Maintenance Archives - Golf Hotel Whiskey

How to get rid or aircraft cabin odor

The Sell That Plane blog, which is focused on tips, tricks and tactics for selling an aircraft, has a useful post about getting rid of aircraft cabin odor which is well worth reading even if you aren’t trying to sell your aircraft.

The post began by noting the lack of air conditioning means you are sweating in those seats – either due to summer heat or perhaps because your flight has gone down to the minimums. Then there always the chance of a passenger loosing their lunch while flying with kids can make the aircraft cabin smell like a “typical minivan.”

Since smells can linger in fabrics, Sell That Plane suggests getting the most mild scented Fabreze to spray down the seats or carpets. Then buy a can of Ozium and spray it in the cabin, closing the door. After sitting overnight with both Fabreze and Ozium in the cabin, airplane cabin odor should be history.

For a more severe aircraft cabin smell issue, the Sell That Plane blog suggests wiping down all cabin surfaces, cleaning out any doors or seat pockets, vacuuming or steam cleaning the carpets (either by renting a machine or having a professional do it), steam cleaning the seats and filling the aircraft cabin with Ozium and just letting it sit awhile (Ozium also works good about an hour before any perspective buyer shows up to look at the aircraft). In other words, taking care of your aircraft cabin and any odor problem in it is no different than taking care of any similar problems in your vehicle.

Finally, the Sell That Plane blog notes that a professional aircraft cabin cleaning (at least in the USA) should not cost more than $75 while a can of Fabreze and Ozium won’t cost more than $20 – small prices to pay if you are trying to sell your aircraft or just don’t want it smelling like your first training aircraft!

Proper constant-speed propeller maintenance

Ron Rapp, the blogger behind the House of Rapp blog, has a lengthy post about a topic that will probably bore most pilots or aviation enthusiasts: Proper or improper maintenance on a constant-speed propeller – a critical safety issue. Ron began his post by telling how Rob Cable, who was the grandson of the founder of Southern California’s Cable Airport, billed as “the world’s largest family-owned public-use airport,” was killed during a post-annual test flight in his twin-engine Beech 95 Travel Air.

The cause? A 2.5 foot-long portion of the right engine’s propeller blade had failed – meaning the hub ended up attached to a three-foot blade on one side and a broken 6″ stub on the other. This imbalance caused a vibration which severely overstressed the engine mount and tore the right engine off the airframe – rendering the aircraft uncontrollable.

Although what happened to Cable was a massive failure, Ron commented that he has seen cases of props shedding just an inch or so off a blade tip – enough to cause a vibration severe enough to shatter instruments in the cockpit, tear cowlings away and cause other serious damage.

However, the NTSB delved the maintenance records of Cable’s aircraft and found that the props had just been overhauled at an FAA-approved Repair Station. The problem was the investigation revealed a whole series of discrepancies between the overhaul procedures specified in maintenance manuals and the physical evidence found in the propellers – meaning the mechanics were criminally negligent in the performance of (or lack of performance in) their work.

Ironically, Ron himself had his propellers serviced at the same shop and was forced to spend another small fortune to have them re-serviced at another shop – meaning the “FAA Certified Repair Station” designation actually means nothing.

Ron also mentioned that props have a recommended Time Between Overhaul (TBO) and for most constant-speed props, it’s 2400 hours or six years. However, there are instances where a TBO is not mandatory – meaning it’s not uncommon to have aircraft where its been 10, 20 or even 30 years since the prop and/or governor were overhauled. And yet, all of those tiny parts or seals inside the propeller are exposed to both the elements (one way or the other) and to age or use related wear and tear (Ron himself would actually rather fly behind a 30 year old engine than a 30 year old prop).

If you fly an aircraft with a constant-speed propeller, Ron’s entire post will be a must read and will encourage you to check up on the maintenance of your constant-speed propeller.

Loose fuel lines lead to accidents

General Aviation News will often reprint excerpts from US National Transportation Safety Board (NTSB) accident reports, including two accidents that involved loose fuel lines after maintenance work or an inspection.

In the first accident report dated February 2010, a Piper Malibu Mirage suffered substantial damage in Nashville but luckily there were no injuries. According to the report, a 2,632-hour commercial pilot was in cruise flight when the alternator light illuminated and he smelled smoke. While diverting to the nearest airport, he lost all power on the descent but safely landed and he then noted light smoke coming from cowling for several minutes after landing.

An inspection by an FAA inspector found that the fuel control unit feed and return lines were “loose at the rear engine baffle fittings immediately above the starter and starter adapter.” A review of maintenance records showed that the starter adapter had just been replaced nine hours before the accident – meaning the mechanic had failed to properly secure the fuel control unit fuel lines.

The second accident report dated May 2010, a Piper Warrior II suffered substantial damage in Chandler (Arizona) resulting in one serious and one minor injury. According to the accident report, a private pilot and a CFI were performing touch-and-goes when smoke began to fill the cockpit – most likely coming through the defroster vents. The smoke soon became so thick that the CFI could not see outside of the windows and he ended up making a hard landing.

A review of maintenance records revealed that the last annual inspection had been completed just two days before the accident and the aircraft had flown about four hours since then. An inspection of the aircraft then revealed that the fuel line leading from the engine-driven fuel pump to the carburetor was disconnected at the fuel pump with no visible impact damage to the “B” nut on the line or to the fitting on the fuel pump – meaning the line was undone before impact.

It was concluded that the “B” nut on the line had not been properly tightened by maintenance personnel and probably backed off due to normal engine vibration. In other words and right after maintenance, check those fuel lines!

Do you know when your fuel selector valve is turned off?

General Aviation News will often reprint accident report excerpts from the US’s National Transportation Safety Board (NTSB), including a February 2010 accident report about an incident involving a Beech Musketeer in Winter Haven (Florida) that led to two fatalities.

Specifically, a private pilot had more than 468 hours but no flight time between November 22, 2003 and October 4, 2008 and then 5.7 hours in the Musketeer between December 6, 2009 and December 16, 2009.

On the day of the fatal incident, the pilot took off but the aircraft engine lost power on the initial climb, stalled and then crashed. An examination of the wreckage revealed no mechanical malfunctions but the fuel selector was observed to be in the off range.

Further testing of the fuel selector revealed no other mechanical problems and the evidence from the crash suggested it was in the off position after takeoff.

However, the mechanic who performed the aircraft’s last 100-hour inspection six months before the fatal accident apparently missed the fact that the fuel selector valve guard and stop lacked the required markings that clearly depict its off range. According to Airworthiness Directive (AD) 85-05-02, there should have been a clear label or decal to indicate when the fuel selector was on or off.

Hence, the probable cause of the accident was the pilot having left the fuel selector valve off during takeoff along with his failure to maintain adequate airspeed after a loss of engine power. A contributory factor was the mechanic’s failure to spot the lack of markings on the fuel selector stop and fuel selector valve.

When is an aircraft too old to fly?

Too old to fly is usually a topic associated with the age of the pilot but when is an aircraft too old to fly? A recent article by Richard Collins for Air Facts Journal noted that 1979 was the last year that a significant number of aircraft were built (along with the few year period before that) while the last time production figures were this low was in 1952. This means that much of the aircraft fleet is around 33 years old or older. Hence and for younger pilots, the aircraft they fly might actually be older than they are.

Moreover, Richard noted that a friend of his has put in at least $30,000 into an old twin for routine maintenance over 12 months – and the aircraft is probably worth only about five times as much that maintenance bill. And while Richard pointed out that its easy to think that some aircraft will never wear out (think of the B-52s or DC-3s that are still flying), that’s only true if you have significant amounts of money to spend on maintenance (the USAF etc.) and perhaps if the aircraft’s maker is still in business. After all, getting parts for an old aircraft can be a challenge – especially if the aircraft maker has long sense merged or been put out of existence.

Finally and aside from the maintenance cost issue, the next concern with older aircraft would be the risks associated with flying one. Richard wrote that he has researched the subject of risk with older aircraft and has concluded that there is no way to know for sure just what the relationship is between the number of hours flown and accident rates.

Of course, mechanical related incidents with older aircraft are always higher than with newer aircraft with poor or inadequate maintenance usually be blamed for any incident.

That brings us to the following question: How comfortable are you flying older aircraft (even if you know its probably been reasonably well maintained) verses newer aircraft? In other words and aside from any cost considerations, do you feel more comfortable flying a newer aircraft verses an older aircraft and just when is an aircraft too old to fly?

When a mechanic accidentally leaves you a surprise…

Jason Miller recently wrote a post for the Let’s Go Flying blog that showed the importance of why you should do a THOROUGH preflight exam – especially after a mechanic has worked on your aircraft. Specifically, he (just barely) found a rag left in the cowling. Jason the wrote that:

The humbling truth is … if this wasn’t my first time in this make and model … and it didn’t have retractable gear … I probably would not have seen this oil soaked rag, wrapped like perfect kindling around a motor that was about to see temperatures in excess of 240 degrees.

The rag was only noticeable when you were “flat on your back looking up through the open gear doors.” Moreover, a pilot would have had to have been looking for it as it was only clearly visible after the cowling was removed. Hence and from now on, Jason teaches his students that during any preflight exam:

“…make sure to look inside the cowling for rags … or wrenches … or anything else a mechanic might have accidentally left inside the cowling. … yes, you’d be surprised, it can happen”

(Not to mention bird or wasp nests or whatever else could show up if the aircraft has been sitting on the tarmac for awhile…).

Jason did not mention whether or not he had a private word with the mechanic who left the rag inside the aircraft… (We can only imagine what was said…)