CPR LTT JET FLC SUFFERS LOSS OF ACFT CTL WHILE ON SHORT FINAL DUE WX FACTORS (WIND GUST; WIND SHEAR); BUT UNABLE TO EFFECT RECOVERY PRIOR TO CONTACT WITH RWY; AT LEAST PARTIALLY DUE TO UNAVAILABILITY OF MEL DEFERRED SPOILERON SYS.

Date: 1993-05 · Aircraft: Light Transport; Low Wing; 2 Turbojet Eng

Anomalies: aircraft-equipment-problem-critical|inflight-event-encounter-loss-of-aircraft-control|inflight-event-encounter-weather-turbulence|other-runway-or-taxiway-excursion|other-unspecified

Synopsis

CPR LTT JET FLC SUFFERS LOSS OF ACFT CTL WHILE ON SHORT FINAL DUE WX FACTORS (WIND GUST; WIND SHEAR); BUT UNABLE TO EFFECT RECOVERY PRIOR TO CONTACT WITH RWY; AT LEAST PARTIALLY DUE TO UNAVAILABILITY OF MEL DEFERRED SPOILERON SYS.

Narrative

I WAS FLYING CPR LTT JET WITH THE SPOILERON SYS INOP AND DEFERRED. ON APCH TO RWY 6 AT BRADLEY INTL ARPT IN CT; (BDL). THE LAST WIND RPT FROM THE TWR WAS VARIABLE 300 DEGS TO 350 DEGS; 16 KTS GUSTING TO 24 KTS. AT 100 FT AGL ON A STABILIZED APCH AT 145 KTS (A REF SPD OF 128 KTS PLUS THE WIND FACTOR) THE SPOILER LIGHT ON THE WARNING PANEL ILLUMINATED INDICATING A FAULT IN THE SPOILER SYS. 3-4 SECONDS LATER THE ACFT MADE AN UNCOMMANDED ROLL TO THE R WHICH FULL L AILERON COULD NOT FULLY CORRECT. THE ACFT WAS STILL ROLLING TO THE R AND THE NOSE WAS DROPPING WHILE I ADDED FULL PWR ON BOTH ENGS TO ATTEMPT A GAR. WE WERE NOW AT ABOUT 20-30 FT AGL. THE ACFT WOULD NOT CLB WITH FULL PWR. 3-4 SECONDS AFTER FULL PWR WAS ADDED; AND IT WAS OBVIOUS THAT WE WERE NOT CLBING; THE STALL WARNING SHAKER WAS ACTIVATED. WE DSNDED ONTO THE RWY WITH ABOUT A 40 DEG BANK TO THE R AND THE NOSE BELOW THE HORIZON WITH THE STICK SHAKER ON AND FULL PWR. AT OR SLIGHTLY BEFORE IMPACT; I REDUCED PWR TO IDLE. I FELT ONE IMPACT AND WE DEPARTED THE RWY ON ABOUT A 080 DEG HDG WHERE I BROUGHT THE ACFT TO A STOP 1100 FT LATER. MY ____ AND I WERE THE ONLY PEOPLE ON BOARD (THIS WAS A FERRY LEG TO PICK UP PAX). NEITHER OF US WERE HURT BUT THE ACFT SUFFERED DAMAGE TO THE R WING; TIP TANKS AND FLAPS. ABOUT 1 OR 2 SECONDS BEFORE THE SPOILER LIGHT WAS ILLUMINATED WE ENCOUNTERED A VERY STRONG GUST OF WIND THAT FELT AS THOUGH THE ACFT WAS BEING LIFTED WITH GREAT FORCE. THERE WAS NO WIND SHEAR ALERT AT THE ARPT BUT I AM INCLINED TO BELIEVE THAT THERE MIGHT HAVE BEEN A SORT OF ROLL CLOUD THAT WAS CREATED BY THE HILLS NW OF THE ARPT. ONE THING THAT LEADS ME TO THIS CONCLUSION IS THAT WITH FULL PWR; THE ACFT SHOULD HAVE CLBED AT ABOUT 3000-4000 FPM IN THE CONFIGN WE WERE IN. I WOULD ALSO RECOMMEND THAT THE SPOILERON SYS NOT BE PERMITTED TO BE DEFERRED ON THE MASTER MEL. I DON'T KNOW HOW MUCH DIFFERENCE THIS WOULD HAVE MADE BUT YOU CAN'T PREDICT WHEN YOU WILL NEED FULL ROLL ABILITY. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: A THIRD PARTY CALLBACK WAS CONDUCTED TO ELICIT SPECIFIC INFO ABOUT CPR LTT JET SPOILER/SPOILERON SYS. THIS SYS CONSISTS OF 4 SPOILER PANELS; 2 PER WING. THE INBOARD SET ARE USED FOR SPD BRAKE AND LIFT DUMP; WHILE THE OUTBOARD SET ASSIST THE AILERONS WITH ROLL CTL WHEN FLAP SETTINGS OF 25 DEGS OR MORE ARE USED (THE SYS IS NOT OPERATIVE IF THE FLAP SETTING IS LESS THAN 25 DEGS). THE RPTR NOTES THAT THE MASTER MEL FOR THE CPR LTT JET PERMITS; UNDER FAR PARTS 91 AND 135; CATEGORY B DEFERRAL OF THE SPOILERON AND/OR SPOILERON COMPUTER SYS -- THE ACFT MAY BE LEGALLY OPERATED WITH THE SYS INOP FOR A MAX OF 72 HRS. (THIS WAS CONFIRMED THROUGH ANOTHER; THIRD PARTY CALLBACK WITH THE MAINT DEPT OF A LARGE CORPORATE OPERATOR). THE RPTR FEELS THAT ALTHOUGH THE UNAVAILABILITY OF THE SPOILERON SYS DID NOT CAUSE THE LOSS OF ACFT CTL; HE COULD HAVE SATISFACTORILY REGAINED CTL OF THE ACFT HAD THE SYS BEEN SVCABLE. THE RPTR FURTHER ADVISED THAT THE FAA HAS CLASSIFIED THIS AS AN 'INCIDENT.' DAMAGE TO THE ACFT WAS SUCH THAT BOTH TIP TANKS REQUIRED REPLACEMENT; AS DID THE OUTBOARD SECTION OF 1 WING. THERE WAS MINOR DAMAGE TO THE FLAPS FROM CONTACTING RWY LIGHTS DURING THE RWY EXCURSION. IT IS THE OPINION OF THE RPTR (AS WELL AS THE MAINT MGR OF THE REFED CORPORATE OP); THAT THE SPOILERON/SPOILER COMPUTER SYS ON THE CPR LTT JET IS PART OF THE ACFT'S PRIMARY FLT CTL AND AS SUCH SHOULD NOT BE DEFERRABLE; EXCEPTING THOSE CIRCUMSTANCES WHERE THE ACFT FLT MANUAL PERMITS LNDG WITH LESS THAN 25 DEGS OF FLAP; IN WHICH CASE THE FLAPS SHOULD BE PLACARDED PROHIBITING LNDG WITH 25 OR MORE DEGS OF FLAP. FURTHER; THE RPTR RECOMMENDS THAT CURRENT SIMULATOR TRAINING PROGRAMS BE MODIFIED TO PERMIT TRAINEE EXPERIENCE WITH SPOILERONS INACTIVE.

Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.