Monday, August 29, 2011
THE AMAZING DITCHING OF PAN AM FLIGHT 6..BOEING 377 STRATOCRUISER N90943 1956
PAN AM B-377
On January 15, 2009 U.S.Air Flight 1549 a regulary scheduled flight from Laguardia Airport in New York to to Charlotte/Douglas International Airport, Charlotte, North Carolina. was successfully ditched in the Hudson River adjacent to midtown Manhattan six minutes after takeoff from LaGuardia Airport after being disabled by striking a flock of Canada Geese during its initial climb out. The incident became known as the "Miracle on the Hudson.
I totally agree that Flight 1547 and Captain Sullenberger's successful ditching was indeed one of the most interesting and successful ditching of an airliner. But for me, the most amazing and intricate ditching occurred 55 years ago on October 16, 1956. With the ditching in the Pacific Ocean of Pan Am Clipper Flight 6, a Boeing 377 Stratocruiser owned and operated by Pan American World Airways and piloted by one of my aviation heroes Captain Richard N. Ogg. Described by Life Magazine writer Herbert Brean as A tall, reticent thoughtful man.
Concerning Captain Ogg, this article was written by Scott Herhold of the Mercury News
The miracle on the Hudson had a local precedent
Richard N. Ogg, a Pan-Am pilot who lived in Saratoga, brought a... (Mercury News archives)
The pilot remembered a "very heavy" impact when the plane hit the water after losing two engines. He praised the passengers for staying calm as they filed out into the three life rafts. When he was acclaimed for rescuing everyone aboard, he was fixedly modest: "To me, it was just a matter of doing my job,'' he said
Chesley B. "Sully'' Sullenberger, the man who landed US Airways Flight 1549 on the Hudson River? No: The hero 52 years ago was Richard N. Ogg, a veteran pilot from Saratoga who landed a Pan American Stratocruiser on the Pacific Ocean, saving all 31 aboard. The miracle on the Hudson had a precedent.
Forever after, his superb ditching defined Ogg's career: He regularly spoke before aviation groups about safety procedures. Once, when he had a faraway look on his face, his wife, Margaret, asked him what he was thinking. Ogg answered that he was pondering the fate of a group of canaries that drowned in the hold when the plane went down.
Peril over the Pacific Ogg, then 42, had been a pilot for two decades when he took off from Honolulu at 9:30 p.m. on Sunday, Oct. 14, 1956, bound for San Francisco with 24 passengers and six other crew members. The name of his craft was "Sovereign of the Skies," but that night, it had to depend on others to survive.
The pilot later told San Jose Kiwanis Club members that he had completed the first leg of his trip when his number one engine, on the far left-hand side, failed. Ogg tried to feather the propeller, or alter the pitch of the blades, but it continued to "windmill," putting a tremendous drag on the plane. With the number four engine also malfunctioning and his air speed reduced to 140 knots, Ogg knew he would probably have to ditch.
Luck was with him: Ten minutes before, he had passed a Coast Guard cutter, the Pontchartrain. Ogg turned the heavy Stratocruiser around and began five hours of circling the Pontchartrain, waiting for daylight and for his tanks to empty of fuel. He practiced ditching at least three times.
At 8:16 a.m. Pacific Standard Time —7:16 a.m. by the Pontchartrain's clock — Ogg brought the Stratocruiser down in 5-foot swells and an 8-knot wind. He knew the tail would probably crack up, and it did. "We hit with a good bump but we knew we would be all right," said the 6-foot-4 captain.
Miraculously, everyone on board was rescued within five minutes, although a few passengers fell into the water as they departed the plane. Only five people reported minor injuries.
A hero's welcome
When he came back to San Francisco and to his home on Winter Lane in Saratoga, Ogg was given a hero's welcome, just as Sullenberger was in Danville last weekend. There was one obvious difference: With fewer lawyers to bring lawsuits, Ogg spoke freely of the ditching. Sullenberger has avoided releasing details in public.
A loyal Pan-Am pilot, Ogg stayed with the faltering airline until he retired in 1971, not long before it went bankrupt. He continued to fly privately for almost two decades afterward, frequently taking his single-wing Mooney aircraft to his home state of Montana.
Before Ogg died of colon cancer in 1991, Margaret once asked him whether he had ever been afraid. "When I went in for open-heart surgery," Ogg responded. What about the ditching? she asked. "Oh, I was just so busy trying to remember everything I learned that I didn't have time," he said.
Below is my story of Clipper Flight 6 amd the amazing ditching.
Editors Note: All flight data and information was taken from the official CAB Accident Investigation Report Released on July 11, 1957.
Times are all Hawaii Standard Time. Actuall times may differ by 2 or 3 minutes.
I also took the personal info from a story written by Herbert Brean Froim Vol. 41 No. 18 October 29, 1956 issue.
In memory of Captain Richard N. Ogg and the flight crew of Clipper flight 6.
The ditching of Pan American Boeing 377, N90943 October 16, 1956.
Pan Am flight 6 was a regularly scheduled around-the-world flight eastbound from Philadelphia, Pennsylvania. to San Francisco, California. with en route stops in Europe, Asia. and various Pacific Islands. All prior segments had been routine and the flight departed Honolulu on the last leg of the -trip on October 15.
The last leg of this around the world flight was from Honolulu to San Francisco was being flown by a veteran Pan Am crew led by:
Captain Richard N. Ogg, age 43, was employed by Pan American World Airways on February 20, 194L. He held a valid airman certificate with airline transport rating and rating for the subject aircraft. Captain Ogg had a total of 13,089:41 flying hours., of which 738:27 were in Boeing 377s. He had passed a CAA medical examination m September 21, 1956. He had completed an emergency equipment training course dry ditching - on June 4., 1956.
First Officer George L. Haaker, age 40, was employed by PAWA on March 1, 1946. He held a valid airman certificate with airline transport rating and rating for the subject aircraft. Mr. Haaker had a total of 7,576.00 flying hours, of which 3.674:06 were in Boeing 377's. His last physical examination was passed m September 4, 1956. He completed an emergency ditching training course on August 2, 1956.
Flight Engineer Frank Garcia, Jr., age 30, was employed by PAWA on August 16, 1954. He held a valid flight engineer certificate, mechanic certificate with A&E rating, and radio operator certificate. He qualified on toeing 377s on March 28, 1956, and had accumulated 1,728 flying hours in B-377's. He received his last CAA physical examination m June 29., 1956.
Navigator Richard L. Brown, age 31, was employed by PAWA on December 9, 1955. He held a valid airman certificate with commercial rating., and a temporary CAA navigation certificate issued August 24, 1056. Mr. Brown had a total of 1,283:16 flying hours, of which 446:00 were in Boeing 377's. His last physical examination was passed on February 28, 1956. He had completed the initial emergency equipment training course - dry drill - on January 13, 1956
B-377 FLIGHT DECK
The cabin crew consisted of:
The Stewardesses Purser Pat Reynolds, Katherine Araki, Mary Ellen Daniel
Purser Patricia Reynolds, age 30, was employed by PAWA on September 23, 1946. She had completed her latest B-377 emergency equipment recheck on February 10, 1956, and had completed the USCG wet drill in San Francisco on July 12, 1956.
Stewardess Mary Ellen Daniel, age 24, was employed by PATTA on June 23, 1954. She had completed the B-377 emergency equipment recheck an March 12, 1956, the USCG wet drill on September 18, 1956.
Stewardess Katherine S. Araki, age 23, was employed by PAWA on March 26, 1955. She had completed the B-377 emergency equipment recheck on May 7, 1956.
The aircraft for this leg of the trip was a Boeing 377, registered as N 90943, S/N 15959. Pan Am owned the aircraft. The aircraft was named “The Clipper Sovereign Of The Skies”. She had accumulated 19, 820:51 flying hours. It was equipped with four Pratt and Whitney R4360-B6 engines, and four Hamilton Standard Model 24260 propellers. The aircraft and engines were in full compliance with prescriped methods and time limitations.
Complete overhaul and maintenance records of N 90943 were kept at San Francisco headquarters of the Pacific-Alaska Division. A study of these records disclosed that the aircraft had been maintained in an airworthy condition according to CAA-approved maintenance procedures. and was properly certificated and equipped. No discrepancies were noted in any of the records of N 90943.
THE FLIGHT DECK FROM TAKEOFF IN HONOLULU TO DITCHING
Arriving at Pan Am flight dispatch Captain Ogg, First Officer Haaker and Navigator Brown were briefed on the current weather conditions at Honolulu and on the filed flight path. The weather they would experience on the filed flight route was not a factor for this accident.
The crew filed an IFR flight plan for an estimated flight time of 8 hours and 54 minutes. Captain Ogg had fleet service load fuel for a flight time of 12 hours and 18 minutes. The estimated gross weight at takeoff was 138, 903 pounds. The Max T.O weight for this particular aircraft was 144,000 pounds. The CG was located within the required range.
The agreed upon flight plan reads: Clipper Flight 6 is cleared to San Francisco via Green Airway 9 then track to Position 30* N 140* W at 13,000 ft., The climb to 21,000 Ft. on course to San Francisco. All three crew members agree with the Pan Am flight dispatcher and Captain Ogg signs the release form and flight plan
Out on the ramp at the aircraft Flight Engineer Garcia was performing his walk around inspection before entering the flight deck and getting ready for the prestart checklist after which the engineer gives the Ready To Start Engines Report.
At the same time Passenger services allowed the 24 passengers three of which were infants to board the aircraft 30 minutes prior to takeoff.
Running through their pre start checklist, to include around 32 different items that need to be pre set or checked.
The engine starting procedure for these massive and powerful R4360’s requires full attention of the flight crew. After all engines are started and checked the pre taxi check list is read.
As ground control gives flight 6 permission to taxi Captain Ogg adds power, with his right hand on the four throttles he advances them to allow the aircraft to roll away slowly. Grasping the nose wheel steering wheel on his left side near his knee he steers the aircraft t to the active runway.
20:24 HST... lining up on the centerline of the runway Captain Ogg advances the four throttles to about 2700 rpm and starts his takeoff roll. Around 100 to 105 IAS the aircraft will lift off. After rotating the aircraft the big B377 departs Honolulu and climbs safely away . As the aircraft climbs and a positive rate of climb is secured Captain Ogg, calls for “Gear Up” 1st officer Haaker moves the landing gear switch and confirms that the red lights go out as the gear locks up. As the gear retracts Captain Ogg applies the brakes to allow the wheel rotation to slow down and stop. to 13,000 feet with no problems experienced.
Cruising at 13,000 feet Clipper Flight 6 heads eastbound on a heading of 062 degrees true.
01:02 HST... Clipper 6 contacts Honolulu on HF and requests a VFR climb to flight level 21.0.
01:06 HST…Honolulu ATC approves VFR climb to 21.0
01:07 HST…Clipper 6 starts its climb to Fl 21.0
Note: The mid point of the flight would be around 1140 nautical miles from Honolulu. And was calculated to be reached at 01:31 HST,
01:19 HST…Clipper 6 levels off at FL 21.0.. The cruising speed was allowed to increase to 188 Knots.
01:19 HST…Stewardess Mary Ellen Daniel the on duty stewardess opens the flight deck door and asks the crew if they wanted coffee. Two of the crew did , but Captain Ogg wanted a Coca Cola.
01:20 HST…Suddenly stewardess Daniel hears the engine noise suddenly go to a loud stridency. The aircraft dips suddenly she staggers and has to grab hold to remain standing.
01:20 HST…First Officer Haaker who was flying the aircraft at this time requested Engineer Garcia to increase the power in order to increase the air speed. Haaker stated he noticed a vibration in the controls and an increase in the propeller noise.
01:21 HST… First Officer Haaker and Flight Engineer Garcia notice that the Tachometer for No. 1 engine is reading about 2,900 RPM. Haaker reaches overhead and activates the feather prop switch for No.1 engine. Reaching down on the engine control panel Haaker and lowered the flaps to 30 degrees.
01:21HST.. Engineer Garcia reaches overhead and immediately activates the No.1 fire switch gang bar, pulls back the No.1 throttle to the stop and cuts the mixture control lever for No.1 engine. Garcia also reduced the power on the other three engines in order to reduce the airspeed.
Note : During the procedure of feathering the prop and shutting down No.1 engine the engine actually exceeded the highest calibration on the engine No.1 tachometer.
From the onset of the engine prop going into over speed, Captain Ogg was out of his seat and working at the Navigators station with navigator Brown. He immediately regained his seat.
01:22 HST… After numerous attempts at feathering the No.1 engine were unsuccessful, Captain Ogg orders Engineer Garcia to cut off the oil supply to engine No.1 so that it will freeze the engine.
Flight Engineer B-377
01:24 HST… The flight crew notices a momentary decrease in the RPM , then a heavy thud, followed immediately by an increase in the prop RPM. The crew decided the engine had frozen and the propeller had uncoupled through a failure in the propeller drive mechanism, and was wind milling in the airstream.
01:25 HST… Captain Ogg calls Ocean Station November. And alerts the ship that they may possibly have to ditch the aircraft. The Coast Guard Cutter Pontchartrain determines with its radar that Clipper 6 is approximately 38 miles from the ship on a bearing of 256 degrees. The Pontchartrain also recommended a heading for ditching the to the crew
Captain Ogg also orders Engineer Garcia to increase power on engines 2, 3, and 4 to help check the rate of descent. At this time Engineer Garcia advised the Captain that No.4 engine was only developing partial power at full throttle. When Garcia advanced No. 4 engine to full throttle the readings were 2, 350 RPM: 80 BMEP, 23 inches manifold pressure; oil and fuel pressures were normal; fuel flow was 600 pounds per hour, oil temp, carb air temp and cylinder head temps were lower then normal; turbo supercharger operation appeared normal. There was a slight rise n manifold pressure and in cabin airflow when the No.4 turbo calibrating control was rotated to the full on position. When Garcia reduced RPM to 1,750, and closed the oil cooler and intercooler, and the cowl flaps to one half inch, The BMEP increased to 90 with 26inches of manifold pressure at the same fuel flow. Looking at his engine analyzer Garcia noted that all patterns were normal, oil temperature, and cylinder head temperature increased slightly, and the engine continued to operate.
Pontchartrain From The Aircraft
01:25 HST… Captain Ogg, Clipper 6 notified “November” that a ditching was imminent . In return the Coast Guard Cutter Pontchartrain plotting the aircraft on its radar gave the crew a heading to the cutter.
01:26 HST… The Pontchartrain immediately alerted other ships and aircraft in the area. They reported to Captain Ogg…The sea weather was clear, the sea exceptionally calm, the winds seven miles per hour from 60 degrees.
Note: During the descent the crew found they could maintain altitude at an airspeed of 135 knots with rated power on engines No. 2 and 3 and partial power on No. 4
01:26 HST… Navigator Brown gets a heading to home on Ocean Station November and has the Captain alter their course slightly. Captain Ogg , alerts the passengers to the emergency and instructs the cabin crew to prepare for a water landing.
01:37 HST… Just prior to over heading November, Flight 6 called its dispatch office in Honolulu and advised them of the situation.
01:37 HST… Clipper 6 arrives overhead Ocean Station November. Prior to arriving overhead November Navigator Brown and Engineer Garcia determined that the remaining fuel was insufficient for the aircraft to to return to Honolulu or to continue on to San Francisco. The range was seriously empaired by the drag created by the wind milling prop and the required lower airspeed. With the remaining fuel on board Navigator Brown computed the maiximum range of the aircraft as 750 miles. The distance to Honolulu or San F4rancisco was well over 1000 miles.
By this time Clipper 6 has descended to 5,000 feet. With an airspeed of 135 knots the crew could maintain this altitude with the flaps up and rated power on engines 2 and 3. Although the aircraft was allowed to settle to 3,000 feet just prior to over heading the cutter.
Note: It was found that the wind milling propeller could be kept under control if the airspeed was kept below 140 knots. . This airspeed is about 20 knots less than that required for efficient two engine flight.
Note: The actual procedure for a Propeller over speeding required the pilot flying to Maintain Directional
Retard the remaining throttles to reduce forward speed.
Pull the aircraft up to hasten the reduction of forward speed.
If the situation warrants have the Flight engineer Feather prop.
Mixture Lever for the over speeding Prop Idle Cut Off.
Ignition Switch off
Complete engine shutdown checklist.
Over the Cutter
01:40 HST… Captain Ogg set up a shuttle pattern over November using the heading of 240 degrees while making eight mile legs. 240 degrees was the heading he will use for the ditching. At this time the cutter laid out a string of electric water lights along the 240 degree heading and was standing by for the aircraft to make its approach for the ditching.
02:00 HST… Captain Ogg after evaluating the situation with his crew decided that ditching by day is in itself a dangerous situation and doing it at night is even more dangerous. At this point knowing he never had ditched an aircraft, makes the decision to delay the ditching until daylight which is 3 hours away. In the meantime Captain Ogg orbited November.
02:15 HST…While talking with the captain of the Pontchartrain Captain Ogg voice held no tone of an emergency. At one point the Captain of the cutter mentioned that the aircraft carrier Bennington was coming to the scene, “Maybe you could land on the carrier” he joked. “I don’t think I‘ll try that”, the chuckling Captain Ogg replied.
O2:45 HST… The No.4 engine backfired and the power immediately dropped off. Engineer Garcia makes an analyzer check and this time the engine shows many low resistance shorts and no combustion pattern on the “B” row of cylinders. Captain Ogg, decides to feather the prop. Garcia reaches over head and feathers the No.4 prop successfully.
02:47 HST…Engineer Garcia set the remain two operating engines, No. 2 and 3 at 2,550 RPM, 190 BMEP and 2,000 pounds per hour fuel flow. The aircraft has settled to 2,000 feet and is flying at 140 knots.
03:00 HST…As the aircraft burns off some fuel weight, Captain Ogg allows the aircraft to climb back to 5,000 feet. At this time the crew perform a few practice approaches to feel the controllability of the aircraft out at the lower airspeeds. Captain Ogg, continues to circle over the cutter to burn as much fuel as possible in order to make the aircraft as buoyant as possible during touchdown on the water.
IN THE CABIN
01:20 HST A sudden dip in the aircraft alerts the Purser Patricia Reynolds and stewardess Katherine Araki. It also awakens Mrs. Richard Gordon, who peered out of the berth she occupied with one of her daughters.
01:23 HST Pat Reynolds leaves the flight deck and returns to the cabin and tells the other cabin crewmembers that the number one engine was in trouble and the Captain was trying to “feather” it .
At this time other passengers sleeping in berths or blanket covered reclining seats began to awaken.
01:26 HST The PA announcement by Captain Ogg is heard by all the passengers. “Sorry to wake you up. “ He said regretfully, “but our no 1 engine is running wild and there might be the possibility of a ditching. Please put on your life jackets, strap on your safety belts and remove sharp objects from your pockets.”
Note : In the aircrafts cabin the passengers stated they did not feel any noticeable vibration or sense of losing altitude. There was just the high unnatural scream of the engine and the racing propeller.
01:27 HST Stewardess Pat Reynolds turned on all the cabin lights.
01:29 HST Checking her Pan Am crew manual for the procedure for ditching she read aloud to the passengers the rues for ditching: They were to bring their reclining seats to a bolt up right position. No smoking, takeoff their shoes and glasses, remove all sharp articles from pockets, pull their seat belts as tight as possible. The passengers did as they were told. According to the crew one woman ever tore the crucifix off her rosary. Stewardess Reynolds explained to the passengers when they gave the order to brace for ditching they were to bend over, resting their faces on in pillows laid in their laps and wrap their arms under their knees. She explained that they should stay in that position until they were sure the aircrafts motion had stopped, since the first shock might not be the last. Life jackets should not be inflated until they were out of the aircraft.
01:30 HST As stewardess Reynolds instructed the passengers all was quiet except for the roaring engine. She stated that no one cried out or betrayed alarm. Most of the passengers pulled out their life jackets and began putting them on without a word. A few asked for instructions.
01:33 HST It took just about three minutes to have all the passengers ready for the brace order.
01:37 HST… In the cabin the stewardesses pointed out the location of all the life rafts, and assigned several passengers to assist in the launching of the rafts. The passengers were then relocated to the safest seats, forward of the tail section, which captain Ogg had believed the tail may break off upon landing.
05:10 HST…In the cabin the stewardesses moved the passengers into seats near the wings; they repeated the ditching instructions once again. They made sure everyone had taken off their shoes and loose personal items were stowed away. The Captain reported regularly that there were plenty of ships coming t their rescue. Pat Reynolds walked down the aisle smiling and asking if anyone wanted a magazine. Mrs. Freida Dix of Jasonville, Ind. A grandmother of seven said, “Are you kidding” and everyone laughed a little. The stewardesses served coffee and orange juice, Katherine Aralki passed chick lets around.
05:15 HST… Captain Ogg announces “We will not be ditching the aircraft for at least an hour. If any passengers wish they could get up and stretch their legs and relax with a smoke if they wanted to”, he said.
THE FLIGHT DECK….DITCHING
Note: In the process of ditching the pilot will fly the aircraft with power on till the last second before flaring in order to settle into the smoothest spot he can see. The danger of ditching lies in the last few seconds of rapid deceleration as the plane touches down o n the water. The flight manual would state the Stratocruiser should attempt ditching with the nose being held about 5 degrees above the horizon.
When daylight broke over the ocean , the sun rose warm and brilliant over a level and blue green sea whose waves were only three or four feet high.
05:00 HST…A revised heading is given to the aircraft for the ditching. The heding will be to the north west at 315 degrees.
Laying Foam On Ocean
05:30 HST…On the Pontchartrain the crew removed the water lights and requested they be notified 10 minutes prior to the time the flight intended to touchdown. This would enable them to be in absolute readiness and allow sufficient time for them to lay a foam path to mark the revised ditching path of 315 degrees.
05:40 HST… As daylight arrives Captain Ogg contacts the cutter and notifies them of their intended ditching time.
05:50 HST…Captain announces to the cabin to take their seats and prepare for the ditching.
05:52HST… Captain Ogg, descends thee aircraft to 900 feet and makes a practice approach on the heading of 315 degrees.
05:55 HST…Captain Ogg, announces over the cabin PA system “Ladies and Gentlemen the water temperature is 74 degrees and the waves are only a matter of inches high. There is absolutely nothing to worry about-things couldn’t be better for us. I’ll soon give you a ten minute warning. Then one minute before touchdown I’ll tell you this is it, Do as the stewardesses tell you please.
06:05 HST… Engineer Garcia jetted carbon dioxide into the wings, a precaution in case of fire. The Pontchartrain spreads a path of fire extinguisher foam on the water, a runway like path some 2,500 yards long and 100 feet wide, this also gave Captain Ogg a point of reference and helped reduce the danger of fire after ditching.
Captain Ogg, announces “10 minutes to ditching time.”
06:13 HST…Captain Ogg, turns and makes his approach , he lines the aircraft up on the spread foam laying on the ocean surface that is perfectly visible from the cockpit. He orders full flaps and slows the aircraft to 90 knots with the gear retracted.
06:13 HST… Second Officer Dick Brown the Navigator, leaves his seat in the cockpit and enters the cabin rushing past the bent over passengers and takes his place near the main door, which he is assigned to open.
Captain Ogg announces over the PA system….”One minute” ..”This is it”.
06:15 HST…With Captain Ogg flying the aircraft, First officer Haaker and Engineer Garcia brace themselves as best they could, which was very little in the cockpit and watched the final seconds till touchdown.
First contact with the water was slight, followed almost immediately by a tremendous impact. The aircraft was partially driven under water but bobbed quickly to the surface and stopped with very little forward travel. As anticipated. the fuselage broke off aft of the main cabin door. Several unoccupied seats remained in this section. A number of seats forward of the fracture were torn loose and several passengers were hurled to the floor. Two children who were being held were thrown from their mothers arms. There were no fatalities or major injuries and no occupants were incapacitated by the crash; however. five people received minor injuries.
Stewardess Katherine Araki told herself, “ Its going to be all right.” Then there was a sudden great shook , followed by a second and worse shook. Passenger Mrs. Jacobe’s daughter Joan was twisted from her arms and so was Maureen Gordon from her mothers arms. There was a sound of thin metal being crushed and crumbling and a sound of water rushing in.
Much of the planes freight was in the lower compartments, in that instant two dogs and 3,300 canaries and a parakeet presumably died! Merchandise of varying types was all lost.
Clipper 6 Hits The Water
Spins off the left in mist
Comes to A Halt
06:18 HST… After the aircraft stopped, members of the crew and the passengers assigned to assist removed the Emergency exit doors. First Officer Haaker went to his emergency station at the port wing, where Stewardess Araki was already telling some men passengers how to take down the life rafts above the windows.
Engineer Frank Garcia took charge of the life raft on the starboard side. Second Officer Dick Brown had the main door open and stewardess Mary Ellen Daniel found herself behind him. It was where she was supposed to be but she did not recall going there.
Brown pushed the life raft out the door and inflated it. It partially blocked the doorway and Stewardess Pat Reynolds and Brown shoved until it dropped into the water. The passengers began dropping into the raft and when stewardess Daniel jumped in she looked up and saw the Pontchartrain speeding toward them like a colt. But the raft was hemmed in next to the fuselage by the left wing and the broken off tail that had drifted alongside.
First Officer Haaker, directing port side operations from the wing ordered the passengers in the raft to climb onto the wing and then get into the other raft, which had been launched between the two engine nacelles on the port side. The women went first while the men held the raft steady while they walked across the wing without slipping. There was no shouting, only low voiced instructions.
The Hero Captain Richard N. Ogg Last To Leave The Aircraft.
Captain Ogg, and Purser Reynolds were the last t leave the aircraft.
A Coast Guard boat came up alongside the raft almost immediately/ The Coast Guard men said very little. They looked like men in a hurry and they threw the raft a line. And pulled the raft away from the sinking aircraft which by now was nose down in the water with the end of the broken and shattered fuselage with a dangling and unused life raft hanging in the air. The rescue was clean and quick.
The Coast Guardsmen helped passengers out of the rafts and into the boats and brought them to the Pontchartrain ladder. As they climbed onto the deck of the Cutter sailors stood in line each one holding a blanket and wrapped the passengers and asking” Can I get you a cup of Coffee?”.
NOTE : Two 20-man life rafts were launched through the emergency exists over the wing and one raft was launched through the main cabin door. All occupants then evacuated the aircraft successfully through these exits. The life raft that had been launched from the main cabin door was trapped against the wing and fuselage by the broken tail section, which had swung to the left. Sane of the occupants transferred over the wing to another raft, enabling the first raft to be freed. The raft launched between Nos. 1 and 2 engines did not inflate properly and filled with water while it was being pulled clear by a Coast Guard rescue launch. All of the occupants of this raft were, immediately transferred to the rescue boat without further mishap. The remaining passengers and crew, who evacuated the aircraft on the starboard side were then transferred from the raft to the cutter Pontchartrain.
06:35 HST…. The “Sovereign Of The Skies” sank .
Since there was no opportunity to examine the aircraft engines and propellers. this analysis must be based on the most logical conclusions drawn by experience and knowledge from the evidence available.
The Board is of the opinion that two separate and unrelated mechanical malfunctions occurred during this flight and the relationship of each failure to the accident should be treated separately.
N 90943 was powered by four Pratt and Whitney R4360-B6 engines and equipped with Hamilton Standard. model 24260, propellers. The initial difficulty encountered resulted in the overspeed of No. 1 engine and inability to feather its propeller. Engine r. p. m. is normally maintained by engine oil
at boosted pressure which is directed by the propeller governor to either side of a piston in the propeller dome. Movement of this piston changes propeller blade angle to maintain the desired r. p. in. Feathering is normally accomplished by auxiliary pump oil taken from the engine oil supply tank and directed by the governor through passages used for r. p. m. control to the outboard side of the piston. Consequently. a portion of the governor and the increased pitch side of the dome piston are common to both feathering and constant speed operation. It is considered most likely that the inability to feather was caused by the sane malfunction which resulted in the original overspeed. If the auxiliary pump had failed there would have to have been a second near-simultaneous failure in the propeller system. This possibility is considered to be remote. Further more. depletion of the oil supply from the No. 1 tank. subsequent to the overspeed, with no external signs of leakage. is most logically attributed to operation of the auxiliary pump during attempts to feather following the stoppage of the engine by freezing.
The most likely causes of the overspeed and inability to feather are that oil was being misdirected at the governor pilot valve or that there was insufficient oil pressure at the do-me piston. Improper direction of the oil would involve governor malfunctions, caused either by a fault within the unit itself or by contaminated oil being supplied to the governor. Contaminated oil would indicate some failure with the engine which would most likely be of a progressive nature. No such failure was evident to the crew prior to the overspeed. Insufficient oil pressure at the dame piston is most generally due to excessive leakage. Leakage usually involves seals, passages. transfer tubes., or bearings in the propeller, propeller control, or the engine.
The Board believes that a sing] e failure occurred which affected the portion of the system common to the constant speed and feathering portion of the propeller control system. Oil was being delivered to the system by 'the feathering pump and then dumped into the engine. A more specific reason for the overspeed cannot be determined.
Subsequent to this accident PAWA Pacific-Alaska Division experienced two uncontrollable engine overspeeds and inability to feather propellers due to failure of the propeller oil transfer bearing. A redesigned propeller oil transfer bearing has been provided by the manufacturer and its use was made mandatory by CAA Airworthiness Directive issued March 25, 1957.
From the information available concerning the No. 4 engine, it would appear that the initial power loss resulted from a reduction of the air flow through the carburetor. Fuel to the engine is metered by the carburetor in pro-portion to the air-mass flow through the throttle body. Engine instrument readings reported by the crew indicate oil and fuel pressures were normal but that temperature indications and fuel flaw were low. Turbo supercharger responses indicated that that system was at least partially operating. These conditions could result from an obstruction caused by a deformation or partial breakup and displacemnent of the carburetor inlet air duct system. or a failure of the engine-driven impeller drive assembly. Although the first possibility cannot be completely discounted, the latter appears to be more probable.
It is significant to the analysis that PAWA records indicate three engine-driven impeller drive failures on like engines prior to this accident. The BMEP and manifold pressure readings. taken subsequent to one of these failures, were almost identical to those on No. 4 engine in this accident. Also, in the prior engine failure the crew reported light back-firing approximately one minute after the propeller drive failure and the propeller was feathered immediately. In the subject accident the engine continued to ran at reduced power for some time before backfiring commenced. Men, indications of many low-resistance shorts and the lack of combustion pattern on the B row of cylinders were observed on the engine analyzer. This evidence is not inconsistent with an impeller drive failure. With the failure of the impeller drive assembly, impeller rotation would stop thus reducing the airflow which in turn would reduce the fuel flow. Turbo supercharger air and normal engine breathing would provide a limited combustible air-fuel mixture to the cylinders; however, distribution of the mixture to the cylinders would be impaired. It is believed, therefore, that all of the indications reported by the crew of Flight 6 could result from the engine-driven impeller drive assembly failure.
Following these failures, the basic design of the Pratt and Whitney R-4360-B6 impeller drive was re-evaluated by the manufacturer and the CAA. No design deficiency was found to exist and it was concluded that this type of failure is not chronic with this model engine. As a result of this study the Board concluded that the design of the impeller drive is adequate and that no corrective measures are necessary.
With the propeller windmilling the range of the aircraft was unquestionably reduced to less than that required either to return to Honolulu or continue to San Francisco. Required fuel for the subject flight was computed an the basis of two-engine operation; therefore, only if the crew had been able to feather the No. 1 propeller and maintain the most efficient two-engine airspeed (165 knots) could it have reached land.
Data received from Hamilton Standard and Boeing, and derived from calculation and tests of the subject type propeller, indicate that the drag resulting from this propeller with the blades on the low pitch stops, 21.3 degrees, 145 knots. 2,000 feet m. s. l., would be:
The additional power necessary to compensate for the additional drag in each of the above conditions is:
BHP (Brake Horsepower)
Since drag resulting from these conditions varies as the square of the velocity, it is evident that exceedingly higher drag forces would be encountered at speeds greater than 145 knots.
This drag information is extremely important because prior to the investigation of this accident it was not widely known. In fact. it is believed. many thought that the drag with the propeller windmilling and coupled was greater than that with the engine and propeller frozen., whereas the drag condition is greatest with the engine and propeller rotation stopped. It is noted, however that the above data apply only to the subject aircraft and propellers.
The Board believes that this report would be incomplete without a word of praise concerning the handling of this emergency by all the personnel involved. The Board highly commends the crew members for their ability in recognizing the malfunctions and taking correct emergency actions consistent with all known procedures. Their calm and efficient control of the situation averted what could have been a major air disaster.
In addition, the prompt response by the Coast Guard to the emergency and the immeasurable assistance rendered to the flight are deserving of particular Praise.
On the basis of all available evidence the Board finds that:
The company, the aircraft, and the crew were properly certificated and the flight was properly dispatched.
The aircraft was properly loaded with respect to gross weight and center of gravity limits.
The flight was normal until the control of the No. 1 propeller was lost and the engine oversped.
It was impossible to control the engine speed or to feather the propeller.
The engine was frozen, however. the propeller became decoupled from the engine and continued to windmill.
There was a partial power loss on engine No. 4; it subsequently failed completely and the propeller was feathered.
Airspeed was restricted to 145 knots to prevent the windmilling Propeller from overspeeding.
Range of the aircraft was so reduced that it was impossible to reach land.
The passengers were thoroughly instructed in correct emergency procedures and the aircraft was ditched under control with no fatalities.
Evacuation of the aircraft was well planned and orderly.
The Board determines that the probable cause of this accident was an initial mechanical failure which precluded feathering the No. 1 propeller and a subsequent mechanical failure which resulted in a complete loss of power from the No. 4 engine. the effects of which necessitated a ditching.
BY THE CIVIL AERONAUTICS BOARD.
JAMES R. DURFKE
HARMAR D. DENNY
G. JOSEPH MINETTI