Date: 201702
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B767 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Aircraft component: Squat Switch
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: First Officer
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew Overcame Equipment Problem
Contributing factors: MEL; Procedure; Aircraft; Human Factors
Primary problem: Aircraft

Narrative: Inbound aircraft had various write-ups that maintenance cleared. Those included an ACARS reporting issue; lavs overflowing; and autobrakes failing to arm. One write-up that wasn't cleared was the landing gear lever lock solenoid was not working properly thus crew has to use the override procedures. It was deferred [a few days prior]. Aircraft was dispatched and departed. Shortly after reaching cruise altitude we passed a waypoint but the HOWGOZIT did not update with actual fuel and time. Dispatch then sent a message asking about our delayed takeoff. I then pulled up ACARS Prog ID/Sensor page which displayed AIR/GND in GND. Flight Manual procedures and systems involved were nonexistent. Very disappointing. Crew felt a normal landing could be made at destination. Several hours later; near coast in; Flight Attendant notified flight deck that the Mid Lavs were overflowing. Did not know at the time that the drain mast heaters still were in ground mode which is inadequate at altitude. Normal landing at ZZZ. ZZZ maintenance was shown a printed page of the ACARS sensor page showing AIR/GND in GND. Outbound crew was briefed on aircraft issues. Hindsight says AIR/GND switch should have been tested [at other airports]. As important; the Flight Manual needs to have systems that are related to this switch.


Second narrative: I was the First officer that operated Aircraft X. When we got to Maintenance that morning we looked at all the paperwork and saw that the landing gear switch up lock was deferred; which at the time we though was a valid deferral. The only other inbound write ups for broken T.V. Screens; which were cleared by Maintenance. We complied with the MEL and after takeoff we overrode the gear switch solenoid and continued the flight. About 90 minutes into the flight we get a message saying that we have been out for 90 minutes and we need to be starting the extended delay checklist. In reality we had been in the air the entire time. We looked in the ACARS and found that there was no valid off time recorded (even though we got a valid off time on the HOWGOZIT.) Then we started thinking there was more to this gear switch latch deferral than meets the eye. So; the first two clues we had were the no ACARS off time and having to override the gear switch. The Captain and I came to the conclusion that the airplane still thinks it is on the ground. We sent out concerns to Maintenance and they came back and told us that they believed the gear latch was a valid deferral. We pressed on. Once we were about 3 hours outside [our destination] we started having more things go wrong. Here is clue number three; and it started in the business class area. We got a call from the flight attendants saying that there was a significant leak coming from right mid lav so we had them shut the water off and block off the lav. Then we got another call that the leak had migrated over to the left mid lav so we did the same thing. We had them shut the water off and lock off the lav. Then the problem migrated back to the aft lavs and then the forward lav in the descent. I had at some point called to the aft galley and had asked them what the total gallons was in the water tank and they came back and said there was still 140 gallons left and holding; so it wasn't a water leak. The sinks were backing up because the aircraft still thinks it's on the ground; and consequently the drain masts were not fully heated and were iced over causing all the drain lines in the aircraft to back up onto the carpets and all over the airplane. The Flight attendants eventually ran out of blankets to sop up the water and they started to use the first class slippers (I didn't know it was that bad until we got to the gate in [our destination].) Clue four; this time the speed brake. On the descent we needed to get down so I used the speed brakes. When we used the speed brakes we had both flight and ground spoilers deploy and we immediately retracted them (aircraft still thinks it's on the ground). At the same time we got a spoiler EICAS message. We ran the QRH and continued. Clue number 5; the auto brake. While briefing the approach and talking about using auto brake we saw that the auto brakes never released from Rejected Take Off (RTO) (aircraft still thinks its on the ground) and we couldn't arm the auto brakes; Landing was uneventful. Get to the gate and there in no Maintenance to meet us; not sure if that is a customs requirement or not that they can't meet the aircraft. So here is what we had.Gear switch up latch wont releaseNo off and on times on the ACARSBasically all lavs leaking (and we only had 86 pax)Full spoiler deployment in flightAuto brakes stuck in RTO and unable to arm them for landing.All of these things are associated with the air/ground system; and the last four items were written up by us before we left the airplane. I figured that Maintenance would put that all together and see that there was something majorly wrong with the aircraft that needed to be investigated. My opinion from the rest of this narrative is driven from what I gleamed off what was written in the Electronic Log Book history that you can pull up and a screen shot is posted with this report. When I have weird things happen to the aircraft I fly I like to pull up the maintenance historyto see how it was fixed so I have a better understanding of what went wrong. That evening I looked at the maintenance history and saw what looked like to me that all of our write-ups were cleared as op checked good and that the plane was on its way to ZZZ. Here are my concerns about how the write-ups were cleared. First; the ACARS was cleared by ops checking the ACARS by cycling the parking brake. My concern was that the ON\IN times are connected to the parking brake not the OFF\ON times which are on the AIR/GND system. The water leak was cleared with a wrench check and no leak was noted; so if there was no leak noted where did all the water in the cabin come from and it was a significant amount of water everywhere (unless it was cleaned by scrubs before Maintenance got on the plane.) The autobrakes and the spoilers were both ops checked good on the ground and that makes sense because they are not going to find a fault on the ground; both the spoilers and the autobrakes were acting like they were on the ground in flight. All of these systems and the already deferred gear latch are all on the AIR/GND system. I didn't read anywhere that that system was looked at. After I saw that the aircraft was on its way to ZZZ I was very concerned for the next crew because on the map it showed that they were airborne but that it still showed them taxiing out to the runway making me believe that it didn't record an off time just like our flight. I was also concerned because it appeared to me that they were going to have the same problems that we had; and that airplane had no business flying until the AIR/GND system had been evaluated. It was at that point I contacted the safety committee to elevate my concerns and to somehow let the crew know what they were getting into so that it wouldn't be a surprise like it was for us that their lavs will leak; they will have no autobrakes and they shouldn't use the spoilers because they would get full flight and ground spoiler deployment in flight. We used to be able to see the major components that were on the AIR/GND system in the flight manuals. That information has since been removed from our flight manuals so I am unsure of what else we had wrong that we didn't know about but I'm sure that it was a lot of other systems.


Synopsis: The flight crew of a B767 reported that various systems were inoperative due to a defective air/ground sensor.