CPA E-ATIS
Volume 15 Issue 05
May 1, 2012
Friday April 27
th Cessna issued Service Letter SEL-57-01 which calls out for a visual inspection of the first 20 inches of the lower spar cap on both wings of 210s with over 5,000 hours total time in service. On aircraft with more than 10,000 hours an external visual inspection must be done before further flight and an internal visual inspection within the next 5 hours. On aircraft with between 5,000 and 10,000 hours an internal visual inspection must be done within 25 hours. On all aircraft with more than 5,000 hours this internal visual inspection must be repeated every 100 hours or 12 months whichever occurs first.
Cessna made a presentation to the FAA’s Wichita Aircraft Certification Office (ACO) on Friday April 27
th during which Cessna requested that the FAA issue an airworthiness directive. Cessna’s presentation so impressed the ACO that at a meeting on Monday April 30th they decided to issue an Immediately Adopted Rule (IAR) that puts the AD in effect with no comment or input from the public or industry until after the fact. This IAR process is supposed to be used only in cases where the threat to public safety is so severe as to preclude the FAA from using its normal rulemaking procedures.
Interestingly, according to the FAA not one cracked spar cap has been found to date on aircraft operated in the US.
So what brought this all about? Look to the Land Down Under. Australia’s Civil Aviation Safety Authority (CASA) is that country’s equivalent to the US’s FAA. CASA reported to Cessna and the FAA that they had reports of 7 incidents of spar cap cracks on Cessna 210s and that this problem was “common knowledge” in that country. The FAA looked around and could find no reports of spar cap cracks in the US but did find one from Canada. Meanwhile these reports had Cessna’s attention big time and they started writing a service bulletin to deal with it.
CPA first became aware of what was in the wind when we were provided a draft of Cessna’s service bulletin late the afternoon of Friday April 27
th. A call to the FAA picked up that there was going to be a meeting on Monday April 30th to decide what action to take.
This is serious business and could have a profound effect on the 210 fleet and the value of the aircraft.
As this was a shot out of the blue for us, CPA staff had to get up to speed quickly. Tom Carr was already here in Santa Maria to teach a 210 class. Phil Kirkham of Coastal Valley Aviation was involved in the class as well. I called Paul New at Tennessee Aircraft and got him on board. Paul is more knowledgeable about the spar system on the 210 than anyone else as he repairs them. So I had a top team of people available to sort this issue out.
The first thing we determined was that none of us had seen or heard of cracks in the lower spar cap on the 210. On Sunday (Monday in Australia) I spoke with three repair stations in Australia, including the largest Cessna Service Center in the country, and none of them knew anything about it. So much for the problem being common knowledge.
Second thing we discovered is that the inspection cannot be carried out with a light and a mirror as called for in the Cessna service bulletin. You can see most of the cap with a light and a mirror but not all of the cap area called out for inspection. This is particularly true for aircraft with de-ice boots and/or avionics bays in the wings. Later we found out that the people at Cessna involved in writing the service bulletin hadn’t actually gone out and looked at a real 210 in this area, they were working from drawings and memory.
And what about those 7 reports in Australia? I searched 10 years of CASA Service Difficulty Reports and could not find a single reference to this. There also were no Australian ADs, Bulletins or Advisories. So how does anyone know about these 7 aircraft. On Sunday, their Monday, I placed a call to CASA and they actually called me back. It turns out that CASA has only two confirmed reports of spar cap cracks. These reports are very recent and apparently have not made their SDR listing yet. The aircraft involved had 15,000 hours and 5,600 hours.
It is the 5,600 hour aircraft that is causing all the knee jerk reaction by government agencies and Cessna. That is way to low a time for this sort of thing to occur, though at this time extenuating circumstances have not been found. However no one from CASA has looked at this aircraft. And what about the other 5 incidents in Australia? Well it seems as if somebody has recently mentioned these aircraft to CASA and now CASA is trying to find out more. So solid, verifiable cases? Only 2, not 7. Throw in the SDR from Canada and that makes 3. So it is 3 aircraft verified, not 8.
And what happened to these aircraft with cracked spar caps? Were the cracked spar caps thrown away? Cessna hasn’t sold a lower spar cap in 6 years. The Canadian aircraft did buy a new wing from Cessna, I am told.
Apparently the FAA and Cessna became aware of these cases in Australia about 10 days ago and have been running around like chickens with their heads cut off since. There are three verified incidents, no accidents, and no cases in the US. These cantilever wing Cessna 210s have been flying for 45 years without this problem rearing its ugly head, you would think we could take more than a few days to gather data and get this right.
First of all somebody knowledgeable needs to look at the 210L in Australia that had a spar cap failure at 5,600 hours (or 5,750 hours, they don’t seem quite able to pin that down). That number is so out of line that we have to be suspicious. Was the spar cap heat treat correct when it was originally manufactured? Was the spar assembled correctly at the factory? Was the aircraft equipped with tip tanks at any time (which would have greatly increased the stress on the lower spar cap)? Was corrosion involved?
The other two verified incidents are on aircraft with over 10,000 hours each, but Cessna’s SB and the impending AD subject a much larger portion of the fleet to onerous inspections because of this one airplane that hasn’t been very well scrutinized?
And here is another little twist. Australia changed their rules a few years ago and now requires their mechanics to abide by FAA issued ADs. CASA only issues a Australian AD if the FAA chooses to pass on issuing an AD on a subject that CASA thinks an AD should be issued on. Instead of rushing off to impose rules, without public input, that will affect 210s in the US where this problem has not been seen, perhaps the FAA should say to CASA, ‘We’d like to help you, bloke, but we need more data, particularly on the low time incident.”
We don’t know yet what the Immediately Adopted Rule AD is going to say, but it really shouldn’t include the reoccurring 100 hour or 12 months inspection called for in Cessna’s new SB. That is something that does not fall any where near the requirements for bypassing public input, and so far there appears to be no engineering data to support it.
Cessna’s SEL-57-01 requires that operators report the results of the inspections, cracks or no cracks, to Cessna. If the FAA is going to impose an Immediately Adopted Rule then the reports should come to the FAA, not Cessna, so that they will be available for public scrutiny. In fairness to Cessna, the factory has always been open about sharing information CPA has requested. However on an issue this big and important it is in everyone’s best interest, including Cessna’s, that there be transparency.
So, on to the inspection. Basically inspection panels are removed on the bottom skin of the aircraft to gain access to the wing spar assembly from the wing root at station 25.52 outboard 20 inches to station 45.00. This is the area where the Huck bolts sandwich the spar cap, spar fittings and spar web together. The spar cap is a tee shaped extrusion with the vertical portion of the tee fastened between the spar fittings and web. The wing skins are lap joint riveted to the cross of the tee.
The area to be inspected is the fore and aft flanges of the spar cap and as much of the vertical flange as can be seen. First the area has to be cleaned. Depending on the conditions the aircraft has been operated in this can range from blowing out with shop air to repeatedly brushing in Varsol and then blasting shop air.
Once clean the edge and face of the flange is visually inspected for cracks. Several of us tried doing this with a light and a mirror but weren’t real happy with what we could see. It became clear if the aircraft had avionics bays and/or deice boots a light and a mirror wasn’t going to cut it. We tried various optical devices with limited success. Then I found the perfect tool at, of all places, Harbor Freight. It is called a High Resolution Digital Inspection Camera with Recorder. Item 67980. On sale for $200. This little flexible ecoscope can fit about anywhere. It takes pictures and videos. It can be hooked up to a monitor or computer. But most importantly we could see all of the spar cap including sections of the vertical. The inspection should take an hour to two hours depending on how much cleaning has to be done. So the inspection shouldn’t be particularly a problem unless of course cracks are found.
This is a developing situation so you can expect change to occur. Right now if you have a high time 210 I think I would hold off until some of this gets sorted out. At this time there is no requirement that you have the inspection done though it will be mandated shortly by an Airworthiness Directive. It going to take Cessna a bit of time to straighten out their service bulletin and then the FAA a bit more time to promulgate their Airworthiness Directive. CPA staff believes when the time comes to get the inspection, it best be done by shops that are intimatelyfamiliar with the 210 and these sorts of inspections. CPA will keep you informed.
You can read and print Cessna Service Letter SEL-57-01
here
We are posting spar pictures provided by Paul New. Links below:
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