Executive Airlines' Jetstream 31
What the public needs to know
The NTSB is investigating Sunday’s crash of Executive Airlines’ Jetstream 31 at the Wilkes-Barre/Scranton International Airport. Apparently, the flight crew reported that they were losing both engines shortly before the ill-fated craft crashed into hilly terrain near the airport.
The Jetstream 31, with nineteen people aboard, can only carry fuel for 450 nautical miles, or a little over 500 statute miles. That’s less than two hours’ flight time for this airplane. It has been reported that after the flight from Long Island to Atlantic City, the crew did not refuel. Total flight time for these two legs would make the airplane about out of fuel when it reached Wilkes-Barre, which would explain the double engine flameout and inability to restart. Since the Jetstream 31 has an auto-relight feature, if flameout occurs, only the lack of fuel common to both engines would seem to explain this accident. The unusable fuel in the Jetstream 31 is ten gallons, more than enough to create the fireball seen by witnesses and set fire to the cabin of the aircraft.
In 1985, another Jetstream 31 suffered a dual flameout while in a holding pattern in icing conditions. The crew had turned on the engine inlet anti-ice, but not the continuous engine ignition. A slug of ice or water ingested into the engines and shut them down, but they were quickly restarted, averting a disaster. While temperatures on the ground at Wilkes-Barre were well above freezing, at an altitude of as little as six thousand feet above the ground, the temperature in the clouds was near freezing or below, resulting in mixed icing likely encountered on the trip from Atlantic City. If the continuous ignition were not selected, another incident of dual engine failure could have occurred with insufficient altitude remaining for a restart before crashing.
The manufacturer of this aircraft recommends not using the continuous ignition for more than one hour. So, if the crew turned it off before its descent, it would not have been available when needed as temperatures near the ground warmed the aircraft and dislodged the ice.
While the NTSB must examine the engines, the chance of dual engine failure for mechanical reasons is virtually out of the question. Sending them back to their manufacturer for this purpose is of questionable judgment, especially when the recently completed Rand Report on NTSB investigative practices criticized this procedure as fraught with conflicts of interest.
All aspects of this crash must be investigated -- the maintenance of the aircraft, the training and experience of the pilots, the fueling of the aircraft, and the procedures used for ensuring that adequate fuel reserves were aboard for all flights, especially in bad weather. Complicating this process are the notoriously unreliable fuel gauges in aircraft. That is the reason aircraft operators and their flight crews must rely not on the gauges, but rather on the time in the air to manage their fuel. The weather conditions at Wilkes-Barre/Scranton on Sunday were such that any flight crew, properly trained and experienced, should have been able to execute a safe landing, unless the fuel reserves were inadequate or the procedures for descent in icing conditions were not followed. Either of these possibilities is high on the list of likely causes of this preventable accident.
- Arthur Alan Wolk