The Jessica Dubroff Accident
You've seen the TV sound bytes, read the sensational stories in the popular press, heard the speeches by congressmen and the FAA administrator. Now read what actually happened and draw your own conclusions. Here's an in-depth report of the NTSB investigation into the April 1997 in-flight loss-of-control accident in Cheyenne, Wyoming, of a Cessna 177B Cardinal that killed seven-year-old Jessica Dubroff, her father, and pilot-in-command CFI Joe Reid.
Loss of Control
(The Jessica Dubroff Flight)
On April 11, 1996, at about 0824 mountain daylight time, a privately-owned Cessna 177B collided with terrain after a loss of control following takeoff from runway 30 et the Cheyenne Airport, Cheyenne, Wyoming. The pilot in command, pilot trainee, and rear seat passenger (the pilot trainee's father) were fatally injured. The pilot trainee was a 7-year-old girl, Jessica Dubroff, who did not hold a pilot certificate. To be eligible for a student pilot certificate, a person must be 16 years old, and to be eligible for a private pilot certificate a person must be at least 17 years old. Instrument meteorological conditions existed at the time and a VFR flight plan had been filed. The flight, which was a continuation of what was described by its promoters as a transcontinental flight "record" attempted by the youngest "pilot" to date (the pilot trainee), was being operated under Part 91.
On the morning of the accident, the pilot in command, the trainee and the passenger arrived at an FBO at the Cheyenne Airport between 0715 and 0730. A copy of a privately recorded videotape made by a bystander, displaying a time hack generated by the camcorder's clock, showed the airplane being loaded with personal effects at 0739. The ramp appeared to be dry and the airplane's shadow could be clearly seen on the pavement. The video recording then showed the pilot in command and the trainee conducting portions of a preflight briefing and a taped television interview. During the interview, rain could be seen streaming off the airplane's wings, and water was forming puddles on the ramp.
The program director of a Cheyenne radio station conducted a telephone interview with the trainee and her father at about 0745. He invited her to stay in Cheyenne because of the weather, but the father indicated that they wanted "to beat the storm" that was approaching.
At 0801:21, the pilot in command telephoned the Casper, Wyoming, Automated Flight Service Station for a briefing for a VFR flight from Cheyenne to Lincoln, Nebraska. The briefer advised of deteriorating weather moving in from the west, an AIRMET for icing, turbulence, and flight precautions for IFR conditions along the route of flight. The briefer described current weather conditions at several points east of Cheyenne, and the pilot in command said, "yea, probably looks good out there from here...lookin east looks like the sun's shining as a matter of fact. The briefer gave the forecast for Cheyenne through 0900 local time which called for 2,000 scattered to 4,000 broken with light rain, thunderstorms, and after 0900 local time lowering ceilings to 1,500 feet along the route of flight, and that rain, fog and thunderstorms were forecast for several points along the intended route of flight. He stated, "so...if you can venture out of there and go get east it looks...," to which the pilot in command replied, "yea, it looks pretty good actually." The briefer then made reference to the "adverse conditions" currently at Cheyenne, and the pilot in command said, "yea, it's raining here pretty good right now[, I] mean it's you know steady but nothin...bad and to the east it looks real good." He then filed a VFR flight plan to Lincoln.
At 0813:06, the pilot in command contacted the Cheyenne Air Traffic Control Tower requesting clearance to taxi and, at 0813:24, the local controller advised the pilot to "taxi to runway three zero, verify you have ATIS echo." The pilot responded, "negative, what's the ATIS?" He was given the ATIS frequency of 134.425 MHz and was requested to "advise when you have echo." The pilot advised he would get the ATIS on frequency 134.25, and the controller corrected him by repeating the correct frequency, 134.425.
In a segment of private videotape which did not have a time hack recorded on it, the airplane's engine was shown running, the airplane's external lights were on, and the nosewheel was still chocked. Rain was falling and there was standing water on the ramp. The recording stopped, and when it resumed, the airplane's engine was no longer running and the airplane's external lights were off. A lineman could be seen removing the nosewheel chock, after which the airplane's external lights came back on and the engine was restarted. The airplane then taxied from its ramp location southeasterly along the parallel taxiway to the approach end of runway 30.
At 0815:39, the pilot in command radioed the controller, "I don't get four two five on this radio," in reference to his inability to receive the ATIS. The controller responded, "Cardinal two zero seven roger, runway three zero, wind two eight zero at two zero occasional gusts three zero altimeter two niner seven zero." No response was received from the pilot and, at 0816:00, the controller asked for an acknowledgement. The pilot responded "OK, two zero seven, are we going the right way for runway 30?" The controller responded, "you are heading the right way for runway 30, did you get the numbers?" The pilot acknowledged, "we got em."
At 0818:12, the controller advised the pilot that a Twin Cessna just departed reported moderate low-level wind shear plus or minus one five knots" and the pilot responded, awe got that thank you." At 0818:53, the local controller advised that "tower visibility Es] two and three quarters [of a mile], field is IFR and say request." The pilot responded, OK two zero seven would like a special IFR um ah right downwind departure." The controller responded, "I'm not familiar with special IFR" and the pilot corrected with "I'm sorry, special VFR."
The tower local controller then coordinated with the local radar controller and, at 0820:19, advised the pilot that he was "cleared out of [the immediate airport vicinity] to the east, maintain special VFR east, maintain special VFR conditions," which was acknowledged by the pilot in command.
At 0820:51, the local controller inquired "let me know when you're ready," and at 0820:56 the pilot responded, "two zero seven's ready." Although the controller did not radio a takeoff clearance until two seconds later, the airplane had already started its takeoff roll.
Ground witnesses observed the airplane depart runway 30 heading in a northwesterly direction, and then execute a gradual right turn to an easterly heading. The witnesses generally described the airplane as having a low altitude, low airspeed, high pitch attitude, and wobbly wings. As it was rolling out of the right turn at several hundred feet AGL, the airplane was observed to rapidly descend to the ground in a near-vertical flight path. The impact occurred approximately 4,000 feet north of the departure end of runway 30 in a residential neighborhood.
PERSONNEL INFORMATION: Pilot In Command: The pilot in command was 52 years old and was a stockbroker by profession. He held a commercial pilot certificate with airplane single-engine land and instrument ratings, and a flight instructor certificate with an airplane single-engine land rating. His flight records for the two years preceding the accident revealed that he had given flight instruction to eight students in addition to the pilot trainee on this flight during that time. A search of FAA records showed no violations or enforcement actions. He instructed students through a flying club which he helped organize at his home base of Half Moon Bay Airport, Half Moon Bay, California.
The NTSB reported that, according to another flight instructor at the Half Moon Bay Airport, during one instructional flight he attempted to taxi out with the tow bar still attached to the airplane. This flight instructor also reported that the pilot in command had developed his own instrument approach into the Half Moon Bay Airport that went down to 500 feet.
The pilot in command had a current second class medical certificate with the limitation that "holder shall wear lenses that correct for distant vision and possess glasses that correct for near vision."
According to the pilot's logs, as of April 8, 1996, he had a total time of 1,484 hours. He had not logged any instrument time during the six months preceding the accident. Records indicated that he had conducted 10 flights from airports located above 4,500 feet MSL.
Pilot Trainee: The pilot trainee did not hold any FAA certificates. Her total instructional time as reported in her personal flight log through April 6, 1996, was 33.2 hours. All of the flights occurred in Cessna aircraft, including 3.7 hours in the accident 177B. A total of 29 flights were logged, all with the pilot in command as her instructor.
SLEEP AND ACTIVITY HISTORY: On Wednesday, April 10, 1996, the airplane departed Half Moon Bay, California, at 0700 p.d.t., and landed at Elko, Nevada, at approximately 1020 p.d.t., and was refueled. The airplane departed Elko at 1115 p.d.t, and arrived in Rock Springs, Wyoming, approximately three hours later. The airport manager at Rock Springs said the pilot in command was "noticeably exhausted." The pilot in command telephoned the Casper, Wyoming, Automated Flight Service Station and received a weather briefing for the flight to Cheyenne, Wyoming. The airplane departed Rock Springs at approximately 1540 and landed at Cheyenne at approximately 1726. The pilot in command telephoned his wife from the airport and said that he was elated at the receptions they had received. According to his wife, he sounded tired, and he stated that he was very tired.
The program director for a local Cheyenne radio station provided transportation for all three occupants from the airport to the hotel. During the ride, they discussed a storm front that was predicted to arrive in Cheyenne the next morning. According to the program director, the pilot in command was "very adamant" that the flight should depart by 0615, and the pilot trainee's father agreed. The program director stated that all three looked tired and discussed being very tired. Upon arrival at the hotel at approximately 1900, the pilot trainee and her father checked into one room and the pilot in command checked into another room.
On the morning of the accident, the pilot in command checked out of his hotel room at 0622. The desk clerk said he looked fairly rested and seemed happy. The trainee and her father checked out of their hotel room at 0714 and, with the pilot in command, returned to the Cheyenne Airport by hotel shuttle.
AIRPLANE INFORMATION: The airplane, a four-place Cessna 177B, was manufactured in 1975 and registered to the pilot in command in 1987. Prior to the accident flight, both the airframe and engine had accumulated 3,582.3 flight hours. The airplane received its last annual inspection on July 8, 1995, at 3,508.4 flight hours.
The airplane was equipped with dual 3-inch aluminum rudder pedal extensions on the left side rudder pedal assembly, which were installed a few weeks before the accident flight. Cushions on the front left seat (to raise up and extend the left seat occupant's forward view) were visible on the video recording made immediately prior to the airplane's departure from Cheyenne.
The airplane was equipped with two 25-gallon wing tanks, providing a total of 49 gallons of usable fuel. It had been topped up with 26.3 gallons of 100LL fuel shortly after its arrival in Cheyenne.
The 1975 Cessna 177B Owner's Manual states in Section II that prior to takeoff from short fields above 3,000 feet elevation, the mixture should be leaned to give maximum power. According to FAA Advisory Circular 61-23B, "Carburetors are normally calibrated at sea level pressure to meter the correct amount of fuel with the mixture control in the 'FULL RICH' position. As altitude increases, air density decreases...If the fuel/air mixture is too rich, i.e., too much fuel in terms of the weight of the air [high density altitude], excessive fuel consumption, rough engine operation, and appreciable loss of power will occur."
WEIGHT AND BALANCE: The airplane's maximum gross takeoff weight was 2,500 pounds. The takeoff weight on the morning of the accident was calculated by Safety Board investigators to be 2,596 pounds. The center of gravity was calculated to have been at 110.4 inches. The aft center of gravity limit for the Cessna 177B at its maximum 2,500 pounds gross weight is 114.5 inches.
WING FLAP SETTING: Examination of the wreckage indicated a 10 degree flap extension at the time of impact. The airplane's Owner's Manual states that takeoffs can be accomplished with the flaps set in the zero to 15 degrees positions. The preferred flap setting for a normal takeoff is 10 degrees.
WEATHER OBSERVATION: Weather observations at Cheyenne are taken by an Automated Surface Observation System (ASOS). The 0823 special observation was: sky condition - 1,600 feet scattered; measured ceiling - 2,400 feet broken, 3,100 feet overcast; visibility - 5 miles; weather thunderstorm, light rain; temperature - 40 degrees F.; dew point - 32 degrees F.; wind - 250 at 20 knots, gusting to 28 knots; altimeter - 29.71; remarks broken variable scattered, thunderstorm began 0823, 0.04 inch rain feel since previous record observation, wind shift began 0800, peak wind 260 degrees at 28 knots recorded at 0817.
The nearest Doppler Weather Surveillance Radar was located at the Cheyenne National Weather Service office located on the southern boundary of the airport. Velocity data from the Doppler radar indicated that the wind direction in the airport area around the time of the accident was from about 260 degrees true near the surface and did not shift substantially through approximately 350 feet AGL. The winds were 15 to 30 knots.
Investigators asked the tower controller why runway 30 was in use at the time. He reported that at his console, the wind readings, which did not come from the ASOS, indicated that the winds were variable and did not favor either runway 30 or runway 26. He also said that the accident airplane was parked closer to runway 30 and would be able to depart faster using that runway. The controller's wind readings came from a National Weather Service anemometer which was located near the threshold of runway 30. No record was kept of the wind directions recorded by that anemometer.
OTHER PILOTS: A pilot with the State of Wyoming, who is based at Cheyenne, holds an ATP rating and has more than 13,800 flight hours, departed from runway 30 in a Cessna 414 at 0816. He told investigators that his radar painted a steep gradient of green/yellow/red echoes beginning about four to five miles from his position on the runway. He requested a 60 degree turn to the right (heading 360 degrees) immediately after takeoff. While on the runway, he observed cloud to ground lightning to the west. The strongest part of the storm appeared to be at about 230 to 240 degrees with echoes extending to about 330 degrees. The pilot recalled strong crosswinds during his takeoff, requiring significant aileron input. He said he experienced control difficulties all the way down the runway, more than he would normally expect under those wind conditions. After rotation, the airplane did not accelerate rapidly at first. He said he experienced moderate turbulence and the airspeed fluctuated +/-15 knots. He said that the airplane began to climb satisfactorily after leaving the airport boundary. At 200 to 300 feet AGL, the turbulence and airspeed fluctuations subsided.
The pilot of the Cessna 414 reported that he was aware that the accident airplane was planning to take off soon after his departure and that he was concerned and gave a pilot report to the tower hoping that the pilot of the Cessna 177B would hear it. He said that he never talked to anyone in the accident airplane.
The captain of United Express flight 7502 (a Beech 1900) landed at Cheyenne Airport at about 0820. He remembered that as the airplane taxied to the gate, the rain showers became heavier. He remembered hearing the pilot report from the Cessna 414. The captain said he decided to delay his planned takeoff until the weather improved. He said that he observed lightning within one or two miles of the airport as his airplane arrived at the gate, and that the rain changed to what appeared to be small hail.
AIR TRAFFIC CONTROL: The Cheyenne ATCT local controller who was on duty at the time of the accident reported that the weather began deteriorating shortly after he took his position shortly before the accident. He recalled that visibility was lowest from the southwest through the north and was better to the east and southeast. He said that the worst weather was in the northwest, and that the weather seemed stationary. At 0818:12, he advised the accident airplane that "twin Cessna just departed reported moderate low level windshear plus or minus one five knots."
He said that the accident airplane did not come to a complete stop at the beginning of the runway, and that it was rolling when he gave the takeoff clearance. He stated that after becoming airborne, the airplane appeared slower than expected.
WRECKAGE AND IMPACT INFORMATION: The airplane came to rest on the south edge of a level, residential street at the entrance to a private residential driveway. The final resting spot was nearly the same as the initial point of impact. The crash site was on a bearing of 321 degrees and 9,600 feet from the departure threshold of runway 30. The wreckage distribution was largely confined to the immediate ground impact site, but a distribution of small fragments extended from the ground impact site southeast into a residential yard.
The airplane was upright and was oriented along a southeast heading. The nose section and forward cabin area were crushed. Both cabin doors evidenced crush lines which indicated that the airplane impacted at a 67 degree nose down attitude.
The two-blade propeller was separated from the engine. One blade was beneath the left wing. The other blade was embedded in the ground impact crater. Both blades exhibited tip curl and blade twist, along with extensive chordwise scratching and small leading edge nicks.
The entire wing structure remained essentially intact, but had separated from the airframe.
The mixture control knob was found in the full rich position. A damaged video recorder and two blank videotapes were found at the wreckage site. No videotape was found inside of the recorder.
Approximately 15 pounds of navy blue baseball caps were recovered at the site. The baseball caps displayed the pilot trainee's name in gold lettering along with the slogan, "Sea to Shining Sea" and "April 1996."
MEDICAL AND PATHOLOGICAL INFORMATION: The Wyoming State Crime Laboratory conducted autopsies on the accident victims. The reports concluded that all three victims died from traumatic injuries. Injuries sustained by the pilot in command, including fractured wrists, fractured ankles and fractured feet, and the lack of comparable injuries to the pilot trainee, indicated that the pilot in command was operating the controls of the aircraft at impact.
The autopsy report on the trainee's father noted that his left shirt pocket contained "numerous slips of paper with appointment times and dates of TV interviews," including one scheduled for that evening in Ft. Wayne, Indiana, and another for the next evening in Massachusetts. There also were numerous business cards from radio stations, TV stations and networks.
MEDIA ASPECTS: The pilot in command's wife reported that her husband was "flabbergasted" by the media coverage. ABC News had provided a video recorder to the trainee's father along with three blank video cassettes to record the first day's flight activities. The first three tapes were to be turned in to ABC News at Cheyenne, and were to be replaced with blank tape cassettes for additional recording.
Numerous media representatives were present when the flight departed Half Moon Bay, California, and the occupants of the aircraft were interviewed on live national television at 0530 that morning. Upon arrival at Cheyenne, a large number of spectators, including news media, were present at the airport. There was a welcome presentation by Cheyenne's Mayor. On the morning of the accident, the airplane occupants participated in at least three media interviews.
...he considered the flight a
"non-event for aviation" and
simply "flying cross country with
a 7-year-old sitting next to you
and the parents paying for it."
ITINERARY PLANNING: The idea for the "record"-attempting cross country flight was proposed by the trainee's father in February, 1996, according to the trainee's mother. The original plan was for the trainee and the pilot in command to fly from California to Massachusetts and to complete the trip by May 5, 1996, which was the trainee's eighth birthday. It was agreed that the pilot in command would be paid his normal hourly rate for flight instruction, with additional compensation for the non-flight time. According to the pilot in command's wife, when the flight was first conceived, he did not expect publicity. She said that he considered the flight a "non-event for aviation" and simply Flying cross country with a 7-year-old sitting next to you and the parents paying for it." She said that he originally planned to return from the East Coast with a business partner after the trip was over.
According to the trainee's mother, about one month before the trip the trainee asked her father to go with her and he agreed. Two to three weeks before the trip, the itinerary was expanded to involve approximately 51 hours of flying over eight days, with no days off, and included planned visits to relatives and other events. The outbound trip was to originate at Half Moon Bay, California. The first day's stops were: Elko, Nevada; Rock Springs, Wyoming; overnight in Cheyenne, Wyoming. The second day's stops would be: Lincoln, Nebraska; Peoria, Illinois; overnight in Fort Wayne, Indiana. The third day's stops would be: Cleveland, Ohio; Williamsport, Pennsylvania; overnight in Falmouth, Massachusetts. The fourth day's flight would stop at: Frederick, Maryland; overnight in Clinton, Maryland. The fifth day's flight would stop at: Raleigh, North Carolina; Charleston, South Carolina; Jacksonville, Florida; overnight at Lakeland, Florida. The sixth day's flight would stop at: Marianna, Florida; Mobile, Alabama; overnight in Houston, Texas. The seventh day's flight would stop at: San Angelo, Texas; Albuquerque, New Mexico; overnight at Sedona, Arizona. The schedule for the eighth day was a stop at Lancaster, California, and a final destination of Half Moon Bay.
PREVIOUS RECORD ATTEMPT: Investigators could find no organization which keeps an official record for "the youngest pilots The father of an 8-year-old boy who flew with his father across the United States in July, 1995, to set a self-proclaimed "youngest pilot flight record" was interviewed by Safety Board investigators. The 8-year-old boy did not hold any FAA certificates. The father reported that a local newspaper published a short item about the flight the day before it began, and that within an hour of the newspaper's publication he was contacted by two radio stations. He said that by the time of departure, there was a media "frenzy" at the airport. He said one reporter explained that "we're looking for a happy story on kids."
ANALYSIS: The pilot in command was properly certificated and qualified for the intended trip. Additionally, evidence indicated that he was wearing the corrective lenses required by his medical certificate at the time of takeoff.
There was no evidence that airplane maintenance was a factor in the accident. Because the ground temperature was above freezing up to the time of the takeoff, and because of the short duration of the flight, airframe icing was not likely a factor in this accident.
THE ACCIDENT SCENARIO: The statements provided by witnesses indicated that the airplane's climb rate and speed were slow and that after the airplane transitioned to an easterly heading, it rapidly rolled off on a wing and descended steeply to the ground in a near vertical flight path, consistent with a stall.
Based on performance data provided by NASA, the Safety Board determined that the rainfall present at the time of takeoff could reduce the airplane's lift by as much as three percent, increasing the airplane's stall speed by about 1.5 percent.
The Safety Board found that the pilot in command decided to turn right immediately after takeoff to avoid the nearby thunderstorm and heavy precipitation that would have been encountered on a straight-out departure. Witness statements indicated a gradual turn, consistent with a bank angle of about 20 degrees. With the flaps set at 10 degrees, this turn would increase the stall speed about three miles per hour, from about 59 mph for steady level flight to about 62 mph.
Because the airplane was about 96 pounds overweight at takeoff, the Safety Board found that this would have increased the stall speed another two percent.
The Cheyenne Airport has a field elevation of 6,156 feet MSL. Density altitude at the time of takeoff was calculated to have been 6,670 feet MSL. According to airplane performance data from Cessna, the high density altitude and the airplane's overweight condition would have decreased the airplane's best rate of climb speed from 84 mph to 81 mph, with a climb rate of 387 feet per minute. Thus, the airplane had decreased performance with an increased stall speed. However, it should have been able to climb and turn safely. The Safety Board analyzed possible reasons why this did not occur.
Investigators believe the evidence shows that the pilot did not lean the fuel/air mixture for maximum power for the high density altitude takeoff. The mixture knob was found in the full rich position at the accident scene. Although it is possible that impact forces moved the knob forward to full rich, investigators noted that the linkage rod was not bent. Investigators also noted that the pilot did not stop at the end of the runway before the takeoff roll, which would have been the most common and appropriate time to adjust the fuel/air mixture.
Carburetor icing conditions existed at the time of takeoff. Investigators noted that without the application of carburetor heat during taxi and runup, ice may have formed the carburetor and reduced the available power at takeoff. The carburetor heat control was found in the "off" position. The pilot's failure to stop at the end of the runway also suggested to investigators that he did not perform a pretakeoff checklist, which would have included a magneto check and check of the carburetor heat.
The Safety Board found that although the horizontal in-flight visibility at the time of the stall was most likely substantially degraded due to precipitation, eliminating a visible horizon, the pilot in command could have maintained ground reference by looking out the side window. However, this could have been disorienting to the pilot because of the need to scan to his left to see the flight instruments in front of the trainee and to his right to see the ground as he attempted to operate the airplane at a low speed, with a lower than normal climb rate.
The Safety Board found that the wind conditions would have made it more difficult for the pilot in command to maintain a constant airspeed and rate of climb and could have resulted in an unintended reduction in airspeed to below the airplane's stall speed. The wind conditions also may have affected the pilot's perception of the airplane's speed. What was initially a crosswind during the takeoff roll and initial climb, became a tailwind after the airplane began its right turn. Because the pilot was most likely looking outside during the special VFR departure, he may have not been adequately monitoring the airspeed indicator, or may have had difficulty monitoring it because of airspeed fluctuations, and may have mistaken the increase in ground speed as an increase in airspeed. This may have led him to misjudge the margin of safety above the airplane's stall speed.
The Safety Board noted that the pilot in command's limited experience in operating out of high density altitude airports should have prompted him to be cautious, in addition to his knowledge of the storm that was moving in and the report of wind shear from the Cessna 414 pilot who had just departed.
Accordingly, the Safety Board concluded that the pilot in command inappropriately decided to take off under conditions that were too challenging for the pilot trainee, and, apparently, even for him to handle safely.
FATIGUE: Although the Safety Board noted that the pilot in command had the opportunity to receive a full night's sleep the night before the accident, the quantity and quality of the sleep he received is unknown. Immediately before the accident, he committed several errors that are consistent with a lack of alertness. However, the errors also could have been caused by rushing, distractions, or bad habits. Therefore, the Safety Board was unable to conclude that fatigue was a factor in the accident.
The errors included:
started the engine while the nosewheel was still chocked;
requested a taxi clearance without first obtaining the ATIS;
read back a radio frequency incorrectly;
accepted a radio frequency he could not dial up on his radios;
failed to acknowledge, as requested, weather information from the controller;
asked "are we going the right way?";
failed to stop at the end of the runway;
requested a "special IFR" clearance.
MEDIA ATTENTION AND ITINERARY PRESSURE: The Safety Board noted that self-induced pressures from media attention can degrade decision making, increasing the perceived importance of maintaining a schedule compared with other factors. The Safety Board concluded that the airplane's occupants' participation in media events the night before and the morning of the accident flight resulted in a later-than-planned takeoff from Cheyenne under deteriorating weather conditions. However, media presence at the airport and interviews scheduled on subsequent stops probably also added pressure to attempt the takeoff and maintain the schedule. The Safety Board found that the itinerary was overly ambitious, and that a desire to adhere to it may have contributed to the pilot in command's decision to take off under the questionable conditions at Cheyenne.
PROBABLE CAUSE: The National Transportation Safety Board determined the probable cause of the accident was the pilot in command's improper decision to take off into deteriorating weather conditions (including turbulence, gusty winds, and an advancing thunderstorm and associated precipitation) when the airplane was overweight and when the density altitude was higher than he was accustomed to, resulting in a stall caused by failure to maintain airspeed. Contributing to the pilot in command's decision to take off was a desire to adhere to an overly ambitious itinerary, in part, because of media commitments.