Boeing 707-331 accident at New York International Airport, New York, 9 May 1960 (N-765TW)

Accident narrative

On May 9, 1960, at 2049 G.M.T., Trans World Airlines Flight 100, a Boeing 707-331 (N 765TW), crashed wheels-up at New York International Airport. The aircraft sustained major damage from contact with the runway and an ensuing fire. Eight of the 100 passengers received minor injuries during the evacuation. The crew of nine was uninjured.

### The flight

Flight 100 was a regular nonstop trip from Los Angeles, California, to New York, New York. The aircraft departed at 1606Z on an IFR flight plan to cruise at 31,000 feet. The takeoff weight of 270,470 pounds and the center of gravity were within limits.

Captain Harry E. Campbell had logged over 27,000 flying hours, with approximately 750 hours in the Boeing 707. First Officer Horace E. Nichols had 15,765 flying hours, including 867 in the 707.

In the New York area, the flight was descended for an instrument approach to runway 22L at Idlewild. Approach control established radar contact and vectored the flight to intercept the ILS localizer about three miles northeast of the outer marker. The flight was advised that the glide slope was inoperative. The tower reported the weather as a measured 400-foot variable broken ceiling, 700-foot overcast, visibility four miles in fog, and wind from the south at 15 knots.

### The approach

Captain Campbell testified that the approach was completely normal. He stated the aircraft was flown on the autopilot's localizer feature, maintaining a constant airspeed and a sink rate between 500 and 700 feet per minute. He testified that about two-thirds of the distance from the outer marker to the runway, the autopilot disengaged for unknown reasons. First Officer Nichols stated he saw the autopilot disengage warning light flashing and sensed a slight right turn.

Visual contact with the runway was established shortly after. The captain stated the aircraft was about 100 feet to the right of the runway, 500 to 1,000 feet from the threshold, at an altitude of approximately 400 feet. He dropped full flaps and maneuvered to line up with the runway.

About halfway down the runway, at an altitude he estimated as 50 feet or less, the captain decided to abandon the landing and go around. He advanced power to approximately 2.0 to 2.30 Engine Pressure Ratio (EPR) and commanded 30 degrees of flaps and gear up.

First Officer Nichols raised the flap handle and then the landing gear handle. He stated he did not know whether the aircraft was still descending when he raised the gear because he was checking indicators and not looking out of the cockpit. The landing gear warning horn sounded as the aircraft contacted the runway. The airplane settled and slid to a stop with all three landing gears retracted.

Fire warning signals sounded for engines 2 and 3. Flight Engineer Mark W. Outhwaite secured his panel in accordance with company procedures for anticipated crash landings, which included turning off the battery switch. This interrupted power to the D.C. bus, making it impossible to actuate the fire extinguishers. (TWA subsequently revised this checklist item to keep the fire extinguishing system powered).

During the evacuation, the left front emergency chute failed to inflate. The captain, first officer, and two passengers descended to the ground and held the chute secure for 25 to 30 people to exit. The right front chute inflated properly, and another 25 to 30 people used it. Two hostesses opened the right rear door, where passengers who had exited over the wing assisted others to the ground. Firefighting equipment arrived promptly and extinguished the engine fires.

### What the investigation found

The Board found no evidence of a failure or malfunction in the aircraft, its powerplants, or its systems. All four engines were capable of normal operation prior to the accident. Tower personnel testified that all runway and approach lighting systems were operating normally, contradicting the captain's suggestion that the approach lights were off.

The aircraft's flight recorder revealed an extremely erratic flightpath. The aircraft crossed the outer marker at about 1,200 feet, below the minimum authorized altitude of 1,500 feet. Airspeed was about 165 knots at the outer marker, increased to 170 knots, decreased to 141 knots at the middle marker, and fell to 128 knots at touchdown. The heading varied by almost 30 degrees during the approach. The descent rate fluctuated from 100 feet per minute to 1,200 feet per minute, followed by a gentle climb near the middle marker, and then a dive of at least 1,000 feet per minute until runway contact. The acceleration trace indicated slight turbulence during the approach and peak loads of 3.2 and 4.2 Gs at runway contact.

The Board concluded that heading and altitude changes of this magnitude indicated the aircraft was either flown by hand or controlled manually through the autopilot, demonstrating a lack of instrument proficiency. Furthermore, company regulations prohibited using the autopilot past the outer marker if any ILS component, such as the glide slope, was inoperative.

The Board concluded the instrument approach was improperly executed, causing the crew to establish visual contact too high and too close to the runway for a normal landing. From the positions described by the crew, a flightpath of 9 to 21 degrees would have been required to land at the threshold, compared to a normal glidepath of 2.5 to 3 degrees.

When the captain initiated the go-around halfway down the runway, his techniques were improper and contrary to company rules. A TWA spokesman testified that standard go-around procedures required advancing power to takeoff thrust, retracting flaps to 30 degrees, and retracting the landing gear only after a positive rate of climb was assured. Instead, the captain applied 2.0 to 2.30 EPR rather than the available takeoff thrust of 2.55 EPR, which would have minimized altitude loss. Additionally, he ordered the landing gear retracted before a positive rate of climb was established. The Board noted the first officer also failed to ensure the aircraft was climbing before moving the gear handle.

### Probable cause

The Board determined the probable cause of this accident was "a poorly conducted instrument approach necessitating a go-around which was initiated too late and improperly executed."