Passenger complaint of excessive vibration on takeoff.

Attributes
ACN	178125
Time
Date	199104
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : twf
State Reference	ID
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	Other
Function	observation : passenger
Qualification	other other : other pilot : private
ASRS Report	178125
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	other anomaly other
Independent Detector	other other : unspecified
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

I have been flying for over 40 yrs (not commercially), been a machinist and held numerous mechanically related jobs. Now retired, but still intensely interested in anything connected with aviation. Having observed the light transport from the ground, I always admired the quiet performance, but had never flown in one. Recently, I had occasion to do so and was seated about midway with a window seat. I was dumbfounded at the vibration, especially on takeoff. My experienced with vibration and machinery has led me to believe that no structure can sustain such vibration indefinitely. I am not an engineer and am not pinpointing the cause, but my contention is that something is wrong, be it propeller, engines or procedure. I asked the attendant if this vibration was only on this individual aircraft. She said no, that it was more or less normal. This was confirmed on the return trip on another light transport. I've owned a # of single engine aircraft and presently own an small aircraft. If I experienced this much vibration, I would be very concerned. It isn't my intention by this letter to cause trouble. From a safety standpoint, your agency will know whether there is any cause for an investigation into this matter.

Original NASA ASRS Text

Title: PASSENGER COMPLAINT OF EXCESSIVE VIBRATION ON TKOF.

Narrative: I HAVE BEEN FLYING FOR OVER 40 YRS (NOT COMMERCIALLY), BEEN A MACHINIST AND HELD NUMEROUS MECHANICALLY RELATED JOBS. NOW RETIRED, BUT STILL INTENSELY INTERESTED IN ANYTHING CONNECTED WITH AVIATION. HAVING OBSERVED THE LTT FROM THE GND, I ALWAYS ADMIRED THE QUIET PERFORMANCE, BUT HAD NEVER FLOWN IN ONE. RECENTLY, I HAD OCCASION TO DO SO AND WAS SEATED ABOUT MIDWAY WITH A WINDOW SEAT. I WAS DUMBFOUNDED AT THE VIBRATION, ESPECIALLY ON TKOF. MY EXPERIENCED WITH VIBRATION AND MACHINERY HAS LED ME TO BELIEVE THAT NO STRUCTURE CAN SUSTAIN SUCH VIBRATION INDEFINITELY. I AM NOT AN ENGINEER AND AM NOT PINPOINTING THE CAUSE, BUT MY CONTENTION IS THAT SOMETHING IS WRONG, BE IT PROP, ENGS OR PROC. I ASKED THE ATTENDANT IF THIS VIBRATION WAS ONLY ON THIS INDIVIDUAL ACFT. SHE SAID NO, THAT IT WAS MORE OR LESS NORMAL. THIS WAS CONFIRMED ON THE RETURN TRIP ON ANOTHER LTT. I'VE OWNED A # OF SINGLE ENG ACFT AND PRESENTLY OWN AN SMA. IF I EXPERIENCED THIS MUCH VIBRATION, I WOULD BE VERY CONCERNED. IT ISN'T MY INTENTION BY THIS LETTER TO CAUSE TROUBLE. FROM A SAFETY STANDPOINT, YOUR AGENCY WILL KNOW WHETHER THERE IS ANY CAUSE FOR AN INVESTIGATION INTO THIS MATTER.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.