CHI04LA129

The airplane flew into a thunderstorm during cruise flight and subsequently entered a flat spin until impact with terrain. The airplane had been given a heading to avoid the adverse weather by Lansing approach control. During transfer of control between Lansing approach and Cleveland center, the Cleveland controller was advised that the aircraft had been given a heading to avoid the adverse weather. After the handoff, the Cleveland controller instructed the pilot to proceed direct to an en-route fix when able, but did not provide any information about radar-observed weather ahead of the aircraft. The Chicago center controller who next handled the airplane was briefed that the airplane was proceeding direct to the en-route fix and had not requested any weather deviations. About seven minutes after the handoff between Cleveland and Chicago centers, the pilot transmitted, "Center this is uh 707SH what do you show us in up here?" Aircraft and weather radar data showed the accident airplane flew into an area of level six precipitation (extreme weather) prior to a rapid loss of altitude. Several witnesses reported first hearing the sound of a revving aircraft engine before seeing the airplane descending rapidly in a spiraling descent. A pilot-rated witness reported that the airplane was in a "flat spin" before impacting the terrain. Before the pilot departed on the accident flight, he was given a weather briefing that indicated his route of flight would take him into areas of thunderstorms, moderate turbulence, and icing. According to available pilot flight records, the pilot did not have a current biennial flight review and was not instrument current, as required by federal aviation regulations. No pre-impact anomalies were found with the airplane during the post-accident inspection.

"This case was modified 11/16/2006."

History of flight

On May 31, 2004, at 1400 eastern daylight time, an amateur-built Hall Lancair IV-P, N707SH, piloted by a private pilot, was destroyed during an in-flight collision with terrain following a loss of control during cruise flight near Vermontville, Michigan. Instrument meteorological conditions (IMC) with thunderstorms were present at the time of the accident. The business flight was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 91 on an instrument flight rules (IFR) flight plan. The pilot and two passengers were fatally injured. The flight departed Willow Run Airport (YIP), Ypsilanti, Michigan, at 1330, and was en route to Billings Logan International Airport (BIL), Billings, Montana.

At 1213, the pilot of N707SH contacted Lansing (LAN) Automated Flight Service Station requesting a weather briefing for a flight from YIP, to Portland International Airport (PDX), Portland, Oregon, with an en route stop to be determined. The briefer advised the pilot to expect thunderstorm and rain shower activity in Michigan, moderate turbulence below 9,000 feet msl, and icing conditions between 7,000 and 14,000 feet msl. The briefer also described an area of thunderstorms extending from south of Milwaukee (MKE) through the Chicago metropolitan area and extending almost to the Iowa border. The briefer did not specify the source of the thunderstorm information, although it coincided with the area covered by SIGMET 43C (valid from 1155 to 1355). This SIGMET reported a developing area of thunderstorms moving from the west at 30 knots, with tops reaching 28,000 feet msl. The briefer advised the pilot to contact Flight Watch or flight service after departure for assistance in avoiding this adverse weather. The briefer then continued to provide weather information from the eastern Michigan area toward PDX and BIL, as well as winds aloft for the pilot's requested cruise altitude of 10,000 feet msl.

When asked where he planned to stop en route to PDX, the pilot replied, "Why don't we plan on Billings." The briefer advised that there were numerous notices to airmen in effect for BIL airport and its associated approach procedures. The pilot then filed an IFR flight plan from YIP to BIL via MKE, requesting a 10,000 feet msl cruise altitude.

N707SH departed YIP at 1330 en route to BIL. The cleared route of flight was YIP direct EARVN intersection, direct MKE, direct to BIL, cruising at 10,000 feet msl. The aircraft was initially in contact with Detroit departure control, and was subsequently handled by LAN approach control, Cleveland Air Route Traffic Control Center (ZOB), and finally Chicago Air Route Traffic Control Center (ZAU).

The pilot contacted LAN approach at 1341 while climbing to 10,000 feet msl. At 1344, the LAN approach controller asked if the aircraft was equipped with weather radar. The pilot responded that it was not, and the controller advised the pilot of weather ahead that might affect the aircraft's flight. The pilot requested vectors around the weather.

At 1345, the LAN controller asked Grand Rapids approach control (GRR) to see if they could provide further information on the extent and intensity of the precipitation. GRR approach control was equipped with an ASR-9 radar antenna that depicted six-level weather information in addition to its basic air traffic control display capabilities. LAN approach control was equipped with an ASR-7 radar antenna that had limited weather capabilities. The GRR controller was unable to assist at that moment due to workload, but said that he would call back. The LAN controller then issued N707SH a 270-degree heading to avoid the weather depicted on the controllers display.

During this period, the aircraft climbed above its assigned altitude of 10,000 feet msl twice, at one instance reaching 10,800 feet msl. At 1349, the pilot requested to climb to 11,000 feet msl because it was "pretty bumpy" in the clouds. The LAN controller told the pilot to expect 12,000 feet msl, but to remain at 10,000 feet msl pending coordination with ZOB.

At 1350, the LAN controller completed an automated handoff to the ZOB Jackson sector. The LAN controller advised the ZOB Jackson controller that N707SH was on a 270-degree heading to avoid weather, and relayed the pilot's request for 12,000 feet msl. At 1351, the ZOB Jackson controller cleared N707SH to climb to 12,000 feet msl and instructed the pilot to proceed direct MKE when able, but did not provide any information about radar-observed weather ahead of the aircraft.

Aircraft radar track data was obtained from the GRR approach control facility. The plotted data showed the accident aircraft turned from the previously assigned 270-degree heading about 20-30 degrees right to a direct course toward MKE.

At 1351:41, the ZOB Jackson sector controller advised the ZAU Sparta sector controller that N707SH was proceeding direct to MKE and had not requested any weather deviations. The ZOB Jackson controller also told the ZAU Sparta controller that ZAU Sparta sector had control for any weather deviations and that the pilot had been having trouble holding altitude while at 10,000 feet msl. At 1354:06, the ZAU Sparta controller checked to see if N707SH was on frequency and asked the pilot to verify his altitude. The pilot stated that he was at 11,900 feet msl. At 1354:55 the ZAU Sparta controller told the pilot to report reaching 12,000 feet msl, which the pilot complied with at 1355:02.

At 1358:34, the pilot of N707SH transmitted, "Center this is uh 707SH what do you show us in up here?" The ZAU Sparta controller twice asked the pilot to repeat his message, with no immediate response. Aircraft radar track data was plotted on a weather radar chart that depicted areas of precipitation and their corresponding intensities. The plotted data showed the accident airplane flying into an area of level six precipitation at 12,000 feet msl, prior to a rapid loss of altitude. Level six precipitation returns are characterized as "Extreme" by the National Weather Service and are the highest intensity classification.

At 1359:09, the pilot transmitted, "707SH SOS I've got something wrong with the flight controls." At 1359:16, the ZAU Sparta controller responded, "707SH go ahead let me know what you need." At 1359:19, the sound of an open microphone was heard on the frequency for 12 seconds. At 1359:40, the pilot said, "Chicago center 707SH we are (going in I) can't maintain altitude. At 1359:53, the ZAU Sparta controller responded, "707SH roger there's no aircraft between you and the airport (unintelligible) for Grand Rapids. Grand Rapids is approximately twelve o'clock about 15 miles." There were no further contacts with N707SH.

At 1400:04, the ZAU Sparta radar associate controller contacted GRR approach to coordinate emergency information on N707SH. He informed GRR that the aircraft had been at 12,000 feet msl but appeared to have departed that altitude. At 1400:47, the ZAU Sparta radar associate told GRR, "... twenty to twenty five southwest of LAN looks like we've gone to a primary only it looks like he's right in the middle of that cell." The GRR controller was unable to assist ZAU Sparta sector in locating N707SH, but at 1402:02 he did report that he could see a weather cell at the location provided by ZAU Sparta sector for the aircraft.

The ZAU Sparta controllers contacted LAN approach, ZOB, and GRR approach and asked other aircraft in the area for assistance in locating or reestablishing contact with N707SH. At 1414:54, GRR approach advised the ZAU Sparta controller that the Eaton County police were investigating a report of an aircraft accident near Vermontville, Michigan. The wreckage site was subsequently located by the police and confirmed to be the accident airplane.

Transcripts of the voice communications and plots of the aircraft radar track data are included with the