NTSB Factual Report

HISTORY OF FLIGHT

On March 28, 2005, about 0936 eastern standard time, a Cessna 172S, N53589, registered to and operated by Dean and Blaylock Inc., as a Title 14 CFR Part 91 instructional flight, encountered severe turbulence while en route to Sarasota-Bradenton Airport, Sarasota, Florida. Instrument meteorological conditions (IMC) prevailed in the area at the time, and an instrument flight rules (IFR) flight plan was filed. The commercial-rated flight instructor and student were not injured, and the airplane incurred substantial damage. The flight originated from Tamiami Airport, Miami, Florida, the same day, about 0845.

The flight instructor stated that the flight had progressed under visual meteorological conditions (VMC) until reaching the Palm Beach area, at which time an area of clouds were noted. He said that upon querying the Palm Beach Approach controller, with whom he was speaking, he was informed that Miami Air Route Traffic Control Center (ARTCC) had been vectoring traffic through a "break" in the clouds. The instructor said that he received a radio communications handoff from Palm Beach Approach to Miami ARTCC, and on initial contact with Miami ARTCC, the Miami ARTCC controller provided a heading to steer. As he proceeded along at the assigned heading, the pilot said he encountered rain, and turbulence, so he elected to make a 180-degree turn, and exit the precipitation. While performing the turn he said the airplane encountered a downdraft, with an immediate decrease of about 2,000 feet, followed by increased turbulence. In the course of the turbulence encounter he said that the airplane door hinge pins fractured, and the passenger side window detached from the airplane and impacted the right side horizontal stabilizer. The pilot said he declared an emergency, and subsequently landed at Palm Beach International Airport, Palm Beach, Florida, without further incident.

The student stated that he was the pilot flying, and they asked Palm Beach departure control about a hole to transit through the weather and were given vectors toward Sarasota (SRQ). He stated they were flying at 4,000 feet, in visual flight rules (VFR) conditions, and were observing building clouds in the distance. They were then passed to Miami Center, and a controller said they were working a hole, near Labelle, and the controller then cleared them toward SRQ, giving them vectors. Along the way they encountered IFR conditions, and asked for and received clearances to 6,000 feet and then to 8,000 feet respectively.

The student said that when they entered IFR conditions they encountered light to moderate rain, and then some light turbulence, and that upon their query, a controller with Miami ARTCC said they had 5 miles of rain, and then they should have passed through those conditions. The student said that the Miami ARTCC controller mentioned nothing about heavy rains or cells. After a few bumps, the student said the instructor took control and became the pilot flying, beginning a 180-degree left turn to exit the showers. At about 90 to 120 degrees of turn, at 30 degrees of bank, the student said they encountered stronger turbulence, updrafts, and downdrafts, and the airplane went into a 90 degree bank. He said the right door blew off the hinges, and back about 8 inches, and a window with its frame blew out. The student said they continued flying with the HSI tumbled, as the instructor finally regained control at 6,000 feet, at which time the HSI returned to showing normal wings level flight.

The student said the instructor declared an emergency, and they headed east, back to Palm Beach International Airport, (PBI), and out of the IFR weather. A few minutes later, he said they hit another cell and went through the same aerobatics, with the HSI indicating that they were upside down, except that positive G's were being felt. The student said the instructor reduced power, and the G's eventually subsided, at which time they were at an altitude of about 2,000 feet. The student said that after some additional jostling, they exited the clouds upright, at about 500 feet. As they headed toward PBI, the student stated that the instructor was having difficulty maintaining straight-and-level flight and asked him to look behind them at the tail. The student said that when he looked back, he saw the right horizontal stabilizer bent down 30 degrees. He said the instructor again declared an emergency, asked for the nearest airport, chose PBI, and asked for the fire trucks to be standing by. The flight landed otherwise uneventfully.

Information obtained from the FAA revealed that after departing Tamiami airport, Miami, Florida, the pilot first contacted PBI approach at 0859, reporting level at 5,000 feet on a heading of 010 degrees. At 0902, the PBI controller amended the aircraft's heading to 040, and the pilot acknowledged. At 0905, the PBI controller asked the pilot of N53589 if he was planning to continue to Vero Beach to do a practice approach and then continue to Sarasota. The pilot responded, "Negative - if we could get Sarasota direct and you could help us out with the weather, that would be greatly appreciated." The controller responded, "I don't see any way of getting to Sarasota without going through the weather." The pilot replied, "Uh, roger that just uh, on the cells." The controller stated, "We're not displaying any right now - it's outside our airspace," and then asked the pilot if he wanted to go direct Sarasota. The pilot replied, "Affirmative, if we can, and if we can get higher it would be greatly appreciated." The controller offered 4,000 or 6,000 feet. The pilot requested 6,000, and the controller instructed him to maintain 6,000. A few seconds later, the controller made three attempts to assign N53589 a left turn to heading 290 for radar vectors to Sarasota. The pilot responded after the third call, acknowledging the heading for vectors to Sarasota. Between 0908 and 0910, the PBI controller assigned N53589 a series of radar vectors for spacing, ending with the aircraft flying heading 270. At 0913, the pilot again requested higher altitude, and the controller assigned 8,000 feet.

At 0914, the Miami ARTCC (ZMA) sector 47 controller asked PBI to put a different aircraft, N659T, on a 300 degree heading toward a "hole" in the weather northwest of PBI, near Pahokee, FL. After assigning the heading, the PBI controller advised the pilot of N659T that there was a line of weather extending about 30 miles. At 0915, the PBI controller advised N53589 that, "apparently at your one o'clock and about 35 miles is a hole the center's working. We've got to keep you westbound for now, expect a turn that way shortly." The pilot acknowledged.

At 0919, there was additional coordination between ZMA sector 47 and the PBI controller referenced another aircraft that would be routed through, "the same hole that 59T and 589 are going to go out." At 0922, the PBI controller instructed N53589 to fly heading 290, and the pilot acknowledged. At 0925, the controller told N53589 to contact Miami Center on 132.45, and the pilot again acknowledged. N53589 contacted ZMA sector 47 at 0925, checking in at 8000 feet on heading 290. The ZMA controller acknowledged and issued the Fort Myers altimeter setting. At 0928, the controller transmitted, "November 53589 after deviations permitting proceed direct Sarasota and advise." The pilot acknowledged direct Sarasota and stated that he would advise on deviations. At 0934:12, the pilot asked, "Center 52859 uh how's the uh weather look in front of us?" The controller responded, "589 I'm showing a line of precipitation that extends five miles along your route of flight, then you should be clear until you get about 25 southeast of Sarasota." The controller did not provide any intensity information.

At 0937:23, the pilot transmitted, "Center I got an emergency." The controller was uncertain which aircraft was calling, and responded, "Aircraft calling the center state your emergency and intentions." At 0937:40, the pilot continued, "53589 I'm in some serious weather can you help us out?" The controller responded, "53589 maintain 8,000 feet if feasible turn right heading 090 weather permitting 53589 your present position ah heading 090 or right 100 degrees heading should get you clear of the weather soonest."

At 0938:04, the pilot of N53589 transmitted, "I can't see a thing we're showing 1,500 feet." The controller advised that there was no other traffic in the vicinity. At 0938:31,the controller asked if N53589 was clear of the clouds, and the pilot replied that he was not. The controller again advised the pilot to head back to the east to get clear of the precipitation. The pilot responded, "I'm trying I'm trying." At 0939:11, the controller reported that he had lost radar contact with N53589. About 40 seconds later, the controller advised the pilot that he had again established radar contact and verified the aircraft's position as 3 miles northeast of Pahokee. The controller told the pilot that continuing on his present heading or slightly further to the right would have him clear of the weather in about 3 miles.

At 0942:23, the controller again advised N53589 that he had lost the aircraft's transponder and asked the pilot for an altitude report. The pilot transmitted, "We're still in trouble we're still in." The controller asked the pilot to repeat the transmission, but the reply from the aircraft was unreadable. At 0942:55, the pilot stated, "OK we are got Okeechobee here." The controller again asked for the aircraft's altitude, and the pilot replied "ah 500." The controller verified that the aircraft was at 500 feet, and then advised the pilot that from his last known radar position the aircraft should be clear of the weather in a mile or less. At 0943:25, the controller told the pilot that the minimum safe altitude in his vicinity was 1,300 feet, and instructed him to climb and maintain 8,000 feet. The pilot refused the climb clearance and stated, "we need to go back to the airport." The controller asked the pilot to state the nature of his emergency and requested destination. The pilot of N53589 responded, "OK uh we're coming out of fine precipitation - we've got it covered ah we're coming out of precipitation, we got the land down below us so we're OK now." The controller acknowledged and again asked the pilot for his intentions. The pilot requested to go to the nearest airport. At 0944:35, the controller instructed the pilot to contact PBI approach for vectors to the nearest airport. The pilot acknowledged.

N53589 contacted the PBI "B" sector controller at 0945, and the controller instructed the pilot to ident. The pilot acknowledged, and the controller asked for his intentions. The pilot said that he wanted to, "land at the nearest airport." The controller asked if the aircraft was in visual conditions. The pilot replied, "That's affirmative, that's affirmative, uh, if we could get to Palm Beach I'd greatly appreciate it." At 0945:32, the controller advised the pilot that the aircraft was in radar contact 10 miles northeast of Pahokee. She continued, "I can get you to Palm Beach or I can get you to North County. Your closest airport right now is North County. The pilot responded, "OK, uh we're OK for now. If we could get to Palm Beach, that would be great." The controller asked if the pilot wanted to maintain VFR for the flight to PBI, and the pilot stated that he did. The controller then instructed the pilot to fly heading 100 for vectors to the right downwind for runway 27R at PBI. At 0947:33, the PBI controller transmitted, "N53589 if you wind up having any problems please let me know." The pilot replied, "Roger we're OK right now." The controller then advised the pilot that the winds at PBI were 220 degrees at 22 knots. The pilot acknowledged and then asked if the controller showed any thunderstorms in their path. She replied, "Negative, sir." At 0951:32, the controller asked, "N53589, how we doing, sir?" The pilot responded, "Oh, we're doing fine. We're back to normal operation." The controller said, "OK, great. The wind at Palm Beach is 210 at 23 so you're going to have a really nice crosswind there." The pilot acknowledged.

At 0952:38, the approach controller advised PBI tower that N53589 was about 12 northwest of the airport, had been having a "lot of problems," and asked that the tower controller leave N53589 on the long runway. At 0954:28, the pilot of N53589 advised the controller that he wished to declare an emergency because of structural damage to the aircraft, and requested that the fire equipment be standing by at the airport. The controller acknowledged. The controller then asked if the aircraft was still flying all right. The pilot reported that it was, but that he wanted to go direct to the airport. The controller then instructed PBI tower to stop departures, advised N53589 that he was 7 miles northwest of the airport, and told the pilot to fly heading 130 and report the airport in sight. The pilot stated that he believed he saw the airport. The controller then advised that the wind was 22 degrees at 22 knots, the best runway would be runway 27R, and the pilot should enter the right downwind. The pilot replied, "OK uh, just stay with us and we'll try to make it." At 0956:12, the pilot asked, "Is there any way I can get a direct landing in?" The controller responded, "N589 proceed direct to the airport, sir, you can land any runway you need to sir, the winds are currently 220 at 22." The pilot stated, "Uh, roger that. 220 at 22? I'm going to try to make runway 27 right." The controller then advised the pilot that he was right between North County airport and PBI, and that, "North County is off your left if that will help any." The pilot elected to continue to PBI.

Between 0956 and 1002, the approach controller continued to provide wind updates to the pilot and relayed clearance for the pilot to land on any runway at PBI. The aircraft landed safely on runway 27R at 1002.

At the time of the accident, N53589 was inside PBI's airspace but under control of Miami ARTCC. Miami ARTCC is equipped with digital weather display capability that is designated to show levels 2 through 6 on the NWS video integrator and processor (VIP) scale. PBI is equipped with an ASR-11 radar, capable of displaying six VIP intensity levels of digitized weather information. For further information, see the NTSB Air Traffic Control Group Chairman's Factual Report.

METEOROLOGICAL INFORMATION

The NWS Surface Analysis Chart for 1500Z depicted the primary synoptic conditions at the surface at the approximate time of the accident and chart depicted a low pressure system with a central pressure of 994-millibars (mb) over eastern Kentucky with an occluded front extending from the low eastward across Virginia to a second low pressure system with a central pressure of 993-mb located at the triple point, where the occluded front split into a warm front to the east and a cold front to the south. The cold front extended southward from the low through North Carolina, into the Atlantic Ocean off the South Carolina and Georgia coasts, into central and southern Florida in the immediate vicinity of the accident site, and then into the Gulf of Mexico.

The southeast section of the NWS Radar Summary Chart for 1519Z on March 28, 2005, depicted an area of very light to light intensity echoes over southeast Florida and portions of the everglades with another area of strong to very strong echoes extending west-southwestward from the east coast across central Florida to the north of Lake Okeechobee, into the Gulf of Mexico. Several areas of intense to extreme intensity echoes were embedded within that area. Another area of echoes extended from the general vicinity of the accident site and eastern Lake Okeechobee northeastward to off the coast, where a solid line of intense to extreme intensity echoes was located. Echo tops in the vicinity of the accident site were identified to 39,000 feet, with cell movement to the northeast at 44 knots.

The satellite imagery (GOES-12) inclusive the time of the accident from 1400Z through 1530Z, showed a line of convective activity and when plotted with the accident airplane's flight track, the track coi

NTSB Probable Cause

The flight crews inadvertent encounter with turbulence in clouds while being vectored by ATC while operating in instrument meteorological conditions. A factor in the accident was the ATC personnel's (ARTCC) inadequate weather avoidance assistance.