LAX94FA073

A Beech liner, Boeing 757 & israel westwind (ww) were vectored for landings on rwy 19R. The 757 & ww were sequenced for visual apchs behind the Beech. Before being cleared for visual apch, the ww was closing 3.5 mi from the 757 on a converging course. The 757 & ww crews were told to slow to 150 KTS. The 757 slowed below 150 KTS & was high on final approach with a 5.6 deg descent. The ww continued to converge to about 2.1 mi behind the 757 on a 3 deg apch. ATC did not specifically advise, and was not required by ATC handbook to advise, the ww pilots that they were behind a Boeing 757. Capt discussed possible wake turbulence, flew ILS 1 dot high, noted closeness to the 757 & indicated there should be no problem. While descending thru aprx 1100 ft MSL, the ww encountered wake turbulence from the 757, rolled into a steep descent & crashed. The crew lacked specific wake turbulence training. Chlorpheniramine (common over-the-counter anti-histamine; not approved for flying) detected in pilot's lung tissue (0.094 ug/ml). (See spcl study NTSB/SIR-94/01)

History of the Flight

On December 15, 1993, at 1733 hours Pacific standard time, an Israel Aircraft Industries 1124A, N309CK, experienced an in-flight loss of control and crashed about 3.5 nautical miles north of John Wayne Airport (SNA), Santa Ana, California. The airplane was on the final approach course for runway 19R. The pilot initially obtained an instrument flight rules (IFR) clearance, but was executing a visual approach at the time of the accident. The flight was an on-demand air taxi passenger operation under the provisions of Title 14 CFR Part 135 and was completing the final leg of a multileg passenger revenue operation.

The airplane, registered to Management Activities, Inc., Long Beach, California, and operated by Martin Aviation, Santa Ana, California, was destroyed by impact and the resulting postimpact fire. Both flight crewmembers and three passengers sustained fatal injuries; there were no ground injuries. Visual meteorological conditions prevailed. The Federal Aviation Administration's (FAA) various air traffic control tower records disclosed the airplane departed Long Beach Airport, Long Beach, California, on December 15, 1993, at 0700 hours to begin the multileg operation. The last flight leg departed Brackett Airport, La Verne, California, at 1713 hours.

National Transportation Safety Board investigators reviewed the recorded radio communications between N309CK, Coast terminal radar approach control (TRACON), and the John Wayne Airport air traffic control tower (ATCT). The review revealed that before departing Brackett Airport the flightcrew requested and received a local tower en route IFR clearance to John Wayne Airport.

After departing Brackett Airport, the flight contacted the FAA, Ontario [California] TRACON and received radar vectors toward John Wayne Airport. At 1728 hours, the Ontario TRACON sector controller instructed the flight to contact Coast TRACON.

According to the cockpit voice recorder (CVR), at 1727:41 hours, the first officer received the automated terminal information service (ATIS) "zulu." [The times noted for the CVR information differ from the FAA ATC communications transcripts; the CVR information was adjusted in this report to match the ATC transcripts.] At 1728:34 hours, the flight contacted the Coast TRACON Tustin Radar sector controller and reported "...climbing to four thousand..." [feet - all altitudes in this report are mean sea level altitudes]. The sector controller instructed the flight to reduce its speed to 170 knots; the flight's first officer acknowledged the clearance. The cockpit voice recorder established that the first officer made all the transmissions to the sector controller.

The sector controller had previously instructed a preceding airplane, also landing at John Wayne Airport, to reduce its speed to 170 knots. This aircraft was United Airlines flight 103 (UAL 103), a Boeing 757-200. The Tustin Radar computer data readout (CDR) showed that N309CK was at 3,700 feet.

At 1729:09 hours, the first officer contacted Martin Aviation and informed the dispatcher that the flight would be landing within ten minutes and would need fuel. At 1730:05 hours, the sector controller instructed the flight to turn to a 100-degree heading (all headings/bearings in this report are oriented toward magnetic north). He then stated, "westwind nine charlie kilo [is] following a united boeing jet on base [leg at] two o'clock four miles southeast bound [at] four thousand [feet] descending." The first officer responded, "in sight charlie kilo."

At 1730:12 hours, the sector controller instructed N309CK to "...follow that traffic cleared visual approach runway one niner right reduce speed to follow he's [UAL 103] slowing through a hundred and seventy [knots]." The first officer acknowledged the clearance and the traffic [UAL 103]. The sector controller then instructed UAL 103, "...cleared visual approach runway one niner right reduce speed to one five zero and contact the tower...." UAL 103 responded that the flight was below 150 knots. The CDR showed that N309CK was at 3,900 feet, and about 3.8 nautical miles to the left (north) of UAL 103 which was at 3,800 feet.

At 1730:26 hours, the first officer then told the captain "...eh he's pretty close...." The captain responded, "...okay I'm ah lets go flaps twelve." The CDR showed that at this time N309CK was at 3,900 feet and about 3.3 nautical miles to the left (north) of UAL 103 which was now about 3,700 feet.

The first officer then pointed out UAL 103 to the captain. The captain responded, "...I got him - okay we can do it...no problem." At 1730:42 hours, the sector controller advised N309CK that "...traffic you're following is at a hundred and fifty knots you can s-turn as necessary to follow that traffic contact john wayne tower...." At 1730:49 hours, the first officer responded, "ok we'll slow it up and do what we have to...."

Meanwhile, at 1730:47 hours, UAL 103 contacted the John Wayne ATCT local controller and reported "...turning final abeam lemon." At 1731:01 hours, N309CK contacted the local controller and reported, "...on a visual behind the ah i believe it's united ...." The CVR indicated a sound similar to the landing gear being lowered. The local controller responded, "westwind three zero nine charlie kilo john wayne tower number three behind the united he's indicating thirty knots slower." The first officer responded, "ok we're slowing ah three zero nine charlie kilo." The CDR now indicated that N309CK was at 3,700 feet and about 2.2 miles behind or north of UAL 103 which was about 3,100 feet.

There were no further communications between N309CK and the FAA air traffic control facility. The CVR showed that the flightcrew proceeded to complete the prelanding checklist and that the landing gear was fully extended. At 1731:43 hours, the captain told the first officer that he was going to slow the airplane to Vref (123 knots) and that he was going to descend the airplane at that speed.

The first officer then told the captain that UAL 103 was "...a little too high on the ah...." The captain responded, "...yeah we'll just sit here and slow down...." He also said, "...I'll slightly "s" [turn] back and forth...", and later said, "...we'll run this a dot high [fly the glide slope one dot above the three degree glide slope]...." The first officer responded, "...yeah we might still get a little wake turbulence there...." At 1732:31 hours, the first officer remarked, "I don't know looks kinda close." The captain responded, "yeah it's close but I think we'll be okay."

At this time, the CVR indicated that both pilots saw UAL 103, and the captain asked the first officer, "what are the surface winds." The first officer responded, "two hundred degrees at ah six knots."

At 1733:02 hours, the captain queried the first officer, "...and we got gear and full flaps...." The first officer responded, "yup yaw damper will complete it...."

At 1733:10 hours, the CVR indicated that the captain took a deep breath, which was followed by the first officer saying, "keep it goin' around keep it goin' around...." The CVR recording ended at 1733:15 hours.

The last CDR radar target on N309CK was at 1733:07 hours. At this time, N309CK was at 1,100 feet, 2.1 nautical miles behind UAL 103.

Safety Board investigators interviewed several ground witnesses. The consensus of the witnesses was that while on final approach the airplane suddenly pitched downward, rolled 360 degrees about its longitudinal axis, and crashed. Two witnesses, both commercial pilots, reported seeing sparks/flames emanating from the airplane during the accident sequence. Other witnesses reported a strange whining sound emanating from the airplane.

Crew Information

Captain:

The captain was an employee of Management Activities, Inc., and was trained under the provisions of the operator's Title 14 Part 135 Air T