Almost the true story on single engine gear up

[aldoradave]

Went out today, determined to test the engine out rate of climb during gear retraction. I pretty much answered my question but don't have good data to report. Got up to 10,000 in about 5 minutes, that was good. Left the POH on the ground, that was not good! I had to guess by recollection as to zero thrust on rear engine, and that guess was 1800 rpm.

Over the Palm Springs area, with slightly more than normal temps, I dropped speed down with 1/3 flaps and cowl flaps open. At 100 mph I retarded the rear throttle to 1800 rpm and tried to climb out. Got zero rate of climb and was more than slightly dismayed. Retracted the gear, which took 12 seconds, but with no degraded rate of climb (or descent) noticeable during the retraction. After the retraction I enjoyed a 50-100 ft rate of climb. That answered my question--with my aircraft the gear is coming up asap.

Later on the ground I found the POH and it said that at 10,000 msl the rear engine zero thrust point is 2300 rpm. So the fact is I had way too much drag as compared to a feathered rear engine. My question had been answered, nonetheless I am sorry that I don't have better data for you. I will try to do this again the right way when on a cross country and give you better numbers.

Keep in mind that my 337 is a 73 P337 with RT Aerospace gear door mod and Horton STOL. My guess is that anyone with older hydraulics and without the door mod should experiment for themselves.

Dave Dillehay
N84E

[Roger]

Had I known you had the door mod kit, I wouldn't even have responded. Glad it worked out the way you intended, which seems logical, now that you mentioned the mod.

[Ernie Martin]

I'm not a stickler for regulations, but don't you always carry the POH on board? It's my resource if I get into an emergency situation. Wouldn't even go aroud the pattern without it.

Speaking of emergencies, I had a mini one yesterday. Door popped open in flight. Completely open. I have the '73 with the air-stair doors, and the upper part popped open all the way up. I was returning from the Bahamas alone, already over land, about 5 miles from (and already talking to) the airport. Aside from being startled, had only minor effect on drag and airplane dynamics. Landed without incident or undue efforts -- just a lot of noise. And, as in so many instances, it was my fault, pilot error: I had failed to lock the door.

Folks, vibration will open your door. Make sure you push the lock button down.

Incidentally, one hour earlier, on the outbound flight, had 3 more adults and two toddlers in the flight. None would have been sucked out the window, but I would have had some very scared passengers, especially if it had happened over water.

Ernie

[skymstr02]

Originally Posted by Ernie Martin

I'm not a stickler for regulations, but don't you always carry the POH on board?

Its not required minimum equipment, as its a handbook, not a flight manual. All of the requirements are in the form of markings and placards on the airplane.

Please refer to the type certificate data sheet for details.

[jhickam]

Originally Posted by Ernie Martin

I'm not a stickler for regulations, but don't you always carry the POH on board? It's my resource if I get into an emergency situation. Wouldn't even go aroud the pattern without it.

Speaking of emergencies, I had a mini one yesterday. Door popped open in flight. Completely open. I have the '73 with the air-stair doors, and the upper part popped open all the way up. I was returning from the Bahamas alone, already over land, about 5 miles from (and already talking to) the airport. Aside from being startled, had only minor effect on drag and airplane dynamics. Landed without incident or undue efforts -- just a lot of noise. And, as in so many instances, it was my fault, pilot error: I had failed to lock the door.

Folks, vibration will open your door. Make sure you push the lock button down.

Incidentally, one hour earlier, on the outbound flight, had 3 more adults and two toddlers in the flight. None would have been sucked out the window, but I would have had some very scared passengers, especially if it had happened over water.

Ernie

I had the door on my 73 337G open inflight about a year ago. No damage but like you said alot of noise. I had my mechanic add shims to the doors jam where the door latches in so the door shuts and latches much tighter. Over the years I had noticed the door was getting easier to open with time. I always locked the door I thought untill it popped open. The moral of the story LOCK THE DOORS WHILE IN FLIGHT IN ANY AIRCRAFT !!!!!!

[edasmus]

Interesting about the doors popping open on your 73G models. I have the same aircraft and have always wondered what would happen to that top door if it opened in flight. Any recollections as to the airspeeds when the door opened you guys? I have a vivid imagination and picture things like the door departing the airframe punching a hole in a fuel tank, taking out the inboard flap, taking out the rear prop, and last but not least, damaging the tail feathers. Not a pretty scene. I was so concerned about this that last annual I had my shop rebuild the latch and lock. I added a velcro tab to ensure the button is held down and my IA added a short cable that is attached to the airframe on the inside in front of the door and on the other end has a pin that locks through a hole that was drilled into the handle which when engaged holds the handle forward. The theory being if the handle stays foward regardless if it is locked with the button, the pins stay engaged and the door cannot open. I figured that not too many of these doors were opening in flight thinking if they were an AD would be in order. But hearing your stories makes me wonder. Good to know though that your doors did not depart the airframe. I am curious to the airspeeds however.

Ed

[jhickam]

On my 77 337G model I believe the airspeed was about 130 mph on climbout. As soon as the door came open I slowed to 100 mph and returned to the airport and landed. It appears the door seal shrinks over the years and allows the door not to latch as it should. Before we put the shims in you could tap on the door and it would open. After the shims where installed the is very positive when it is shut.

[Ernie Martin]

My speed was probably around 130 MPH. Like I said, the fully open door had little effect on airspeed, dynamics or handling. I inspected the door as soon as I exited the aircraft and there was damage to the articulating linkake that holds the door open, but zero damage to the hinge at the top of the door. Nothing flew off and there was no bending or any sign of stress along the top hinge, so nothing to suggest that the door was close to separation. We have removed the damaged pieces and the door closes flush against the fuselage. Agsin, this was my fault, in failing to lock it.

Ernie

[edasmus]

Thanks guys. Again, glad to know it all ended well. I wonder what the result would be at 180 or 190 mph descending. Lets keep those doors latched!!!!!