On August 31, 2019, about 0758 central daylight time, a Piper PA-28-140 airplane, N55633, sustained substantial damage when it was involved in an accident near Conroe, Texas. The private pilot and passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The pilot reported that he departed with the airplane fueled “to the tabs” (36 gallons total) on the 25-minute flight to pick up the passenger. They subsequently departed on the accident flight about 0700. The pilot planned to use the right fuel tank until the descent into the destination airport. About 15 nautical miles north of the destination, the pilot turned on the electric fuel pump and switched to the left fuel tank. As the airplane approached traffic pattern altitude and with the airport in sight, the pilot performed the before landing checklist, which included adjusting the mixture to full rich and turning on the carburetor heat. The pilot reported that, as soon as he turned the carburetor heat on, the engine went to idle. He immediately turned the carburetor heat off. He surmised that having the carburetor heat off would not fix the problem and subsequently turned the carburetor heat back on. The pilot continued to troubleshoot as he maneuvered the airplane for a forced landing to a nearby road; however, realizing that he would not be able to land on the road, he chose to land in a pond. The airplane came to rest inverted in the water. The left wing sustained substantial damage from the water impact.
The airplane began to fill with water and the pilot turned the safety latch at the center top of the cockpit door, which was under his feet, and reported "it didn't feel right." He then pulled the locking latch located on the rearward side of the door, but it would not move. Since he could not open the door to egress, he then punctured and pushed out the acrylic door window. The pilot and passenger waded to shore without further incident.
Postaccident photographs showed a visible fuel sheen on the water near the submerged inverted airplane. The airplane was recovered from the pond after being submerged for several hours and moved to a secure location. The left wing fuel tank contained no fuel. The right wing fuel tank was drained through the gascolator; about 3 gallons of a clear liquid was collected, which contained about 1 pint of fuel. The amount of fuel onboard at the time of the accident could not be determined.
The carburetor heat control cable was found connected to the carburetor heat box. The carburetor heat valve reacted properly to the position selected on the handle at the control panel; however, the valve did not travel to the full close position when heat was selected. A postaccident examination of the engine revealed no mechanical failures or malfunctions that would have precluded normal operation.
The weather conditions reported about the time of the accident included an outside air temperature of 73°F and a dew point of 72°F. Federal Aviation Administration Special Airworthiness Information Bulletin No. CE-09-35, Carburetor Icing Prevention, indicated that the airplane was operating in an area that was associated with a risk of serious carburetor ice accumulation at glide power settings.
During the postaccident examination, both interior door handles worked properly. The top exterior door handle was broken off and was missing. The bottom exterior door handle worked properly. No door operation instruction placards were located on the interior or exterior of the airplane. The NTSB has previously identified egress difficulties with the Piper PA-28 series, particularly with an accident involving a fire or water egress. NTSB Safety Recommendation Letter A-81-26 through -28, based upon several Piper PA-28 accidents, states in part:
The cabin door on the Cherokee, like several other single-engine aircraft designed for five or less persons, is the only available exit. Therefore, when the cabin door becomes jammed, blocked, or otherwise unusable during an accident, there are no alternate means of egress. Furthermore, the Cherokee door is designed with two separate latches: a locking latch located on the rearward side of the door, and a safety latch at the center top of the door which should be latched prior to the flight to provide a proper seal around the door. The prompt location and operation of the top safety latch can be difficult for occupants and rescuers alike.