CHI01FA312

The airplane impacted terrain after striking trees and a power line in a residential area during initial climb from runway 27. Recorded wind data from two weather observation stations reported winds from 170 degrees at 14 knots gusting 17 knots and 200 degrees at 16 knots gusting 22 knots. The pilot used a power setting of 35 inches of manifold pressure and a flap setting of 10 degrees for the takeoff configuration. The only takeoff configurations cited in the pilot's operating handbook and checklists are with the use of 36 inches of manifold pressure and a flap setting of either 0 or 25 degrees. There is no performance data within the pilot's operating handbook for flight configurations using 10 degrees of flaps. A review of the airplane's weight and balance forms found a discrepancy in the empty weight values. The airplane's weight and balance forms were reviewed and Safety Board calculations indicated that the airplane had an empty weight of 2,357.57 pounds and a center of gravity of 79.9 inches, compared to an empty weight of 2,261.67 pounds and a CG of 83.3 inches listed in the latest revision forms. The pilot reported using a basic empty weight of 2,304 pounds and a CG of 83.3 inches in his weight and balance calculations. The Safety Board calculated the weight and CG location for the accident flight as 3,490 pounds and 87 inches, respectively. The forward CG range for the accident airplane's weight was between 89 inches and 95 inches. Information about the effects of CG location and wind velocity on takeoff performance is available to pilots from the Federal Aviation Administration and commercial publications. Postaccident examination of the engine found evidence of some spark plug fouling, and camshaft and lifter body wear, although the negative effect of this wear on engine performance is not known because the proper short field takeoff procedures were not followed. The airplane's engine logs did not specify whether oil filters were inspected for metal debris during oil and filter changes.

On September 7, 2001, at 1153 central daylight time, a Piper PA-32R-301T, N81557, owned and piloted by a private pilot, was destroyed on impact with terrain during initial climb from runway 27 (2,800 feet by 40 feet, asphalt) at the Brookridge Air Park Airport (LL22), Downers Grove, Illinois. The airplane impacted terrain in a residential neighborhood following an in-flight collision with trees and a power line. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan but had filed an instrument flight rules flight plan. The pilot and two passengers received serious injuries, one passenger was uninjured, and there were no ground injuries. The flight originated from LL22 en route to Mackinac Island, Michigan.

The pilot reported the following in a written statement, "...I completed the balance of the Ground Check Check List and the Before Take Off Check List then set the Altimeter at 750 ft. MSL and set the flaps at 10 degrees. Prior to takeoff, the wind sock at the East end of the runaway was out of the varying out of the South at 10-15 knots. I looked at the windsock at the West end of the runway and could not tell if it was true out of the South, so I taxied to the West end to observe the windsock. A couple of houses to the East on the North side of the runway there was an American Flag above a garage and it looked like the wind was slightly out of the South Southwest. I taxied back to the East end of the field and prepared to use runway 27."

"At approximately 11:30 am, announced my departure on Runway 27 on 122.9. I then taxied on to the runway, held the brakes until the engine reached 35 inches of Manifold. I released the brakes, approximately half was down the runway, reached 70 KMH and rotated."

"I began to climb, a few seconds after lift off, the stall warning came on, I lowered the nose to gain more air speed and retracted the landing gear. I was able to climb above the trees. I turned to the Southwest thinking that above the trees I would get more lift from the wind and again lowered the nose trying to gain airspeed. After a few seconds the plane began to sink and I announced to the passengers that we were going down. I then concentrated on keeping the wings level as we descended."

"...Just after take off I flew over [a resident's] house to the South East and he observed the windsock, which is 100 yards from his kitchen, to be out of the Northeast. This was a 180 degree wind shift from what I had observed prior to takeoff."

According to a police report, "...[The witness] stated that he was in his back yard working in his garden when he heard a 'very very low plane'. [The witness] said that he heard the plane's engine and it appeared to be working normally. [The witness] viewed the plane overhead banking hard to the left. The plane then hit a large pine tree in his front yard, it continued into the power lines. [The witness] heard a large boom when he plane crashed into the ground across the street..."

During a postaccident interview with the National Transportation Safety Board and the Federal Aviation Administration (FAA), the pilot stated that the maximum altitude he attained during climbout was approximately 80 feet agl and his use of 10 degrees of flaps was described as something that he began on his own. He did not weigh the baggage that was on the airplane and he did not perform performance calculations for the accident flight. He added that he used 35 inches of manifold pressure so as not to overboost the engine.

The pilot reported using the following weights in his weight and balance calculations:

Basic empty weight: 2,304 lbs

Center of gravity: 83 inches

Pilot and front passenger: 335 lbs

Rear passengers: 310 lbs

Front baggage: 50 lbs

Rear baggage: 75 lbs

Fuel: 61 gallons or 366 lbs

The recovered baggage was weighed by the local law enforcement's forensic unit who reported it to weigh 172 lbs. The pilot stated during an initial interview with the FAA that there was 100 lbs of baggage on board the airplane. The pilot attributed the difference in weight due to water that was used by the fire department. A portable oxygen tank, which had a weight of 13 lbs, was mounted between the aft facing seats of the airplane. The pilot stated that the oxygen tank came with the airplane, and he thought that its weight was included in the airplane's basic empty weight. The oxygen tank was not included as an item in any of the aircraft weight and balance forms.

The airplane's weight and balance forms found in the airplane's POH are included in this report. They begin with the airplane's licensure on January 22, 1980 and include 7 revisions with the latest revision being dated October 25, 1994. The latest revision lists a basic empty weight of 2,261.67 lbs and a center of gravity (CG) of 83.3 inches. The pilot determined, through the use of a graphical plotter and calculations, a weight of 3,455 lbs with an approximate CG location of 89.9 inches for the accident flight.

The CG limits, with a straight line variation between points, for the airplane are:

weight forward limit rearward limit

3,600 lbs 91.4 95.0

3,200 lbs 82.75 95.0

2,400 lbs 78.0 95.0

One of the effects of CG location is described in AC 61-21A as, "...The airplane will cruise faster with an aft CG location because of reduced drag. The drag is reduced because a smaller angle of attack and less downward deflection of the stabilizer are required to support the airplane and overcome the nose-down pitching moment."

The POH stipulates the use of 0 degrees of flaps, full power and a rotation speed of 70-80 KIAS for a "normal takeoff". The liftoff speeds for a maximum effort takeoff using 0 degrees of flaps are listed for the following weights in the performance charts included in the POH, which are:

3,600 lbs 66 KIAS

3,200 lbs 64 KIAS

2,800 lbs 62 KIAS

The rotation speed for a short or soft field takeoff, obstacle clearance takeoff is 59-62 KIAS which is then followed by accelerating to 65-68 KIAS after breaking ground. The lift off speeds for a 25 degree flap takeoff as:

3,600 lbs 62 KIAS

3,200 lbs 61 KIAS

2,800 lbs 59 KIAS

The POH does not include performance charts for a 10 degree flap takeoff. Federal Aviation Regulation (FAR) 91.03, Preflight action, states, "Each pilot in command shall, before beginning a flight, become familiar with all available information concerning that flight. This information must include...(b) For any flight, runway lengths at airports of intended use, and the following takeoff and landing distance information: (1) For civil aircraft for which an approved Airplane Flight Manual or Rotorcraft Flight Manual containing takeoff and landing distance data is required, the takeoff and landing distance data contained therein..."

The power setting for all takeoff configurations listed in the POH cite a propeller speed of 2,700 rpm and a manifold pressure of 36 inches before brake release on a paved, level, dry runway.

Factors that affect takeoff performance listed in Flight Theory for Pilots are: aircraft gross weight, thrust on the aircraft, temperature, pressure altitude, wind direction and velocity, runway slope, and runway surface. The effect of weight change has a threefold effect on takeoff performance: (1) takeoff velocity is increased, (2) there is more mass to accelerate and, (3) there is more rolling friction. The coefficient of rolling friction is about 0.03 (an increase in weight of 1,000 lbs. means a loss in accelerating force of 30 lbs). If rolling friction is ignored the effect of weight change to takeoff distance can be derived from the following equation:

w1: original weight

w2: new weight

s1: original takeoff distance

exp: exponent

*: multiplication

/: division

s2=s1*[(w2/w1)exp2]

The effect of runwa