Aircraft would not accelerate with both skis in contact with the ground above 80 KTS and lift off. B...

Attributes
ACN	321855
Time
Date	199511
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : tka
State Reference	AK
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : instructional
Make Model Name	Skywagon 185
Operating Under FAR Part	Part 135
Flight Phase	climbout : takeoff
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 200 flight time total : 7000 flight time type : 250
ASRS Report	321855
Events
Anomaly	other anomaly other
Independent Detector	other other : unspecified cockpit
Resolutory Action	flight crew : overcame equipment problem
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

An unusual condition occurred and I am looking to find an answer to the following. Departing a frozen lake on skis the following occurred. Acceleration, slightly less than normal. IAS of 80 KIAS obtained. Ambient temperature 33 degrees F, approximately 1 inch of snow on the ice. The aircraft would not lift off the lake. A distance of approximately 2500 ft had been paced off prior to the takeoff for a gross weight takeoff. An effort such as a glassy water takeoff was used lifting one ski then the other. The C185 nearly jumped into the air after the first ski came off the ice. My question is this. Why? My weight and balance is attached. The skis were hydraulic wheel skis. Please respond should you be able to find an answer. I have contacted our local FSDO-03 in anchorage and they have as of yet not found why. Callback conversation with reporter revealed the following information: the reporter stated he was trying to takeoff from shell back lake. The cessna 185 on hydraulic skis accelerated to about 80 KTS and then slowed down. The analyst asked if there was the possibility that there was a little melting of water under the inch of snow and he said he did not believe so. He said the snow usually takes on a different color when there is water underneath. The performance decay remains a mystery. He has not contacted the manufacturer of the skis. He runs an aviation business with about 10 airplanes that are chartered to take people on to the glaciers.

Original NASA ASRS Text

Title: ACFT WOULD NOT ACCELERATE WITH BOTH SKIS IN CONTACT WITH THE GND ABOVE 80 KTS AND LIFT OFF. BY RAISING ONE SKI AS IN A GLASSY WATER TKOF THE ACFT NEARLY JUMPED INTO THE AIR.

Narrative: AN UNUSUAL CONDITION OCCURRED AND I AM LOOKING TO FIND AN ANSWER TO THE FOLLOWING. DEPARTING A FROZEN LAKE ON SKIS THE FOLLOWING OCCURRED. ACCELERATION, SLIGHTLY LESS THAN NORMAL. IAS OF 80 KIAS OBTAINED. AMBIENT TEMP 33 DEGS F, APPROX 1 INCH OF SNOW ON THE ICE. THE ACFT WOULD NOT LIFT OFF THE LAKE. A DISTANCE OF APPROX 2500 FT HAD BEEN PACED OFF PRIOR TO THE TKOF FOR A GROSS WT TKOF. AN EFFORT SUCH AS A GLASSY WATER TKOF WAS USED LIFTING ONE SKI THEN THE OTHER. THE C185 NEARLY JUMPED INTO THE AIR AFTER THE FIRST SKI CAME OFF THE ICE. MY QUESTION IS THIS. WHY? MY WT AND BAL IS ATTACHED. THE SKIS WERE HYD WHEEL SKIS. PLEASE RESPOND SHOULD YOU BE ABLE TO FIND AN ANSWER. I HAVE CONTACTED OUR LCL FSDO-03 IN ANCHORAGE AND THEY HAVE AS OF YET NOT FOUND WHY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED HE WAS TRYING TO TKOF FROM SHELL BACK LAKE. THE CESSNA 185 ON HYD SKIS ACCELERATED TO ABOUT 80 KTS AND THEN SLOWED DOWN. THE ANALYST ASKED IF THERE WAS THE POSSIBILITY THAT THERE WAS A LITTLE MELTING OF WATER UNDER THE INCH OF SNOW AND HE SAID HE DID NOT BELIEVE SO. HE SAID THE SNOW USUALLY TAKES ON A DIFFERENT COLOR WHEN THERE IS WATER UNDERNEATH. THE PERFORMANCE DECAY REMAINS A MYSTERY. HE HAS NOT CONTACTED THE MANUFACTURER OF THE SKIS. HE RUNS AN AVIATION BUSINESS WITH ABOUT 10 AIRPLANES THAT ARE CHARTERED TO TAKE PEOPLE ON TO THE GLACIERS.

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.

Aircraft would not accelerate with both skis in contact with the ground above 80 KTS and lift off. By raising one ski as in a glassy water takeoff the aircraft nearly jumped into the air.