Chicago-Executive (Palwaukee)

On August 21, 2023, about 1315 central daylight time, an Israel Aircraft Industries 1125 Westwind Astra airplane, N39TT, sustained substantial damage when it was involved in an accident near Wheeling, Illinois. The pilot and co-pilot were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 positioning flight. According to the flight crew, they were cleared to land on runway 16 at Chicago Executive Airport, Wheeling, Illinois, and the airplane touched down within the touchdown zone. The pilot applied the brakes and deployed the thrust reversers. The pilot applied additional brake pressure and “found they were not grabbing.” The pilot released the brakes and reapplied brake pressure with no effect and advised the co-pilot he had no brakes. The co-pilot applied his brakes with no effect. The pilot selected the emergency brake handle and applied emergency braking. The pilot reported the emergency braking produced some slowing, and with the airplane’s nose wheel tiller, he attempted a right turn to exit the runway onto the 45° taxiway D, which he thought provided additional stopping distance. Due to the airplane’s energy and momentum, the airplane slid off the taxiway and into the adjacent grass. The airplane’s right main landing gear collapsed, and the airplane came to rest upright.

Before departure, the pilot performed fuel calculations and determined that he had enough fuel to fly to the intended destination. While enroute the pilot flew around thunderstorms. On arrival at his destination, the pilot executed the instrument landing system approach for runway 16. While on short final the right engine experienced a total loss of power. The pilot switched the fuel flow from the right tank to the left tank. The left engine then experienced a total loss of power and the pilot made an emergency landing on a road. The airplane received substantial damage to the wings and fuselage when it struck a tree. A postaccident examination revealed only a few gallons of unusable fuel in the left fuel tank. The right fuel tank was breached during the accident sequence but no fuel smell was noticed. The pilot performed another fuel calculation after the accident and determined that there were actually 170 gallons of fuel onboard, not 230 gallons like he originally figured. He reported no preaccident mechanical malfunctions that would have precluded normal operation and determined that he exhausted his entire fuel supply.

The airplane was dispatched on an emergency medical services flight. While being vectored for an instrument approach, the pilot declared an emergency and reported that the airplane was out of fuel. He said the airplane lost engine power and that he was heading toward the destination airport. The airplane descended through clouds and impacted trees and terrain short of its destination. No preimpact anomalies were found during a postaccident examination. The postaccident examination revealed about 1.5 ounces of a liquid consistent with avgas within the airplane fuel system. Based on the three previous flight legs and refueling receipts, postaccident calculations indicated that the airplane was consuming fuel at a higher rate than referenced in the airplane flight manual. Based on this consumption rate, the airplane did not have enough fuel to reach the destination airport; however, a 20-knot tailwind was predicted, so it is likely that the pilot was relying on this to help the airplane reach the airport. Regardless, he would have been flying with less than the 45-minute fuel reserve that is required for an instrument flight rules flight. The pilot failed to recognize and compensate for the airplane’s high fuel consumption rate during the accident flight. It is likely that had the pilot monitored the gauges and the consumption rate for the flight he would have determined that he did not have adequate fuel to complete the flight. Toxicology tests showed the pilot had tetrahydrocannabinol and tetrahydrocannabinol carboxylic acid (marijuana) in his system; however, the level of impairment could not be determined based on the information available. However, marijuana use can impair the ability to concentrate and maintain vigilance and can distort the perception of time and distance. As a professional pilot, the use of marijuana prior to the flight raises questions about the pilot’s decision-making. The investigation also identified several issues that were not causal to the accident but nevertheless raised concerns about the company’s operational control of the flight. The operator had instituted a fuel log, but it was not regularly monitored. The recovered load manifest showed the pilot had been on duty for more than 15 hours, which exceeded the maximum of 14 hours for a regularly assigned duty period per 14 Code of Federal Regulations Part 135. The operator stated that it was aware of the pilot’s two driving while under the influence of alcohol convictions, but the operator did not request a background report on the pilot before he was hired. Further, the operator did not list the pilot-rated passenger as a member of the flight crew, yet he had flown previous positioning legs on the dispatched EMS mission as the pilot-in-command.

The flight was scheduled to pick up cargo at the destination airport and then deliver it to another location. During the descent and 14 minutes before the accident, the airplane encountered a layer of moderate rime ice. The captain, who was the pilot flying, and the first officer, who was the monitoring pilot, made multiple statements which were consistent with their awareness and presence of airframe icing. After obtaining visual flight rules conditions, the flight crew canceled the instrument flight rules clearance and continued with a right, circling approach to the runway. While turning into the base leg of the traffic pattern, and 45 seconds prior to the accident, the captain called for full flaps and the engine power levers were adjusted several times between 50 and 95 percent. In addition, the captain inquired about the autopilot and fuel balance. In response, the first officer stated that he did not think that the spoilerons were working. Shortly thereafter, the first officer gave the command to add full engine power and the airplane impacted terrain. There was no evidence of flight crew impairment or fatigue in the final 30 minutes of the flight. The cockpit voice recorder showed multiple instances during the flight in which the airplane was below 10,000 feet mean sea level that the crew was engaged in discussions that were not consistent with a sterile cockpit environment, for example a lengthy discussion about Class B airspeeds, which may have led to a relaxed and casual cockpit atmosphere. In addition, the flight crew appears to have conducted checklists in a generally informal manner. As the flight was conducted by a Part 135 operator, it would be expected that both pilots were versed with the importance of sterile cockpit rules and the importance of adhering to procedures, including demonstrating checklist discipline. For approximately the last 24 seconds of flight, both pilots were likely focusing their attention on activities to identify and understand the reason for the airplane's roll handling difficulties, as noted by the captain's comment related to the fuel balance. These events, culminating in the first officer's urgent command to add full power, suggested that neither pilot detected the airplane's decaying energy state before it reached a critical level for the conditions it encountered. Light bulb filament examination revealed that aileron augmentation system and stall warning lights illuminated in the cockpit. No mechanical anomalies were found to substantiate a failure in the aileron augmentation system. No additional mechanical or system anomalies were noted with the airplane. A performance study, limited by available data, could not confirm the airplane's movements relative to an aileron augmentation system or spoileron problem. The level of airframe icing and its possible effect on the airplane at the time of the accident could not be determined.

The airplane was destroyed and the occupants fatally injured when it impacted the ground during approach to landing. Examination of the airplane, its engines and propellers, revealed no anomalies that were determined to have existed prior to impact. The propellers were found to have been in their normal operating range and neither propeller was in a feathered position. The quill shafts of both engines showed evidence of damage due to the production of torque. A sound spectrum examination of audio transmissions showed signatures that both engines were operating during the last two radio transmissions from the airplane. Based on radar data, communications and meteorological information obtained during the investigation, the airplane was operating in visual meteorological conditions below an overcast layer of clouds. The radar data showed the airplane as it approached the airport and as it entered a left hand traffic pattern for runway 34. Radio communications confirmed that the airplane had been cleared for a left hand traffic pattern to runway 34. The radar data showed the airplane as it made a turn to the left while its speed decreased to about 82 knots calibrated airspeed as of the last received radar return. This radar return was about 0.1 nautical miles from the accident site and 0.8 nautical miles and 216 degrees from the approach end of runway 34. The airplane owner's manual listed stall speeds ranging from 81 to 94 knots calibrated airspeed for airplane configurations including gear and flaps up to gear down and flaps 15 degrees, and bank angles from 0 to 40 degrees. Flap position could not be determined because the flap chain had separated from the flap drive motor. The owner's manual also listed an approach speed of 103 knots.

The twin-engine airplane sustained substantial damage when it impacted the top of a single story industrial building and then impacted a landscape embankment and trees during an attempted single-engine go-around. The pilot reported that the left engine failed during initial climb. He feathered the left propeller and returned to the airport to execute an emergency landing. The pilot reported that he had "excessive speed" on final approach and "overshot the runway." When the airplane was at mid-field, the pilot elected to do a go-around. He did not raise the landing gear and the flaps remained about 15-degrees down. The airplane lost altitude and impacted the terrain about .5 miles from the airport. A witness reported seeing the airplane attempt to land on the runway twice during the same approach, but ballooned both times before executing the go-around. The Pilot's Operating Handbook (POH) "Rate-of-Climb One Engine Inoperative" chart indicated that about a 450-foot rate-of-climb was possible during the single-engine go-around if the airplane was in a clean configuration. The chart also indicated that a 350-foot penalty would be subtracted from the rate-of-climb if the landing gear were in the DOWN position, and additionally, a 200-foot penalty would be subtracted from the rate-of-climb if the flaps were in the 15-degree DOWN position. Inspection of the left engine revealed that the starter adapter shaft gear had failed. Inspection of the engine maintenance logbooks revealed that the Teledyne Continental Motors Service Bulletin CSB94-4, and subsequent revisions including the Mandatory Service Bulletin MSB94- 4F, issued on July 5, 2005, had not been complied with since the last engine overhaul on July 17, 1998. The service bulletin required a visual inspection of the starter adapter every 400 hours. The engine logbook indicated that the engine had accumulated about 1,270 hours since the last overhaul. The service bulletin contained a WARNING that stated, "Compliance with this bulletin is required to prevent possible failure of the starter adapter shaft gear and/or crankshaft gear which can result in metal contamination and/or engine failure."

As the airplane was descending to the airport, the pilot-in-command (PIC) calculated that the required distance to land on a dry runway would be 2,720 feet. The second-in-command (SIC) stated to the PIC, "all right if I touch down and there's no brakes I'm going around." The ILS Runway 23 approach was in use, and the braking action was reported "poor" by a Hawker Jet, which had landed prior to the accident flight. All runway surfaces were covered with a thin layer of snow. The airplane touched down with about 2,233 feet of runway remaining, of the 5,101-foot long runway. The airplane departed the end of the runway, and proceeded into an overrun grassy area, where the nose landing gear assembly collapsed. The tower controller advised the flightcrew prior to landing that the wind conditions were from 330 degrees at 18 knots. According to the airplane's Pilot's Operating Manual, the estimated landing distance on a dry runway, for the conditions at the time of the accident, was about 2,750 feet. No charts were available in the FAA approved Airplane Flight Manual, to compute a landing distance incorporating a contaminated runway. Review of 14 CFR Part 25.1, which prescribed airworthiness standards for the issue of type certificates, and changes to those certificates, for transport category airplanes, revealed, "For landplanes and amphibians, the landing distance on land must be determined on a level, smooth, dry, hard-surfaced runway." There were no requirements for the applicant to determine landing distances on a wet or contaminated runway. The latest weather recorded at the airport, included winds from 330 degrees at 12 knots, gusts to 22 knots; visibility 3/4 statute mile, light snow; and overcast clouds at 300 feet.

The flight was executing a precautionary landing at the airport due to a reported fuel transfer problem. Witnesses described hearing engine variances and observed the aircraft roll and impact the ground nose first. There was a post crash fire mainly confined to the right wing area. Inspection of the flight control system, engines, and propellers did not reveal any preexisting anomalies with these systems. The left fuel selector and left fuel pumps passed functional tests. The right fuel selector and right fuel pumps could not be tested due to fire damage.

The flightcrew of a Gulfstream G-IV began taking off on Runway 34 with a crosswind from 280° at 24 knots. About 1,340 feet after the takeoff roll began, the airplane veered left 5.14° to a heading of 335°. It departed the runway, and tire marks indicated no braking action was applied. One of the pilots said, "Reverse," then one said, "No, no, no, go, go, go, go, go." The airplane traversed a shallow ditch that paralleled the runway, which resulted in separation of both main landing gear, the left and right flaps, and a piece of left aileron control cable from the airplane. The airplane became airborne after it encountered a small berm at the departure end of the runway. Reportedly, the left wing fuel tank exploded. The main wreckage was located about 6,650 feet from the start of the takeoff roll. Examination of the airplane indicated no preexisting anomalies of the engines, flight controls, or aircraft systems. The Nose Wheel Steering Select Control Switch was found in the "Handwheel Only" position, and not in the "Normal" position. The pilot-in-command (PIC) routinely flew with the switch in the "Normal" position. The PIC and copilot (pilot-not-flying) comprised a mix crew in accordance with an Interchange Agreement between two companies which operated G-IV's. The companies' operation manuals and the Interchange Agreement did not address mixed crews, procedural differences, or aircraft difference training.

High sink rate developed on short final. Acft touched down 13 feet prior to runway before sink rate could be arrested. Landing gear collapsed after contacting edge of runway which is 7 inches higher than surrounding terrain. Tail section of aircraft caught fire just prior to coming to a complete stop 2,900 feet down the runway. Pilots who frequently fly in and out of the airport stated, wind shifts near the runway are common in gusty conditions because of hilly terrain.