Cap 10b/c

[Aerobatic Flyer]

Bad news for CAP 10 enthusiasts.....

Last Thursday the DGAC issued an AD that limits the CAP 10B to +4.3g when flown dual (+5g solo). If you exceed it, further flight is forbidden. Given the light stick forces in the CAP 10, 4.3g is easily exceeded.

A few days before that, they issued a recommendation that pilots of the new carbon-winged CAP10C shouldn't use negative g and descend at the same time, due to the inverted stalling characteristics of the wing - which apparently need further investigating. Apparently this problem manifested itself when a pilot was pushing forward from level flight to inverted.... not a situation where you want an unexpected accelerated stall.

I hope the problems are resolved soon.

AF (a CAP fan!)

[undertheweather]

Apparently the new AD is in response to an in-flight wing spar fracture in a Cap 10b in June this year. It happened in the USA, and according to my source, the aircraft was licenced to fly in the 'experimental' category. This Cap 10b was one of the older ones, and it is suspected that the spar fracture may have been the cumulative result of excessive G over many years.

However, until the incident is fully investigated, Cap 10b's are to be placarded to +5/-3 solo (less with two up) - hopefully temporarily.

As pointed out before, the Cap 10b is a very slippery aircraft, and in any kind of downline it can be easy to build up speed, which may result in excessive G being pulled.

Its very worrying to think, that in multi-user aerobatic aircraft, ie in group or solo training situations, that some people may inadvertently pull excessive G, and it goes unreported. Then, months, perhaps years later, their stupidity results in someone getting killed. Thats why I don't let anyone else fly aeros in my plane, unless I'm there with them.

[Aerobatic Flyer]

The one I fly has a recording accelerometer, which can't be reset - so if anyone pulls too much g, the next pilot will know - which is reassuring.

What is sad is that the 4.3g limit will severely limit the CAP's usefullness as a trainer. Here in France, it is the standard aeroplane for basic aerobatics training. Instructors won't be able to let their students make a mess of things before taking control.

[djpil]

The best recording accelerometer is the DA-55 from
Spruce and Specialty (http://www.aircraftspruce.com/catalog/inpages/accelerometers.php)
I just have a mechanical g meter in my current airplane with a bracket on it so pilots cannot reset it without a spanner. In a previous life I've used a DA-55 and its good to be able to get the full history with date and time of high g levels.
I tell pilots that anyone who pulls more than 6g in my Decathlon has bought the wings.

[Volume]

We had an inflight spar fracture of a CAP 10 in Germany in July 2001, killing the flight instructor and the student during aerobatic training. For those who understand german the anual report (http://www.bfu-web.de/fustat/2001/v161_jb2001.pdf) of the air accident inverstigation department (BFU) might be of interest (first chapter on page 17).
The BFU recommends to limit the CAP 10 to Utility category and to avoid rough airstrips, because the fracture was related to small damages at the undercarriage attachment to the wing spar !
A more detailled report can be found on page 21 of this bulletin (http://www.bfu-web.de/Bulletin/Bulletin0107.PDF), the final accident report is still not finished.
During the last annual check, small cracks (not unusual to wooden planes) were found in the paint near the wing root and near the undercarriage attachment point. If you own or fly a CAP, check it carefully and take even small annormalies very serious. (of course this should apply to any plane you fly). Wooden planes have normally no problems with fatigue or corrosion, but they should be maintained with the same care in this respect, small cracks in the paint, water ingestion over longer period, and your structural strength might be no longer sufficient for aerobatics.
Anyway enjoy flying your CAP within the allowable limits.

[FNG]

Here is an extract from the AD explaining why it has been issued

Origin of this new AD

Further to a new fracture in flight of a CAP 10B wing in June 2003, the investigation in process seems to point out that a wrong application of CAP 10B Service Bulletin N° 16 (CAP 10B-57-004) would lead to the impossibility of detecting the potential spar damage while performing the Type Certificate holder upper spar flange inspection.

While waiting for the results of the Type Certificate holder investigations, new operating limitations are enforced by this AD that replaces AD 2001-616(A)