RivetBangers.com

RV-7 - ASN Report - N977RV

East bound and down.... reminds me of the RV-9A that went down last year on the way to Oshkosh trying to punch through the weather at 10K ft plus. they found the rudder, then the horizontal stabilizer, then the wings, etc. in that order. this will probably be similar. when these things happen over and over again, you can begin to say "hey, don't do that". RV's are delicate, fun to fly, machines. If you want to take on thunderstorms, they are not the correct aircraft.

from that altitude, the pilot would have had a long time to think about it. all I can offer is a song.

Ben Böhmer - Slow Wave feat. Gordi (Official Visualiser)
https://youtu.be/F1JkJSFdLi4

N977RV

RV-7 - ASN Report - N977RV

from the preliminary report, it doesn't appear that this aircraft broke up in-flight. he simply augured in. perhaps spatial disorientation caught in a graveyard spiral, but he was IFR rated. surprised he didn't make a 180 and ride it out of there. he did mention that he was picking up ice, I wonder if the aircraft developed an ice jam between the elevator horn and the fairing. some make that gap so tight you can't get a credit card thickness in there and a small amount of ice could easily jam the elevator.

in my opinion, it is stupid to make a tight elevator horn to fairing clearance. there is negligible performance increase with a large increase in risk for an elevator ice jam. if the gap is too tight, fix it.

https://data.ntsb.gov/carol-repgen/api/ ... 192292/pdf

On June 2, 2023, at about 0907 Central Daylight Time, a Vans RV-7, N977RV, was destroyed
when it was involved in an accident in Gibbon, Nebraska. The pilot was fatally injured. The
airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
Automatic Dependent Surveillance – Broadcast (ADS-B) data revealed that the airplane
departed Rocky Mountain Metropolitan Airport (BJC), Denver, Colorado, at 0610 and
proceeded direct toward Red Oak Municipal Airport (RDK), Red Oak, Iowa. The pilot filed an
instrument flight plan. About two hours after departure from BJC, at an altitude of 15,000 ft
mean sea level (msl), the pilot requested a lower altitude from air traffic control (ATC) due to
encountering ice. The controller gave the pilot a block altitude between 11,000 and 15,000 ft
msl, and the pilot began a descent. Shortly after the pilot began his descent, the controller
advised him that there was “extreme precipitation” in the area. About one minute later, the
controller told the pilot that he was permitted a lower altitude if he wished to continue to
descend. There was no further response from the pilot.
Dashboard camera footage from a car traveling east bound on Interstate 80, captured the
airplane descending in a nose-down attitude. The airplane impacted an open grassy area
surrounded by trees about 260 ft south of the interstate. The debris field was generally aligned
on a 257° heading, and the main wreckage came to rest upright. Ground scaring at the
accident site confirmed that the airplane was in a nose-down attitude when it struck the
ground. The initial impact point consisted of a two-foot deep crater with the propeller
embedded in it. The propeller was still intact at the hub; however, it was separated from the
engine flange.
The dashboard board camera footage also revealed that it was raining heavily at the time of
the accident with a low overcast cloud layer. Weather radar images at the time of the accident
depicted heavy precipitation and thunderstorms in the vicinity.

RV-7 - Final Report - N977RV

well, don't mess around with icing and thunderstorms in these small homebuilt aircraft. they were not designed for that environment.

https://data.ntsb.gov/carol-repgen/api/ ... 192292/pdf

Analysis
Before taking off on an instrument-flight-rules (IFR) cross-country flight, the pilot obtained a standard weather briefing of the forecast and observed weather conditions along the flight route, which included thunderstorms, convective Significant Meteorological Information (SIGMETs), and Airmen’s Meteorological Information (AIRMETs) for icing conditions.

A review of air traffic control (ATC) information revealed that, while the pilot was en route to the destination airport, an air traffic controller told the pilot that there was moderate to heavy precipitation about 5 miles ahead and the pilot acknowledged. About 4 minutes later, the pilot requested a lower altitude due to ice accumulation. ATC gave the pilot a block altitude to maintain and the pilot began to descend the airplane. About 40 seconds later, ATC told the pilot he could descend below the block altitude if needed. The pilot acknowledged by saying, “roger.” Immediately after the pilot acknowledged that he could go lower, ATC told him that if he was turning toward the west, there was extreme precipitation that extended to the southwest. The pilot did not respond. ATC made several subsequent attempts to contact the pilot; however, the pilot never responded. The airplane impacted a grass field and was destroyed. Airplane debris was scattered in the field for several hundred feet. The rudder and vertical stabilizer separated from each other and most of the pieces of the rudder and vertical stabilizer were found before the impact site in a tree and on the ground.

The investigation estimated the airplane’s airspeed based on recorded ADS-B data and atmospheric conditions at the time of the accident. The ADS-B pressure altitude data was used to calculate the vertical airspeed at the end of the flight based on the rate of descent. The computed maximum airspeed at the last reliable pressure altitude, about 10 seconds before impact,was about 286 KTAS, which surpassed the never exceed speed (Vne) listed in the airplane’s pilot operating handbook of 210 knots.

Analysis of the ADS-B data also revealed that, in the final 2 minutes of flight, the airplane pitched back and forth between 10° above the horizon and -60° below the horizon and rolled to the right at bank angles between 10° and 120°. Examination of the separated rudder and vertical stabilizer depicted signatures of overstress, and the location where they were found indicated that they separated from the airplane before impact. However, due to their proximity to the rest of wreckage, the separation likely occurred immediately before impact and the inflight breakup was not causal to the accident. The vertical stabilizer and rudder separated from the empennage due to “rudder flutter” when the airplane exceeded the Vne for the airplane. Examination of the engine and remaining systems revealed no mechanical anomalies. Based on the pilot’s reported accumulation of ice, the adverse weather conditions, and the airplane’s variations in pitch and roll in the final minutes of flight, the pilot likely experienced a loss of control after encountering adverse weather due to a combination of ice accumulation on the airplane’s control surfaces.

Toxicological testing revealed ethanol was present in samples taken during the autopsy. Given the putrefaction of the samples, it is likely that all detected ethanol was the result of postmortem production.

Probable Cause and Findings
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The pilot’s improper decision to fly the airplane into known adverse weather and icing conditions which resulted in a loss of control.