Date: 201604
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Night
Aircraft: Learjet 35
Operator: Air Taxi
Operating under: Part 135
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Initial Approach
Airspace: Class B ZZZ
Aircraft component: Fuel Crossfeed
Component problem: Improperly Operated
Reporter organization: Air Taxi
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Human-Machine Interface; Situational Awareness
Second reporter function: Captain; Pilot Flying
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Ground Strike - Aircraft; Inflight Event / Encounter Fuel Issue; Inflight Event / Encounter Unstabilized Approach
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; Flight Crew Became Reoriented; Flight Crew Landed in Emergency Condition
Contributing factors: Human Factors; Aircraft
Primary problem: Human Factors

Narrative: I was the Second in Command (SIC)/Pilot Monitoring for the leg. During preflight; all systems worked properly per Learjet 35 Expanded Normal Procedures and appropriate checklists. Upon departure we noticed that many of the electroluminescent backlights on panels were inoperative. This included the autopilot panel; fuel panel; two circuit breaker rows on Right Hand (RH) side of aircraft and several others. We were able to see what we needed with the 'arm burner' side lights and personal flashlights. During cruise; when the PIC engaged the autopilot; he engaged altitude hold; the airplane moved in response that altitude hold was working but no light appeared. It took pressing the button twice more to get a light.At approximately 100nm from destination; we noted ATC had not given us a descent instruction yet and concluded we would ask at 85nm. Around this time; the PIC noted a fuel imbalance of approximately 200 lbs heavy on the left side. He then turned on the left standby fuel pump and crossflow valve; both lights operated normally. At around 90nm ATC gave us a descent to 10;000 feet followed by 9;000 feet. We started a descent and descent checklist. We descended normally and somewhere above 10;000 feet the PIC disengaged autopilot and flew by hand. Throughout the descent; we both referenced the Garmin GPS multiple times to reference our descent profile planning. The GPS sits just aft of the fuel panel. The fuel panel was somewhat dark as previously mentioned. A bright standby fuel pump switch would have been very noticeable with the contrast. To our best recollection; throughout the descent neither of us saw the fuel standby pump light on. At approximately 30nm from field I asked the PIC if he would like an Approach Checklist to which he agreed. I ran the approach checklist and used the arm burner light to check the fuel balance and quantity as we both observed. Airplane was balanced. To my best recollection; again; did not see a fuel pump light on. I again looked at the fuel panel/total to see fuel used in order to calculate a Vref speed of approximately 123 kts. We saw the airport at approximately 20nm out and were cleared for the visual approach to runway 27. We then cancelled our IFR flight plan. I switched to CTAF; turned the lights on and made a radio call inbound for downwind runway 27. On a long downwind the PIC noticed a need to hold left aileron to hold the aircraft level. I checked the aileron trim and advised him to adjust that if necessary. On downwind the PIC called for flaps 8 and I did. On a circle from downwind to base to final; as gear and flaps were extended the rolling tendency worsened. A Before Landing Checklist was completed. The approach was unstable and the PIC complained of control effectiveness. I gave a speed call out reference to Vref and told him to let me know if he needed me to do something extra. He again complained about the left aileron needed; and at that time I told him that a go around was an option if he didn't feel comfortable. At approximately 500ft the PIC initiated a go around and the aircraft was cleaned up per procedure. I referenced the VFR sectional to check for airspace in our immediate vicinity; and advised the PIC that airspace was clear westbound if we wanted to go troubleshoot. He turned a left crosswind; southbound; and again I checked for airspace and told him southbound was clear to fly out and troubleshoot. He said 'I just want to get this thing on the ground I can't control it...it's too hard to control.' He made a continuous circle for runway 27 and called for gear down. He advised we would land with no flaps and approach at Vref+30 per the Airplane Flying Manual (AFM). Upon rollout to final approach we had 4 red PAPI lights. I advised the PIC we were Vref+30 and very low. He advanced the thrust levers to attain a better vertical profile. We approached at Vref+30 and in the instant prior to touchdown the airplane still kept attempting to roll right. The PICapplied slight asymmetrical thrust in attempt to raise the right wing. This action yawed the aircraft nose left and still tended to roll right. The PIC had almost full left aileron deflection in and the airplane touched what seemed like simultaneously on the right wingtip fuel tank and right wheel followed by the left wheel and then nose wheel. I urgently advised him we needed brakes and spoilers as the runway was 7200ft and we landed 30kts above normal speed. He hit brakes and yelled for me to deploy spoilers which I did. The airplane came to a safe speed and we exited at taxiway Foxtrot. We taxied to the FBO and shut down. After the PIC opened the door; the line technician grabbed our attention that the airplanes right tip was leaking fuel; this was the first time we noticed. The PIC noted that he now knew why the airplane was unstable and pointed to the fuel panel; this was because of fuel imbalance. To our best recollection; we both then looked at the dark fuel panel to see the left fuel pump switch on but no light. We turned off the necessary equipment and departed the airplane.As with many events; this is no different; there is not just one factor that leads to the result. In fact; I believe several items had a hand in the result of this incident. Therefore I have several suggestions and thoughts on improving both personally and operationally as a company to ensure this type of event is never repeated. First and foremost; I believe there was a breakdown in communication among us crew during the initial fuel transfer. We were both aware the fuel pump came on; however that fact became lost in the descent and approach phase.In the future when I transfer fuel I will ensure that it is done in a less demanding phase of flight. If it is required to be during that time; I will implement a technique to ensure it is continuously known that a transfer is in progress. As a company and flight operation; I believe we can make a standardized flow or check to ensure correct interpretation. In both cases; ensuring switch position should have a higher priority than light/annunciation illumination. In our case; both crew members believed the fuel light was not lit and therefore 'out of sight; out of mind.' I believe this mechanical irregularity also contributed to the incident. The lack of backlighting on the fuel panel also was a factor in this event; and provided an opportunity to overlook that area; especially when attention was required elsewhere. I also suggest a change to the checklist wording. The Cruise and Descent checklists both have wording 'Fuel management.' The Approach Checklist has wording 'Fuel (balance & quantity).' I believe the approach checklist should also read Fuel Management for the fact that fuel balance and quantity can be checked with only the fuel gauge and selector. In a dark or poorly lit cockpit; I admit now it is easy to overlook the other switches in the fuel panel. As we learned in this flight; there may be the case where the crew is indeed moving fuel just prior to the approach checklist. Our operation has a 'flow' and canned response during 'Flight Instruments' during the taxi checklist. When the pilot monitoring reads 'flight instruments' the pilot flying responds by reading through each instrument in a standardized call out. I propose when 'Fuel Management' is read on any checklist; there should be a similar read back call. Such as: 'xxx left tip; xxx right tip; xxx left wing; xxx right wing; xxx trunk; xxx total; transferring left/right/forward/aft/none.' This forces the person checking to look at balance; quantity; and switch positions. I feel that this is a fairly effective and simple way that all company flight crews can ensure proper fuel management during all phases of flight.After our initial unstable approach and subsequent go-around; I believe there was also a breakdown in communication regarding conflict resolution. Twice; I prompted the Captain/PIC to bug out of the airspace and fly the aircraft in order to troubleshoot the issue. I firmly believe that had we as a crew flown the airplane even a few minutes more whilst troubleshooting the rolling tendency; we would have found our error; corrected; and landed without damaging the aircraft. As the aircraft was sped up and cleaned up; although not at the controls; I believe control effectiveness increased. With a right rolling tendency; we did still have enough control to make a complete left hand traffic pattern. I fully understand in that state of unknown near-loss of control; tensions are high; however time should be allotted to understand and potentially remedy the issue. I believe there should have been more cooperation and communication among us crew. In the future; I undoubtedly will speak up more and as a future captain/pilot flying assess the concerns of the other crewmember(s).I believe this to be an unfortunate error that ultimately can be used as an assessment and tool for learning both personally and as a company flight operation. I have; without a doubt; learned from this error and breakdown of Crew Resource Management (CRM) and will immediately implement personal changes to flying and crewmember duties to ensure this does not ever happen again.


Second narrative: In our Lear 35; 80 nms out; we started our descent for landing. We preformed the 'Descend Checklist' and noticed that we had a 200-300 fuel imbalance; making the left tank heavier. I elected to balance the tip tanks. The 'Left Standby Pump' and 'Crossflow' valve were turned on; The Standby Pump Indictor light came on. At 30 nms we did the 'Approach Check' list. I physically saw and orally heard the FO do the fuel balance check; which was included as an item on the checklist. The 'standby pump' light was not illuminated. On downwind I began to notice I had to put extra ailerons inputs and re-trimming the rudder. Having seen and [heard] the FO do the checklist; our being new to this plane; the plane having been flown in 2 mouths and the increasing uncontrollability of the plane; I decided to land as soon as possible on runway 27; to avoid our window of safety closing further. Runway 27 was right below us. Our first attempt ended in a go around. On final; we had ten percent controllability. With the second attempt by keeping a 155+ kts speed; we had 20 to 25 percent controllability. We made our final approach at 155 kts; lowered the gears and touched down on the first 500 feet. The right tip tank struck the runway due to its excess fuel load in the right tip tank. The standby pump had been missed in the 'Approach' check due to the light not illuminating.1. use an indirect alerting system: told card or checklist between the trust levers and/or2. change the checklist from 'fuel' to '7 Fuel Items' or 'Fuel Panel' stressing-balance; quantity; jet pump; standby pump; jettison; crossflow; transfer/fill switches.3. do this on 'descend; approach; and before landing' checklists


Synopsis: LR-35 flight crew reported landing with a large fuel imbalance due to the fuel crossflow valve light being inoperative. An earlier fuel crossfeed had been set up to address a fuel imbalance and was never secured during the Approach Checklist; due to the missing light indication. The right wingtip tank was damaged during the landing.