# NTSB NYC94FA065: Piper Aerostar 601P, N36444, Limerick, PA, March 18, 1994 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: March 18, 1994, 11:26 local (16:26 UTC) - Place: Limerick, PA - Coordinates: 40.179527, -75.529228 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.1795&lon=-75.5292&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 2 fatal, 1 serious - Status: Completed, report August 1, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 38669 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC94FA065 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/38669/pdf - Page: https://openairdocs.org/ntsb/NYC94FA065 ## Probable cause THE PILOT'S FAILURE TO ENSURE THAT ICE WAS PROPERLY REMOVED FROM THE AIRPLANE BEFORE FLIGHT, POSSIBLY DUE TO IMPAIRMENT OF JUDGMENT CAUSED BY A PRESCRIPTION DRUG (VALIUM) THAT WAS NOT APPROVED FOR USE WHILE FLYING. FACTORS RELATED TO THE ACCIDENT WERE: THE PILOT'S FAILURE TO PROPERLY REPORT HIS MEDICAL HISTORY ON HIS FAA MEDICAL APPLICATION, AND FAILURE OF THE DESIGNATED MEDICAL EXAMINER TO REPORT THE PILOT'S KNOWN MEDICAL HISTORY. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, takeoff - initial climb - weather condition - snow - weather condition - icing conditions - airframe - ice (cause) - ice/frost removal from aircraft - not performed, pilot in command (cause) - stall/mush - uncontrolled, pilot in command - impairment(drugs), pilot in command (cause) - information insufficient, pilot in command (contributing factor) - information insufficient, designated examiner (contributing factor) - In flight collision with terrain/water, descent - uncontrolled ## Analysis AT 0815 EDT, N36444 LANDED WITH LIGHT SNOW FALLING & THE TEMPERATURE ABOVE FREEZING. SNOW CONTINUED FALLING & THE TEMPERATURE DROPPED BELOW FREEZING. AT ABOUT 1100, THE PILOT FILED AN IFR FLIGHT PLAN & HAD A LINEMAN BRUSH SNOW FROM THE WINGS. THE LINEMAN NOTED THAT PATCHES OF ICE REMAINED ON THE LEFT WING, BUT THE PILOT DECLINED TO DEICE THE PLANE. (AT AN AIRPORT 3 MILES AWAY, ANOTHER FLIGHT WAS DELAYED DUE TO ICE THAT HAD FORMED BELOW A SNOW COVER ON A PLANE THAT SAT OUTSIDE FROM 0945 TO 1100.) THE SURVIVING PASSENGER SAID THAT AFTER TAKEOFF, N36444 LOST LIFT & YAWED LEFT. IT APPEARED TO RECOVER, THEN VIBRATED, YAWED, BANKED LEFT, DESCENDED, & IMPACTED THE GROUND. AFTER THE ACCIDENT, THE ENGINES WERE TEST RUN WITH NO NOTABLE DEFICIENCIES. THERE WAS EVIDENCE THE PILOT WAS TAKING PRESCRIPTION MEDICATION. TESTS OF HIS BLOOD SHOWED 0.157 UG/ML OF DIAZEPAM & 0.134 UG/ML OF NORDIAZEPAM. TESTS OF HIS URINE SHOWED 0.152 UG/ML OF NORDIAZEPAM & 0.167 UG/ML OF OXAZEPAM. ON 3/2/90, THE PILOT HAD SURGERY FOR A TUMOR OF (OR NEAR) THE LEFT OPTIC NERVE. IN HIS LAST FAA MEDICAL APPLICATION, HE DENIED THAT HE HAD MEDICAL TREATMENT IN THE PREVIOUS 5 YEARS & DID NOT REPORT USE OF ANY MEDICATIONS. THE AVIATION MEDICAL EXAMINER HAD PRESCRIBED RESERPINE (FOR HYPERTENSION) & WAS AWARE OF THE SURGERY, BUT THIS WAS NOT REPORTED IN THE PILOT'S FAA MEDICAL RECORD. ## Factual narrative HISTORY OF FLIGHT On March 18, 1994, about 1126 eastern standard time, an Aerostar 601P, N36444, owned by K&L Micro-Wave Electronics and piloted by Frederick G. Erb, was destroyed when it struck the ground during initial climb-out, about 1 mile from the Pottstown- Limerick Airport (PTW), Pottstown, Pennsylvania. The pilot and one passenger were fatally injured and a second passenger received serious injuries. An instrument flight plan had been filed for the flight operating under 14 CFR 91. The airplane was based at the Salisbury (SBY) Airport, Salisbury, Maryland. The pilot and two passengers were employed by the same company and the flight originated that morning from SBY. The airplane arrived at PTW about 0815. Upon arrival at PTW, the passengers confirmed the expected departure time from PTW was 1100, and then departed by ground vehicle for their scheduled business meeting. According to personnel at the airport, the pilot met with local friends at the airport. At 1040, Mr. Erb telephoned the Salisbury Flight Service Station (FSS). He requested an abbreviated briefing for an instrument flight from PTW to the South Jersey Regional Airport (7MY), Mount Holly, New Jersey. Mr. Erb was given the weather requested, which included an AIRMET for icing. He did not file a flight plan at that time. The passengers arrived back at PTW at 1055. The pilot advised the passengers that due to weather, it would be "safer" to fly back to SBY and not make the planned stop at 7MY. The passengers agreed that the stop at 7MY was not essential. At 1100, Mr. Erb called the Salisbury FSS. He stated that the weather was worse than he expected and filed an instrument flight plan from PTW to SBY, with a proposed off time of 1100. After filing the flight plan, the pilot escorted the passengers to the airplane. When the passengers and cargo were secured in the airplane, the pilot returned to the hanger where he returned with a line service person (lineman) and a broom. According to the lineman, the pilot entered the hanger and asked him to clean snow off of the wings of the airplane. The pilot and lineman returned to the airplane where the pilot observed the lineman remove some of the snow with a broom and then told the lineman, "I'll get in and get setup till you finish." In a telephone interview on March 19, 1994, the lineman stated that he had swept the right wing and nacelle clean of snow without a problem. He then swept the left nacelle clean, but the left wing had little patches of ice on it. He pointed at it to the pilot who was at the controls. He offered to pull the aircraft into the hanger, but the pilot stated no, it was "OK." In his written statement submitted on March 31, 1994, the lineman stated: "...I finished up [brushing the snow] and he looked out. I pointed to the wing, he shook his head, I stepped back and he started the engines...I observed a little flaky ice on [the] right wing, [the] left wing was clear. He did not ask me to clean anything else. I observed him working the controls systems and [they] seemed to work OK...I just glanced up when he took off and saw his nose gear lift off (2000 - 2500 feet)...Saw him at end of runway very low, then he disappeared into the snow." The surviving passenger stated that he had flown in this airplane on several occasions. In his written statement he stated: "...The man with the broom began to remove the snow off the wings. The amount of snow was about 1/4 to 1/2 inch. I did not see any ice nor did I pay attention to how much snow remained ...The time from when the snow had been removed, taxing to the runway, and clearance for takeoff was approximately 5 to 10 minutes...the takeoff was normal...Shortly after takeoff we lost the lift in the plane, and twisted very slightly to the left, maybe 5 to 10 degrees...I don't think we lost any altitude, but just stopped gaining altitude. Fred did some adjustments...we started to ascend again after a few seconds...Once Fred regained lift, roughly 30 seconds later, the plane did the same thing as before but more drastic. What I mean...is...the plane began losing altitude and twisted to the left more. The twist was 45 degrees or more this time with an abnormal vibration...I saw power lines through the front windows...I saw ...a field below us and the plane falling while it twisted. I can't say if we were turning hard to make the field or just twisting..." A witness driving by on a highway, 1/4 mile from the departure end of the runway, observed the airplane fly overhead. He stated: "...I would say the plane was roughly around 100 feet, heading down, banking towards its left (about 20 to 30 degrees roughly banking). Noticed no landing gear...Engine noise was extremely loud...Losing altitude fast. Weather condition was rain and snow mixed, icy patches forming on road. In the police report, a witness on the ground at the accident site stated: "He saw the plane over the trees. It was very low. [He] didn't hear anything out of the ordinary. Next, he saw the plane drop (as if pushed downward). Then, the left wing tilted downward. 'He hit and skidded (to point of rest)'." The accident occurred during the hours of daylight at approximately 40 degrees, 14 minutes north latitude, and 75 degrees, 20 minutes west longitude. PERSONNEL INFORMATION The pilot, Mr. Frederick G. Erb, held an Airline Transport Pilot Certificate with ratings for airplane multiengine land, a Commercial Pilot Certificate for airplane single engine land and glider, and a Flight Instructor Certificate with ratings for airplane single and multiengine land, and instrument airplane. His most recent Federal Aviation Administration (FAA) First Class Medical Certificate was issue on November 15, 1993. Mr. Erb's total flight time was estimated to be 19,950 hours. He had logged about 7,500 hours in Aerostars. METEOROLOGICAL INFORMATION The following weather reports and forecasts were available to the pilot of N36444, by the SBY FSS at the 1040 briefing: Philadelphia (PHL), 15 miles west of 7MY - Record Special 0951 EDT, Ceiling measured 1,700 broken, 3,500 overcast, visibility 2 1/2 miles, light snow, temperature 35 degrees fahrenheit (F), and winds from 270 degrees at 6 knots. PHL Forecast: Until 1300 EDT, 4,000 overcast, visibility 3 miles, light snow, occasionally 1,500 overcast, visibility 1 1/2 miles, light snow and fog. After 1300 until 1500 EDT, 2,500 overcast, 3 miles, light snow, occasionally 1,000 overcast, 1 mile visibility, light rain, light snow and fog, with a chance of 300 sky obscured, 1/2 mile visibility and snow. North Philadelphia (PNE), 11 miles north west of 7MY - Record 0950 EDT, Ceiling estimated 12,000 overcast, visibility 12 miles, temperature 34 degrees F, and winds from 210 degrees at 5 knots. PNE Forecast: From 1100 until 1300 EDT, 4,000 overcast, occasionally 2,500 overcast, visibility 3 miles, light snow. After 1300 until 1500 EDT, 2,500 overcast, 3 miles, light snow, occasionally 1,000 overcast, 1 mile visibility, light rain, light snow and fog, with a chance of 300 sky obscured, 1/2 mile visibility and snow. Salisbury (SBY), Record 0948 EDT, Ceiling estimated 7,000 overcast, visibility 10 miles, temperature 37 degrees F, and winds from 160 degrees at 10 knots. SBY Forecast: Until 1300 EDT, 25,000 thin broken. After 1300 until 1500 EDT, 3,500 scattered, 7,000 overcast, with winds from 220 degrees at 12 knots, gusting to 22 knots, occasionally 3,500 overcast, 3 miles visibility, light rain and fog. The following weather reports were for the indicated periods near the time of the accident: Navy Willow Grove (NXX): 1200 EDT, indefinite ceiling 500 obscured, 1/2 mile visibility, light snow and fog, temperature 31 degrees F, winds from 190 degrees at 5 knots. ## Aircraft - Registration: [N36444](https://openairdocs.org/deregistered/N36444-1996-02-16), registration cancelled 1996-02-16, S/N 61P08438163444 (OpenAirDocs) - Reported make and model: PIPER AEROSTAR 601P (AEROSTAR 6) - Registry model: [Piper AEROSTAR 601P](https://openairdocs.org/model/piper-aerostar-601p) (registry code 7106012) (OpenAirDocs) - Category: Airplane - Serial number: P08438163444 - Airframe hours: 4356 - Engines: LYCOMING IO-540-S1A5 290 horsepower reciprocating - Damage: Destroyed - Flight: Executive/Corporate, Part 91 - Registered owner: K & L Microwave Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 28, 1993, 257 hours before - Departed: PTW, POTTSTOWN, PA - Destination: SBY, SALISBURY, MD - Flight plan: IFR - Airport: PTW, Pottstown-Limerick, runway 28, 3,371 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; commercial, airline transport, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 19,950 total, 7,500 in this make and model, 19,150 as pilot in command, 100 in the last 90 days, 30 in the last 30 days ## Weather - Conditions: Instrument (IMC), Day - Wind: 190° at 5 knots - Visibility: 0.5 statute miles - Lowest ceiling: 500 ft - Temperature: 30 °F, dew point 28 °F - Altimeter: 29.00 inHg - Observed at: NXX, 20 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19940318005849A](https://openairdocs.org/incident/19940318005849A), Mar 18, 1994: Piper PA60601P, Pottstown, PA, Destroyed, 2 fatal. Lost control on climbout. Impacted left wing low and cartwheeled. Ice on airframe. Using medical impairing drugs. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.