropped straight down into an automobile dealership and exploded.
Honolulu Center radar showed the airplane cruising at 7,000 feet MSL. It descended as it got closer to the destination and, at about 7:08 p.m., the tower controller at Kahului cleared the airplane to land on runway 02. The airplane's track showed that it crossed the local harbor area at 1,200 feet MSL and an average ground speed of 134 knots.
At 7:11:33 p.m., the pilot reported to the Kahului tower that they lost an engine and were in a right-hand turn. The pilot requested assistance. The radar track continued to show a descent and right-hand turn about 1.9 miles west of the approach end of runway 02. The average ground speed had dropped to 110 knots. The altitude fluctuated between 400 and 600 feet, and the track stabilized on a heading of about 100 degrees.
This heading put the airplane on a left base for runway 02. The average ground speed was down to 86 knots. The track entered another right-hand turn with the altitude showing 500 feet and an average ground speed of 76 knots. At 7:12:54, the pilot radioed, "Zero one Charlie, we lost an engine." There were no more radio transmissions, and radar contact was lost.
FAA records showed that the pilot held ATP and flight instructor certificates with ratings for airplane multi-engine land, airplane single-engine land, and airplane instrument. The pilot held a first class medical certificate. Records indicated he had 3,141.6 hours with 1,518.6 hours of multi-engine time.
The chief pilot for the operator said the accident pilot had a very good feel for the airplane and was an above-average pilot by company standards.
The pilot had been involved in an airplane accident at Honolulu Airport, in which he was acting as an instructor. He told the NTSB at the time that the left engine couldn't be restarted following a practice shutdown and feather. Because the hydraulic pump is located on the left engine, the instructor was aware that the landing gear would have to be manually extended. The emergency gear extension procedures didn't produce three green lights. While on final approach, the tower controller radioed that the gear appeared down and locked.
On short final, an unidentified pilot radioed on the tower frequency that the nose gear wasn't down and locked. The instructor told the NTSB that he didn't think that it was feasible to perform a go-around, so he landed the airplane on runway 4R.
Upon touchdown, the airplane veered to the left and approximately four feet of the outboard left wing sheared off when it impacted a taxiway light. Neither the instructor nor the pilot receiving instruction was injured.
A review of the pilot's 72-hour history prior to the Maui accident revealed that he had family visiting him in Honolulu, and he kept his normal sleep periods. On the day of the accident, he had a late breakfast and went surfing before reporting to work.
A sound spectrum study revealed that one engine was operating at 2,630 rpm and the other engine was operating at 1,320 rpm. Propeller damage indicated that the right engine was operating at the higher power. Neither propeller had been feathered. Teardown of both engines failed to reveal evidence of mechanical malfunction. Wreckage examination found that the landing gear was down, and the flaps were fully deployed.
The Cessna 414A Information Manual says that one engine-out performance is calculated using the aircraft weight, pressure altitude and outside air temperature. The one engine inoperative performance calculation assumes that the inoperative engine propeller is feathered, the landing gear is up, and the flaps aren't deployed.
The Kahului Airport temperature was about 77 degrees F. Using sea level pressure altitude, and an aircraft weight of 6,500 pounds, the rate of climb with one engine inoperative was calculated to be plus 260 feet per minute. Subtracting values for a windmilling propeller, landing gear down, and flaps at 45 degrees, the airplane's climb performance becomes minus 1,290 feet per minute.
The NTSB said the accident was due to the pilot failing to follow emergency procedures, which would have allowed him to maintain minimum controllable airspeed and level flight and avoid a stall.
Peter Katz is editor and publisher of NTSB Reporter, an independent monthly update on aircraft accident investigations and other news concerning the National Transportation Safety Board. To subscribe, write to: NTSB Reporter, Subscription Dept., P.O. Box 831, White Plains, N.Y. 10602-0831.