Incident Overview
A loss of separation occurred between Southwest Airlines (SWA) Flight #821, a Boeing 737-700, and N1487C, a Cirrus SR-22, in the vicinity of Orlando, Florida. Both aircraft were assigned an operating altitude of 11,000 feet mean sea level (MSL). The closest point of approach was 100 feet vertical and 0.1 nautical mile lateral. The minimum required IFR separation between the two aircraft is 1,000 feet vertical or 3 nautical miles lateral.
Cirrus SR-22 (N1487C)
N1487C was on a 14 CFR Part 91 IFR flight from Picayune Municipal Airport (MJD), Picayune, Mississippi, to Kissimmee Gateway Airport (ISM), Orlando, Florida, with a pilot and one passenger on board. After departure, the pilot obtained an IFR clearance from Houston Air Route Traffic Control Center (ARTCC) and was assigned a transponder code of 7427 and an en route altitude of 11,000 feet MSL. The pilot was subsequently directed to contact various ATC facilities, including Pensacola Approach, Eglin Approach, and others. Approximately 60 to 100 nautical miles from ISM, the pilot became concerned after not being contacted by ATC despite hearing communications. He attempted to reestablish contact with previous frequencies and tried Jacksonville ARTCC without success. The pilot did not attempt contact on VHF emergency frequency 121.5. While referencing a low altitude navigation chart, the Skywatch traffic alerting system alerted of traffic. The pilot observed a large jet on the left side at the same altitude. The jet approached from behind and was banking left from the Cirrus's 10 o'clock position. The Cirrus pilot then established communications with Jacksonville ARTCC and was directed to Central Florida TRACON, which provided vectors for an uneventful landing at ISM.
Boeing 737-700 (SWA821)
SWA821 was on a scheduled 14 CFR Part 121 IFR flight from Phoenix Sky Harbor International Airport (PHX) to Orlando International Airport (MCO) with a crew of five, one jump seat observer, and 137 passengers. The flight departed PHX at 1338 EST. The first officer was pilot flying, and the captain was pilot monitoring. As the aircraft approached MCO under Jacksonville ARTCC control, an ARTCC controller asked the crew to attempt contact with a Cirrus that ATC had lost communications with. The captain switched frequencies and made multiple unsuccessful attempts. Later, Central Florida TRACON requested a visual inspection of the Cirrus, and the captain agreed. The crew did not brief the maneuver or contingencies, nor did they inform flight attendants or passengers. The flight crew turned the TCAS transponder from TA/RA to TA ONLY to avoid resolution advisories. Central Florida TRACON directed the B737 to descend to 10,000 feet, then back to 11,000 feet after visual acquisition, and instructed to slow to 190 knots and navigate as close as safely possible. The B737 approached the Cirrus from below and left, noting a left turn by the Cirrus. The B737 paralleled the turn. The crew reported the Cirrus flying straight and level with no apparent damage and observed a black silhouette in the cockpit. No communication occurred between the aircraft. Radar data showed the closest approach at 0.1 mile lateral and 100 feet vertical. The B737 was then vectored for an uneventful landing at MCO.
Air Traffic Control
After the Cirrus departed MJD, it communicated with Houston ARTCC and was transferred through multiple ATC facilities. Eglin TRACON directed the pilot to contact Tyndall TRACON at 16:41, but the pilot did not respond. Eglin made 12 attempts to contact the Cirrus on frequency 132.1 and VHF Guard 121.5 without success. The Cirrus then transited Tyndall airspace without communication. Jacksonville ARTCC accepted the handoff, and at 15:09 the watch manager notified the Domestic Events Network (DEN) that the Cirrus was NORDO. Additional efforts included air-to-air relays and a request to a flight service station. As the Cirrus approached Central Florida TRACON airspace, the operations manager (OM) solicited an aircraft of opportunity for visual inspection. The OM set up a terminal control workstation and directed the B737 to 11,000 feet, provided vectors, and reduced speed. The front line manager (FLM) took control, vectored the B737, and after visual acquisition, directed it to navigate as close as safely allowed. The B737 passed with 100 feet vertical and 0.1 mile lateral separation. The B737 reported two occupants but no movement. The FLM then vectored the B737 away. The Cirrus reestablished communications with Jacksonville ARTCC at 1703 and was directed to Central Florida TRACON, which provided services for an uneventful landing at ISM.
Additional Observations
The controllers at Central Florida TRACON considered the Cirrus an emergency due to the prolonged NORDO status and potential threat to the Disney World complex and NASA space center, where a space shuttle was on a launch pad. The OM considered the visual inspection a prudent action based on FAA Order 7110.65. The B737 crew did not brief the maneuver or contingencies before complying with the ATC request.