ILS approach Goes Wrong..”I think i Hit Something ”

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On 10 July 2019, Cessna 172 N677DM was flying an ILS approach at night in instrument meteorological conditions near Vineyard Haven, Massachusetts. Near decision altitude, the pilot observed full course-deflection indications in opposite directions while correcting the approach. She then heard and felt a loud bang, the airplane turned left and she immediately abandoned the approach. The aircraft was vectored to another airport and landed, but the left wing had sustained substantial damage from a collision with a tree.

Accident Facts

Date
10 July 2019
Registration
N677DM
Timeline
10 July 2019, night —
N677DM conducted an ILS approach to Runway 24 in instrument meteorological conditions.
1.
Near decision altitude —
The pilot observed full right deflection, corrected left, then observed full left deflection on the course indicator.
2.
Immediately afterward —
The pilot heard and felt a loud bang and the aircraft turned left.
3.
After the impact —
The pilot discontinued the approach, executed a missed approach and declared an emergency.
4.
Following the missed approach —
ATC vectored N677DM to a nearby airport.
5.
After landing —
The aircraft was found to have substantial damage to the left wing.
6.

The approach became unstable close to decision altitude

The NTSB report places the aircraft in night IMC on an ILS approach to Runway 24. The pilot described seeing the course indicator reach full right deflection, correcting left, and then seeing full left deflection. That sequence occurred around decision altitude, leaving little vertical margin for troubleshooting.

The pilot then reported a loud bang and an abrupt left turn. Rather than continue the approach, she executed a missed approach and declared an emergency. The aircraft was subsequently vectored to a nearby airport where the landing was completed without further incident.

The wing damage identified the physical contact

After the aircraft landed, the left wing had sustained substantial damage. The FAA examination found pine needles in the damaged section, providing physical evidence consistent with contact with a tree.

The investigation did not identify a pre-existing mechanical failure that would have prevented normal operation. Weather observations around the time of the occurrence showed fog, visibility of one-quarter statute mile and a very low vertical visibility, reinforcing the difficult visual environment in which the approach was being flown.

The investigation focused on lateral position

The NTSB's probable-cause determination did not assign the event to a mysterious ILS malfunction or an aircraft mechanical defect. It focused on the aircraft's lateral position relative to the approach course while the pilot was operating at night in IMC.

That finding is narrower than the dramatic phrase 'I think I hit something.' The physical evidence established contact with a tree; the investigation then connected that contact to the failure to maintain the aircraft's position on the instrument approach course.

The documented finding

“The pilot's failure to maintain lateral position in relation to the instrument approach course at night in instrument meteorological conditions, which resulted in collision with a tree.” — National Transportation Safety Board, GAA19CA401

Conclusion

N677DM did not become an accident because the pilot continued after the bang. The pilot immediately discontinued the approach, declared an emergency and reached another airport. The substantial damage was discovered afterward, and the investigation used the physical evidence in the wing to establish what had been struck. The final finding keeps the event grounded in the actual evidence: difficult night IMC, loss of lateral position during the ILS approach and contact with a tree. The successful diversion after the impact does not erase the seriousness of the approach event, but it did prevent a much worse outcome.

Sources

Audio from the original air traffic control recording, sourced from public recordings and released investigation records. The reconstruction, animation and written account are our own.
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