Full opinion text
MEMORANDUM OPINION BELEW, District Judge. This lawsuit arises out of an airplane crash that occurred at Dallas/Fort Worth International Airport (“DFW”) on August 2, 1985. At the time of the accident, the aircraft, a Lockheed L-1011-385-1, was cleared for an ILS approach to Runway 17 Left (17L). The flight, identified as Delta Flight 191 (hereinafter DL 191) originated in Fort Lauderdale, Florida and was bound for Los Angeles, California, with an intermediate stop at DFW. It was equipped with a Bendix model RDR-1F monochromatic weather radar system. At the time of the crash there were one hundred sixty-three (163) people on board— one hundred fifty-two (152) passengers and eleven (11) crew members. As a result of the crash, one hundred thirty-seven (137) people were killed — one hundred twenty-eight (128) passengers, eight (8) crew members, including the Captain, First Officer and Second Officer, and one (1) person on the ground. I. STATEMENT OF THE CASE One hundred eighty-two (182) claims were made and one hundred fifteen (115) lawsuits were filed against Delta Air Lines, Inc. (“Delta”) as a result of the crash of DL 191. In a separate action, Kathleen E. Connors, widow of the pilot Edward N. Connors (“Captain Conners”), and Jean R. Nas-sick, widow of the Second Officer Nick Nassick, sued the United States individually and on behalf of the statutory beneficiaries under the Texas Wrongful Death Act and on behalf of the estates of Connors and Nassick under the provisions of the Texas Survivors Act. These two suits were consolidated with Delta’s suit by Order of the Court. Delta joined as a Plaintiff in these suits against the United States of America alleging negligence on the part of the employees of the Federal Aviation Administration and the National Weather Service to establish liability and to recoup damages suffered by Delta as a result of the crash. These damages include money paid pursuant to settlements of personal injury and death claims and judgments against it, as well as for the value of the aircraft. On September 9, 1986, the Court granted leave to Delta to file a third-party complaint in all cases in which it had been named as a defendant. Once the consolidated pre-trial proceedings mandated by order of the Judicial Panel on Multi-Dis-trict litigation was completed, Delta’s third-party claims were bifurcated from all individual Plaintiff’s cases. This Court retained jurisdiction over all the third-party claims and tried those claims with the original suit filed by Mrs. Conners, on the issue of liability alone. At the conclusion of this trial it was estimated that the total value of claims paid and those still pending would amount to between one hundred fifty million ($150,-000,000.00) and two hundred million ($200,-000,000.00) dollars, including the loss of the L-1011 aircraft, valued at twenty-four million seven hundred thousand ($24,700,-000.00) dollars. II. BACKGROUND INFORMATION A. DFW Airport Dallas/Fort Worth International Airport is one of the largest in area and busiest with respect to landings and takeoffs in the United States. There are four principal runways that run north and south. These runways are 11,388 feet in length and have a heading of 173 degrees. They are numbered according to their magnetic bearing: 17L, 17R, 18L, and 18R. The innermost runways, 17R and 18L, are approximately one mile apart. The Tower, terminals, hotels, and other buildings are located between the innermost runways. There are four points that are considered gateways to the airport. Each point, or “corner post,” is about 35 miles from the ends of the runways. The comer posts are known as Blue Ridge (northeast), Scurry (southeast), Acton (southwest), and Bridgeport (northwest). Depending on the direction of arrival, planes are brought over these comer posts by the Air Route Traffic Control Center (“ARTCC”) and turned over to the Terminal Radar Approach Control (“Tracon”) for landing alignment and sequencing. Generally, planes coming in from the west use Acton or Bridgeport and land on runways 18L or 18R, and planes coming in from the east use Blue Ridge or Scurry and land on 17L or 17R. B. The Federal Aviation Administration In 1958, Congress passed the Federal Aviation Act to centralize in a single entity, the Federal Aviation Administration, the authority to make mies and regulations concerning air safety and to develop a system for the safe and efficient use of the National Airspace. In 1966, the Federal Aviation Administration (FAA) was placed in the Department of Transportation. Pursuant to its responsibilities under the Act, the FAA divided the continental United States and the airspace above into twenty (20) contiguous regions. Within each region is an Air Route Traffic Control Center (ARTCC). The Fort Worth ARTCC covers parts of five (5) states: Oklahoma, Texas, Arkansas, Louisiana, and New Mexico. (1) The Air Route Traffic Control Center The ARTCC is staffed by Air Traffic Controllers who utilize radar and radio communications to coordinate and regulate the flights of all airborne craft within the region. The radar and communications systems are extremely elaborate and sophisticated. Also assigned to the ARTCC is the Central Weather Service Unit (“CWSU”) which aids the controllers in the dissemination of weather information to pilots in the region. (2) Tracon ARTCC controllers are responsible for bringing the planes bound for DFW to a corner post approximately thirty-five (35) miles from the airport, at which point the planes are turned over to the Tracon controllers. These controllers are located on the ground floor of the Tower at DFW. It is their responsibility to sequence, or align and space, the planes in an orderly fashion for landing. Tracon then turns the planes over to the Tower controllers as they begin their final approach seven (7) to ten (10) miles from touchdown or landing on the assigned runway. (3) The Tower Controllers in the Tower use radar, visual sightings, and verbal communication to provide air traffic control services and weather information to aircraft arriving at and departing from DFW. Once an airplane is “passed off” from Tracon to the Tower, the tower controller directs the final approach, landing, and taxi. The Tower is located in the area between runways 17R and 18L and is about equal distance (approximately one mile) from either end of the runways. C. Weather Facilities After the Weather Bureau was abolished in 1965, the National Oceanic and Atmospheric Administration (NOAA) was created as the administrative head of the various weather agencies and transferred with other weather related entities to the Department of Commerce. The organizational name of the Weather Bureau was changed to the National Weather Service (“NWS”). 15 U.S.C. § 811, et seq. The NWS provides the aviation community with a variety of services from a number of different facilities. These services include general forecasting, issuance of warnings and advisories, consultations, and briefings. NWS personnel do not communicate with pilots. Their role for aviation interests is to create weather information products for relay to FAA facilities, Air Traffic Controllers, airlines, and other such users. (1) The Central Weather Service Unit Following an air crash in 1977, the National Transportation Safety Board (“NTSB”) recommended to the FAA that immediate action be taken for the development and implementation of a system for controllers to relay severe thunderstorm and tornado bulletins to aircraft in an airport terminal area. The FAA was urged to: formulate rules and procedures for the timely dissemination by air traffic controllers of all available severe weather information to inbound and outbound flight crews in the terminal area. Following this pronouncement, the Department of Transportation/FAA and the NOAA/NWS entered into an agreement in 1980 whereby the NWS would operate CWSU’s at each ARTCC. In order to implement this agreement for the Fort Worth Center, the NWS installed a radar facility at Stephenville, Texas (“SEP”), 72 miles from DFW Airport. The CWSU is located in the ARTCC building just south of DFW. The CWSU receives its radar image from SEP. The image received by CWSU is two minutes old due to the time it takes for the information to be translated into digital form, transmitted by phone lines, and re-translated. The primary function of the CWSU at Fort Worth ARTCC is to provide weather information to air traffic controllers and staff, including ATC’s in the ARTCC, Tra-con, and Tower. The CWSU meteorologists do not communicate with the pilots, but pass the weather information to the ATC’s in the form of briefings and forecasts. After the information is received from the meteorologist or weather coordinator, the ATC’s disseminate it to the pilots. The Weather Coordinator (“WC”) functions as an interface between the NWS meteorologist and the Air Traffic Controllers. The WC is primarily responsible for the inter/intrafacility disseminations of Sigmets, CWA’s and urgent Pireps. WC’s also provide assistance in the collection and dissemination of other significant weather information. (2) The Weather Service Forecast Office Responsibility for weather forecasting is divided into fifty geographic areas. There is roughly one forecast office for each state, although larger states, such as Texas, have more than one office. The Weather Service Forecast Office (“WSFO”) in Fort Worth is located in the Federal Building in downtown Fort Worth. The principal function of the WSFO is to provide general weather forecasts. The WSFO also performs specialized services for the aviation community. It provides a forecast for a particular airport, or “terminal forecast,” which generally addresses weather conditions affecting airport ground functions. The WSFO also issues TWEBS (Transcribed En Route Weather Broadcasts), describing weather conditions along the most frequently flown routes across North Texas. A third type of forecast is given for International Travel. (3) Weather Service Contract Meteorological Office The Weather Service Contract Meteorological Office (“WSCMO”) is located on the second level of the Delta hanger at DFW Airport in space leased from Delta. The observer makes visual surface weather observations each hour and relays such observations electronically to various NWS and FAA facilities. The observer notes cloud conditions, precipitation, temperature, dew point, wind, etc. If conditions warrant (i.e., weather deteriorates), the observer may make a special weather observation. The observer was functioning as an independent contractor on August 2, 1985. D. Weather (1) Radar Precipitation is the only weather observable by radar. Detectable precipitation appears as an image on a radar screen and is measured by Video Integration Processor (VIP) levels. These indices reflect the level of intensity of precipitation from VIP 1 (lowest) to VIP 6 (highest). Radar measures only the intensity of precipitation and does not measure the intensity of the winds, turbulence, etc. in the echo. It is sometimes difficult for a meteorologist to determine whether the radar echo is precipitation, ground clutter, or anomalous propagation. Anomalous propagation is caused by atmospheric conditions other than precipitation. (2) Downbursts Thunderstorms can produce a down-burst, or strong downdraft inducing an outburst of damaging winds on or near the ground, as occurred at DFW on the day of the crash. The downburst consists of the downdraft and its outflow. It originates from a convective storm. Initially, an updraft forms due to the local heating of the terrain. When the updraft reaches condensation level, it cools and a cloud forms. If the cloud continues to grow, the air goes higher and higher, and all of the water vapor in the air condenses out. Finally, the water comes rushing down out of the cloud. The cold air associated with the downburst produces a very intense downdraft that comes down with the rain and, when it gets near the ground, spreads out horizontally and causes an outflow of air in different directions. Downbursts are subdivided into macro-bursts and microbursts according to the horizontal scale of damaging winds. A ma-croburst is a large downburst with its outburst winds extending in excess of 4 Km. (2.5 miles) in horizontal dimension. An intense macroburst often causes widespread, tornado-type damage. Damaging winds can be as high as 134 miles per hour. A microburst is a small downburst with its outburst and damaging winds extending only 4 Km. (2.5 miles or less). In spite of its small horizontal scale, an intense micro-burst can induce damaging winds as high as 168 miles per hour. Clouds producing downbursts are formed by convective activity. One type of such conductive cloud is the cumulus cloud, generally appearing puffy with a flat base. They range in size from small clouds to large thunderstorms with damaging winds and hail and lightning within. (3) Wind shear and Advisory Circular AC 00-50A Wind shear is best described as a change in wind direction and/or speed in a very short distance. For example, if the wind changes from a 30 knot headwind to a 30 knot tailwind, the result is a 60 knot shear. There are several general categories of wind shear, such as frontal wind shears and downdrafts. DL 191 was confronted with wind shear emanating from a downdraft or downburst. Advisory Circular AC 00-50A gives an excellent description and explanation of the classic thunderstorm “downburst cell” which is as follows: DOWNDRAFT SHEAR There is a strong downdraft in the center of the cell. There is often heavy rain in this vertical flow of air. As the vertical air flow nears the ground it turns 90 degrees and becomes a strong horizontal wind, flowing radially outward from the center. Point A represents an aircraft which has not entered the cell’s flow field. The aircraft is on speed and on glide slope. At Point B the aircraft encounters an increasing headwind. Its airspeed increases, and it balloons above the glide slope. Heavy rain may begin shortly. At Point C the “moment of truth” occurs. If the pilot does not fully appreciate the situation, he may attempt to regain the glide slope and lose excess airspeed by reducing power and pushing the nose down. Then in the short span of time between Points C and D the headwind ceases, a strong downdraft is entered and a tailwind begins increasing. The engines spool down [go to idle], the airspeed drops below V.ref, and the sink rate becomes excessive. A missed approach initiated from this condition may not be successful. Note that a missed approach initiated at Point C (or sooner) would probably be successful since the aircraft is fast and high at this point. Note also that the pilot of an aircraft equipped with a groundspeed readout would see the telltale signs of a down-burst cell shortly after Point B; i.e., rapidly increasing airspeed with decreasing groundspeed. This advisory further provides that “[i]f the airplane is below 500 feet AGL and the approach becomes unstable a go-around should be initiated immediately. Airspeed fluctuations, sink rate, and glide slope deviation should be assessed as part of this decision.” Dr. Fujita points out that an accident during the final approach can occur when an aircraft attempts to land through a strong microburst located on the glide slope near the approach end of a runway. In nearly all cases, an aircraft first experiences a headwind increase while entering a shower or virga. As a result, the aircraft gains altitude. When the pilot brings the aircraft altitude down to the glide slope, downflow and a tailwind are awaiting the aircraft. Unless full power is applied early enough to regain the altitude, the airplane could continue its rapid descent to the ground. III. THE SEQUENCE OF EVENTS A. Overview After crossing the Blue Ridge corner post at 5:52:09 Central Daylight Time (“C.D.T.”) and heading southwest for landing at DFW, the crew of DL 191 saw building cumulus clouds north and northeast of DFW. They had a view of the airport where the sun was shining. As they approached, there were at least two cumulus clouds in the area. One of these clouds had been there for some time, developing over the outer marker. This cell has been referred to in the litigation as Cell C. South of and between Cell C and the north end of Runway 17L there was a second cumulus cloud evidencing more rapid development. This cloud became Cell D, the cell from which the microburst descended. When DL 191 approached DFW it was vectored to the north (downwind leg), west (base leg), and then south (final). When the aircraft was put on final approach, rain was visible between the aircraft and Cell D. At that point it was possible to see the airport, but as the rain increased the airport went out of view. ATIS Romeo had been issued at 4:47 and DL 191 received the following report at 5:35:33: Weather six thousand scattered, two one thousand scattered, visibility one zero, temperature one zero one, dewpoint six seven, wind calm, altimeter two niner niner two, runway one eight right one seven left, visual approaches in progress. Persons at various locations at the air- port were able to see the weather deteriorate. Mr. Del Prete, the WSCMO weather observer, completed observations during which he saw cumulonimbus clouds to the north and northeast, blanketing the entire sky to the north, northeast at 5:51. Personnel in Tracon were aware of thunder and the Tower’s auxiliary generators were activated as a precaution. A Tracon controller had received a Pirep from a plane flying east through Cell D to the effect that it was difficult to hear over the rain. DL 191, however, was not on the frequency. Others on the ground watched the storm develop. It appeared to one observer to be a bad thunderstorm, a wall or curtain of water. The tower controller saw moderate rain progress to “heavy, heavy rain.” A controller notified all aircraft that there was a little rainshower just north of the airport, apparently referring to Cell C. There were observations of lightning in the west and northeast by persons in the Tower and on the ground. In eight minutes, Cell D developed from a YIP 2 to a VIP 4. Since the storm was near the airport, SEP called the WFSO to advise them of its apparent severity. The WSFO was aware that a thunderstorm existed north of DFW airport. As DL 191 was coming in to land it lost its altitude and made contact with the ground in a plowed field about 360 feet east of the extended center line of runway 17L and 6336 feet north of the runway threshold. The plane was in a wings level, nose high altitude, and on a heading of about 167 degrees magnetic. Following the initial impact, the plane ascended, went a short distance, and hit the ground again. After this second impact the plane continued, traversing Highway 114, striking a car and killing the occupant. The plane then proceeded toward two water tanks about 1700 feet beyond the highway. The airplane grazed the north tank and struck the south water tank about 3195 feet beyond the initial touchdown point, breaking apart. The plane made four separate and distinct ground contacts before breaking up and coming to a stop. There was no evidence of pre-impact separation or failure; the damage to the plane was caused entirely by the impact with the ground and subsequent structures. Upon examination after the accident, it was noted that the thrust rever-sers had been deployed on each of the three engines, all of which were located in the tail section of the airplane. B. Arrival Sequence From 5:48:15 to 6:03:25 fifteen planes landed at DFW on Runways 17L and 17R. Immediately prior to the attempted landing of DL 191, one of these fifteen planes had to go around due to ground traffic, and two landed on 17R. The remainder landed on 17L. Reports from the landing crews are varied. Some experienced little weather; others were in heavy rain inside the outer marker. The Learjet, the last plane to land before DL 191, entered rain shortly after passing the outer marker. It then encountered heavy rain at 6:04 and exited heavy rain about one mile to IV2 miles from the threshold of 17L. No crew, except DL 191, saw lightning coming out of Cell D. Approximately twelve planes had taxied down the taxiways in preparation for takeoff on 17L or 17R. As they were waiting at the north end of the taxiway for entrance onto 17L or 17R, they were in an excellent position to see Cell D. These planes were approximately one mile north of the Tower. Specific observations will be discussed in the following section of this opinion. C. Specific Chronology The following is a chronology of the most significant events which took place during the flight of DL 191. All of the following times are stated in Central Daylight Time, August 2, 1985. Time Event 5:03:59 Fort Worth ARTCC Controller told DL 191 to expect Blue Ridge arrival. 5:09:18 Fort Worth ARTCC attempted to give DL 191 vectors towards Scurry VOR. Time Event 5:09:35 Captain Connors, in response to the foregoing ATC direction, asked, “How’s the weather over Scurry?” 5:10:53 Internal discussion between two controllers at Fort Worth ARTCC during which the PAX-TO controller acknowledged with respect to the attempt to send DL 191 into an area of weather, “He didn’t want no part of it.” 5:11:16 Fort Worth Center controller for Texarkana Sector directed DL 191 to “expect a further clearance direct to Scurry.” Captain Connors replied, “So we’ve been told, okay, sure looks better over Blue Ridge though. Weather looks better over Blue Ridge.” 5:11:36 After being told by the controller that the traffic doesn’t look very good over Blue Ridge, Captain Connors stated: “I’d rather wait for an airplane than, uh, go fight a bunch of weather.” 5:12:26 After being told to go into a holding pattern south of Texar-kana for 30 minutes, Captain Connors responded, “Okay, we appreciate that, it sure looks a lot better that way, it looks kind of crummy down there at Scurry...." 5:25:00 Richard Douglass, CWSU Meteorologist, left his post to take a dinner break. 5:35:26 Flight Engineer received ATIS Romeo which bore a time of 4:47 and contained the following weather information: “Weather six thousand scattered, two one thousand scattered, visibility one zero, temperature one zero one, dewpoint six seven, wind calm, altimeter two niner niner two, runway one eight right one seven left, visual approaches in progress.” Time Event- 5:43:56 Captain Connors told Fort Worth Center, “I’m looking at a cell at about heading of two five five and it’s a pretty good size cell and I’d rather not go through it I’d rather go around it one way or the other.” Reference was to the so-called “Blue Ridge thunderstorms.” 5:45:00 A1 Magazzine, a DFW Airport employee in Tower Cab for purposes of traffic count, noticed a build-up of clouds towards Las Colinas, a community northeast of DFW. 5:49:00 Cell D first appeared on Oklahoma city radar, and would have appeared on Stephenville radar at approximately the same time. 5:50:00 Jack Williams observed Cell C in northwest corner of Dallas County within 10 miles of DFW Airport. 5:50:50 American 351 announced its intention to go around. American 351 then commenced go-around and later made a second approach, despite an FAA Inspector in the cockpit jumpseat having observed lightning during first approach. 5:51:00 Del Prete (NWS Airport Weather Observer) completed observation during which he saw cumulonimbus clouds to the north-northeast, blanketing the entire sky to the north and northeast. 5:51:19 Second Officer Nassick observed, “Looks like it’s raining over Fort Worth”; an unknown voice commented “... Dallas.” Time Event 5:52:00 Radar photos confirmed the existence of Cell D on Stephenville radar as a VIP level l. DL 191 was at 11,500 feet and pointed straight at Cells C and D. These returns would likely have appeared clearly on DL 191’s radar. As the flight descended from Blue Ridge, there would have been good radar returns from cells C and D until the aircraft turned northbound at approximately 6:00. 5:52:08 Captain Connors made radio contact with DFW Approach Control. He was talking with Feeder East Controller Robert Hub-bert. At the time of this initial contact, DL 191 was approximately over the Blue Ridge VOR, which is approximately 35 miles northeast of the airport, and was at an altitude of 11,100 feet MSL. 5:54:00 Tollenaar, Captain of Metro 1756, encountered light rain just south of Lewisville, which he was in for approximately one mile; the area of rain was fairly confined and clearly discernable. Tollenaar was able to see 17L during his entire approach, including while flying in the rain. Tollenaar painted a cell without difficulty; it was a red area, which is a contouring area, surrounded by a thin yellow area indicating a steep gradient. Tollenaar testified that he would not have flown through what his radar was painting; he would have executed a missed approach. Time Event 5:55:00 Tower controller Ferguson observed from the Tower Cab a cloud-to-ground bolt of lightning to the east-northeast associated with the gray cloud and area of rain. 5:55:00- Lee Ankerson, walked outside 6:00:00 and joined two other mechanics. The three of them watched the storm develop. Ankerson says it “was big and it looked real bad.” He said it “looked like a bad thunderstorm.” He said it looked like a “wall of water,” “a curtain,” and the heaviest rain he had seen during his nine years at DFW. 5:56:00 Since 5:52, Cell D had become a VIP 3, was quite pronounced, and was growing quite rapidly north of DFW. Cell D had enlarged on radar imaging five or six times its size at 5:52. At this time DL 191 was 17 to 18 miles from Cell D and could have scanned up to at least 32,000 feet with its radar, allowing it to see whatever weather Stephenville was painting. Both cells could have contoured on airborne radar. The aircraft was pointed directly toward the cells. 5:56:26 Feeder East Radar Controller Hubbert notified all aircraft: “There’s a little rain shower just north of the airport and they’re starting to make ILS approaches ...” Hubbert testified that he was talking about a weather area located in the position now identified as Cell C. Time Event 5:58:00 Before going on break at 5:59, Jim Brecheen, an Air Traffic Assistant in the Tower Cab, saw one flash or bolt of cloud-to-ground lightning in the proximity of the rain to the northeast of the Tower. Even with two-minute delay, CWSU radar would have displayed VIP 3 intensity of Cell D by 5:58. It was the practice of the CWSU to notify Tracon of a VIP 3. Dixon, Captain of Cessna 340, with his radar on the 10 mile range, observed an intense echo with a very heavy rainfall gradient; these observations had to be Cell D, and it was contouring and had a sharp gradient; Dixon was at 1,000 feet and was using a much wider radar beam than DL 191’s, and even with his less capable radar Dixon had no problem depicting a contouring cell. Dixon was within a couple of miles of DL 191’s location at this time. While Dixon was making his radar observations, DL 191 was pointed straight at the cell and these cells remained directly ahead of it for the next 2 minutes; the crew should have been able to see Cell D contouring on radar almost straight ahead, slightly to the right, at a range of 10-15 miles; Cell C would have been 30 degrees to the right and smaller, not contouring. DL 191 was at 5,800 feet AGL, considerably higher than Dixon, so 191 should have had less problem with ground clutter. The cells Dixon painted unquestionably were within the tilt range of DL 191’s radar at this time. As DL 191 approached the airport, its radar would have gone through Cell C and show Cell D. Cell C would not have shadowed or blocked the view of Cell D. Time Event According to CWSU Chief Meteorologist Paup, between 5:52 and 6:06, radar information about the VIP level of Cell D was available to the CWSU but was not communicated because Douglass was not at his post. Paup also acknowledged that the CWSU can help pilots avoid thunderstorms by providing this type of information. 5:58:00- According to his own testimony, 5:59:00 controller Tarbet informed supervisor Joe Connors about hearing thunder during this time period. Tarbet assumed there was possibly a thunderstorm going on outside. 5:59:43 Feeder East Controller Hubbert referred to “little bitty thunderstorm” that “looks like a little rain shower.” Hubbert was talking about a cell in the location of Cell C. (Note: DL 191 did not hear this transmission.) 5:59:47 As DL 191 turned back to the north, Price said, “We’re gonna get our airplane washed” referring to a visual observation by Price. Price was looking forward and could see something coming out of the base of the cloud. At this time Delta Flight 963 was seeing the bowl-shaped cloud outside the outer marker and they anticipated flying through it. DL 191 was flying almost due west and could see Cell D straight ahead and to the left of them. DL 191 was at 5,000 feet, and just about to turn right to 340 degrees. They obviously were flying close to some type of convective activity and rain. The First Officer was pointing out that they were going to be flying through some rain, and it is likely he was expecting a fair amount of rain. Time Event 6:00:00 NWS Stephenville Weather Radar Operator Encinas observed “a small thunderstorm cell.” He referred to it as “a rapidly developing thunderstorm.” Encinas acknowledged that a storm that developed from VIP 2 to VIP 4 in eight minutes (such as Cell D) would have strong convective activity. Encinas observed Cell D as having a pinpoint VIP 4 intensity. VIP 4 echo indicated the “probability” of a thunderstorm, according to Richard Douglass. According to the testimony of Paup, Chief Meteorologist at the CWSU and Mr. Douglass’ immediate supervisor, there is a correlation with level 4 returns and thunderstorm activity, and the CWSU would report a VIP 4 intensity to the Tracon (not just the presence of an echo). The CWSU Meteorologist, had he been at his post, could have seen that the thunderstorm was in the vicinity of the airport to the north of the DFW Airport. FAA Air Traffic Assistant Barbara Foe observed lightning to the east-northeast from the FAA Tower Cab. Time Event 6:00:13 Feeder East Controller Hubbert observed a “little rain shower” just north of the airport. This transmission was not heard by DL 191, because it was not on the frequency. 6:00:33 AR-1 Controller asked American Flight 351, “Do you see the airport yet?” American 351 First Officer Patrick Davis replied, “As soon as we break out of this rain shower we will.” DL 191 heard this transmission. During American 351’s second approach, FAA Inspector Neu-meier, a licensed air transport pilot, again sighted lightning. Neumeier took no action to prevent the flight from continuing, nor did he suggest or order it to execute a missed approach or to make a Pirep. 6:00:00- Captain Sam Toler, Piedmont 6:04:00 Flight 70, saw from DFW a large sheet of water emanating from an intense thunderstorm. Captain Toler testified that it was the worst thunderstorm he had ever seen: It was a solid sheet or wall of water moving toward the airport with unbelievable intensity. Time Event 6:01:00 Bill Glenn, a Department of Public Safety employee, observed from DFW cloud-to-cloud lightning north of the airport all the way across each runway approximately five minutes before the accident. Mike Porter, an FAA Local Control West Controller in the Tower Cab, observed two lightning strikes to the west of the area of weather, and another lightning strike to the east-northeast where Cell D was located. Encinas called Fort Worth WSFO to alert them that there was a thunderstorm over DFW. Encinas believed that the storm was of consequence because it was located near an airport. He reported a pinpoint VIP 4 cell with a top of 40,000 feet. By this time, Williams, of the Fort Worth WSFO, acknowledged that he knew that a thunderstorm existed over the town of Coppell, Texas, which is located immediately to the north of Runway 17L at DFW Airport. Del Prete observed lightning to the north-northeast of DFW. First Officer Chris Robbins, Delta Flight 1051, observed from DFW a cloud developing rapidly, which was, in his words, “billowing, boiling, exploding.” There was dark, heavy rain and a bamboo curtain effect one-half to one mile from the end of the runway, which appeared to be a thunderstorm. The easternmost part of the cloud was right off 17L. 6:01:20 Feeder East Controller Hubbert transmitted that a “little rain shower just popped up north of the airport.” DL 191 was not on the frequency. This return was in the area of Cell D. Time Event 6:02:00 The United States claims that a conversation between Tarbet and Joe Connors regarding thunder occurred at about 6:02. Thus, Joe Connors was aware of thunder by no later than 6:02. A1 Magazzine, a DFW Airport employee in the Tower Cab, observed a thunderstorm consisting of a heavy dark area of precipitation to the north end of the Runway 17 complex. Del Prete heard thunder and associated the rainshower with the thunderstorm. After the accident, Del Prete told Jeff Brown, “Conditions at least should have prompted concern among air traffic controllers.” 6:02:30 DL 191 was advised that they were 6 miles from the outer marker. They were requested to turn left heading 180 to join the localizer at or above 2,300 feet, and they were cleared for the ILS 17 Left approach. This was acknowledged by Captain Connors at 6:02:43: “Delta one-niner-one Roger, all that appreciated.” The rain should have contoured on DL 191’s radar; they were on base leg just south of Lewisville (a small city east of DFW) heading west. The radar would have been showing the crew that if they flew ahead for a mile or two and then turned left toward the airport, they would be turning toward a contouring cell. At this time, Dixon was seeing a contouring cell and other pilots were seeing red cells. With their radar tilted up 7 degrees the crew could have interrogated the whole base of the cloud. Even if they had the bottom of the beam parallel to the ground they would have seen rain beneath the cloud. Time Event 6:03:04 Tracon received a Pirep from Southwest Flight 99 (not heard by DL 191) that it was hard to hear in the rain he was in. At this time, Southwest Flight 99 was inside Cell D, approximately IV2 miles from the end of Runway 17L, at an altitude between 6,300 feet and 6,900 feet. The Pirep was not disseminated by Tracon to pilots or to other controllers. 6:03:06 DL 191 was approximately 8 miles north of the threshold of 17L at 2800 feet. At this time, the north side of the microburst was about 2.5 miles north of the end of the runway and it was above the surface at some altitude; therefore, DL 191 was between 5 and 6 miles from the microburst. Under Dr. Fuji-ta’s analysis, DL 191 was then at an altitude of less than 1000 feet and below the altitude of the mi-croburst. The microburst likely was directly ahead of the aircraft, and at the same altitude, when the crew turned final. Thus, the microburst would have been within the tilt range capability of DL 191’s radar. DL 191’s radar had the ability to scan up to 15 degrees, meaning at this distance from Cell D it could scan about 8600 feet above the altitude of the aircraft. The microburst would have been straight ahead of the airplane at that time, enabling the crew to scan it with the beam parallel to the surface of the earth; that is, the radar operator would not have had to tilt up the radar to see the microburst. Rain falling from Cell C at this time would not have attenuated the radar signal and a good display of Cell D would still be on DL 191’s radar scope. This factual finding was also made by the NTSB, which found there would have been a radar display up to two miles to the cell. The DFW microburst itself (Cell D), as opposed to precipitation associated with Cell C, might have caused a ground shadow on DL 191’s radar before they penetrated the cell whether or not the radar was adjusted properly. Nonetheless, even if DL 191’s radar beam had been fully attenuated and a radar shadow were present, this should have not have misled the crew into flying into the microburst. Time Event 6:03:20 Skipworth, the Local East Controller in the Tower Cab who took control of DL 191 inbound from outer marker, saw moderate rain progress to heavy rain when the Learjet was four or five miles final. He described it as “a definite wall of rain.” 6:03:31 AR-1 "'Controller advised Delta Flight 557 that “we’re getting some variable winds out there due to a shower on short final out there north end of DFW.” DL 191 was on frequency, so it should have heard the transmission. An unidentified crew-member of DL 191 remarked “stuff is moving in ....” Time Event 6:03:32 Captain Joe Coughlin and First Officer Dave Davis of DL 963 saw from DFW what appeared to be a water spout. Both observed dark sky and heavy rain off the approach end of 17L and two bright shining parallel phenomena extending to the ground. 6:03:58 Captain Connors called Controller Skipworth and said that DL 191 is “out here in the rain, feels good.” This rain was so light it could not be seen by other aircraft 6 to 8 miles away; further, it is implausible that DL 191 was in rain so heavy that the crew could not see forward. DL 191 was in rain from the time Captain Connors said “out here in the rain feels good” until they entered the microburst. The intensity of this rain was very light; two aircraft that were not far off could not see any rain, and the Learjet, which immediately preceded, and American 539, which immediately followed, reported that they did not enter any precipitation until they got down to about the point where DL 191 entered the rain shaft; the only possibility is that some very light rain came down between these two airplanes, because no one else could see it; it was not enough to seriously impair 191’s ability to see where they were going. If there had been enough rain to impair their ability to see forward, other aircraft would have been able to see it. Light rain does not negate forward visibility in an airplane. At approximately the same instant, the following conversation occurred between Kennedy (Tower Cab) and Joe Connors (Tracon Supervisor): Time Event “We’ve been busy with these SWAPS and hadn’t paid any attention, but that is heavy, heavy rain off the approach end of both runways ... Joe Connors, referring to his radar, replied to the Tower: “Yeah, I can see that.” Joe Connors’ reply referred to Cell D, which was a solid area about two miles in width, two miles north of the airport. Because of the time it took for Kennedy to answer Joe Conners’ call, it is clear that Kennedy actually observed the heavy, heavy rain at or before 6:03:30. 6:03:58 Joe Connors earlier had seen a speckled area on the radar in the vicinity of the outer marker (presumably Cell C); by this time he saw a solid area (Cell D) about two miles wide and about two miles north of the airport. 6:04:00 Hildebrand, Fujita and others concluded that the microburst impacted the ground very close to 6:04, maybe as early as about 6:03:30 or 6:30:35, but not significantly later; at 6:04, the rain shaft was on the ground and the Learjet’s encounter confirms this fact. Based on the observations of American 351 of the area in which they entered heavy rain, and other pilot observations and witness statements, bounds can be placed on the descent of the microburst. The 6:04 timing of impact is accurate and consistent with these pilot observations. Furthermore, the pilot observations confirm that the location of the impact was a little over 2 miles out. Time Event According to the data, there were a number of rain shafts that descended from the cloud base at different times; there was some light rain that descended from the cloud prior to the microburst. The microburst itself started descending some time after 6:00, probably about 6:01, although it may have started descending slightly later if it fell at a higher rate, but certainly no later than about 6:02. The Stephenville radar bisected Cell D at about 17,000 feet down to some altitude below the cloud base. In doing so, SEP radar measured a VIP 3 level echo and then at 6:04 saw a VIP 4. Thus, between 6000 feet and 17,000 feet there was a sufficient amount of rain for the SEP radar to see. The base of the clouds in the DFW area was 6000 feet. This figure is based upon pilot observations, the fact that the temperature from DL 191’s DFDR showed a temperature inversion between 6000 and 7000 feet, additional information from ground observers, the Roxbury photos which confirmed the 6000 feet base, and Dr. Fujita’s conclusion that the bases were 6000 feet. Specifically, the bases of Cells C and D were both about 6000 feet. The microburst descended at a rate between 2000 fpm and maybe 3000 fpm. It exited from the base of the cloud at around 6:01 and hit the ground at 6:04 traveling 6000 feet in three minutes (2000 fpm). Dr. Fujita plotted the microburst descent at about 3500 feet or so in the minute between 6:03 and 6:04; extrapolating from that figure, the mi-croburst exited the cloud base at 6:02. Dr. Fujita has the micro-burst traveling the 6000 feet from the base of the cloud to the ground in two minutes (3000 fpm). It is more likely that the descent rate was 2000 fpm based upon looking at peak vertical velocities of the winds measured by DL 191 as it flew through the microburst, which were about 3000 fpm. The maximum velocity of the microburst downward would be higher than the velocity of the progression of the microburst toward the ground because the microburst had to push all this air out of the way as it fell down toward the ground. It is not possible to determine the exact descent rate, but between 2000 and 3000 fpm is scientifically sound. Time Event 6:04:18 First Officer Price: “Lightning coming out of that one.” Captain Connors: “What?” First Officer Price: “Lightning coming out of that one.” Captain Connors: “Where?” First Officer Price: “Right ahead of us.” DL 191 had entered and been in the rain continuously since at least 6:03:58, until after initial impact. DL 191 was already inside the rain falling out of Cell D at this time, and hence in the thunderstorm, at the time of the First Officer’s sighting of the lightning. Time Event The First Officer made a very clear statement that he saw lightning. He unambiguously stated that he saw it out of “that one,” meaning a specifically identifiable piece of weather. At this time, Price clearly was looking forward and saw lightning coming out of “that one ahead of us.” The lightning came from a rain shaft in Cell D. They did not penetrate that rain shaft until approximately a minute later, when Captain Connors said “watch your speed” at 6:05:17 and commented “wash that off a bit” at 6:05:05. 6:04:30 The “lightning coming out of that one” exchange was followed by 7 seconds of silence. When Captain Connors made no response, Second Officer Nassick responded at 6:04:30, “you get good legs don’t ya.” Second Officer Nassick’s comment was not a casual cockpit comment. His reference to “good legs” was to legs of the trip, as it was the practice at Delta that the Captain and First Officer alternate flying legs. Second Officer Nassick was concerned and was pointing out a deteriorating situation and poor flying conditions. 6:04:00- Eastern Airlines Flight 654, Cap- 6:05:00 tain A1 Stanley, saw from DFW what appeared to be a tornado. Captain Stanley described the rain as a wall of water or a sheet or shaft of heavy rain. The Copilot of Eastern 654 called it a “hail shaft,” and the Flight Engineer referred to it as a “micro-burst.” Captain Stanley saw one or two lightning strikes in the right side of the rain before observing the tornado. The storm he observed undoubtedly was a thunderstorm. Time Event After encountering extremely heavy rain and light to moderate turbulence, the Captain of the Learjet, Lewis, added an extra 25 knots to his approach speed; he also decided to fly his approach high and not go all the way to minimums because of the weather he had encountered. Captain Lewis admitted that while he was flying his approach he had his hands full; these observations are consistent with Hildebrand’s microburst descent rate and times. As he was turning inbound (6:03:36-6:04:26), Captain Dobson of American 539 was able to see DL 191. American 539 was cleared for the approach 7 miles from the outer marker and was in visual meteorological conditions, with at least 3 miles of forward visibility. There was no rainshower in front of Dob-son, except the one just off the runway; Dobson did not see a second rain shaft at any point during his approach. Dobson did not encounter any rain until he executed his go-around and actually penetrated the cloud that was generating the storm. Dobson neither saw nor encountered any other rain shaft that would have prevented him from seeing the one that was just north of 17L. Dobson testified that there were no other cells producing lightning at 6:04:18 when Price commented about lightning on the DL 191 CVR. Dobson was not in rain when he got to the location where 191 said “out here in the rain feels good.” Time Event 6:05:00 Robertson was flying an Aero Commander northeast of the storm at this time looking south at the weather. Robertson was bothered by DL 191 approaching this weather, thus he watched the aircraft continuously as it entered and then exited the rain. He was bothered because of the storm’s intensity and location; Robertson could not say exactly why, but he did say he expected to be wrong about his caution and thought he would see DL 191 roll out into the bright sunshine, but of course 191 did not. Robertson actually witnessed DL 191 penetrate the rain shaft. At the time DL 191 flew into the rain shaft, Robertson said that the “storm had such a defined edge, there was no gradual thing going into it, it was so defined that if you entered the storm, if you froze the frame right there, you could see the forward half of that aircraft was obscured, back half of the aircraft was in bright sunshine; I mean it was just that quick.” Robertson indicated that there was nothing to the north of the storm that would have prevented DL 191 from seeing it. Time Event 6:05:05 DL 191, on glideslope, passed 1,000 feet AGL. According to Delta procedure, the flight is supposed to be stabilized below 1,000 feet. At 6:05:08, Captain Connors commented, “762 in the baro.” This was an indication to First Officer Price that Captain Connors intended to go down to 200 feet, which is the decision height for the approach, and at that time he would decide whether they would land or execute a missed approach. When he advised Price of this, it told First Officer Price that they were going to continue down to 200 feet and then make a decision on .whether to execute a missed approach. The Captain announced this decision height after First Officer Price had advised of “lightning right ahead of them coming out of that one.” 6:05:04- DL 191’s airspeed increased from 6:05:18 153 to 173 knots. 6:05:19 Captain Connors recognized the airspeed increase by stating, “Watch your speed.” 6:05:20 Sound of intense rain can be heard on CVR. 6:05:21 DL 191 continued descending along the final approach course toward the area of developing weather. At 6:05:21, the Captain warned the First Officer, “You’re gonna lose it all of a sudden, there it is.” To exhortations of “push it up, push it up, way up” by both the Captain and the Second Officer, the First Officer added airspeed. Time Event 6:05:28 Delta experienced a performance loss (wind shear) of 44 knots. 6:05:30 Eleven seconds after Captain Connors noted the airspeed increase at 6:05:19, he stated, “That’s it.” 6:05:35 Sound of microphone keying from DL 191's air-to-ground radio. 6:05:35- Upon encountering a descending 6:05:36 and violent vortex, the first of the three multiple vortices encountered by DL 191, the aircraft began experiencing a roll to the right of at least 22 degrees even though the pilot attempted to control the roll by using full left aileron input. 6:05:36 From this point forward, the crew of DL 191 was no longer attempting to land the aircraft on that approach but was attempting to perform what some people call an escape maneuver, a go-around, or a missed approach. Others have characterized it as simply trying to fly the aircraft and avoid ground impact. 6:05:52 Initial touchdown while DL 191 was still in heavy rain. 6:05:56 Gene Skipworth instructs Delta Flight 191: “Delta go around.” IV. APPLICABLE LAW 1. These actions are brought pursuant to the Federal Tort Claims Act, 28 U.S.C. § 2671 et seq. 2. Jurisdiction and venue properly lie with this Court under 28 U.S.C. § 1346(b) and 28 U.S.C. § 1402(b), respectively. 3. Texas law applies to determine the rights and liabilities of the parties. 28 U.S.C. § 2674. Richards v. United States, 369 U.S. 1, 82 S.Ct. 585, 7 L.Ed.2d 492 (1962). Brooks v. United States, 695 F.2d 984 (5th Cir.1983). See Opinion filed by this Court on September 22, 1986. 4. Parties who asserted that the air traffic controller’s negligent conduct was a substantial cause of crash of aircraft during landing have the burden of persuasion. Delta Air Lines, Inc. v. U.S., 561 F.2d 381 (1st Cir.1977). 5. Under Texas law, liability of the United States for negligence allegedly causing an aircraft accident is to be determined by the ordinary rules of negligence and due care. American Airlines, Inc. v. United States, 418 F.2d 180, 191 (5th Cir.1969); United States v. Schultetus, 277 F.2d 322, 325 (5th Cir.1960), cert. denied, 364 U.S. 828, 81 S.Ct. 67, 5 L.Ed.2d 56 (1960); Associated Aviation Underwriters v. United States, 462 F.Supp. 674, 681 (N.D.Tex.1978). Brooks v. United States, 695 F.2d 984 (5th Cir.1983). 6. Under Texas law, a plaintiff has the burden of establishing each of three essential elements of actionable negligence. The elements are as follows: (1) a legal duty owed by one person to another; (2) a breach of that duty; and (3) damages proximately resulting from such breach. Atchison, Topeka & Santa Fe Ry. v. Standard, 696 S.W.2d 476, 478 (Tex.App.1985); Gray v. Baker and Taylor Drilling Co., 602 S.W.2d 64, 65 (Tex.Civ.App.1980); Abalos v. Oil Development Co., 544 S.W.2d 627, 631 (Tex.1976). 7. Whether or not a legal duty exists under a given set of facts is essentially a question of law to be determined by the Court. Gray v. Baker and Taylor Drilling Co., 602 S.W.2d 64, 65 (Tex.Civ.App.1980); Abalos v. Oil Development Co., 544 S.W.2d 627, 631-633 (Tex.1976). 8. Under Texas law, proximate cause includes two elements: (1) cause in fact, and (2) foreseeability. Williams v. Steves Industries, Inc., 699 S.W.2d 570, 575 (Tex.1985); Nixon v. Mr. Property Management Co., 690 S.W.2d 546, 549 (Tex.1985). 9. Cause in fact is established if the injury would not have occurred “but for” the act or omission. Harrison v. Harrison, 597 S.W.2d 477, 484 (Tex.Civ.App.1980); Biggers v. Continental Bus Sys tem, 157 Tex. 351, 303 S.W.2d 359, 365 (1957); Hopson v. Gulf Oil Corp., 150 Tex. 1, 237 S.W.2d 352, 355 (1951). Texas courts use the term “substantial factor” in the context of the “but for” requirement; that is, if a negligent act or omission is a substantial factor in bringing about the injury or without which no harm would have occurred, the act or omission is a cause in fact of the injury. See Nixon v. Mr. Property Management Corp., 690 S.W.2d 546, 549 (Tex.1985). 10. The foreseeability requirement under Texas law requires that the injury be of such a general character as might reasonably have been anticipated, and that the injured party should be so situated with relation to the wrongful act that injury to him or to one similarly situated might reasonably have been foreseen. Harrison v. Harrison, 597 S.W.2d 477, 484 (Tex.Civ. App.—Tyler, 1980); Motsenbocker v. Wyatt, 369 S.W.2d 319, 323 (Tex.1963). 11. Under Texas law proximate cause cannot be established by mere guess or conjecture; it must be proven by evidence of probative force. McClure v. Allied Stores of Texas, Inc., 608 S.W.2d 901, 903 (Tex.1980). See also, Moorhead v. Mitsubishi Aircraft Int’l, Inc., 828 F.2d 278, 283 n. 24 (5th Cir.1987). 12. Though falling below requisite standard of care, an act or omission is not actionable unless also shown to be a substantial cause of complained of injury. Delta Air Lines v. U.S., 561 F.2d 381. V. DELTA LIABILITY A. Crew Responsibility 1. It is well-established that the pilot-in-command of an aircraft is directly responsible for, and is the sole authority as to, the operation of that aircraft. 14 C.F.R. § 91.3; Carney v. United States, 634 F.Supp. 648, 652 (S.D.Miss.1986), aff'd, 813 F.2d 405 (5th Cir.1987); See also, Moor-head v. Mitsubishi Aircraft Int’l., Inc., 828 F.2d 278, 285 (5th Cir.1987); American Airlines, Inc. v. United States, 418 F.2d 180, 191-92 (5th Cir.1969); Associated Aviation Underwriters v. United States, 462 F.Supp. 674, 681 (N.D.Tex.1978). 2. The duties of the pilot and of the controllers are concurrent. However, the operational control of the aircraft is not assigned to air traffic control; this is assigned to the air carrier and the pilot-in-command. 14 C.F.R. § 121.537; Baker v. United States, 417 F.Supp. 471, 485 (W.D. Wash.1975). 3. Pilots of all commercial passenger-carrying planes have a specific obligation to fully apprise themselves of prevailing and expected weather conditions along the route of their flights. In re Air Crash Disaster at Boston, Mass., July 31, 1973, 412 F.Supp. 959, 968 (D.Mass.1976), aff'd sub nom Delta Air Lines, Inc. v. United States, 561 F.2d 381 (1st Cir.1977), cert. denied, 434 U.S. 1064, 98 S.Ct. 1238, 55 L.Ed.2d 764 (1978). 4. The pilot has a continuing duty to be aware of danger when he can gather adequate information with his own eyes and instruments; a pilot cannot disregard the weather conditions he sees around him. Moorhead v. Mitsubishi Aircraft Int’l Inc., 828 F.2d 278, 285 (5th Cir.1987); Spaulding v. United States, 455 F.2d 222, 226-27 (9th Cir.1972) (applying Texas law); Peters v. United States, 596 F.Supp. 889, 895 (E.D.Pa.1984) (a pilot cannot ignore the weather information he has been given or disregard the weather conditions he sees around him). 5. Where dangerous weather conditions are clearly visible or known, a pilot should recognize them through his mandatory weather training and is obligated to look out for and avoid these weather conditions. Associated Aviation Underwriters v. United States, 462 F.Supp. 674, 681 (N.D.Tex.1978); Black v. United States, 441 F.2d 741, 743 (5th Cir.1971), cert. denied, 404 U.S. 913, 92 S.Ct. 233, 30 L.Ed.2d 186 (1971). 6. The crew of an airline transport is required to conduct its operations pursuant to applicable regulations, good operating practices, and the procedures imposed by the airline itself. Baker v. United States, 417 F.Supp. 471, 483 (W.D.Wash.1975). 7. Delta’s Flight Operations Procedures Manual contains a notation regarding the use of radar in thunderstorm conditions. This notation states that thunderstorm conditions should be avoided whenever possible. If early evasive action is not practicable, the manual indicates that certain practices should be followed: Avoid areas where sharp changes in rainfall intensity occur, any echoes which are rapidly changing in shape, size, or intensity, or any echoes which have prominent scallops, hooks or fingers by at least: —5 miles at 10,000 feet or below. These clearances are predicated on using the 50 or 100-mile range on the L-1011’s airborne weather radar. The manual further states that weak echoes or areas of weak rainfall gradient may be flown through or adjacent to “if judgment dictates this to be the most desirable procedure.” 8. It is negligence on the pilot’s part to land or take off in an obvious thunderstorm. Spaulding v. United States, 455 F.2d 222, 227 (9th Cir.1972) (applying Texas law); Neff v. United States, 420 F.2d 115, 116 (D.C.Cir.1969), cert. denied, 397 U.S. 1066, 90 S.Ct. 1500, 25 L.Ed.2d 687 (1970). 9. A pilot who is not certain as to the presence of a wind shear nevertheless may be negligent in flying too close to thunderstorm activity even if he does not penetrate the thunderstorm cell itself. McKinney v. Air Venture Corp., 578 S.W.2d 849, 859-60 (Tex.Civ.App.1979). Flying into the thunderstorm 10. Prior to departure from Ft. Lauderdale, Delta’s Flight Control Dispatch and Meteorology Department provided the flight crew of DL 191 with a routine dispatch package. This package contained the following weather documents: the reported weather at DFW Airport and at the flight’s alternate destination, San Antonio; a terminal weather forecast for DFW indicating widely scattered moderate rainshow-ers and thunderstorms with moderate rain-showers; an en route forecast indicating isolated thunderstorms, moderate rain-showers over Oklahoma and northern and northeastern Texas with a few isolated tops above 45,000 feet; and Delta Metro Alerts applicable to the route of flight, one of which stated that an area of thunderstorms was expected over Northern and Northeastern Texas. These forecasts were prepared by Delta meteorologists. These forecasts advised the flight crew of DL 191 that the atmosphere around the DFW airport was unstable and capable of producing an airmass thunderstorm. 11. As noted, the flight crew received ATIS Romeo at 5:35:26 containing weather information including the temperature (101), and dewpoint (67). 12. By 5:51:19, the flight crew was aware of rain over the DFW area as indicated by comments on the CVR: “Looks like it’s raining over Ft. Worth.” 13. At 5:56:28, the Feeder East controller broadcast to all airplanes that “there’s a little rainshower just north of the airport and they’re starting to make ILS ap-proaches_” DL 191 was on the frequency and its flight crew heard this transmission. 14. At 5:59:37, DL 191 was about seven miles northeast of the storm and was requested to turn right to 340 degrees. Between 5:51 and 6:00, the microburst-produc-ing cell (Cell D) had intensified from VIP 1 to VIP 4; the nose of the aircraft was pointed southwest toward this cell until 5:59:37. Except for a period between 5:55:53 and 5:57:19, during which a pre-landing checklist was completed, the flight crew was relatively free of in-cockpit duties. During this period the flight crew would have been free to use the weather radar to observe Cell D and to manipulate the antenna tilt to analyze the storm structure and intensity. Since the storm cell had reached a VIP 4 by 6:00, the cell would have contoured on their radar during this period. 15. By 5:59:47, with the statement by the First Officer, “we’re gonna get our airplane washed,” the Captain’s reply, “What?” and the First Officer repeating the statement, it was apparent to the flight crew of DL 191 that their flight path would take them through the area of rain about which they had been advised and which they had observed. The Comment by Second Officer Nassick regarding Price “getting good legs” was an acknowledgment that flying conditions were not optimal. 16. At 5:59:54, the flight crew of DL 191 switched to Arrival Radar-1 frequency and contacted the Arrival controller. 17. At 6:00:36, the Arrival Radar-1 controller asked American Flight 351, two aircraft in front of DL 191, if it was able to see the airport. The flight crew replied, “As soon as we break out of this rainshower we will.” This transmission was overheard by the flight crew of DL 191, and they thus were aware that the rainshower they were to encounter was of sufficient intensity to obscure forward vision by pilots of landing aircraf