Thursday, August 05, 2010

Track of my 5-hour glider flight

Here's what a 5-hour flight that doesn't go anywhere looks like. It's not very sharp at this size, so click on it for a full-size image.

Monday, August 02, 2010

Wings Off, Wings On

Sometimes the real world intrudes on our pleasant hobby of flying aircraft without engines. Two aspects of the real world presented themselves recently. 1:We fly real aircraft with real risks. 2:We operate a geographically dispersed glider club, not an central operation.

In late June, we got word that the European Aviation Safety Agency (EASA) had initiated an action regarding Blanik L13 gliders. Seems there was a crash somewhere in Europe in which a wing separated from the glider, and metal fatigue was a possible factor. (It's also possible that improper aerobatics overstressed the wing joint, but the final report has not been issued.) The manufacturer Aircraft Industries a.s. (which we know as LET) issued inspection instructions and limitations on aerobatics, to be carried out immediately. As of that date, the FAA had not issued any Airworthiness Directive.

Wings Off! Our club operates two Blanik L13's, so any grounding would put a halt to our training activities. The club sprang into action, getting copies of the instructions and gathering a crew to take off the wings to perform the inspection. I won't dare say "I told you so", but some of us mentioned that the FAA's instructions, if and when eventually issued, might differ from the EASA's, but being proactive seemed a good thing. On a Saturday morning, the crew took the wings off and an IA followed the EASA's instructions and documented the results. No fatigue found! Wings On!

About three weeks later, the FAA issued an Airworthiness Directive. The inspection instructions were basically the same, but specified using a more precise method which we had not known to use the first time around, so the previous inspection is not acceptable. Wings Off! We borrowed the appropriate equipment for the IA to do the inspection again, and rounded up a crew again. (It takes about 4-5 people about an hour to take them off and put them on again.) No fatigue found! Wings On!

The EASA and FAA directives both included a reporting requirement: they want to know the service and damage history of all L13's, to help determine whether usage limits or further inspection requirements might be required, and to help determine if and when to lift or revise the limitations on aerobatics. Filling out the required report means going through all the logbooks looking for damage entries, and looking for dates and serial numbers of any major replacements. Here's where the dispersed nature of our club comes into play. Since being displaced from Hemet, the Maintenance Officer keeps the most recent logbooks for all aircraft, and the Secretary keeps the club archives, which includes the old logbooks. This request came in when the Secretary (me) was on a week-long business trip, so getting the old info had to wait. The old logbooks revealed certain minor damage and repairs to be reported on the form. Scanning the most recent logbooks, the MO find that the wings were replaced some years ago on one ship, before we owned it. The serial numbers of the new wings were not recorded in the logbook, and can only be determined by looking inside the wings. Would have been nice to know this before either of the previous two wing inspections. (I'm guilty as well... I saw that on the form, but had no idea the wings had ever been replaced. So once again, it will be Wings Off, Wings On...

Sunday, August 01, 2010

Short flights under cloudy skies

Southern California has been having an unusually cool summer. We usually have "June Gloom" which means a thick layer of clouds extends inland from the coast and doesn't burn off until midday. This year it started in mid-May and continued off and on through most of July, with only one hot week so far. Saturday's forecast was for scattered cirrus, but over Elsinore there was a layer of cloud that was almost thick enough to be called stratus, at about 11,000 feet, which blocked a lot of the sunlight. The temperatures aloft and a forecast inversion indicated that lift would only go to about 5,000' at most even if got hot on the ground.

It was hot, in the mid-90's F, and humid for our area. I flew at 12:30 and got about 25 minutes. I let off at 4300' MSL and got lift up to about 4700'. The lift was probably partly thermal, but it was narrow enough that I began to suspect light ridge lift. The wind was from the southeast, which is unusual for that site, so I tried working the ridges that faced that wind. Didn't find much, but it was fun to try.

Another fellow flew at 13:30 and got about 35 minutes. The cloud layer retreated about 2:00-2:30 but none of us were motivated enough to try it again. I stayed for most of the afternoon helping to launch and retrieve the gliders, and talking with the student pilots and their parents.