Knoepflein LANCAIR LEGACY 2000 N98SN

Summary

On 1 August 2004 at about 23:49 local time, a Knoepflein LANCAIR LEGACY 2000 registered N98SN was involved in an accident near Madison, Wisconsin, United States. One person was on board and one died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

1 August 2004 at 23:49

Classification

Accident

Location

Madison, Wisconsin, United States

Nearest airport

Dane County Regional (MSN)

Coordinates

43.1397, -89.3375

Aircraft

Knoepflein LANCAIR LEGACY 2000

Registration

N98SN

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Oshkosh → Lebanon

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

CHI04FA203

1 person died.

A loss of engine power due to high engine temperatures which resulted in a failure of the number three piston, the pilot's continued operation of the airplane with known high temperature problems, the pilot's poor inflight planning, and the pilot's failure to maintain a proper emergency descent rate. A factor associated with the accident was the light pole that the airplane contacted.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The amateur-built airplane was destroyed when it impacted a light pole and terrain during an off airport landing following a loss of engine power. The airplane was at an altitude of 8,000 feet mean sea level (msl), 15 miles southeast of the airport, when the pilot informed air traffic control (ATC) that he was having an engine problem and he needed to land. The controller cleared the airplane to land on either runway 32 or runway 21. The pilot told the controller, "Alright uh if you don't mind I'm going to circle around up here and uh see if I can iron out the problem and then uh I'll try to let you know what I need to do." Two minutes later, the controller informed the pilot that he was now eight miles from the airport. The pilot responded that he had the airport in site. The controller informed the pilot that runway 32 was the closest runway to his present position to which the pilot responded that he would enter a left base for runway 21. Nineteen seconds later, the pilot reported he was "really having problems" and he was going to land on runway 32. The pilot then stated that he was losing altitude "really bad" and he did not think he was going to make it to the airport. The airplane contacted a light pole and the terrain along a 4-lane divided roadway. The pilot was also the aircraft builder. He installed a supercharger system on the Continental IO-550 engine. Acquaintances of the pilot reported he told them he was experiencing problems with high oil temperatures and high cylinder head temperatures on the number one and number three cylinders. One acquaintance stated the pilot mentioned the problem approximately 10 months prior to the accident and others stated the pilot talked about the continuing problem on the day prior to the accident. Post accident inspection of the engine revealed a hole in the top of the engine case near the number two cylinder. An engine teardown revealed the engine had suffered internal heat and impact damage. Metal debris was found throughout the engine. All of the pistons and cylinders sustained heat and/or impact damage. The number three piston head was burned through along an approximate 60 degree arc around the circumference and down the side of the head past the rings The piston head was black in color. The piston rings were distorted and were out of their grooves. The airplane was equipped with an electronic flight instrument system (EFIS). The EFIS data showed the engine oil pressure was at its maximum of 69 pounds per square inch (psi) prior to takeoff and it decreased throughout the flight as the oil temperature increased. The data also indicated that after the pilot informed ATC of the engine problem, the airplane's rate of descent varied between 100 and 4,000 feet per minute.

Quoted verbatim from the NTSB record.