Nearly out of gas, then out of control; failure to verify fuel first link in crash

 - May 6, 2008, 11:58 AM
It is usually easier to find fault with a flight crew during an ensuing accident investigation than it was for the crew to make the right decisions instantly as the event unfolded. However, some accidents reveal procedural flaws that forge the first link in a chain of events long before a critical situation arises.

Just such a situation appears to have occurred when a British Aerospace Jetstream 31 (N16EJ) crashed about 11 mi south of Wilkes-Barre/Scranton (Pa.) International Airport (AVP) the morning of May 21, 2000. All 17 passengers and both crewmembers were killed, and the aircraft–operated by East Coast Aviation Services dba Executive Airlines–was destroyed.

On the day of the accident the aircraft flew from Farmingdale (N.Y.) Airport (FRG) to Atlantic City (N.J.) Airport (ACY) and then on to Wilkes-Barre (Pa.) Airport (AVP). The airplane was originally scheduled to depart FRG at 0900 for ACY and to remain there until 1900, when it was scheduled to return to FRG. During the preflight inspection the pilots were told by Executive Airlines’ CEO that they had been assigned an additional flight from ACY to AVP, with a return flight to ACY later in the day.

The flight departed FRG at 0921 with 12 passengers on board and arrived at ACY at 0949. Passengers testified the captain flew that leg. After arrival the flight crew checked the weather for AVP and filed an IFR flight plan. Local records indicated that no additional fuel was uplifted, and the aircraft departed about 1030.

Executive Airlines’ policy is for pilots to alternate flying duties each leg, and ATC recordings from AVP approach and tower facilities also identified the captain as the pilot speaking with ATC in all radio transmissions. Based on these facts it is likely the first officer was flying the leg to AVP.

According to ATC transcripts, the pilots first contacted AVP Approach  at 1057 and were vectored for an ILS approach to Runway 4. The flight was cleared for approach at 1102:07, and the approach controller advised the pilots that they were five nautical miles from Crystal Lake, which is the initial approach fix for the ILS approach to Runway 4. The pilots were told to maintain 4,000 ft until established on the localizer.

At 1104:16, the approach controller advised that a “previous landing…aircraft picked up the airport at minimums [decision altitude].” The pilots were instructed to contact AVP Tower at 1105:09, which they did. The airplane then descended to about 2,200 ft, flew level at 2,200 ft for about 20 sec, and began to climb again about 2.2 nm from the runway threshold when a missed approach was executed.

According to the published instrument procedure, the decision altitude for the ILS Runway 4 approach is 1,263 ft msl, about 300 ft above the runway touchdown zone. At 1107:26 the captain reported executing the missed approach.

The tower controller advised the north-sector radar approach controllers of the missed approach and then instructed the crew to fly runway heading, climb to 4,000 ft and contact approach control (the procedure published on the approach chart). The pilots reestablished contact with the approach controllers at 1108:04 as they climbed through 3,500 ft to 4,000 ft and requested another ILS approach to Runway 4.

The flight was vectored for another ILS approach and at 1110:07 the approach controller advised the pilots of traffic two nautical miles away at 5,000 ft. The captain responded that they were in the clouds. At 1014:38 the controller directed the pilots to reduce speed to follow a Cessna 172 on approach to the airport and the captain responded, “OK, we’re slowing.” The flight was cleared for a second approach at 1120:45 and advised to maintain 4,000 ft until the airplane was established on the localizer.

‘We’d Like To Declare an Emergency’

At 1123:49 the captain transmitted, “For uh one six echo juliet, we’d like to declare an emergency.” At 1123:53, the approach controller asked the nature of the problem and the captain responded, “Engine failure.” The approach controller acknowledged the information, told the pilots that the airplane appeared to be south of the localizer, off course to the right, and asked if they wanted a vector back to the localizer course. The crew accepted, and at 1124:10 the controller directed a left turn to heading 010 deg, which the captain acknowledged.

At 1124:33 the controller asked for verification that the airplane was turning left. The captain responded, “we’re trying, six echo juliet.” At 1124:38 the controller asked if a right turn would be better. The captain asked the controller to “stand by.”

At 1125:07 the controller advised the pilots that the minimum vectoring altitude (MVA) in the area was 3,300 ft to which the captain replied, “Standby for six echo juliet, tell them we lost both engines for six echo juliet.” At that time, ATC radar data indicated the airplane was descending through 3,000 ft.

The controller immediately issued the weather conditions in the vicinity of the airport and advised the flight crew about the location of nearby highways. Weather data at the time indicated that the airplane remained in IMC, with clouds and possibly occasional light rain and during the second approach with intermittent ground visibility until just before ground impact. Turbulence and icing conditions were not factors in the accident, the NTSB said.

At 1126:17 the captain asked, “How’s the altitude look for where we’re at?” The controller responded that he was not showing any altitude readout from the airplane. The NTSB subsequently determined by that time the airplane had descended below the MVA of 3,300 ft and radar was unable to record its altitude because of terrain interference. The controller issued the visibility (2.5 mi) and altimeter setting.

At 1126:43, the captain transmitted, “Just give us a vector back to the airport please.” The controller cleared the flight to fly heading 340 deg, advised the flight crew that radar contact was lost and asked the pilots to verify their altitude. The captain responded that they were “level at 2,000.” At 1126:54, the controller again advised the flight crew of the 3,300-ft MVA and suggested a 330-deg heading to bring the airplane back to the localizer.

At 1127:14 the controller asked, “Do you have any engines,” and the captain responded that they appeared to have gotten back “the left engine now.” At 1127:23 the controller told the pilots that he saw them on radar at 2,000 ft and that there was a ridgeline between them and the airport. The captain responded, “That’s us, we’re at 2,000 feet over the trees.” The controller instructed the pilots to fly a 360-deg heading and advised them of high antennas about two nautical miles west of their position.

At 1127:46 the captain transmitted, “We’re losing both engines.” Two seconds later the controller advised that the Pennsylvania Turnpike was right below the airplane and instructed the flight crew to “let me know if you can get your engines back.” There was no further radio contact with the airplane. The ATC supervisor initiated emergency notification procedures and at about 1236 a Pennsylvania State Police helicopter located the wreckage some  11 mi south of the airport at an elevation of 1,755 ft msl.

The airplane wreckage was found on top of a mountain. It had crashed in a 60-deg nose-low attitude in a 135-deg left bank. All of the airplane’s primary structure was found at the accident site. Fire damage was confined to the immediate impact area, with little fire damage to surrounding trees and foliage. The gear was in the extended position.

The NTSB determined the accident was not survivable because of high impact forces, and autopsies confirmed all deaths were the result of blunt-force trauma.

The Crew and Aircraft

The 34-year-old captain held an ATP certificate and was type rated in the Jetstream 31, Jetstream 41 and Fairchild Dornier 328JET. His FAA first-class medical was current. He had about 8,500 flying hours, including 1,874 as PIC in the Jetstream.

The first officer, 38, held a commercial pilot certificate and had a current FAA first-class medical. He had approximately 1,282 hr TT, about 742 of which were in the Jetstream 31. Alcohol and drugs were not determined to be factors for either pilot.

According to FAA and company records, the airplane had about 13,972 flight hours and about 18,503 cycles since new (CSN). It had a record of a previous accident in 1989 and a precautionary engine shutdown in 1991, but neither were determined to have contributed to the fatal accident. The left engine had 14,027.5 hours time since new (TSN), 18,602 CSN and 469 hr since the last overhaul. The right engine had accumulated 5,939.5 hr TSN, 6,017 CSN and 56.9 hr since the last overhaul. No unresolved discrepancies were noted.

The cockpit voice recorder (CVR) was determined to be operational at the time of the accident. Inexplicably, no information pertaining to the accident flight or any other flight was on the tape. A flight data recorder was not required for the aircraft.

There were no visible signs of uncontained failure of either the left or right engine, and both propellers remained attached. Failing to find any credible system or equipment failures, NTSB investigators focused on fuel exhaustion.

Executive Airlines’ CEO stated that he originally told the accident first officer to calculate the airplane’s weight and balance based on nine passengers from ACY to AVP to determine if the airplane’s fuel tanks could be topped off with fuel in FRG. He said the first officer told him that fuel tank measuring sticks indicated that about 1,100 lb of fuel were on board.

The CEO said he learned that 17 passengers would be on board for the flight from ACY to AVP and advised the first officer. He stated that the first officer told him that 90 gal (about 600 lb) of fuel would be added to each tank and told him that “we are going almost topped off.” The CEO added that according to company procedure, pilots “would normally stick the tanks and then order the fuel.”

The FBO fueler at FRG said the accident flight crew was at the airplane when he arrived in his fuel truck. He said one pilot (his description fit that of the copilot) requested the fuel tanks be topped off. The fueler stated that the larger pilot (indicating the captain) later requested 60 gal of fuel, 30 gal in each tank. He said he could not see the refueling meter while he was refueling and asked the captain to monitor the meter. The fueler stated at one point he stopped fueling and asked the captain to tell him the meter indication and stated that he was told 45 gal.

The fueler said he asked the captain if he wanted him to put 15 gal in the other tank, for a total of 60 gal, and the captain told him to put 45 gal in the other tank for a total of 90 gal. Fuel truck and billing records confirmed the purchase of 90 gal of fuel. The pilots did not receive a copy of the fuel receipt because Executive Airlines had a fueling contract with the FBO. The fueler stated that he “did not observe either pilot check the fuel dipsticks, climb up the fueler’s ladder to check the fuel or walk around the airplane.”

The first officer’s fiancée, a passenger on the FRG to ACY leg, said he told her one fuel gauge read 300 lb and that the other read 900 lb. She said she subsequently saw these gauge readings herself. She stated that the 300-lb indication was on “the right side.” She stated that her fiancée remarked, “I don’t even know how to tell how much fuel we have on board.” She also said the pilots stayed inside the aircraft during fueling because it was raining, and she didn’t know if either pilot had been involved with the fueling.

The company’s director of operations said its pilots normally used high-speed climb power for the climb to altitude and used high-speed cruise power during the cruise portion of the flight. However, the airline’s CEO stated they use long-range cruise power during cruise flight. Based on this inconsistency, the NTSB calculated fuel burn for the nine previous flights and the accident flight using manufacturer performance information for both high-speed cruise and long-range cruise power. Fuel burn calculations were based on flight times listed in the airplane logbook.

According to calculations, high-speed cruise power settings would have resulted in 209 lb of usable fuel remaining at the time of the crash, sufficient for about 15 min of flight at high-speed cruise power settings. Long-range cruise power settings would have resulted in 1,154 lb of usable fuel. Fuel-burn calculations did not take into account potential unknown factors such as altitude changes, temperature variations, the use of engine bleed air and airplane configuration.

It was determined that the airplane was properly certificated and equipped in accordance with federal regulations and approved procedures. Passengers and fuel were properly loaded in accordance with FAA-approved company weight-and-balance procedures. The airplane’s weight and balance were within prescribed limits during all phases of the flight and were not factors in the accident, according to the Safety Board.

There was no indication of pre-existing maintenance discrepancies that could have contributed to the accident. There were no pre-impact failures of any flight-control system component or fuel-system component on either engine, and no evidence of engine damage or in-flight fire. It was determined the left engine was running on impact, but the right engine was not.

The NTSB noted that, based on the Jetstream 31’s performance capabilities and simulator tests, the accident airplane was controllable after the initial engine stoppage, and its subsequent deviation from the ILS approach course should have been sufficiently correctable to enable the flight crew to execute a single-engine ILS approach and landing. Further, the NTSB noted that during simulator tests, when a left engine failure was induced along with a failed right engine on an ILS approach, the airplane remained controllable with minimal difficulty. However, the airplane was more difficult to control and required constant flight-control and trim inputs when the left engine was intermittently failed and restored.

All available information indicated the crew planned to add a total of 180 gal of fuel to the airplane, and in that event it would have been common industry and company practice to ask for 90 gal on each side. However, based on the evidence, it appears that a breakdown in communication between the pilots and the fueler resulted in only 90 gal (about 600 lb) of fuel being added, a total amount confirmed by the fuel-order receipt. Further, it is likely that the flight crew did not confirm the amount of fuel loaded before departure because flight crews do not see the fuel receipts after fueling and because the pilots were not outside the airplane monitoring the fuel loading. There was no evidence that the flight crew asked for additional fuel to be added during the stop at ACY.

According to the NTSB, the apparent difficulties with the left engine could be explained by unporting of whatever fuel remained in the left tank. Banking and acceleration can cause fuel to flow away, or become unported from, the airplane’s fuel pumps, which are located in the inboard section of the fuel tanks near the fuselage.

Conditions would have been conducive to unporting if, for example, the airplane was in a left bank and in a nose-right sideslip following the loss of the right engine. This would have been consistent with flying straight while attempting to turn to the left, as indicated by the pilot statement “we’re trying” when the controller queried if the airplane was in a left turn. Assuming some usable fuel was in the left tank, it is probable that the flight crew’s maneuvering after the right engine stoppage may have intermittently unported it, causing the sequential stoppage and restarting of the left engine.

The NTSB determined that the probable cause of the accident was the flight crew’s failure to ensure an adequate fuel supply for the flight, which led to the stoppage of the right engine due to fuel exhaustion and the intermittent stoppage of the left engine due to fuel starvation. Contributing to the accident were the flight crew’s failure to monitor the airplane’s fuel state and the flight crew’s failure to maintain directional control after the initial engine stoppage.