United Air Lines Flight 615
By Nicholas A. Veronico
United DC-6B, identical to the plane that crashed in the hills behind Union City, California
Photo courtesy William T. Larkins
United Air Lines Flight 615, a Douglas DC-6B N37550, left Boston Massachusetts, at 5:32 p.m. EST on Aug. 23, 1951, en route to San Francisco. Three stops were made as the plane traveled westward; first at Hartford, Connecticut., next at Cleveland, Ohio, and finally at 9:59 p.m. CST, at Chicago, Illinois. During the layover at Chicago, Flight 615 changed crews.
When the flight departed Chicago at 10:59 p.m. CST, Captain Marion W. Hedden, 42, was at the controls. His First Officer was George A. Jewett, 35, assisted by Flight Engineer Marion A. Durante, 36, and Assistant Chief Flight Engineer Arthur W. Kessler, 43. Seeing to the passenger's needs were stewardesses Marilynn Murphy, 24, and La Verne Sholes, 22.
Captain Hedden began his career with United Air Lines on Nov. 1, 1939, and held an Airline Transport rating. He had accumulated 12,032 flight hours, including 417 in the DC-6 and 14 in the new DC-6B. He was granted a DC-6 rating on Jan. 15, 1951, and qualified on the DC-6B on April 26, 1951. The airplane Hedden was flying on the night of Aug. 23/24, was delivered new to United Air Lines on April 14, 1951. It had accumulated 361 hours total time without any engine changes or major mechanical problems.
Upon take-off from Chicago, Flight 615 carried 44 passengers, including two infants, and six crew members. The flight to California was filed as an instrument flight plan from Chicago to Oakland and then under visual flight rules across the bay to San Francisco. The flight plan's assigned altitude for the route was 18,000 feet, passing Denver, Colorado, and Milford, Utah, before heading direct to Oakland. The flight from Oakland to San Francisco was to be accomplished at an altitude ranging from 300 to 500 feet.
The cross-country flight was uneventful. All radio transmissions were routine and at 3:54 a.m. PST, Flight 615 was cleared to the Newark (California) fan marker with instructions to maintain 6,000 feet and to contact Oakland Approach Control over Altamont Pass, which separates the San Francisco Bay Area from California's fertile San Joaquin Valley.
Although some 40 miles from the San Francisco Bay, the Altamont Pass area and its low-lying Livermore Valley are less than 15 miles from the Sacramento River Delta. During the summer months this area usually is blanketed by a marine layer with ground-hugging fog. When flying over the Altamont Pass, it would have been in clear air with a thick undercast.
The flight reported over Stockton, California, at 4:11 a.m., at an altitude of 9,500 feet and descending. The flight was radioed the Oakland altimeter setting of 29.88 inches, which was acknowledged. Five minutes later, the flight reported passing the Altamont Intersection, and then contacted Oakland Approach Control for the first time. Approach Control cleared Flight 615 to the Oakland radio range station with instructions to remain no less than 500 feet above the cloud tops. United 615 then requested direct clearance to Newark with a straight-in range approach. The DC-6B reported that it was approaching the Hayward compass locator (between Altamont and Newark), and requested a straight-in Instrument Landing System (ILS) approach to Oakland. Flight 615 was instructed to stand-by for clearance until another aircraft in the area cleared. Captain Hedden then requested Oakland Approach Control to cancel his ILS approach request.
Oakland Approach Control's last instructions to the flight came at 4:25 a.m. The plane was cleared to fly from Newark on a straight-in approach on the southeast course of the Oakland radio range beacon. No further transmissions were received.
14.8 Miles Short Of Oakland
The San Francisco Chronicle's banner headline on the morning of Aug. 25, 1951, read, "Air Crash Kills 50: Big Liner Rams East Bay Hill." N37550 crashed 14.8 miles short of Oakland Airport in the hills behind Union City, California, at an altitude of 983 feet above sea level. The plane was on a course of 296 degrees, flying straight, and descending at the time of impact. A descent was confirmed by the fact that the hill it passed over prior to the crash was taller than the hill of impact. The DC-6B impacted, then cartwheeled over the peak and scattered itself across a small saddle and then into the canyon beyond. The wreckage field was 900 feet wide and 1,640 feet long. The fuel tanks exploded upon impact, causing a small grass fire.
The CAB report stated that "the main landing gear was extended at the time [of impact], and reasonable proof exists that the nose wheel was retracted, or nearly retracted. The main landing gear on this model extends before the nose gear and retracts after it. Wing flaps were between the fully retracted and 30 degrees extended position. All four engines were producing substantial power at the time of impact. Examination of propeller blade cuts in the earth and blade index settings showed that the blades were in the forward thrust range. Evidence indicated that the ground speed upon impact was between 225 and 240 miles per hour."
Weather conditions at the time of the crash were low broken stratus clouds with ceilings between 1,000 and 1,500 feet. Visibility below the clouds was better than six miles. Winds were reported below 10 knots and icing was not a factor as the freezing level was stated to be at 13,000 feet. The crew should have been able to see lights through the undercast from the towns of Niles, Centerville/Fremont, and Newark. The CAB went on to state that "the crash occurred during morning twilight and some light was also available from the moon. As Flight 615 broke out under the stratus at about 1,500 feet, downward visibility was possible, but ground objects and contours were probably difficult to recognize and identify. For this reason, it is believed that weather conditions were closer to Instrument Flight Rules (IFR) than VFR at the time of the accident.
"Three witnesses saw the flight in the vicinity of Newark. They stated that it was flying in and out of low clouds and noted nothing abnormal except that it was low. The impact site was shrouded in wisps of fog."
The Crash Site Today
Flight 615 crashed in the rising foothills on the eastern side of the San Francisco Bay near the borders of Hayward and Union City, California. The crash site is 14.8 miles from Oakland Airport on a true bearing of 123 degrees. The DC-6's final resting place is at the top of Dry Gulch Canyon on the eastern side of Tolman Peak.
In August 1951, the area was pasture land and the geographic features had not yet been named. The crash site is only 1.5 miles from Mission Boulevard, as the crow flies, at the southeastern end of Dry Creek Pioneer Regional Park. Dry Creek Pioneer and its adjoining Garin Regional Park are part of the extensive and well-managed East Bay Regional Park system. This system has preserved large amounts of open space and ridge tops in the East Bay hills.
Getting to this wreck, on a scale of one to 10 - 10 being hardest, is about a three. Depending on how adventurous you are once at the wreck site, going home can be a one (all downhill), or a seven if you decide to explore the wreckage that landed on the canyon sides of Dry Gulch.
Make sure to study the topo map for this crash site well in advance. Remember to carry the map. Two U.S. Geologic Survey 7.5 Minute Quadrangle maps will be required (see Appendix IV, How To Obtain A Topo Map). First obtain the Newark, California, quad for the walk into the wreck site. The crash site is located on the Niles, California, 7.5 Minute Quad in the upper left-hand corner at Tolman Peak.
Also highly recommended is a copy of the Garin & Dry Creek Pioneer Regional Parks guide map available from the East Bay Regional Park District. These maps can be found in a stand at the park's entrance gate, but do not count on it. Obtain one prior to your trek by calling +1(510) 562-7275. This may cost about $1 plus postage.
Getting To The Site
Driving to the starting point of this Wreck Chase is relatively simple. From San Jose travel north on Highway 880, or from San Francisco/Oakland drive south on 880 to the Whipple Avenue offramp. Proceed east towards the hills until coming to Mission Boulevard. Turn left (north) and continue about one-half of a mile to Tamarack Drive. Turn right and follow the street to the end where you will come to the Dry Creek Pioneer Regional Park gate. Find a place to park on the street as there is no parking lot at this gate. This is an upscale neighborhood so your car should be safe.
Rattle Snakes, Poison Oak, And Scorpions:
Getting To The Site And Back - Safely
Even though this crash site is "near civilization," proper precautions must be taken and common sense heeded. First, never hike alone. Wear long pants, a hat, and carry a long- sleeved shirt to avoid poison oak - lots of it! Carry enough water for the hike. Double what you consider to be an adequate amount of water. Bring a camera and, if you own or can rent one, a metal detector. Often just another heavy, useless piece of equipment lugged over Hell's half acre and never used, for this expedition it is highly recommended.
From the Tamarack Drive gate take the High Ridge Loop Trail for about half a mile. Then continue towards the right onto the Tolman Peak Trail. This will take you to Tolman Peak. It is a five-mile walk, relatively easy as hikes go. The trails are wide and well marked.
Once at the summit of Tolman Peak, continue to the saddle just behind it. The trail makes a 90-degree turn to the right at the saddle, leaving you facing a flat area with the brush filled canyon to the left and small peaks to the right.
The DC-6 impacted the peaks to the right and continued over to crash on the saddle in front of you. A number of large engine and firewall parts continued on into the canyon and still are there today.
Arriving at the saddle, my hiking companions and I agreed, "This is the place." Unable to locate any witnesses from the crash, we used aerial photos obtained from the San Francisco Chronicle to determine our position.
Splitting into three groups, Ed Davies gave the saddle a "once over" for any items visible through the tall grass. This would be a long shot as the property had been grazing land before becoming a park. The surface debris had been cleaned out years before, but it was worth a look. Ken Miller and Bob Swanson headed to the end of the saddle and proceeded to look down into Dry Gulch Canyon. Ian Abbott and I took the near and middle of the saddle and began to comb the brush on the rim of the canyon. Abbott was the first to locate debris, a small stringer with rivets on it, which confirmed the site.
Miller and Swanson came across a rattlesnake and an old encampment of some kind. The rattler was guarding a number of discarded cans, bottles, and ceramic dishes. While avoiding the snake, Miller noticed a shiny piece of metal on the far side of the canyon. Through binoculars the item looked round and spoked like a wheel. The group put off the decision to investigate the "wheel" until ready to depart the crash site. It would be a long slide down the near side and a real adventure to try and locate the wheel from the canyon bottom.
After searching the canyon side of the saddle, numerous small pieces of wreckage were found including an instrument case, stringers, and small sections of engine cylinders. Once the decision to head back was made, our group headed, more accurately slid, down the hill into Dry Gulch. More parts were found including an oil tank and assorted rubber seals. At the canyon bottom, we split into two groups in an attempt to find the wheel. It was located without too much effort, but turned out to be a magneto. Other firewall forward parts including an engine mount and cowl flaps were found there.
Following the contour of the canyon's bottom, the group was able to exit directly onto the Tolman Peak trail. This shaved about 30 minutes off the hike out.
The Aug. 28, 1951, issue of the Oakland Tribune reported that "...Fifty persons might be alive today if radar surveillance equipment had been functioning in the Oakland Municipal Airport control tower.." Installation of the equipment had been delayed by the Korean War as well as product setbacks. Radar would have instantly told controllers that the DC-6 was off course on its descent. This information could have been relayed to the crew, thus saving 50 lives.
Further information on this wreck can be obtained in Wreckchasing 2: Commercial Aircraft Crashes and Crash Sites.