The fuel tank selector valve was between Both and Right on the Cessna 172 that collided with two vehicles in an emergency landing on a bridge in Miami on May 14. The crash killed the pilot and injured two passengers and five people in one of the vehicles. That was the only obvious anomaly with the aircraft mentioned in the NTSB’s preliminary report on the accident. The full report is copied below. Although the fuel valve was out of position, there was fuel in the line to the carburetor, which was functioning normally, the engine had compression on all cylinders and the ignition system was fine. The throttle was pushed all the way in, the mixture was full rich and the carb heat was turned off.
The plane took off from Homestead Airport and landed at North Perry Airport in Hollywood where the pilot added 11.2 gallons of fuel and met the passengers. The NTSB checked the fuel at the airport and found no contamination. The plane took off for Key West and was flying below the Miami Class B along the waterfront at 1,200 feet when the pilot called a MayDay, saying he’d lost engine power and was going down. “There’s three souls, there’s um a road right here … a little bridge, I’m going to make that, 54Z,” the pilot said in his last radio transmission. The plane landed straddling the median of the four-lane bridge, hit a vehicle from behind, crossed the median and collided head-on with a van before flipping over and catching fire. The pilot was a Miami tower controller.
Nope. The 172 is either on on off.
Nope. It depends on the model. Earlier ones had L/Both/R/Off.
I don’t know of any model year 172 that only had selections of ON or OFF. You may be thinking of the 150/152. The 172 always had a fuel selector. Some years (newer) also had a separate shut-off valve. Older years had OFF as a position on the selector to accompany Left and Right and BOTH.
David, Cameron, sorry about that. I think you guys are right. We used to have Brand C pilots come over and fly school Grummans and inevitably many landed off-airport with one full tank and one empty tank. I just assumed that 152/172’s were all on/off because of that. Thanks for the correction!
Soo…you committed to make an authoritative declaration having no actual experience in that model airplane?
I flew one twice some 45 years ago. Instructor had me always fly on Both and we only toughched it to turn it off. It was a tacit ON or OFF. So not being a 172 pilot I assumed others were taught the same. Basically you’re screwed in an engine/fuel situation. Evet make a comment with limited experience in type? Happened to me 😉
inevitably “many” landed off-airport? How many exactly? I flew a Cessna 177 for 10 years before I bought my Grumman 6 years ago and have never heard of that being a thing. For what it’s worth, 177 has left, right both and off fuel selector.
It was a thing baclk in the 70’s when I was in flight school. They brought them back to teh school on flatbed trailers. When did you learn to fly and how would you know if you were not there?
C172 and C182 and later models of the C210 all have left, both, right on the fuel selector. C150/152 and older C185 (IO470 engine)fuel selector is either on or off. Not sure about the C180. The C208 Caravan has fuel selectors on,off for each wing tank.It will be interesting if ever to find out why the fuel selector on the accident plane was moved from both selection in the first place. RIP to the pilot who died, quick recovery to those injured.
C180 – is four position. L/B/R and Off.
Just UGH!
So preventable
That’s just sad
The control valve was on and in the correct position. During the crash the pilots hand flailing around hit the valve handle.
Possible. Or the egress by the passenger. Feet scrambling around to get out in a hurry kicking it into that position? Will never know
It’s really hard to flail into the fuel selector on a 172. It’s down at the floor level.
More likely it had been moved to a side tank prior to refueling and not moved fully back to Both before flight. Many operators (including the CAP) stipulate putting the selector on a side tank while parked or during refueling.
While that may be possible (operating on only one tank) it doesn’t explain the selector being placed into a different position. Nor does the pax comment implying that the engine sounded “normal”.
It was one of the Continental-powered airplanes (more inclined to develop carb-ice than later Lyc powered 172s).
The selector lever position between tanks implies it was dislodged during or subsequent to the impact, IMO. Anyone who’s operated a 172 will confirm that if the fuel selector is in any position to prevent fuel flow that the airplane cannot get from the pumps to the runway without engine shut-down.
Yep. When refueling my C182 I will place the selector to either L or R to prevent flow from one tank to the other while filling. This way I get both tanks fully topped off.
That is the only time the selector is not on both. POH checklist includes fuel selector position prior to flight.
Have they tested that position in another aircraft to see if it does starve the engine of fuel?
This is a know issue on several airplanes that have detents when the selector is not completely in the detented position.
Troubleshooting steps are:
fuel selector – both
Mixture – rich
Carb heat – on
Magnetos – on
With everything apparently working fine on the engine, I suspect carb ice.
The picture on this article looks like a Continental dual exhaust. If this is an O-300 carb ice is a good possibility. Highly unlikely if a Lycoming engine. Since there was a fire not likely we will ever know.
OPERATION ON BOTH TANKS
Should power irregularities occur with the fuel selector on both tanks,
the following steps are to be taken to restore power:
(1) Switch to a single tank for a period of 60 seconds.
(2) Then switch to the opposite tank and power will be restored.
The NTSB report says it is a Cessna 172H. That would be a 1967 model with the Continental O-300. Carb ice would have been a real possibility.
Sure sounds like carb ice to me. I can imagine a scenario where after the engine first showed signs of trouble, he tried moving the fuel selector. Since there was still fuel being delivered to the engine, and it was getting fire from the mags/plugs, I can’t see anything but carb ice causing this outage.
Yeah, we had an F model built (but not taken by) USAF as a T41A, and it had all of the Skyhawk goodies, including a carb temperature gauge. I’m at a loss as to why that wasn’t a “thing” in ever carbureted recip. We never worried about carb ice, and never thought twice about applying a little heat, even in slow cruise. As that’s the plane I learned on, and flew for 16 years, I never experienced icing, even on a plane that was apparently more prone to ice up.
Carb Ice in May at 1200 ft in Miami? Doubtful. Maybe pilot kicked the fuel selector to either off position or in between two detents. Possibility of a blockage at the fuel outlet or at the carb end around the filter area.
Hundreds and hundreds of hours flying 150/172 aircraft and that is exactly the conditions in which I experienced carb ice…. except it was in the Houston/Gulf-Coast area.
Yes. I have experienced carb ice after excessive ground idling waiting for take off after an air show at Millville NJ in August on a humid 90 degree day. Needless to say I did not take off when it was my turn?
Absolutely. Take a look at a Carb Ice Graph. A quick search for “carb ice graph” will show some that indicate a possiblity of carb ice in ambient temps as warm as 105°F.
I’m pretty sure it is possible to get carb icing at 86 degrees, oppressive humidity, and low cruise power setting.
I have had carb ice with those weather conditions also. Not many pilots run their fixed pitch prop engines at full throttle in cruise flight. Throttle settings at 2200-2500rpm is prime carb ice forming in humid weather conditions no matter the OAT.
Emergency Landing without Power: Fuel Shutoff Valve OFF.
Yeah good point.
Beware that seriously injured passenger’s comment about engine sounding normal could be out of context (reader assumes is just before crash not at takeoff and in most of the flight), could be just confusion after turmoil and injury.
In PW314 at least one passenger said touchdown was hard, but surviving F/A said normal and baggage handler waiting for the flight said normal. (Handler was a pilot trainee, watched the airplane land at least twice a day.)
(Experience in flying is a factor, B737 touchdown into short slippery runway is noticeably firm.)
Does anyone know if the fuel selector lever (in this C172) placed in between BOTH and RIGHT restrict fuel flow? And since the pilot declared engine problems, went full rich and full throttle, was he supposed to add carb heat?
When I built a Glasair, I checked for this by blowing into the fuel selector with it set at mid-position. IIRC, it flowed, albeit not at full flow.
I never have understood the attraction of freeways and bridges for off airport landings… by all means, go for the landing zone with two ton obstacles that move and can hit you at 70 mph?!? Even if you do everything right you can get creamed in the end. Do everything right in a water landing and you all have a great story.
The H model has a four position fuel selector. In my experience, being between detents doesn’t allow fuel to flow (with a normally operating fuel selectors).
The NTSB accident db has several mishaps where loss of power resulted when fuel selectors were not in the correct detent. It’s improbable, IMHO, that flail or a bump from a panic stricken front seat occupant bumped the selector out of a detent.
Sad event.
Carb ice is also a possibility. If carb ice was ‘the’ problem, to me it suggests that the pilot might not have leaned aggressively during ground ops – which puts more heat into the engine nacelle as a preventative measure, or the carb heat might not have functioned correctly, or the carb heat wasn’t on long enough at runup to fully clear any carb of ice (if it was present) during a thorough runup. Or…
In any case, the accident – like every other – offers us a chance to think through our own procedures that might benefit from a tuneup.
Absolutely. Take a look at a Carb Ice Graph. A quick search for “carb ice graph” will show some that indicate a possiblity of carb ice in ambient temps as warm as 105°F.
Has anyone mentioned that the airplane flew right by three golf courses on its way to the bridge?
(I’m not sure why my username HokieAero doesn’t show up here …)
If the selector valve was in a position to restrict the flow of fuel, and he did the proper
pre flight procedure, crank the engine, engage carb heat, check right mag, left mag, both, taxi to runway, get clearance for takeoff, full throttle for takeoff. The carburetor would not hold enough fuel to do all those things, he would have run out of fuel before he ever got to the runway, therefore ice seems more reasonable.
DB.
I am prone to agree with those suspecting carb ice. I am also prone to think that the fuel selector was repositioned by the pilot while he was trying to get the engine started again or inadvertently placed in that position during or after the accident. I do not believe that the engine would have ran as long as it did if the selector was in that position before engine start or even before takeoff.