Christen Industries PITTS S1-T accident near Naples, Florida, March 21, 1993
On March 21, 1993 at about 4:42 pm local time, a Christen Industries PITTS S1-T, registered N218MC, was substantially damaged in an accident near Naples, Florida (Naples Municipal airport). It was a personal flight under general aviation rules (Part 91). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE INSTALLATION OF AN IMPROPER DESIGNED INTAKE TUBE AND AIR FILTER BY THE NONMECHANIC RATED PILOT-IN-COMMAND, WHICH RESULTED IN MOISTURE BUILD UP AND COLLAPSE OF THE AIR FILTER, WHICH RESULTED IN BLOCKAGE OF AIR FLOW TO THE ENGINE AND LOSS OF ENGINE POWER. CONTRIBUTING TO THE ACCIDENT WAS THE FAILURE OF THE PILOT-IN-COMMAND TO MAINTAIN AIRSPEED AND FLARE PROPERLY DURING A FORCED LANDING.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 21, 1993 · about 4:42 pm local time
- Place
- Naples, Florida · Naples Municipal
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Christen Industries PITTS S1-T
- Registration
- N218MC · no longer on the register · serial 1041
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT, WHO DOES NOT HOLD AN AIRFRAME OR POWERPLANT MECHANIC'S LICENSE STATED HE INSTALLED A STRAIGHT AIR INTAKE TUBE ON HIS AIRCRAFT. THIS TUBE DID NOT HAVE ANY MEANS FOR ALTERNATE AIR OR FILTERING OF INCOMING AIR. HE FURTHER MODIFIED THE TUBE BY INSTALLING A SCREEN AND A PIECE OF AIR FILTERING MATERIAL IN THE TUBE. DURING THE FIRST TAKEOFF AFTER THE MODIFICATION THE AIRCRAFT CLIMBED TO 200 FEET, AT WHICH TIME THE MANIFOLD PRESSURE DROPPED AND THE ENGINE LOST POWER. HE WAS UNABLE TO MAINTAIN ALTITUDE AND THE AIRCRAFT TOUCHED DOWN HARD ON THE RUNWAY AND NOSED OVER INVERTED. POSTCRASH EXAMINATION AND TESTING OF THE INTAKE TUBE WAS PERFORMED BY AN FAA INSPECTOR. WHEN A VACUUM CLEANER WAS ATTACHED TO THE ENGINE SIDE OF THE INTAKE TUBE AND TURNED ON THE AIR FLOW THROUGH THE TUBE WAS NORMAL FOR SEVERAL MINUTES. AFTER THIS, MOISTURE BUILT UP ON THE AIR FILTERING MATERIAL AND THE FILTER COLLAPSED. THE VACUUM CLEANER THEN BEGAN TO STRAIN DUE TO LACK OF AIR FLOW.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot, flight instructor
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
- Flight time: 14,000 hours in all; 350 in this make and model
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 470 hours
- Last inspection: annual inspection, June 20, 1992; 25 hours since
- Maximum gross weight: 1,100 lb
- Seats: 1
- Landing gear: fixed
- Engine: Lycoming AEIO-360 (piston); 0 hours total
The flight
- Departed from: APF at 4:42 pm
- Flight plan: none
- Runway 4, 5,000 ft by 150 ft
Weather at the time
- Light: daylight
- Wind: from 100° at 3 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 4,000 ft; scat at 3,000 ft
- Temperature: 75°F (24°C), dew point 66°F (19°C)
- Altimeter: 30.00 inHg
- Observation at 4:42 pm from APF, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.