A chief at a major east coast city police department was wondering why the helicopter inspection was taking so long. After all, the unit's maintenance technicians were well trained and top-notch; why couldn't they quickly get the helicopter back into service? The conversation between the chief pilot and chief went something like this:
Why can't you tell me how long this will take? I can take my car into 'Super Fast Lube' and they take about 10 minutes. This is the same just a little more complicated.
We can all see where this conversation went. The oft made comparison between vehicles and aircraft often lead to these types of - well let's say interesting conversations.
The Reality of Aircraft Maintenance
Many people are surprised to learn of the age of airborne law enforcement aircraft. Some military surplus aircraft can be approaching 40 years old! However, comparing an aircraft to a car, or any other vehicle for that matter, is like comparing apples and oranges, because all aircraft are routinely and often vigorously inspected. Most airborne law enforcement operators follow the maintenance schedule prescribed by the aircraft manufacturer. This includes required inspections at certain flight intervals, usually at intervals of 25 hours of flight time. Quite often at the 100 hour mark, there is a more detailed inspection and usually a very thorough annual inspection is completed. These scheduled inspections are often combined with an aircraft maintenance technicians daily inspection and the pilot's pre-flight inspection which insure the aircraft is airworthy and safe for flight.
The Inspections
The aircraft maintenance technicians daily is primarily a visual inspection that includes a general look at the aircraft, the inspection of all fluids and a specific look at any common problem areas. The inspection is normally conducted on any aircraft that has flown the previous day and is designed to uncover major safety of flight problems. Before launching on a mission, the pilot-in-command or designee is required to do a pre-flight inspection checking the aircraft over for any obvious safety items or maintenance issues. The pilot will generally do a walk around the aircraft checking such items as lights and any other abnormal conditions. Picture a driver checking all fluid levels, tire pressures and looking under the hood every time they drove their vehicle!
The scheduled inspections are more detailed and require more time. In these inspections, the aircraft manufacturer and engine manufacturer usually have a comprehensive and detailed checklist of items that must be inspected. Often, preventive maintenance is completed. The length of time for an inspection is entirely dependent on what is found. For example, if an aircraft maintenance technician finds a dent in a tail boom, they are required to consult maintenance manuals in order to determine the course of action. After noting the location of the damage and measuring certain parameters, the technician will often consult with the aircraft manufacturers engineering department to determine what, if any corrective will need to be done. If the damage needs to be repaired, the inspection will obviously take longer.
The technician is required to inspect and subsequently sign-off on numerous items. The sign-off is a certification by the inspecting technician that the particular item has been inspected and was found to be within limits or required repair. In addition to the inspection items, there are some life-limited parts that may need to be changed. Some aircraft parts come with a time limit and they must be retired regardless of condition. For example, a particular engine requires a valve to be replace every 5000 hours of flight times, regardless if it is pristine condition or badly worn. Once again, these small items take time in order to be replaced correctly. At certain intervals, major components such as the engine or transmission need to be sent out for major overhaul before being returned into service.
The Annual Inspection
Once a year, most aircraft are subjected to an annual inspection. This inspection, which is very detailed and comprehensive, can require the removal of parts and items for non-destructive testing or advance metallurgical or boroscope inspection. The aircraft will often be in pieces and to the untrained person it can appear to be completely stripped and gutted! It is during this inspection that the technician will look closely for corrosion, wear and other signs of worn parts. In most cases, access panels are removed for close and detailed inspection at what lies beneath. In one instance, a very diligent technician discovered a small crack in the tail boom of a helicopter. This crack was discovered through the use of a hand held mirror deep inside the tail. It was a crack that undiscovered, could have proven fatal. The tail boom needed to be removed and the crack repaired. The subsequent repair took approximately three weeks.
Paperwork, paperwork and more paperwork
Much like their patrol counterparts, the aircraft maintenance technician has to properly record and document every repair and action taken. If simply changing a light, the technician is required to make recorded entries as to what exactly was done and they must reference how the repair was made. If a landing light is changed, the entry would read something like, changed front landing light in accordance with (aircraft manufacturer) maintenance manual. Just like in every other aspect of police work, documentation is critical. In many agencies and maintenance companies, all work is inspected by another technician for quality and correctness as a back-up. Finally, the technician signs off authorizing the aircraft to return to service.
The Aircraft Maintenance Technician
The hard work and dedication of the aircraft maintenance technician is often overlooked and almost never seen. They work diligently and often under difficult circumstances to make certain their aircraft are safe. Ultimately, it is their work that allows airborne law enforcement aircraft to support the officers on the street.
Sorry chief; the aircraft maintenance inspection process is nothing like your ten minute oil change at Super Quick Lube!
About the Author
Kenneth J. Solosky
Lt. Kenneth J. Solosky retired after 21 years of service with the New York City Police Department and had been assigned to the Warrant Division and as a police academy instructor, serving in the ranks and assignments as a. patrol officer, patrol sergeant, lieutenant, and patrol platoon commander, He retired as the Chief Pilot/Director of Training in the NYPD Aviation Unit. Ken recently was appointed the Chief Pilot for the Newark, NJ Police Aviation Unit. Ken has a BA degree in Public Administration from St. John's University and a Masters degree in Criminal Justice from the City University of New York, John Jay College of Criminal Justice. He holds FAA Airline Transport Pilot ratings in both airplanes and helicopters, is a certified flight instructor and a member of the Airborne Law Enforcement Association (ALEA). He can be reached via e-mail at [email protected].