1968 — Oct 25, Northeast Air 946, approach crash in fog, Moose Mt., ~Hanover, NH– 32

lornajarrettblanchard October 25, 1968

–32 Aviation Safety Network. Accident Description. Northeast Air Flight 946, 25 Oct 1968.
–32 Kimura. World Commercial Aircraft Accidents 3rd Ed., 1946-1993, V.1. 4-11-1994, p. 3-11.
–32 NTSB AAR. Northeast Airlines… N380NE, Near Hanover, New Hampshire, Oct 25, 1968

Narrative Information
NTSB Synopsis:

“A Northeast Airlines, Inc., Fairchild Hiller FH-227C, N38ONE, crashed approximately 1817 e.d.t., October 25, 1968, near Hanover, New Hampshire. The aircraft, Flight 946, had been cleared for an approach the Lebanon Regional Airport, West Lebanon, New Hampshire, at 1808. The aircraft crashed 3.8 nautical miles northeast of the VOR station at an altitude of approximately 2,237 feet m.s.1. At this point in a standard instrument approach, the aircraft should have been no lower than 2,800 feet m.s.1. Witnesses on the ground and survivors of the accident reported that the mountaintop was shrouded in cloud or fog at the time of the accident.

“Of the 39 passengers and three crewmembers aboard the aircraft, nine passengers and one crewmember, the stewardess, survived the accident. The aircraft was destroyed by impact and post-impact fire.

“The Board determines that the probable cause of this accident was the premature initiation of a descent towards the Minimum Descent Altitude, based on navigational instrument indications of an impending station passage in an area of course roughness. The crew was not able to determine accurately its position at this time because they had performed a nonstandard instrument approach and there were no supplemental navigational aids available for their use.

“As a result of the investigation of this accident, the Board forwarded recommendations to the Federal Aviation Administration concerning the operating characteristics of the Lebanon VOR and their relationship with airborne navigation receivers and instrumentation. The Administrator indicated he had taken or planned actions which were basically in accord with the intent of the Board’s recommendations.

History of the Flight.

“Northeast Airlines, Inc., Fairchild Hiller FH-227C, N38ONE, crashed at approximately 1817 e.d.t., October 25, 1968, near Hanover, New Hampshire.

“The aircraft was being operated in scheduled domestic passenger service as Flight 946 from Boston, Massachusetts, to Montpelier, Vermont, with an en route stop at Lebanon, New Hampshire.

Of the 39 passengers and three crewmembers aboard the aircraft, nine passengers and one crewmember, the stewardess, survived the accident. The aircraft was destroyed by impact and post-impact fire.

“Flight 946 departed from Boston at 1742 and was cleared to Lebanon, New Hampshire. The flight was cleared to proceed in accordance with a flight plan which called for a cruising altitude of 8,000 feet m.s.1. and an estimated time en route of 33 minutes at an estimated airspeed of 245 knots. The original scheduled departure time of 1655 was not met due to a delay in getting the aircraft to the gate for passenger loading.

“The flight was reported to be normal and routine, and was observed on radar, until it reached a point reported by the radar controller to be 2.5 nautical miles (NM) south-southeast of the Lebanon VOR. The flight was cleared, at 1808, for an approach to the Lebanon Airport to cruise at 5,000 feet and report leaving 6,000 feet. At 1810:45, the controller advised the crew that radar service had been terminated and the flight was cleared to contact the Lebanon Flight Service Station.

“At 1811, the crew contacted the Lebanon Flight Service Station, reported that they were ‘SIA’ (Standard Instrument Approach), and requested the Lebanon weather. They were advised that the Lebanon weather was an estimated ceiling of 2,000 feet overcast; visibility was 10 miles; there were breaks in the overcast; the altimeter setting was 29.55; and the wind was calm. They were also advised that Runway two five was in use and there was no other reported traffic. The crew acknowledged this information and there were no further recorded transmissions from the crew.

“One passenger stated that “. . . As we approached Lebanon, the cloud cover had been gradually thinning and before we began our descent, ground had been visible in patches between the clouds for several minutes. On the early part of the descent, the ground continued to be visible. After the turn to the final approach, with the wheels down, we were flying between two nearly vertical cloud banks in the gentle smooth descent… There was no cloud directly below us and the level of the base of the clouds at this point was slightly below the level of the aircraft so that the ground was clearly visible under the cloud to a substantial distance ahead and to the side. I was looking out and observed a pond and that the terrain had very few roads and no houses.

“As we continued our descent, I continued to observe and watched the slope of the ground rising ahead of us at about twenty degrees in the direction of flight. We were so near the ground at this time that I could clearly see the individual trees which appeared fist size and began to look ahead in the direction of flight for airport approach lights as I assumed that we must be very near the touch down point. I observed the rising ground until I suddenly lost all visibility as we had entered a cloud.

“After a few seconds in the cloud, I felt the initial impact which was gentle and seemed no more severe than a normal touch down. I do not remember any severe impact. “There was no change in course, speed, bank angle, descent angle or engine sound from the time the aircraft completed its turn and started its gradual descent until impact. . . .

“Most of the survivors described the impact as “smooth,” “not a crash but more as settling,” “a rough landing,” etc.

“A ground witness, south of the accident site, heard the aircraft approaching. When he looked toward the sound, he saw the “slightly fog covered mountain,” but did not see the aircraft until the landing lights appeared in the fog. A few seconds later, the aircraft crashed into the mountain….

“The accident occurred on the side of a steep, rocky, heavily wooded mountain, the top of which was 2,294 feet above sea level. The first impact marks were 57 feet below the summit at 2,237 feet m.s.l., where the aircraft struck a tree. From this point, a swath was cut through the trees, parallel to the east side of the mountain…

”Since the accident, the State of New Hampshire has installed a low frequency non-directional beacon and a co-located 75 MHz marker beacon 2.2 NM northeast of the Lebanon VOR on the approach radial. The use of these navigational aids has been approved by the FAA and two new approach procedures have been published for use by pilots….

“The aircraft broke up as it passed through the trees and was almost completely destroyed by impact and fire….

“Due to darkness, the remoteness of the accident site, as well as the terrain and heavy ground cover, it was extremely difficult for the rescue groups to get to the scene.

“All 10 survivors were seated in the aft end 3f the cabin. They made their escape from the burning wreckage through the rear cabin service door or through factures of the fuselage….

“During the investigation, data was supplied to the Board indicating that the Lebanon VOR facility was unreliable and on occasion caused the airborne navigation equipment to give incorrect navigation indications to flightcrews….

ASN: “Follow-up / safety actions: Acting upon an NTSB recommendation, the FAA on Nov. 7, 1968 issued an Operations and Maintenance Alert regarding the erratic operation and false reversals of Wilcox 806 VOR receivers. One month later the FAA issued Advisory Circular No. 91-18, regarding course needle oscillations on VHF Omni directional Range (VOR) receivers. The Wilcox company also took action to recommending three modifications to the Wilcox 806A receiver to improve the performance of the receiver.” (ASN. Northeast Flight 946, 25 Oct 1968.)

Sources

Aviation Safety Network. Accident Description. Northeast Airlines Flight 946, 25 Oct 1968. Accessed 3-2-2009 at: http://aviation-safety.net/database/record.php?id=19681025-2

Kimura, Chris Y. World Commercial Aircraft Accidents 3rd Edition, 1946-1993, Volume 1: Jet and Turboprop Aircrafts. Livermore, CA: Lawrence Livermore National Laboratory, Risk Assessment and Nuclear Engineering Group. 4-11-1994.

National Transportation Safety Board. Aircraft Accident Report. Northeast Airlines, Inc., Fairchild Hiller FH-227C, N380NE, Near Hanover, New Hampshire, October 25, 1968 (NTSB-AAR-70-7; File No. 1-0024). Washington, DC: NTSB, Adopted April 1, 1970, 61 pages. Accessed at: http://www.airdisaster.com/reports/ntsb/AAR70-07.pdf