Water takeoff of amphib experienced reduced climb rate immediately after liftoff. Unable to climb ov...

Attributes
ACN	172212
Time
Date	199103
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : jnu airport : nju
State Reference	AK
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air taxi
Make Model Name	Small Aircraft
Flight Phase	climbout : takeoff climbout : initial
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial
Experience	flight time last 90 days : 120 flight time total : 1850
ASRS Report	172212
Events
Anomaly	inflight encounter other non adherence : far
Independent Detector	other other : unspecified cockpit
Resolutory Action	flight crew : regained aircraft control
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

After back taxiing more than would normally be adequate, for a safe departure on water in my aircraft, I completed a 180 degree clearing turn and announced my intentions on 122.9. I started my takeoff run heading ese, planning to make a 180 degree turn and proceed towards juneau international airport. After lifting off and accelerating to vy I started a climb to a safe altitude to make my 180 degree turn. At approximately 50 to 100' I encountered 3 severe downdrafts, forcing me back down into ground effect. It was at this time that I decided to abort takeoff and attempt to land. I turned right 25-30 degrees, avoiding the boat harbor, and reduced the power bringing the aircraft back into ground effect. The wind was now 90 degrees to the aircraft and exceeded the crosswind component of the aircraft. I then added power and xed under the highest point in the bridge (approximately 200') in ground effect and was able to then climb out safely. The obvious way to avoid this situation in the future would be to not to depart in this type of wind. However, if it were necessary to depart in this situation obviously a longer back-taxi should be used.

Original NASA ASRS Text

Title: WATER TKOF OF AMPHIB EXPERIENCED REDUCED CLIMB RATE IMMEDIATELY AFTER LIFTOFF. UNABLE TO CLIMB OVER BRIDGE OBSTRUCTION. FLEW UNDER THE BRIDGE BEFORE CONTINUING INITIAL CLIMB.

Narrative: AFTER BACK TAXIING MORE THAN WOULD NORMALLY BE ADEQUATE, FOR A SAFE DEP ON WATER IN MY ACFT, I COMPLETED A 180 DEG CLRING TURN AND ANNOUNCED MY INTENTIONS ON 122.9. I STARTED MY TKOF RUN HDG ESE, PLANNING TO MAKE A 180 DEG TURN AND PROCEED TOWARDS JUNEAU INTL ARPT. AFTER LIFTING OFF AND ACCELERATING TO VY I STARTED A CLB TO A SAFE ALT TO MAKE MY 180 DEG TURN. AT APPROX 50 TO 100' I ENCOUNTERED 3 SEVERE DOWNDRAFTS, FORCING ME BACK DOWN INTO GND EFFECT. IT WAS AT THIS TIME THAT I DECIDED TO ABORT TKOF AND ATTEMPT TO LAND. I TURNED R 25-30 DEGS, AVOIDING THE BOAT HARBOR, AND REDUCED THE PWR BRINGING THE ACFT BACK INTO GND EFFECT. THE WIND WAS NOW 90 DEGS TO THE ACFT AND EXCEEDED THE XWIND COMPONENT OF THE ACFT. I THEN ADDED PWR AND XED UNDER THE HIGHEST POINT IN THE BRIDGE (APPROX 200') IN GND EFFECT AND WAS ABLE TO THEN CLB OUT SAFELY. THE OBVIOUS WAY TO AVOID THIS SITUATION IN THE FUTURE WOULD BE TO NOT TO DEPART IN THIS TYPE OF WIND. HOWEVER, IF IT WERE NECESSARY TO DEPART IN THIS SITUATION OBVIOUSLY A LONGER BACK-TAXI SHOULD BE USED.

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.

Water takeoff of amphib experienced reduced climb rate immediately after liftoff. Unable to climb over bridge obstruction. Flew under the bridge before continuing initial climb.