Tag Archives: Pratt & Whitney JT9D-7A

19 February 1985

China Airlines' Boeing 747SP, N45522V. Thi saircraft few as Dynasty 006, 18 February 1985. (Andrew Hunt)
China Airlines’ Boeing 747SP, N4522V. This aircraft few as Dynasty 006, 18 February 1985. (Andrew Hunt)

19 February 1985: At 10:16 a.m., Pacific Standard Time, while enroute from Taipei, Republic of China, to Los Angeles, California, China Airlines’ Flight 006 (call sign “Dynasty Six”), a Boeing 747SP-09, FAA registration N4522V, was cruising at 41,000 feet (12,497 meters), 300 nautical miles (556 kilometers) northwest of San Francisco, California. It had a crew of 23 with 251 passengers. The airliner had a flight crew of five under command of Captain Min-Yuan Ho, with a co-pilot and flight engineer, as well as a relief captain and flight engineer, due to the length of the trans-Pacific flight.

Captain Min-Yuan Ho, describing the incident to reporters at San Francisco Airport, 19 February 1985.
Captain Min-Yuan Ho, describing the incident to reporters at San Francisco Airport, 19 February 1985.

The Number 4 engine, the outboard engine on the airplane’s right wing, a Pratt & Whitney JT9D-7A turbofan, refused to respond with the other engines as the throttles were advanced, and it “hung” and remained at a low power level. It did not flame out, as the crew believed. The crew attempted restart procedures, however they did so incorrectly.

The airliner’s autopilot was engaged and the aircraft began to yaw and bank because of the asymmetric thrust. The copilot, First Officer Ju Yu Chang, used full opposite aileron to stop the roll, but neither pilot or copilot applied any rudder inputs to correct the yaw. (It was later determined that they believed, incorrectly, that the autopilot controlled rudder position.)

The airplane departed controlled flight, rolled over and dived. It lost 30,000 feet (9,144 meters) of altitude before the crew was able to recover, however the airplane was severely damaged, with bent wings, a damaged left aileron, lost parts of its elevators and horizontal stabilizers and damaged landing gear doors. It had experienced acceleration forces as high as 4.8 Gs as it descended through 30,552 feet (9,312 meters) and a peak 5.1 Gs at 19,083 feet (5,816 meters).

This illustration, based on the NTSB accident investigation, shows the various attitudes of China Airlines Flight 006 as it descended out of control, 19 February 1985. (Wikipedia)
This illustration, based on the NTSB accident investigation, shows the various attitudes of China Airlines Flight 006 as it descended out of control, 19 February 1985. (Wikipedia)

Of the 287 persons on board, 24 were injured. Two were seriously hurt and the flight diverted to San Francisco. The 747SP was substantially damaged. It was nearly two years before repairs completed.

China Airlines’ Boeing 747SP-09 N4522V, photographed at Amsterdam, 16 June 1991. (Torsten Maiwald/Wikimedia)

The National Transportation Safety Board investigation made the following findings:

3.1 Findings

1. The flightcrew was properly certificated and qualified.

2. The changing airspeeds encountered by Flight 006 and the resultant compensating throttle adjustments were caused by wind speed variations.

3. The No. 4 engine did not flame out, but “hung” at about 1.0 EPR.

4. During his attempt to recover the No. 4 engine, the flight engineer did not close the bleed air valve switch before advancing the No. 4 throttle.

5. The other three engines did not lose thrust nor did they flame out.

6. The captain did not disengage the autopilot in a timely manner after thrust was lost on the No. 4 engine. The autopilot effectively masked the approaching onset of the loss of control of the airplane.

7. The captain was distracted from his flight monitoring duties by his participation with the flight engineer in the evaluation of the No. 4 engine’s malfunction.

8. With the exception of the loss of thrust on the No. 4 engine, no other airplane malfunction affected the performance of the airplane; the loss of thrust on the No. 4 engine did not contribute to the accident.

9. The captain was also distracted by his attempts to arrest the airplane’s decreasing airspeed, and this also contributed to his failure to detect the airplane’s increasing bank angle.

10. The lateral control deflections required to maintain level flight under conditions of thrust asymmetry and decreasing airspeed exceeded the limits of the autopilot’s lateral control authority, causing the airplane to roll and yaw to the right. The captain lost control of the airplane when, after disengaging the autopilot, he failed to make the proper flight control corrections to recover the airplane.

11. The damage to the airplane was a result of the acceleration forces and high airspeeds that occurred during the upset and recovery maneuvers.

3.2 Probable Cause

The National Transportation Safety Board determines that the probable cause of this accident was the captain’s preoccupation with an inflight malfunction and his failure to monitor properly the airplane’s flight instruments which resulted in his losing control of the airplane.

Contributing to the accident was the captain’s over-reliance on the autopilot after the loss of thrust on the No. 4 engine.

The captain had not slept during his previous rest period and his tiredness was considered a factor in this incident.

Damage to the tail surfaces of Boeing 747SP N4522V.
Damage to the tail surfaces of Boeing 747SP N4522V.

The Boeing 747SP (“Special Performance”) is a very long range variant of the 747-100 series airliners. It has a shorter fuselage and larger tail surface than the standard model. The weight savings allows it to carry more fuel for longer flights, and it is also faster. Boeing built 45 747SPs.

The 747SP is 184 feet, 9 inches (56.312 meters) long, with a wingspan of 195 feet, 8 inches (59.639 meters). It has an overall height of 65 feet, 10 inches (20.066 meters). It has a maximum takeoff weight of 670,000 pounds.

The airliner has a cruising speed of 0.88 Mach (616 miles per hour, or 991 kilometers per hour) and a maximum speed of 0.92 Mach (680 knots, 1,094 kilometers per hour). The service ceiling is 45,100 feet (13,746 meters) and the range is 7,650 miles (12,311 kilometers), carrying 276 passengers and baggage. The fuel capacity is 47,210 gallons. (178,709 liters).

Damaged horizontal stabilizer and elevators of Boeing 747SP-09 N4522V (NTSB)

The FAA registration of N4522V expired 31 December 2016. It was last registered to Global Peace Initiative Inc., Huffman, Texas. The airplane has been stored at Tijuana International Airport (TIJ), just south of the U.S./Mexico border, since 16 December 2005.

Boeing 747SP 09 serial number 22805. The airliner’s U.S. registration expired 31 December 2016. (Global Peace Initiative)

© 2018, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

21 December 1988

Clipper Maid of the Seas, Pan American World Airways' Boeing 747-121, at Los Angeles International Airport (LAX) 12 March 1987. (Ted Quackenbush via Wikipedia)
Clipper Maid of the Seas, Pan American World Airways’ Boeing 747-121 N739PA, takes off at Los Angeles International Airport (LAX) 12 March 1987. (Ted Quackenbush via Wikipedia)

21 December 1988: Pan American World Airways’ Flight 103 was a scheduled transatlantic passenger flight, originating at Flughafen Frankfurt am Main (FRA) with stopovers at London Heathrow Airport (LHR) and John F. Kennedy International Airport (JFK), with a final destination of Detroit Metropolitan Wayne County Airport (DTW).

The first leg from Frankfurt to London was flown with a Boeing 727. The transatlantic segment of Flight 103 was flown by a Boeing 747-121, N739PA, named Clipper Maid of the Seas. It departed Heathrow at 1825 hours UTC, with 16 crewmembers and 243 passengers. The 747 climbed to the north and leveled off at at 31,000 feet (9,449 meters) at 1856 hours.

At approximately 1903, a time bomb which had been placed inside luggage carried in the airliner’s cargo hold detonated. Explosive decompression magnified the effects of the bomb. The airliner broke into five large sections and fell to the ground at the town of Lockerbie, Scotland.

The impact crater of Boeing 747 N739PA at Sherwood Crescent, Lockerbie. The wings and fuselage center section struck here, 49.5 seconds after the explosion. 200,000 pounds (91,000 kilograms) of jet fuel ignited, destroying many homes. (Martin Cleaver/syracuse.com)
The impact crater of Boeing 747 N739PA at Sherwood Crescent, Lockerbie. The wings and fuselage center section struck here, 49.5 seconds after the explosion. 200,000 pounds (91,000 kilograms) of jet fuel ignited, destroying many homes. (Martin Cleaver/syracuse.com)

All 259 persons on board the 747 were killed, as were another 11 persons on the ground.

The time bomb is believed to have been placed aboard the airliner by agents of the Great Socialist People’s Libyan Arab Jamahiriya, acting on orders of the Brotherly Leader and Guide to the Revolution of Libya, Muammar al-Gaddafi. One of these, Abdelbaset Ali Mohmed al-Megrahi, was convicted of 270 counts of murder in a Scottish criminal court seated in The Netherlands. The defense twice appealed the case, but prior to a decision in the second appeal, al-Megrahi dropped his appeal and asked to be released from jail because it was believed that he would very soon die of cancer. The Scottish court did release him and he returned to Libya on 14 August 2009, on board Colonel Gadaffi’s personal aircraft. He reportedly died 20 May 2012.

Boeing delivered N739PA to Pan American 15 February 1970. The airliner was originally named Clipper Morning Light. At the time of the bombing, it had accumulated 72,464 total flight hours.

The forward section of Clipper Maid of the Seas, near the village of Tundergarth, Scotland.
The forward section of Clipper Maid of the Seas, near the village of Tundergarth, Scotland.

The 747-100 series was the first version of the Boeing 747 to be built. It was operated by a flight crew of three and was designed to carry 366 to 452 passengers. It is 231 feet, 10.2 inches (70.668 meters) long with a wingspan of 195 feet, 8 inches (59.639 meters) and overall height of 63 feet, 5 inches (19.329 meters). The interior cabin width is 20 feet (6.096 meters), giving it the name “wide body.” Its empty weight is 370,816 pounds (168,199 kilograms) and the Maximum Takeoff Weight (MTOW) is 735,000 pounds (333,390 kilograms).

The 747-100 is powered by four Pratt & Whitney JT9D-7A high-bypass ratio turbofan engines. The JT9D is a two-spool, axial-flow turbofan engine with a single-stage fan section, 14-stage compressor (11 high- and 3 low-pressure stages) and 6-stage turbine (2 high- and 4 low-pressure stages). The engine is rated at 46,950 pounds of thrust (208.844 kilonewtons), or 48,570 pounds (216.050 kilonewtons) with water injection (2½-minute limit). This engine has a maximum diameter of 7 feet, 11.6 inches (2.428 meters), is 12 feet, 10.2 inches (3.917 meters) long and weighs 8,850 pounds (4,014 kilograms).

The 747-100 has a cruise speed of 0.84 Mach (555 miles per hour, 893 kilometers per hour) at 35,000 feet (10,668 meters). The maximum certificated operating speed is 0.92 Mach. The airliner’s maximum range is 6,100 miles (9,817 kilometers).

The Boeing 747 has been in production for 48 years. More than 1,536 have been delivered as of September 2017. 205 of these were the 747-100 series. The U.S. Air Force has selected the Boeing 747-8 as the next presidential transport aircraft.

The Names. (StaraBlazkova/Wikipedia)

© 2017, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

30 September 1968

Boeing 747-121 RA001 on public display, Everett, Washington, 30 September 1968. (Boeing)

30 September 1968: The first Boeing 747, City of Everett, was rolled out at Boeing’s Everett, Washington plant. It was registered as N7470, and carried Boeing’s serial number, 20235.

Identified internally as RA001, the Boeing 747-121 was the first “jumbo jet.”

The 747-100 series was the first version of the Boeing 747 to be built. It was operated by a flight crew of three and was designed to carry 366 to 452 passengers. It is 231 feet, 10.2 inches (70.668 meters) long with a wingspan of 195 feet, 8 inches (59.639 meters) and overall height of 63 feet, 5 inches (19.329 meters). The interior cabin width is 20 feet (6.096 meters), giving it the name “wide body.” Its empty weight is 370,816 pounds (168,199 kilograms) and the Maximum Takeoff Weight (MTOW) is 735,000 pounds (333,390 kilograms).

The 747-100 is powered by four Pratt & Whitney JT9D-7A turbofan engines which can produce 47,670 pounds of thrust, each, with water injection (2½ minutes). Its cruise speed is 0.84 Mach (555 miles per hour, 893 kilometers per hour) at 35,000 feet (10,668 meters) and it’s maximum speed is 0.89 Mach (594 miles per hour/893 kilometers per hour). The maximum range at MTOW is 6,100 miles (9,817 kilometers).

The 747 has been in production for 48 years. More than 1,500 have been built. 250 of these were the 747-100 series.

N7470 made its first flight on 9 February 1969. It last flew in 1995. City of Everett is on static display at The Museum of Flight, Boeing Field, Seattle, Washington.

The first Boeing 747, N7470, after rollout at Everett, Washington, 30 September 1968. (The Museum of Flight)
The first Boeing 747, N7470, after rollout at Everett, Washington, 30 September 1968. (The Museum of Flight)

© 2018, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather