CEN16LA283

NTSB accident investigation · Bristell E-LSA · Oshkosh, WI · July 24, 2016

Accident · Serious injuriesLimited investigationFinal report
Date
July 24, 2016, 18:05 local (23:05 UTC)
Place
Oshkosh, WI
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N167BLBristell E-LSA
Defining event
Approach-VFR pattern final: Loss of control in flight
Weather
Visual (VMC) · Day
Status
Completed · report March 19, 2018
Report
Approved by Office Director
NTSB office
Central Region
Parties
FAA
FAA report
20160724006489A
Case key
93668

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The pilot’s exceedance of the airplane’s critical angle of attack on short final approach, which resulted in an inadvertent aerodynamic stall and subsequent loss of control. Contributing to the accident was the pilot’s distraction with other traffic in the area.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Performance/control parameters: angle of attackAircraft › Aircraft oper/perf/capability · Not attained/maintainedBRM Aero S R O BRISTELL E-LSA: 1 caseAll aircraft: 990 casesProbable cause
Performance/control parameters: airspeedAircraft › Aircraft oper/perf/capability · Not attained/maintainedBRM Aero S R O BRISTELL E-LSA: 1 caseAll aircraft: 1,681 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The accident airplane was the trailing airplane in a flight of two landing on runway 36L at Experimental Aircraft Association AirVenture when the accident occurred. The pilot reported that, while on final approach, he heard an air traffic control transmission telling a canard airplane to land on runway 36R. Mistaking the transmission for 36L, the pilot stated that he began to look for the canard airplane, which diverted his attention from the lead airplane and resulted in a loss of separation. As he approached the lead airplane's right wing, he reduced the engine power and pitched up to slow his airplane. He stated his airplane banked "hard to the right;" he corrected by banking to the left, which, combined with the airplane's nose-high pitch attitude, resulted in an aerodynamic stall. Although the pilot stated that he was directly behind and below the lead airplane, and encountered the airplane's wake turbulence and prop wash, a GoPro camera mounted on the left wing of the accident airplane showed that the airplane remained behind and above the lead airplane; therefore, it is unlikely that the accident airplane encountered wake turbulence. The GoPro footage was consistent with the accident airplane slowing then subsequently experiencing an aerodynamic stall. It is likely that the pilot slowed the airplane excessively as he attempted to maintain separation and exceeded the airplane's critical angle of attack.

Factual narrative

On July 24, 2016, at 1805 central daylight time, a BRM Aero S R O, Bristell E-LSA, collided with the terrain following a loss of control while landing at the Wittman Regional Airport (OSH), Oshkosh, Wisconsin. The pilot received serious injuries. The airplane was substantially damaged. The aircraft was registered to Sport Flying USA, Inc., and was operated by an individual under the provisions of 14 Code of Federal Regulations Part 91 as a business flight. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The last leg of the cross country flight originated from the Watertown Municipal Airport (RYV), Watertown, Wisconsin, at 1630.The airplane was the trailing airplane in a flight of two that were landing on runway 36L at OSH during Experimental Aircraft Association AirVenture. The pilot in the lead aircraft stated they were cleared to land on the purple dot. The purple dot was located 3,052 ft down the 8,002 ft long runway. He did not see the accident occur. The accident pilot stated he turned onto final approach for runway 36L, and was established with 20 ° of flaps at 65 knots. He then heard an air traffic transmission telling a canard airplane to land on runway 36R not 36L. The pilot stated he began to look for the canard airplane which took his attention off the lead airplane resulting in a decrease of the separation between the airplanes. He stated he got within 10 ft of the lead airplane's right wing at which time he reduced the engine power and pitched up to slow his airspeed. The pilot stated that was then directly behind the lead airplane and below his altitude, when he encountered the lead airplane's wake turbulence and prop wash, and his airplane banked "hard to the right". He corrected by banking to the left, but must have had back pressure on the stick and the airplane stalled. The pilot stated he was about 150 ft above the ground when the loss of control initially occurred. Witnesses reported the airplane was low and slow as it approached the runway. They stated it stalled, rolled left, and descended to impact with the terrain. A GoPro camera was located amongst the wreckage. The 128GB Micro SD card was retrieved from the camera and downloaded by the National Transportation Safety Board (NTSB) Vehicle Recorder Laboratory. It was determined that the camera was mounted on the left wing. A summary of the video was prepared and is attached to this report. The lead airplane was visible in front of the accident airplane as they approached the airport. At one point while the airplanes were descending and approaching the airport, the accident airplane was about the same altitude as the lead airplane. Both airplanes then made a left turn [onto base leg] at which time at least two other airplanes were visible in the distance ahead of the lead airplane. At this point the lead airplane was below the altitude of the accident airplane. Both airplanes then made another left turn onto finalapproach. About 27 seconds after the accident airplane was established on final approach, the distance between the accident airplane and the lead airplane began to reduce. Other than the lead airplane, no other flying airplanes were visible on approach to either runways 36L or 36R. The distance between the two airplanes continued to reduce. The lead airplane was at or below the attitude of the accident airplane until the accident airplane entered a left bank and began to descend. The left bank continued to increase such that the airplane was nearly inverted as it descended to ground impact. The air traffic control audio recording was reviewed by the NTSB Investigator-in-Charge. At 03:00 [lapsed recording time, minutes (MM): seconds (SS)], the controller cleared a canard airplane to land on runway 36L. About 31 seconds later, the controller changed the canard's landing runway to 36R. At 04:04, a second canard pilot requested landing on runway 36R and 14 seconds later, it was cleared to land on runway 36R. About 15 seconds later, the controller cleared the accident airplane and his lead airplane to land on runway 36L. At 04:42, the controller instructed the canard airplanes to keep rolling to the end of the runway. At 05:00, the accident is announced over the radio. A damaged SD card from a Garmin GPS was also retrieved from the wreckage and sent to the NTSB Vehicle Recorder Laboratory. The card was cracked through its memory chip which prevented data recovery from the card.

Aircraft

Registration
N167BL
Reported as
Bristell E-LSA
Category
Airplane
Serial number
167-2015
Airframe hours
35
Engine
Rotax 912 IS, 100 horsepower, reciprocating
Damage
Substantial damage
Flight
Business · Part 91
Operator
Sport Flying USA, Inc.
Registered owner
Sport Flying USA, Inc.
Airworthiness certificate
Special, Experimental light sport (Special)
Last inspection
Condition · July 22, 2016
Departed
RYV · Watertown, WI
Destination
OSH · Oshkosh, WI
Airport
OSH · Witmann Regional Airport, runway 36L, 8,002 × 150 ft, concrete
Equipment
Angle of attack indicator, ADS-B, Stall warning system, Onboard weather, Electronic primary flight display, Electronic multifunction display, Electronic flight bag or handheld device, Auto-pilot

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
39
Injuries
Serious
Certificate
Sport Pilot
Airplane ratings
Single-engine land
Medical
Sport pilot
Seat
Left
Restraint
4-point
Flight hours
361 total · 150 in this make and model · 314 as pilot in command · 50 in the last 90 days · 24 in the last 30 days · 5 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
290° at 9 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
88 °F, dew point 73 °F
Altimeter
29.81 inHg
Observed at
OSH

Docket · 7

The files NTSB released with the investigation on December 5, 2017, on NTSB’s docket system: statements, records, photos and specialists’ reports. 2.1 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.