Interstate S-1B1 accident near Lititz, Pennsylvania, August 17, 2013
On August 17, 2013 at about 5:35 pm local time, a 1943 Interstate S-1B1, registered N46336, was substantially damaged in an accident during initial climb near Lititz, Pennsylvania (Lancaster Airport). It was an air show or air race flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot’s failure to control the airplane’s pitch attitude, which resulted in an aerodynamic stall during the initial takeoff climb. Contributing to the accident was the pilot’s failure to set the trim in accordance with the pretakeoff checklist and the airplane’s encounter with wake turbulence from a preceding airplane.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 17, 2013 · about 5:35 pm local time · cases in 2013
- Place
- Lititz, Pennsylvania · Lancaster Airport · cases near this airport · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Interstate S-1B1, built 1943 · all S-1B1s on the register
- Registration
- N46336 · registry record · serial 159
- Damage
- Substantial damage
- Flight
- Air show or air race flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The airplane departed as the fifth airplane in a formation of six airplanes during an airshow demonstration and was about 75 feet to the trailing right of the preceding airplane during the takeoff and initial climb. The pilot reported that, about 10 feet above ground level (agl), the airplane drifted right of the runway centerline and that he then realigned the airplane with the centerline. About 35 feet agl, he encountered "severe turbulence," and the airplane banked left uncontrollably. He attempted to regain control of the airplane; however, it stalled and subsequently impacted the ground in a nose-low attitude. A left crosswind of about 3 knots existed at the time of the accident. According to Advisory Circular 90-23F, "Aircraft Wake Turbulence," "a crosswind will decrease the lateral movement of the upwind vortex." Postaccident examination revealed that the pitch trim was set in an almost full nose-up position. The pilot likely did not comply with the before takeoff checklist and confirm that the trim setting was at 0 before takeoff. In addition, the airplane likely encountered wake turbulence from the preceding airplane. The pilot reported no mechanical malfunction or abnormality that would have precluded normal operation.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Turbulence encounter during initial climb
- Loss of control in flight during initial climb defining event
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Aircraft › Aircraft systems › Flight control system › Elevator tab control system › Incorrect use/operation other cases naming the flight controls
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Pitch control › Not attained/maintained
- cause Personnel issues › Action/decision › Action › Forgotten action/omission › Pilot
- cause Personnel issues › Task performance › Planning/preparation › (general) › Pilot
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- factor Environmental issues › Conditions/weather/phenomena › Turbulence › Wake turbulence › Awareness of condition
- factor Environmental issues › Conditions/weather/phenomena › Turbulence › Wake turbulence › Contributed to outcome
- factor Personnel issues › Task performance › Use of equip/info › Use of checklist › Pilot
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; instrument: airplane
- Flight time: 1,626 hours in all; 15 in this make and model; 39 in the last 90 days; 19 in the last 30 days; 1,558 as pilot in command
- Last flight review: June 22, 2013
- Medical certificate: Class 2
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 892 hours
- Last inspection: annual inspection, April 13, 2013
- Maximum gross weight: 1,650 lb
- Seats: 2
- Landing gear: fixed
- Engine: Franklin 4ACG199H3 (piston); 0 hours total
- Operator: Commemorative Air Force - Delaware Flying Wing
The flight
- Departed from: LNS Lititz PA at 5:35 pm
- Destination: LNS Lititz PA
- Flight plan: none
- Runway 13, 4,102 ft by 100 ft
Weather at the time
- Light: daylight
- Wind: from 070° at 4 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 79°F (26°C), dew point 54°F (12°C)
- Altimeter: 30.22 inHg
- Observation at 5:53 pm from LNS
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
9 documents, released by the NTSB on March 14, 2014. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Memorandum for Record: Telephone Interview with Pilot | PDF, 1 page | View Download |
| 3 | FAA Interview with Pilot | PDF, 2 pages | View Download |
| 4 | Memorandum for Record: Telephone Briefing by an FAA Inspector | PDF, 1 page | View Download |
| 5 | Lancaster Weather | PDF, 1 page | View Download |
| 6 | Most Recent Annual Inspection | PDF, 1 page | View Download |
| 7 | Memorandum for Record - Pilot Flight Operating Instructions [excerpts] | PDF, 1 page | View Download |
| 8 | Photo 1: Left Side of Airplane at Rest (Courtesy of the FAA) | PDF, 1 page | View Download |
| 9 | Photo 2: Elevator Trim Position as Found (Courtesy of the FAA) | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Connections how this case links to the rest of the register
- N46336 on the register today · the tail number may have moved to another aircraft since
- Interstate S-1 104 registered today · the model family and its accident history
- Interstate 107 aircraft on the register
- Engine: Franklin 4ACG199H3 6 aircraft carry this series today · as the NTSB recorded it
- Lancaster Airport · nearest airport
- Accidents and incidents in Pennsylvania 1,836 since 1982 · 235 in the last ten years
- Pennsylvania 6,188 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/ERA13LA366.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.